Short-term Outcomes in obese patients undergoing anterior minimally invasive total hip arthroplasty Nabila Goga MBChB, FC Orth (SA) Student number 0503841V A research report submitted to the Faculty of Health Sciences, University of the Witwatersrand, in partial fulfilment of the requirements for the degree of Master of Medicine Johannesburg, 2023 i Declaration I, Dr Nabila Goga, declare that this research report in the format of a “submissible” paper is my own, unaided work. It is being submitted for the Degree of Master of Medicine in the branch of Orthopaedic Surgery at the University of the Witwatersrand, Johannesburg. It has not been submitted before for any degree or examination at any other University. ………………………… (Signature of candidate) 19th day of July 2023 in Johannesburg ii Dedication This research paper is dedicated to my family, both by blood and choice. iii Presentations and publications arising from the research project SAOA September 2022 Cape Town Wits Orthopaedic Research Day November 2022 Johannesburg iv Acknowledgements This paper would not have been possible without my supervisors who sacrificed time and energy for this project; Dr JRT Pietrzak for his encouragement and guidance through each step of the process, Dr JN Cakic who trusted me to utilize his data and provided support and feedback despite his busy schedule and Prof SK Magobotha who availed himself as both a mentor and supervisor. I would also like to mention Dr M Jingo for his assistance, enthusiasm and efficiency and Dr I Cassimjee who assisted with the data visualisation. v Table of contents Declaration ................................................................................................................................. i Dedication .................................................................................................................................. ii Presentations and publications arising from the research project ..................................... iii Acknowledgements .................................................................................................................. iv Table of contents ....................................................................................................................... v List of Figures .......................................................................................................................... vi List of Tables ........................................................................................................................... vii Nomenclature ......................................................................................................................... viii “Submissible” format of a paper ............................................................................................. 1 Appendices .............................................................................................................................. 21 vi List of Figures Figure 1: A. Obese patient positioned on conventional surgical table. B. Obese patient positioned on AMIS® Mobile Leg Positioner………………………………………………….4 Figure 2: Perioperative Findings: A. Surgical duration. B. Estimated blood loss. C. Radiation dose. D. Radiation exposure. E. Length of stay…………………………………………………8 Figure 3: Radiographic Outcomes: A. Preoperative limb length discrepancy. B. Postoperative limb length discrepancy. C. Acetabular cup inclination. D. Acetabular cup version. E. Femoral stem version. F. Femoral offset differential…………………………………………………….9 vii List of Tables Table 1: Patient demographics………………………………………………………………….7 Table 2: Clinical and Functional Outcomes…………………………………………………...10 Table 3: Complications………………………………………………………………………..11 viii Nomenclature AMIS Anterior minimally invasive surgery ASA American Society of Anesthesiologists AVN Avascular Necrosis BMI Body Mass Index CI Confidence Interval COPD Chronic obstructive pulmonary disease DAA Direct anterior approach DVT Deep vein thrombosis FAI Femoroacetabular impingement FJS Forgotten joint score mHHS Modified Harris Hip Score LLD Limb length discrepancy LOS Length of stay OR Odds ratio PE Pulmonary embolus PJP Patient joint perception PROM Patients reported outcome measures SD Standard deviation THA Total Hip Arthroplasty TJA Total Joint Arthroplasty UPAT Universal Pain Assessment Tool WHO World Health Organization 1 “Submissible” format of a paper Short-term outcomes in obese patients undergoing anterior minimally invasive total hip arthroplasty Authors and affiliations: Nabila Gogaa (FC Orth (SA), MBChB), Jurek Rafal Tomasz Pietrzaka (FC Orth (SA), MMed (Orth), MBBCh), Josip Nenad Cakica,b (PhD, FCS (Orth) SA, MMed (Orth), MD), Sebastian Keith Magobothaa,c (FCS (Orth) SA, MBChB, BSc Hons) a. Division of Orthopaedic Surgery, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa b. Life Fourways Hospital, Fourways, Johannesburg, South Africa c. Netcare N17 Hospital, Springs, South Africa 2 ABSTRACT Introduction Obesity affects over 774 million individuals worldwide. It is associated with an accelerated onset and progression of osteoarthritis, resulting in an increased need for total hip arthroplasty (THA). Obese patients have a higher risk of perioperative complications. The direct anterior approach (DAA) for THA is gaining popularity globally, however, there are concerns over its suitability for obese individuals. This study compares short-term clinical, functional, and radiological outcomes of obese and non-obese patients undergoing THA via the DAA. Methods We conducted a retrospective study of 356 consecutive patients who underwent elective primary THA via the DAA using a specialised leg positioner (Medacta International, Switzerland) and intraoperative fluoroscopy. Obese patients (BMI  30 kg/m2) were compared to the control group using baseline patient information, perioperative data and postoperative outcomes at minimum one-year follow-up. Results The study included 107 (30%) obese patients. Cohorts were well-matched for age, sex, preoperative diagnosis and baseline PROMs. In the obese cohort, surgical time and blood loss increased by a mean of 8.32  6.9 minutes (p = 0.03) and 58.19  25.37 ml (p = 0.0003) respectively. There were no significant differences in intraoperative radiation (mGys), time to discharge and discharge destination between the groups. Obese patients had a higher incidence of wound-related complications (5.6% versus 2.4%), however overall complication rates were similar (9.3% versus 6.8%, p = 0.67). Functional outcomes were equivalent with a mean postoperative mHHS of 97.57  4.86 and 98.05  5.59 in the obese and non-obese cohorts respectively (p = 0.54). PROMs including the Forgotten Joint Score (p = 0.34), Patient Joint Perception score (p = 0.2) and patient satisfaction rates (p = 0.085) were comparable. Conclusion The AMIS DAA is a safe and effective approach for obese patients with excellent short-term outcomes, however an increased risk of wound-related complications remains. Keywords: Total hip arthroplasty, Direct anterior approach, Obesity, Anterior minimally invasive total hip arthroplasty, AMIS 3 1. INTRODUCTION The worldwide prevalence of obesity has risen exponentially over the last few decades with obesity affecting over 774 million individuals.1 Within South Africa, 41% of women and 11% of men are classified as obese.2 Obesity is associated with an earlier onset of osteoarthritis due to physiological and biomechanical mechanisms.3,4 Obesity results in a state of chronic inflammation, which contributes to the severity, and progression of osteoarthritis by reducing pain tolerance, accelerating cartilage degradation, and stimulating osteophyte formation.3–5 Affected individuals typically have altered gait patterns and abnormal joint loading.4,5 The relative risk of undergoing total joint arthroplasty (TJA) correlates with increasing body mass index (BMI). 3,4 Morbidly obese patients are 8.5 times more likely to require THA than non-obese individuals.3,4 Obese and morbidly obese individuals respectively are likely to require THA two and nine years earlier than their non-obese counterparts.3,4 Obesity is associated with a cluster of comorbidities, which contribute to increased perioperative risk.4 Obese individuals typically have increased surgical duration, length of stay (LOS) and analgesic requirements.3,6–9 Obesity is an independent risk factor for complications during TJA including combined complications; systemic complications; hip dislocation; re-intubation; re- operation; surgical site and deep infections.3,4,6–8,10–13 A 2019, meta-analysis by Onggo et al. of over two million patients found an increased risk of all complications in obese patients undergoing THA (OR = 1.53, 95% CI:1.30 – 1.80, p < 0.001).8 THA is a highly regarded and cost-effective surgical intervention with reported survivorship of up to 95% at 10 years, > 80% at 25 years and patient satisfaction of > 96% at 10 years.10,14–16 Utilisation of THA continues to grow and current projections suggest a perpetuation of this trend as demand, eligibility, technology, and skills evolve, however there is still no consensus on the optimal surgical approach.14,17 The DAA has seen a recent surge in popularity with DAA utilisation for primary THA amongst American Association of Hip and Knee Surgeons’ members increasing from 12% in 2009 to 45% in 2020.18,19 The DAA is an anterior-based minimally invasive surgical approach that accesses the hip via intermuscular and internervous planes, potentially limiting muscle damage.20–22 Reported advantages include reduced postoperative pain, LOS and dislocation risk; improved mobility; and superior HHS during the early postoperative period.20,21,23–26 Despite these benefits, the DAA is not the panacea as it has been associated with a steep learning curve, longer surgical duration, and a higher rate of certain complications, most notably surgical site infections (SSI) and intraoperative fractures.7,10,12,13,19–21,24–27 Fifty-three percent of DAA surgeons consider obesity to be a relative contraindication for DAA use.19 4 While common, the use of specialised leg positioners for the DAA remains controversial.28,29 The AMIS mobile leg positioner (Medacta International, Switzerland) was developed for use with the AMISDAA technique to allow controlled intraoperative manipulation of the hip.30 A potential benefit of this device in obese patients, is that the suspended thigh allows some of the excess adipose tissue to fall away from the surgical site compared to a conventional table on which the excess adiposity is supported by the table and pushes up towards the surgical site thus making exposure more challenging (Fig. 1).28 Considering the trifactor of THA demand, DAA utilisation and the global obesity epidemic outlined above, we sought to compare short-term outcomes of obese and non-obese patients undergoing THA via the AMIS DAA. 2. MATERIALS AND METHODS 2.1 Study Design This was a retrospective analysis using prospectively collected data from a single-surgeon, evaluating 356 consecutive, adult patients who underwent elective, unilateral primary THA via the AMIS DAA, between 01 January 2018 and 31 December 2020. Exclusion criteria included patients who declined or were incapable of giving informed consent, and/or did not complete a minimum one-year follow-up. Ethics clearance was obtained from the Human Research Ethics Committee, University of the Witwatersrand. Figure 1. A. Obese patient positioned on conventional surgical table. B. Obese patient positioned on AMIS® Mobile Leg Positioner A B 5 2.2 Surgical Protocol A standardised protocol was utilised with all patients undergoing preoperative medical evaluation and optimisation by a single physician. All patients were operated on in a single laminar-flow theatre under general anaesthesia and a lumbar plexus block, administered by a fellowship-trained anaesthetist. Patients were positioned supine with padded perineal support. The affected leg was placed in the AMISMobile Leg Positioner, controlled by an experienced table-operator. A weight-adjusted dose of intravenous antibiotic prophylaxis (Cefazolin or Clindamycin in cases of a known allergy) was administered preoperatively and for 24 hours postoperatively. A longitudinal skin incision of 6 – 10cm was made 2 ‒ 3 cm lateral and parallel to a line between the anterior superior iliac spine and Gerdy’s tubercle. The underlying perimysium was divided to allow access to the interval between tensor fascia lata and sartorius. The lateral aspect of the rectus femoris was retracted medially to expose the joint capsule. An anterior capsulotomy was used to enter the joint. The femoral neck was osteotomised under traction while protecting the posterior capsule. The acetabular labrum was preserved where possible, and the acetabulum prepared as per conventional THA. Preparation of the femur was done in a position of extension and external rotation, optimising access to the proximal femur. Soft tissues were released as necessary to allow adequate access to the femoral canal while protecting the ligaments. Femoral broaching was performed using AMIS® broaches via conventional broaching techniques. Uncemented implants with 36 mm ceramic femoral heads and highly cross-linked polyethylene cups were used preferentially as allowed by patient anatomy. Intraoperative fluoroscopy (Philips, BV Pulsera) was performed by a single radiographer at three different time points: 1) to assess optimal positioning of the acetabular cup; 2) to assess optimal sizing and position of the femoral component during broaching; and 3) after reduction of the implants, prior to soft tissue closure. An intra-articular negative-pressure drain was placed intraoperatively and removed within 24 hours. Intermittent pneumatic compression devices were employed postoperatively until discharge and inpatient physiotherapy provided twice daily. Patients were required to be ambulatory on crutches before discharge. Patients were discharged on oral thromboprophylaxis (Rivaroxaban 10 mg daily) for two weeks. The surgical site was assessed by a clinical associate 10 days postoperatively and all suspicious wounds reviewed by the primary surgeon. A routine duplex Doppler was performed three weeks postoperatively to assess for occult deep vein thrombosis (DVT). The surgeon conducted follow- up assessments at six weeks, six months and one year postoperatively. 6 2.3 Variables and outcome measures Preoperatively, the following baseline patient information was captured for all patients: age (years), sex, primary diagnosis, comorbidities, and BMI. Limb length discrepancy (LLD) was measured radiographically using Woolson’s technique.31 Patients’ preoperative functional status were evaluated using the mHHS – a validated tool that factors in pain, gait and activities.32 Pain was quantified using the Universal Pain Assessment Tool (UPAT); a combination tool comprising the verbal numeric rating scale, the verbal descriptor scale and the Wong-Baker FACES® pain rating scale.33,34 Intraoperatively, the following data was collected: surgical duration in minutes from incision to completion of the last suture; estimated blood loss in millilitres and fluoroscopy use (radiation exposure in milligrays and duration of exposure in seconds). Perioperative data included: the use of blood products; LOS in days measured from date of admission to date of discharge and discharge destination; home or step-down facility. Postoperatively, at minimum one year, clinical, functional and radiographic outcomes were assessed using the following tools: mHHS, UPAT, Forgotten Joint Score (FJS), joint functionality, Patient Joint Perception (PJP) and a Likert-type patient satisfaction scale. The FJS is a validated PROM, designed to determine patient awareness of the artificial joint.35 The PJP is a single- question PROM that correlates moderately with FJS.36 Standard radiographic imaging was used to assess LLD, component position and component loosening. Complications were classified as intraoperative or postoperative; medical (related to the patients’ baseline and physiological effect of the surgery) or surgical (directly related to the surgery); and temporal (early  4 weeks, late > 4 weeks). 2.4 Data Analysis The study compared the outcomes of obese (BMI  30) and non-obese (BMI < 30) patients, based on a series of parameters.1 The means of these parameters were compared using t-tests with statistical significance at p < 0.05. Confidence intervals were calculated at 95%, and used in conjunction with the p-values to determine clinical significance. Groups were tested for linear model assumptions: normality and homogeneity of variances. In the event of a violation of the linear model assumptions, the Wilcoxon rank-sum alternative was used to hypothesis test between the two cohorts. The statistical package used was the R version 4.0.4 (2021-02-15); University of Auckland, New Zealand. 7 3. RESULTS 3.1 Demographics In total, there were 356 patients of which 107 (30%) were obese and 205 (57.6%) were female (p = 0.05). The mean age of the obese group was 60.19 years versus 60.82 years in non-obese patients. The most common diagnosis was primary osteoarthritis, affecting 67.1% of non-obese and 74.8% of obese patients (p = 0.7). For further demographic details see Table 1. Table 1: Patient Demographics Total n = 356 (%) Obese n = 107 (%) Non-obese n = 249 (%) p-value Sex (n; %) 0.05 Male 151 (42.4%) 56 (52.3%) 95 (38.2%) Female 205 (57.6%) 51 (47.7%) 154 (61.8%) BMI (kg/m2) ( SD) 27.95 ± 5.37 35.34 ± 3.7 25.21 ± 3.2 < 0.000 Age, years ( SD) 60.33 ± 12.75 60.19 ± 11.65 60.82 ± 13.23 0.73 Diagnosis (n; %) Primary Osteoarthritis 247 (69.4%) 80 (74.8%) 167 (67.1%) 0.7 Congenital hip dysplasia 37 (10.4%) 12 (11.2%) 25 (10.0%) AVN 22 (6.2%) 5 (4.7%) 17 (6.8%) 0.66 Inflammatory arthritis 16 (4.5%) 5 (4.7%) 11 (4.4%) FAI 16 (4.5%) 3 (2.8%) 13 (5.2%) 0.84 Previous trauma 4 (1.1%) 1 (0.9%) 3 (1.2%) Other 12 (3.4%) 1 (0.9%) 11 (4.4%) Comorbidities (n; %) Hypertension 69 (19.4%) 23 (21.5%) 46 (18.5%) 0.48 Asthma/COPD 34 (9.6%) 9 (8.4%) 15 (6.0%) Diabetes 33 (9.3%) 12 (11.2%) 21(8.4%) 0.21 Cardiac 26 (7.3%) 11(10.2%) 15 (6.0%) 1 Epilepsy 19 (5.3%) 6 (5.6%) 13 (5.2%) Thyroid 19 (5.3%) 4 (3.7%) 15 (6.0%) 0.51 Previous DVT/PE 12 (3.4%) 3 (2.8%) 9 (3.6%) Cancer 7 (2%) 2 (1.9%) 5 (2.0%) 0.21 Other 25 (7.0%) 7 (6.5%) 18 (7.6%) ASA grade (n; %) 1 132 (37.1%) 34 (31.8%) 98 (39.4%) 2 204 (57.3%) 66 (61.7%) 138 (55.4%) 3 20 (5.6%) 7 (6.5%) 13 (5.2%) 8 BMI, Body mass index; AVN, avascular necrosis; FAI, Femoroacetabular impingement; COPD, chronic obstructive pulmonary disease; DVT, Deep vein thrombosis; PE, Pulmonary embolus; ASA, American Society of Anaesthesiologists 3.2 Perioperative findings Mean surgical duration was 92.71 ± 24.24 minutes for obese and 84.39 ± 23.92 minutes for non- obese patients (p = 0.03). Blood loss averaged 233.05 ± 100.93 ml and 174.86 ± 99.11 ml for obese and non-obese individuals respectively (p = 0.0003). One obese patient required a transfusion. Intraoperatively, the mean radiation dose was 3.51 ± 1.16 mGy in the obese cohort (range 1.87 ‒ 7.91 mGy) with an average exposure time of 28.31 seconds (range 17.61 ‒ 51.17 seconds). The mean radiation dose in the non-obese cohort was 3.13 ± 1.81mGy (range 1.58 ‒ 7.21 mGy) and average exposure time was 24.56 seconds (range 14.9 ‒ 46.75 seconds). The average LOS of obese patients was 2.4 ± 0.49 days and non-obese patients 2.5 ± 0.72 days (p = 0.16). Two obese and four non-obese patients required discharge to a step-down facility (p = 1). For further details, see Fig. 2. 9 3.3 Radiographic outcomes Eight (7.5%) obese patients and two (0.8%) non-obese patients had acetabular cup inclination of 31°‒ 40° (p = 0.01) with an inclination of 41° ‒ 55° achieved in 99.2% of the non-obese cohort versus 90.7% of the obese cohort (p = 0.02). LLD and other aspects of the implant placement demonstrated no statistical difference (see Fig. 3). 10 3.4 Clinical and Functional Outcomes Postoperative mHHS scores were 97.57 ± 4.86 and 98.05 ± 5.49 in the obese and non-obese cohorts, respectively (p = 0.54). The mean FJS in obese patients was 77.81 ± 22.19 versus 71.43 ± 28.56 in the non-obese (p = 0.34). Satisfaction was > 92% in both cohorts (p = 0.085). For details on other PROMS, see Table 2. Table 2: Clinical and Functional outcomes Total n = 356 (%) Obese n = 107 (%) Non-obese n = 249 (%) p -value mHHS Preoperative  SD 51.74 ± 12.02 49.92 ± 13.44 52.51 ± 11.22 0.19 Postoperative  SD 97.91 ± 5.3 97.57 ± 4.86 98.05 ± 5.49 0.54 Change in mHHS 46.17 47.65 45.54 FJS  SD 73.34 ± 25.67 77.81 ± 22.19 71.43 ± 28.56 0.34 Satisfaction rate (n; %) Overall satisfaction 333 (93.5%) 99 (92.6%) 234 (94%) 0.085 Very dissatisfied 7 (2.0%) 2 (1.9%) 5 (2.0%) Dissatisfied 6 (1.7%) 2 (1.9%) 4 (1.6%) Neutral 10 (2.8%) 4 (3.7%) 6 (2.4%) Satisfied 66 (18.5%) 22 (20.6%) 44 (17.7%) Very satisfied 267 (75%) 77 (72.0%) 190 (76.3%) PJP (n; %) 0.2 Natural joint 216 (60.7%) 62 (57.9%) 154 (61.8%) Artificial joint, no restriction 71 (19.9%) 22 (20.6%) 49 (19.7%) Artificial joint, minimal restriction 61 (17.1%) 19 (17.8%) 42 (16.9%) Artificial joint, major restriction 5 (1.4%) 2 (1.9%) 3 (1.2%) Non-functional joint 3 (0.8%) 2 (1.9%) 1 (0.4%) Joint Functionality (n; %) 0.53 Severely limited 8 (2.2%) 2 (1.9%) 6 (2.4%) Limited 17 (4.8%) 4 (3.7%) 13 (5.2%) Can do most things 136 (38.2%) 40 (37.4%) 96 (38.6%) 11 Can do anything 195 (54.8% 61 (57.0%) 134 (53.8%) UPAT  SD Preoperative day 5.81 ± 1.98 5.99 ± 1.79 5.44 ± 2.3 0.13 Postoperative day 0.4 ± 1.28 0.45 ± 1.43 0.28 ± 0.82 0.29 Change day 5.39 ± 2.31 5.49 ± 2.24 5.2 ± 2.47 Preoperative night 5.15 ± 2.62 4.92 ± 2.54 5.28 ± 2.65 0.42 Postoperative night 0.35 ± 1.33 0.23 ± 0.96 0.41 ± 1.46 0.32 Change night 4.82 ± 2.64 4.91 ± 2.32 4.78 ± 2.79 Preoperative sport/activity 7.16 ± 2.21 7.13 ± 2.75 7.17 ± 2.06 0.97 Postoperative sport/activity 1.31 ± 3.19 0.43 ± 1.33 1.59 ± 3.58 0.2 Change sport/activity 5.64 ± 4.01 5.33 ± 4.73 5.72 ± 4.05 mHSS, modified Harris Hip Score; FJS, forgotten joint score; LLD, Limb length discrepancy; PJP, Patient joint perception; UPAT, Universal pain assessment tool 3.5 Complications Overall, the complication rate was 7.6% (n = 27), 9.3% and 6.8% of the obese and non-obese groups respectively (p = 0.67). Twenty-six of the complications were surgical and resulted in eight re-admissions (two obese (1.8%) and six (2.4%) non-obese). Three cases were revised at a mean follow-up of 29.45 months (one obese and two non-obese). Twelve patients presented with wound complications, six (5.6%) obese and six (2.4%) non-obese patients. In the obese cohort, one prosthetic joint infection (PJI) and one intraoperative fracture were diagnosed. Three postoperative periprosthetic fractures (1.2%), two dislocations (0.8%) and one confirmed DVT were documented in the non-obese cohort. Aseptic loosening occurred in two obese (1.9%) and five (2.0%) non-obese patients (2%). (See Table 3). Table 3: Complications Total n = 356 Obese n = 107 Non-obese n = 249 p-value Total 27 (7.6%) 10 (9.3%) 17 (6.8%) 0.67 Early (<4 weeks) Late (>4 weeks) 15 (4.2%) 12 (3.4%) 4 (3.7%) 6 (5.6%) 11 (4.4%) 6 (2.4%) 0.4 12 Medical 1 (0.3%) 0 1 (0.4%) DVT 1 (0.3%) 0 1 (0.4%) Surgical 26 (7.3%) 10 (9.3%) 16 (6.4%) 0.8 Wound Problems 12 (3.4%) 6 (5.6%) 6 (2.4%) Wound dehiscence 11 (3.1%) 5 (4.7%) 6 (2.4%) Surgical site infections 1 (0.3%) 1 (0.9%) 0 Deep PJI 1 (0.3%) 1 (0.9%) 0 Aseptic loosening 7 (2.0%) 2 (1.9%) 5 (2.0%) Acetabular loosening 1 (0.3%) 0 1 (0.4%) Femoral component loosening 6 (1.7%) 2 (1.9%) 4 (1.6%) Dislocation 2 (0.6%) 0 2 (0.8%) Periprosthetic Fractures 4 (1.1%) 1 (0.9%) 3 (1.2%) Intraoperative Fractures 1 (0.3%) 1 (0.9%) 0 Postoperative Fractures 3 (0.8%) 0 3 (1.2%) Vancouver B2 2 (0.6%) 0 2 (0.8%) Vancouver C 1 (0.3%) 0 1 (0.4%) Readmissions 8 2 (1.9%) 6 (2.4%) <30 days 3 (0.8%) 1 (0.9%) 2 (0.8%) 31 – 60 days 2 (0.6%) 0 2 (0.8%) 61 – 90 days 3 (0.8%) 1 (0.9%) 2 (0.8%) Re-operations 3 (0.8%) 1 (0.9%) 2 (0.8%) < 4 weeks 2 (0.6%) 0 2 (0.8%) > 4 weeks 1 (0.3%) 1 (0.9%) 0 DVT, Deep vein thrombosis; PJI, prosthetic joint infection 4. DISCUSSION To our knowledge, this is the first study in South Africa to compare outcomes between obese and non-obese patients undergoing THA via the AMISDAA. Cohorts were well-matched in terms of age, gender, primary diagnosis, and comorbidities. No differences were found in LOS, discharge destination, intraoperative fluoroscopy use, functional outcomes, PROMS and overall 13 complication rates however, increases in surgical duration, blood loss and risk of wound complications were noted in the obese group. In this study, mean surgical duration was longer in the obese cohort by 8.32 minutes. Obesity adversely affects surgical time regardless of approach.6–8,10,28,37,38 Onggo et al. calculated a difference in the mean surgical duration of 8.71 minutes between obese and non-obese patients, which widened further with increasing BMI, without assessing specific approaches.8 In the DAA, Russo et al. reported an increased surgical duration of 12.7 minutes in obese patients.7 Prolonged surgical duration is associated with increased perioperative risks including: prolonged admission; re-admission and re-operation; surgical site complications; systemic complications; and the need for blood transfusion.9,39 Despite the increased intraoperative blood loss noted in the obese cohort, only one patient required a transfusion implying limited clinical impact. Blood transfusions in THA are associated with a higher risk of PJI, increased LOS and cost.40 Neither Argyrou et al. nor Hartford et al. found a relationship between BMI and blood loss in the DAA, however, Antoniadis et al. noted increased blood loss in severely obese patients (BMI  35kg/m2) undergoing the DAA.10,28,37 Onggo et al., did not find a significant difference in blood loss between obese and non-obese patients regardless of approach.8 There were no statistically significant differences in average fluoroscopy duration or dosage between the obese and non-obese cohorts. Previous research by Curtin et al. identified a relationship between radiation dose and BMI based on the energy required to create the image.41 While the average fluoroscopy duration and dosage was greater than elsewhere in the literature, with Baksh et al. noting a mean fluoroscopy time of 21.4 seconds and a mean patient radiation dose of 1.8 mGy; the radiation dose across both cohorts remained within safe limits.41,42 Intraoperative fluoroscopy improves the accuracy of component positioning at the expense of radiation exposure to patient and staff.42 The authors found no difference in LOS or need for step-down facilities. Antoniadis et al. reported a longer LOS in both cohorts than found in this study and further noted a higher LOS in the severely obese cohort (7.3 versus 5.3 days).10 In obese patients, Russo et al. noted an increased LOS (2.4 versus 2.6 days) and need for step-down care (7.6% versus 15.4%).7 Hartford et al. noted 14 equivalent outcomes regardless of BMI in terms of LOS (p = 0.70) and discharge destination (p = 1.7).37 There was a significant improvement in UPAT score in both cohorts (p < 0.000). Postoperatively, obese patients reported higher levels of day pain (0.45  1.43 versus 0.28  0.82, p = 0.29) and lower night (0.23  0.96 versus 0.41  1.46, p = 0.32) and activity-related pain (0.43  1.59, p = 0.2) however this trend existed preoperatively and differences were statistically insignificant. Macheras et al. found equivalent postoperative pain scores for the obese and non-obese cohorts who underwent the DAA with both groups scoring significantly better than matched candidates who underwent the Hardinge approach.43 Though statistically insignificant, we found a greater improvement in mHHS scores in the obese cohort, despite the mean postoperative mHHS remaining lower than those of the non-obese. This was similar to the findings of Argyrou et al., Antoniadis et al. and Macheras et al.10,28,43 Macheras et al., in an RCT, noted better mHHS in DAA patients than Hardinge patients regardless of BMI.43 FJS in both of our cohorts reflected successful surgery but contrary to Singh et al., who noted a trend of higher scores in non-obese patients, (68.11 versus 62.45; p = 0.349), our study demonstrated higher scores in the obese cohort (77.81 ± 22.19 versus 71.43 ± 28.57) however these findings were statistically insignificant (p = 0.34).44 Other PROMS were similar indicating equivalent functional outcomes between obese and non-obese patients. There were no statistically significant differences in overall complication rates, re-admissions or re-operations. These have all been associated with increased risk in obese patients, regardless of approach.7,8,10,13,28,37,38 In our study, obese patients were more likely to have late complications and more likely to have wound complications (5.6% versus 2.4%, OR 2.4). An increased risk of wound complications and PJI in the obese cohort is in keeping with previous literature.7,10,13,28,37 Russo et al. noted a 3.6 times risk for wound complications in obese patients with an 8.8 times risk of major complications.7 Purcell et al. noted an incidence of 2.5% for PJI and 2% for SSI in patients with a BMI of  35kg/m2; Argyrou et al. noted an SSI rate of 8.1% in the obese versus 1.2% in the non-obese and Antoniadis et al. documented a 2.3% incidence of deep infection and 4.7% incidence of SSI in the obese compared to 0.8% of each respective complication in the non- obese cohort.10,13,28 In our study, non-obese patients were more likely to have early complications, including fractures and dislocations. There were no dislocations in the obese cohort. Onggo et al. and Lui et al. both noted an increased dislocation risk for obese patients undergoing THA however, Verhaegen et al. who only assessed patients undergoing the DAA did not find a difference.8,45,46 In our population, potentially protective factors include the tendency towards a more closed acetabular cup in the obese cohort and the intermuscular nature of the approach. 15 There were several limitations to this study including its retrospective nature. As the dataset was limited to a single, high-volume hip surgeon at a single institution, results may not be replicable in settings without equivalent expertise or resources. The BMI was used to classify obesity due to widespread use and convenience however it is often considered to be a crude measure of obesity. While we used broad categories of obese and non-obese patients, the further grading of BMI would have allowed for a more refined analysis of the data and comparison to other literature. 5. CONCLUSION This study shows that AMIS® DAA is a safe option for obese patients with equivalent outcomes to non-obese patients. As in other THA approaches, obese patients have a higher risk of wound- related complications, longer duration of surgery and increased volume of blood loss. This should be discussed during preoperative counselling and surgical planning. Funding statement This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Ethics approval and consent to participate Ethics clearance was obtained from the Human Research Ethics Committee: University of the Witwatersrand (Ethics clearance No.: M210819). Author contributions NG: Analysis, Writing – original draft, Visualisation. JRTP: Conceptualization, Analysis, Writing - Review and editing, Supervision. JNC: Writing - Review and editing, Supervision. SKM: Writing - Review and editing, Supervision. 16 Declaration of competing interest None. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. REFERENCES 1. World Health Organization. Obesity and Overweight.; 2021. Accessed July 7, 2021. https://www.who.int/news-room/fact-sheets/detail/obesity-and-overweight 2. National Department of Health (NDoH), Statistics South Africa (Stats SA), South African Medical Research Council (SAMRC)ICF. South Africa Demographic and Health Survey 2016.; 2019. 3. Haynes J, Nam D, Barrack RL. Hip arthroplasty: Avoiding and managing problems obesity in total hip arthroplasty does it make a difference? Bone and Joint Journal. 2017;99B(1):31-36. doi:10.1302/0301-620X.99B1.BJJ-2016-0346.R1 4. Bryan D, Parvizi J, Austin M, et al. Obesity and Total Joint Arthroplasty. J Arthroplasty. 2013;28(5):714-721. doi:10.1016/j.arth.2013.02.011 5. Messier SP. Obesity and Osteoarthritis: Disease Genesis and Nonpharmacologic Weight Management. Rheumatic Disease Clinics of North America. 2008;34(3):713-729. doi:10.1016/j.rdc.2008.04.007 6. Liu W, Wahafu T, Cheng M, Cheng T, Zhang Y, Zhang X. The influence of obesity on primary total hip arthroplasty outcomes: A meta-analysis of prospective cohort studies. Orthopaedics & Traumatology: Surgery & Research. 2015;101(3):289-296. doi:10.1016/j.otsr.2015.01.011 7. Russo MW, Macdonell JR, Paulus MC, Keller JM, Zawadsky MW. Increased Complications in Obese Patients Undergoing Direct Anterior Total Hip Arthroplasty. J Arthroplasty. 2015;30(8):1384-1387. doi:10.1016/j.arth.2015.03.002 8. Onggo JR, Onggo JD, de Steiger R, Hau R. Greater risks of complications, infections, and revisions in the obese versus non-obese total hip arthroplasty population of 2,190,824 patients: a meta-analysis and systematic review. Osteoarthritis Cartilage. 2020;28(1):31-44. doi:10.1016/j.joca.2019.10.005 17 9. Surace P, Sultan AA, George J, et al. The Association Between Operative Time and Short- Term Complications in Total Hip Arthroplasty: An Analysis of 89,802 Surgeries. J Arthroplasty. 2019;34(3):426-432. doi:10.1016/j.arth.2018.11.015 10. Antoniadis A, Dimitriou D, Flury A, Wiedmer G, Hasler J, Helmy N. Is Direct Anterior Approach a Credible Option for Severely Obese Patients Undergoing Total Hip Arthroplasty? A Matched-Control, Retrospective, Clinical Study. J Arthroplasty. 2018;33(8):2535-2540. doi:10.1016/j.arth.2018.03.071 11. Ward DT, Metz LN, Horst PK, Kim HT, Kuo AC. Complications of Morbid Obesity in Total Joint Arthroplasty: Risk Stratification Based on BMI. J Arthroplasty. 2015;30(9):42-46. doi:10.1016/j.arth.2015.03.045 12. Watts CD, Houdek MT, Wagner ER, Sculco PK, Chalmers BP, Taunton MJ. High Risk of Wound Complications Following Direct Anterior Total Hip Arthroplasty in Obese Patients. J Arthroplasty. 2015;30(12):2296-2298. doi:10.1016/j.arth.2015.06.016 13. Purcell RL, Parks NL, Cody JP, Hamilton WG. Comparison of Wound Complications and Deep Infections With Direct Anterior and Posterior Approaches in Obese Hip Arthroplasty Patients. J Arthroplasty. 2018;33(1):220-223. doi:10.1016/j.arth.2017.07.047 14. Pivec R, Johnson AJ, Mears SC, Mont MA. Hip arthroplasty. The Lancet. 2012;380(9855):1768-1777. doi:10.1016/S0140-6736(12)60607-2 15. Mariconda M, Galasso O, Costa GG, Recano P, Cerbasi S. Quality of life and functionality after total hip arthroplasty: a long-term follow-up study. BMC Musculoskelet Disord. 2011;12(1):222. doi:10.1186/1471-2474-12-222 16. Elmallah RK, Chughtai M, Khlopas A, et al. Determining Cost-Effectiveness of Total Hip and Knee Arthroplasty Using the Short Form-6D Utility Measure. J Arthroplasty. 2017;32(2):351- 354. doi:10.1016/j.arth.2016.08.006 17. Singh JA, Yu S, Chen L, Cleveland JD. Rates of Total Joint Replacement in the United States: Future Projections to 2020–2040 Using the National Inpatient Sample. J Rheumatol. 2019;46(9):1134-1140. doi:10.3899/jrheum.170990 18. Abdel MP, Meneghini RM, Berry DJ. Current Practice Trends in Primary Hip and Knee Arthroplasties Among Members of the American Association of Hip and Knee Surgeons: An Update During the COVID-19 Pandemic. J Arthroplasty. 2021;36(7):S40-S44.e3. doi:10.1016/j.arth.2021.01.080 18 19. Patel NN, Shah JA, Erens GA. Current Trends in Clinical Practice for the Direct Anterior Approach Total Hip Arthroplasty. J Arthroplasty. 2019;34(9):1987-1993.e3. doi:10.1016/j.arth.2019.04.025 20. Petis S, Howard JL, Lanting BL, Vasarhelyi EM. Surgical approach in primary total hip arthroplasty: anatomy, technique and clinical outcomes. Canadian Journal of Surgery. 2015;58(2):128-139. doi:10.1503/cjs.007214 21. Kyriakopoulos G, Poultsides L, Christofilopoulos P. Total hip arthroplasty through an anterior approach. EFORT Open Rev. 2018;3(11):574-583. doi:10.1302/2058-5241.3.180023 22. Bergin PF, Doppelt JD, Kephart CJ, et al. Comparison of Minimally Invasive Direct Anterior Versus Posterior Total Hip Arthroplasty Based on Inflammation and Muscle Damage Markers. Journal of Bone and Joint Surgery. 2011;93(15):1392-1398. doi:10.2106/JBJS.J.00557 23. Wang Z, Hou J zhao, Wu C hua, et al. A systematic review and meta-analysis of direct anterior approach versus posterior approach in total hip arthroplasty. J Orthop Surg Res. 2018;13(1):229. doi:10.1186/s13018-018-0929-4 24. Sun X, Zhao X, Zhou L, Su Z. Direct anterior approach versus posterolateral approach in total hip arthroplasty: a meta-analysis of results on early post-operative period. J Orthop Surg Res. 2021;16(1):69. doi:10.1186/s13018-021-02218-7 25. Awad ME, Farley BJ, Mostafa G, Saleh KJ. Direct anterior approach has short-term functional benefit and higher resource requirements compared with the posterior approach in primary total hip arthroplasty. Bone Joint J. 2021;103-B(6):1078-1087. doi:10.1302/0301- 620X.103B6.BJJ-2020-1271.R1 26. Jia F, Guo B, Xu F, Hou Y, Tang X, Huang L. A comparison of clinical, radiographic and surgical outcomes of total hip arthroplasty between direct anterior and posterior approaches: a systematic review and meta-analysis. HIP International. 2019;29(6):584-596. doi:10.1177/1120700018820652 27. Aggarwal VK, Elbuluk A, Dundon J, et al. Surgical approach significantly affects the complication rates associated with total hip arthroplasty. Bone and Joint Journal. 2019;101 B(6):646-651. doi:10.1302/0301-620X.101B6.BJJ-2018-1474.R1 28. Argyrou C, Tzefronis D, Sarantis M, Kateros K, Poultsides L, Macheras GA. Total hip arthroplasty through the direct anterior approach in morbidly obese patients. Bone Jt Open. 2022;3(1):4-11. doi:10.1302/2633-1462.31.BJO-2021-0166.R1 19 29. Sarraj M, Chen A, Ekhtiari S, Rubinger L. Traction table versus standard table total hip arthroplasty through the direct anterior approach: a systematic review. HIP International. 2020;30(6):662-672. doi:10.1177/1120700019900987 30. Medacta International. AMIS experience. Anterior minimally invasive surgery in hip replacement. Accessed February 16, 2023. https://media.medacta.com/media/9998xp11-03.pdf 31. Woolson ST, Hartford JM, Sawyer A. Results of a method of leg-length equalization for patients undergoing primary total hip replacement. J Arthroplasty. 1999;14(2):159-164. doi:10.1016/S0883-5403(99)90119-5 32. Kumar P, Sen R, Aggarwal S, Agarwal S, Rajnish RK. Reliability of Modified Harris Hip Score as a tool for outcome evaluation of Total Hip Replacements in Indian population. J Clin Orthop Trauma. 2019;10(1):128-130. doi:10.1016/j.jcot.2017.11.019 33. Gupta R, Dhiman U, Sharma K. Effect of a combination of oral midazolam and low-dose ketamine on anxiety, pain, swelling, and comfort during and after surgical extractions of mandibular third molars. Indian Journal of Dental Research. 2012;23(2):295. doi:10.4103/0970- 9290.100460 34. Registered Nurses’ Association of Ontario. Assessment and Management of Pain. 3rd edition. Registered Nurses’ Association of Ontario; 2013. www.rnao.ca/bestpractices 35. Adriani M, Malahias MA, Gu A, Kahlenberg CA, Ast MP, Sculco PK. Determining the Validity, Reliability, and Utility of the Forgotten Joint Score: A Systematic Review. J Arthroplasty. 2020;35(4):1137-1144. doi:10.1016/j.arth.2019.10.058 36. Cieremans DA, Huang S, Konopka JA, Davidovitch RI, Schwarzkopf R, Slover JD. Validation of Single-Outcome Questionnaire in Primary TKA and THA. J Arthroplasty. 2022;37(10):1987-1990. doi:10.1016/j.arth.2022.04.036 37. Hartford JM, Graw BP, Frosch DL. Perioperative Complications Stratified by Body Mass Index for the Direct Anterior Approach to Total Hip Arthroplasty. J Arthroplasty. 2020;35(9):2652-2657. doi:10.1016/j.arth.2020.04.018 38. Matar HE, Pincus D, Paterson JM, Aktar S, Jenkinson R, Ravi B. Early Surgical Complications of Total Hip Arthroplasty in Patients With Morbid Obesity: Propensity-Matched Cohort Study of 3683 Patients. J Arthroplasty. 2020;35(9):2646-2651. doi:10.1016/j.arth.2020.04.044 20 39. Sikov M, Sloan M, Sheth NP. Effect of operative time on complications following primary total hip arthroplasty: analysis of the NSQIP database. HIP International. 2021;31(2):231-236. doi:10.1177/1120700020949701 40. Iacobelli DS, Syku M, Abutalib Z, et al. Transfusion Avoidance in Severely Anemic Total Hip and Total Knee Arthroplasty Patients: An Analysis of Risk. Arthroplast Today. 2022;14:128- 132. doi:10.1016/j.artd.2022.01.033 41. Curtin BM, Armstrong LC, Bucker BT, Odum SM, Jiranek WA. Patient Radiation Exposure During Fluoro-Assisted Direct Anterior Approach Total Hip Arthroplasty. J Arthroplasty. 2016;31(6):1218-1221. doi:10.1016/j.arth.2015.12.012 42. Baksh N, Wei L, Ho ES, et al. Radiation exposure in fluoroscopy-guided anterior total hip arthroplasty: a systematic review. European Journal of Orthopaedic Surgery & Traumatology. 2022;32(5):891-897. doi:10.1007/s00590-021-03060-7 43. Macheras G, Stasi S, Sarantis M, Triantafyllou A, Tzefronis D, Papadakis SA. Direct anterior approach vs Hardinge in obese and nonobese osteoarthritic patients: A randomized controlled trial. World J Orthop. 2021;12(11):877-890. doi:10.5312/wjo.v12.i11.877 44. Singh V, Yeroushalmi D, Lygrisse KA, Schwarzkopf R, Davidovitch RI. Impact of Obesity on the Forgotten Joint Score Following Primary Total Hip Arthroplasty. J Arthroplasty. 2021;36(4):1342-1347. doi:10.1016/j.arth.2020.10.027 45. Liu W, Wahafu T, Cheng M, Cheng T, Zhang Y, Zhang X. The influence of obesity on primary total hip arthroplasty outcomes: A meta-analysis of prospective cohort studies. Orthopaedics & Traumatology: Surgery & Research. 2015;101(3):289-296. doi:10.1016/j.otsr.2015.01.011 46. Verhaegen JCF, Wei R, Kim P, Beaulé PE, Corten K, Grammatopoulos G. The Safety and Efficacy of the Anterior Approach Total Hip Arthroplasty as per Body Mass Index. J Arthroplasty. 2023;38(2):314-322.e1. doi:10.1016/j.arth.2022.08.021 21 Appendices Appendix A: Data Collection Form Appendix B: Ethics Certificate Appendix C: Hospital Manager Consent Appendix D: Universal Pain Assessment Tool Appendix E: Journal guidelines Appendix F: Student’s contribution to research & writing of the “submissible” paper Appendix G: Research protocol 22 Appendix A: Data Collection Form Title: A Comparison of the Short-Term Outcomes of Obese and Non-obese Patients undergoing Total Hip Arthroplasty using the Direct Anterior Approach Demographic Data Study Number: Age: ___ years Sex: M/F Height:____m Weight: ____kg BMI: ____kg/m2 Medical comorbidities: ☐Diabetes ☐Hypertension ☐Epilepsy ☐Asthma ☐Previous MI ☐Cardiac Arrythmias ☐Thyroid disease ☐HIV ASA grade: ____ Allergies: Intraoperative Data Surgical time: _____minutes Cemented femoral component: Y/N 23 Intra-operative complication: ☐Femoral fracture ☐Acetabular fracture ☐Nerve injury ☐Vascular injury ☐Need for cables Blood loss: ______ml Blood transfusion: Y/N Acetabular component size: ___ Polyethylene component size: ___ Femoral component size: ___ Screws acetabular component: Y/N Clinical Data Preoperative Modified Harris Hip Score: ______ UPAT score (at rest): _______ UPAT score (with activity): ______ LLD:_____mm Postoperative Length of hospital stay: _____days 24 Blood transfusion in ward: Y/N 6 weeks/6 months/1 year post operatively Modified Harris Hip Score: _____ UPAT score at rest: _______ UPAT score on activity: ______ Complications Early (<4weeks): Y/N Late (>4weeks): Y/N Type of complication: ☐Medical ☐Surgical Medical complications ☐Cardiac ☐Pulmonary ☐Renal ☐Deep vein thrombosis ☐Other Surgical complications ☐ Intraoperative ☐Postoperative ☐SSI ☐Deep PJI ☐Wound dehiscence ☐Periprosthetic fracture ☐Hip dislocation ☐Loosening. If Yes ☐Acetabular component ☐Femoral component 25 ☐Nerve injury ☐Vascular injury ☐Greater trochanter pain syndrome ☐Iliopsoas impingement ☐Leg length discrepancy ____mm Radiological Evaluation Fixation Type ☐ Cemented ☐ Uncemented ☐Hybrid Acetabular Cup Inclination ☐<30° ☐30-40 ☐41-55° ☐>55° Acetabular Cup Version ☐0° ☐1-10° ☐11-20° ☐>20° Femoral Stem Version ☐Neutral ☐Valgus ☐Varus 26 Appendix B: Ethics Approval 27 Appendix C: Hospital Manager Consent 28 Appendix D: Universal Pain Assessment Tool: Available from: South African Acute Pain Guidelines 29 Appendix E: Journal guidelines JOURNAL OF ORTHOPAEDICS An official publication of the Prof. PK Surendran Memorial Educational Foundation and Indo Korean Orthopaedic Foundation AUTHOR INFORMATION PACK TABLE OF CONTENTS XXX • Description p.1 • Abstracting and Indexing p.1 • Editorial Board p.2 • Guide for Authors p.6 ISSN: 0972-978X DESCRIPTION Journal of Orthopaedics aims to be a leading journal in orthopaedics and contribute towards the improvement of quality of orthopedic health care. The journal publishes original research work and review articles related to different aspects of orthopaedics including Arthroplasty, Arthroscopy, Sports Medicine, Trauma, Spine and Spinal deformities, Pediatric orthopaedics, limb reconstruction procedures, hand surgery, and orthopaedic oncology. It also publishes articles on continuing education, health-related information, case reports and letters to the editor. It is requested to note that the journal has an international readership and all submissions should be aimed at specifying something about the setting in which the work was conducted. Authors must also provide any specific reasons for the research and also provide an elaborate description of the results. http://www.jortho.org/pksurendran.htm http://ikof.org/ 30 Benefits to authors We also provide many author benefits, such as free PDFs, a liberal copyright policy, special discounts on Elsevier publications and much more. 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ABSTRACTING AND INDEXING PubMed/Medline Scopus Embase Emerging Sources Citation Index (ESCI) Web of Science Gale Academic OneFile EBSCOhost PubMed Central EDITORIAL BOARD Editor-in-Chief Raju Vaishya, Indraprastha Apollo Hospitals Institutes of Orthopaedics, New Delhi, India Knee, Arthroplasty, Sports Medicine, Joint preservation, Bibliometric studies, Arthroplasty, Sports Medicine Co Editor-in-Chief Heiko Graichen, Asklepios Orthopaedic Hospital Lindenlohe, Department of Arthroplasty and General Orthopaedic Surgery, Schwandorf, Germany Arthroplasty https://www.elsevier.com/journal-authors/author-services https://www.elsevier.com/journal-authors/author-services https://www.elsevier.com/journals/journal-of-orthopaedics/0972-978X/guide-for-authors https://service.elsevier.com/app/home/supporthub/publishing/ 31 Senior Editor Ye Yeon Won, Ajou University School of Medicine, Ajou Medical Center, Department of Orthopaedic Surgery, Suwon, South Korea Arthroplasty Managing Editor Patinharayil Gopinathan, Kerala University of Health Sciences Government Medical College, Department of Orthopedics, Kozhikode, Kerala, India Sports Medicine Associate Editors Manjula Bansal, Hospital for Special Surgery, New York, United States of America MSK Tumors Anil Bhat, Manipal Academy of Higher Education, Manipal, India Hand and Microsurgery Bancha Chernchujit, Thammasat University, Department of Orthopedics, Faculty of Medicine, Pathumthani, Thailand Orthopaedics Pascal Christel, Dr Sulaiman Al Habib Medical Group, Riyadh, Saudi Arabia Orthopaedic Surgery Riccardo D'Ambrosi, IRCCS Galeazzi Orthopaedic Institute, Milano, Italy Arthroplasty, Sports Medicine Ish Kumar Dhammi, University College of Medical Sciences, New Delhi, India General Orthopaedics, Trauma Mandeep S. Dhillon, Post Graduate Institute of Medical Education and Research, Chandigarh, India Arthroscopy, Sports medicine, Foot & Ankle, Trauma Jorg Eschweiler, RWTH Aachen University Hospital, Department of Orthopaedics, Trauma, and Reconstructive Surgery, Aachen, Germany Bioengineering, Research Vincenzo Filardi, University of Messina, Research and Internationalization, Messina, Italy Bioengineering, Orthopedics, Medical devices, FE modelization 32 Brij Mohan Gupta, Council of Scientific & Industrial Research, New Delhi, India Bibliometric Analysis, Research Hiroshi Hagino, Tottori University, Tottori, Japan Bone Metabolism, Orthopaedics, Epidemiology, Rheumatoid Arthritis, Orthopaedic Surgery Abid Haleem, Jamia Millia Islamia, New Delhi, India healthcare Technologies, Additive Manufacturing, 3D Printing, advanced technologies, Supply chain management, Operations management Chang Whan Han, Catholic University of Korea Daejeon St Mary's Hospital, Department of Orthopaedics, Daejon, South Korea Sports Medicine Masayuki Iki, Kindai University, Faculty of Medicine, Department of Public Health, Sayama, Japan Public Health Karthikeyan P. Iyengar, Southport and Ormskirk Hospital NHS Trust, Southport, United Kingdom Upper limb, Trauma, General Orthopaedics Vijay Jain, Dr Ram Manohar Lohia Hospital Post Graduate Institute of Medical Education and Research Orthopaedics Department, New Delhi, India General Orthopaedics, Trauma Atul Joshi, Covenant Medical Center - 19th Street Campus, Lubbock, United States of America Arthroplasty Darren Tay Keng Jin, Singapore General Hospital, Singapore, Singapore Orthopaedic Surgery Santosh Kumar, King George's Medical University, Lucknow, India Arthrhoplasty, Trauma Vinod Kumar, Maulana Azad Medical College, New Delhi, India Sports Medicine, Trauma Danilo Leonetti, University of Messina, Department of Orthopedics and Trauma Surgery, Messina, Italy Foot and Ankle, Trauma Nicola Maffulli, Queen Mary University of London, London, United Kingdom Sports Medicine 33 Rajesh Malhotra, All India Institute of Medical Sciences, Department of Orthopaedics, New Delhi, India Arthroplasty Ajay Malviya, Northumbria Healthcare NHS Foundation Trust, Newcastle, United Kingdom Arthroscopy, Hip dislocation, Hip Preservation Filippo Migliorini, RWTH Aachen University Hospital, Department of Orthopaedics, Trauma, and Reconstructive Surgery, Aachen, Germany Arthroscopy, Arthroplasty, Biologics, Cartilage and bone regeneration Colin Nnadi, Oxford University Hospitals NHS Foundation Trust Nuffield Orthopaedic Centre, Oxford, United Kingdom Orthopaedic Surgery Sandeep Patwardhan, Sancheti Institute for Orthopaedics and Rehabilitation, Pune, India Paediatric Orthopaedics Rocco Paolo Pitto, The University of Auckland, Auckland, New Zealand Orthopaedic Surgery Shanmuganathan Rajasekaran, Ganga Medical Centre and Hospitals Pvt Ltd, Coimbatore, India Spine, Trauma Salvatore Risitano, University of Turin, City of Health and Science of Turin, Turin, Italy Total knee Arthroplasty, Arthroscopy, Sports Medicine, Knee surgery, Trauma Vinod Scaria, CSIR Institute of Genomics & Integrative Biology, New Delhi, India Technology, Basic Science Oliver Loannis Schmidt, HELIOS Park Hospital Leipzig, Department of Orthopedics, Leipzig, Germany Orthopaedics Hemant Sharma, University of Hull, Hull, United Kingdom Adult Reconstruction, bone infections, Complex trauma, Non Unions Ajoy P. Shetty, Ganga Medical Centre and Hospitals Pvt Ltd, Coimbatore, India Spine, Trauma Gautam M. Shetty, Mullaji Knee Clinic, Mumbai, India Arthroplasty 34 Bijayendra Singh, Canterbury Christ Church University, Medway Foundation NHS Trust, Gillingham, United Kingdom Upper Limb, Spine Sibin Surendran, Kerala University of Health Sciences, Thrissur, India Orthopaedic Surgery Bruno Toussaint, Clinique Générale Ste Anne, Annecy, France Upper Limb Abhishek Vaish, Indraprastha Apollo Hospitals Institutes of Orthopaedics, New Delhi, India Arthrosocpy, Sports Medicine, Trauma Piers Yates, Fremantle Hospital, Department of Orthopaedics, Fremantle, Australia Orthopaedic Surgery Yon Sik Yoo, Hallym University Medical College of Hallym University, Department of Orthopedic Surgery, Hwaseong, South Korea Orthopaedic Surgery Assistant Editors Pawan Agarwal, Netaji Subhash Chandra Bose Medical College and Hospital, Department of Surgery, Jabalpur, India Plastic and Reconstructive surgery, Hand Raju Ahluwalia, King's College Hospital, London, United Kingdom Foot and Ankle Alice Baroncini, RWTH Aachen University Medical Faculty, Aachen, Germany Spine Rajesh Botchu, Royal Orthopaedic Hospital, Birmingham, United Kingdom MSK Radiology Gautam Chakrabarty, Calderdale and Huddersfield NHS Foundation Trust, Huddersfield, United Kingdom Arthroplasty Bosco Francesco, University of Turin, Department of Public Health and Pediatric Sciences, Torino, Italy Trauma and Knee surgery Sudhir Kumar Garg, Government Medical College and Hospital, Chandigarh, India MSK Tumors, Trauma 35 Prasad Gourineni, Advocate Children's Hospital, Oak Lawn, United States of America Paediatric Orthopaedics Ariful Haque, Kunming Medical University, Kunming, China Orthopedics, Sports Medicine, Trauma Surgery, Joint Surgery, Arthroscopy, Arthroplasty, 3D Orthopedics, Public Health, Mental Health, Occupational Health, Global Health Madhan Jeyaraman, Sri Lalithambigai Medical College and Hospital, Department of Orthopaedics, Chennai, India Arthroscopy, General Orthopaedics Ashok Johari, Children's Orthopaedic Centre, Mumbai, India Paediatric Orthopaedics Raju Karuppal, Kerala University of Health Sciences Government Medical College, Department of Orthopedics, Kozhikode, India Trauma, Arthroscopy and Arthroplasty James Kigera, University of Nairobi School of Medicine, Nairobi, Kenya Arthroscopy and Trauma Philippe Landreau, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Qatar Sports Medicine Rujuta Mehta, Bai Jerbai Wadia Hospital for Children, Parel, India Paediatric Orthopaedics Samarth Mittal, Jai Prakash Narayan Apex Trauma Center AIIMS, New Delhi, India Trauma Raj M. Murali, Wrightington Hospital, Department of Orthopaedics, Wigan, United Kingdom Upper Limb Mohit Kumar Patralekh, Vardhman Mahavir Medical College and Safdarjung Hospital Central Institute of Orthopaedics, New Delhi, India Systematic Reviews, , S. Dilip Chand Raja, Fortis Hospital, Vadapalani, Chennai, India Spine 36 Salvatore Risitano, University of Turin, City of Health and Science of Turin, Turin, Italy Total knee Arthroplasty, Arthroscopy, Sports Medicine, Knee surgery, Trauma Giuseppe Rovere, Catholic University of the Sacred Heart, Milano, Italy Trauma, Hip and Knee surgery Dhananjaya Sabat, MAMC and LNJP Hospitals, New Delhi, India Arthroscopy, Trauma Federico Sacchetti, University of Florence, Firenze, Italy MSK Oncology Abhijeet Salunke, The Gujarat Cancer and Research Institute, Ahmedabad, India MSK Tumors Saseender Shanmugasundaram, Sri Lakshmi Narayana Institute of Medical Sciences, Puducherry, India Arthroscopy and Arthroplasty Amit Sinha, Spire Yale Hospital, Wrexham, United Kingdom Hand, Trauma, Upper Limb (shoulder. elbow). Knee surgery Norimasa Takahashi, Funabashi Orthopaedic Hospital Shoulder and Elbow Center, Funabashi, Japan Orthopaedic Surgery Vivek Tiwari, All India Institute of Medical Sciences - Nagpur, Nagpur, India Trauma, General Orthopaedics Amit Tolat, Medway Maritime Hospital, Gillingham, United Kingdom Arthroscopy, Trauma Jayesh Trivedi, Robert Jones and Agnes Hunt Orthopaedic Hospital NHS Foundation Trust, Oswestry, United Kingdom Spine Elizabeth Vinod, Christian Medical College and Hospital Vellore, Department of Physiology, Vellore, India Others Karthik Vishwanathan, Parul University, Vadodara, India Arthroplasty, Trauma 37 Editorial Board Kunal Aneja, Max Super Speciality Hospital Shalimar Bagh, New Delhi, India Arthroplasty, Sports Medicine, Arthroscopy, Trauma, Joint Preservation, Regenerative Medicine Nicholas Antao, Holy Spirit Hospital, Mumbai, India Sports Medicine, Arthroplasty Giustra Fortunato, University of Turin, Maria Vittoria Hospital, Department of Orthopaedic and Traumatology, Turin, Italy Trauma and General orthopaedics Nijith Govindan, MIOC Ortho Clinic, Kochi, India Arthroplasty Upper and Lower limb, Arthroscopy and Sports Medicine Nidhi Goyal, Indraprastha Apollo Hospitals, New Delhi, India MSK Radiology Amit Joshi, B & B Hospital Pvt. Ltd., Kathmandu, Nepal Arthroscopy and Sports Medicine Vikram Khanna, Akasha Institute, New Delhi, India Trauma, General Orthopaedics Rajiv Maharjan, BP Koirala Institute of Health Sciences, Dharan, Nepal Trauma, General Orthopaedics, Arthroplasty, Spine Anwar Marthya, IQRAA International Hospital and Research Centre, Kozhikode, India Orthopaedic surgery Prem Haridas Menon, Kerala University of Health Sciences, Thrissur, India Trauma, Arthroplasty, Arthroscopy, Geriatric fractures, Randomised Clinical Trials Mubder Mohammed saeed, University of Basrah College of Medicine, Basrah, Iraq Trauma, General Orthopaedics, Orthopaedics Trauma and Spine Gaurav Neupane, Chitwan Medical College, Bharatpur, Nepal Arthroplasty, Trauma 38 Raja Bhaskar Rajasekaran, Royal Orthopaedic Hospital, Birmingham, United Kingdom MSK Tumors Himanshu Rohilla, Rajiv Gandhi Cancer Institute and Research Centre, New Delhi, India MSK Tumors Binoti Sheth, Lokmanya Tilak Municipal Medical College and General Hospital, Mumbai, India Paediatric Orthopaedics 39 GUIDE FOR AUTHORS INTRODUCTION We publish original research work across all disciplines of orthopedics and allied sciences, continuing education, evidence updates, students' pre-specified contributions, journal clubs, health-related information of interest to our readers and letters to editors are published. Journal of Orthopaedics seeks to be the pre-eminent Orthopaedics Journal. The content is aimed to deliver significant impact on the clinical practitioners and for improvement of the quality of health care. We are keen to encourage the submission of papers from authors whose first language is not English, although it is recommended that before submitting your manuscript to the journal you ask a colleague familiar with written English to read it through. This will greatly speed up the time taken to publish your paper. It is requested to note that the journal has an international readership and all submissions should be aimed at specifying something about the setting in which the work was conducted, why any specific reason for the research and also an elaborate description of the results. Article categories The categories of articles that are published in the Journal are listed and described below. Please select the category that best describes your paper. If your paper does not fall into any of these categories, please contact the Editorial Office. You need to follow all the guidelines of this journal and the International guidelines, as per the article type (see table below): 40 JOO_article-specifications-list.jpg - Table with article specifications per article type Original Research Article: Original, in-depth clinical research that represents new and significant contributions to medical science. The entire manuscript should not exceed 3000 words and should have maximum 50 references and 8 authors. Randomized Control Trial (RCT): These studies should follow CONSORT guidelines and should not exceed 3500 words and 60 references. An Institutional Ethical Committee approval is required before the start of the study. Systematic Review Article: These are comprehensive review articles on topics of current clinical interest in Orthopaedic targeting specialists. The entire manuscript should not exceed 3500 words with not more than 60 references. Please use structured abstract for all the review articles (including narrative reviews). Narrative Reviews: These comprehensive reviews should cover upto date information about the subject. The manuscript should not exceed 2500 words and should have a maximum of 50 references and 6 authors. Short Communication: Short communications can be personal opinions, or mini review on a burning topic, related to Orthopaedics. They should be up to 1000 words and can have up to 10 references, 3 authors and 2 figures/tables. Case Reports: These should be novel, describing a new pathology, or management of a case. The manuscript should not exceed more than 2000 words and maximum limit of authors is 4 and https://www.elsevier.com/__data/promis_images/JOO_article-specifications-list.jpg 41 the references up to 20, for this category. Please use structured abstract for all case report articles. Clinical Practice Guidelines: These articles summarize and suggest the guidelines for the clinicians about a common medical or surgical problem, based on currently available evidences from the literature. These should have a maximum of 300 words, 50 references, and up to 8 authors. Editorials: The Editor usually commissions editorials but ideas or suggestions are welcomed. Letters/Opinion: Are up to 500 words and are subject to copyediting, with the maximum of 2 authors and 5 references. Preference will be given to letters responding to points raised by articles published recently in this Journal. Authors will not receive proofs. Opinion articles relevant to newer developments in relation to Internet that would be of significance to medical profession are invited. Address all correspondence to Prof. Dr. Raju Vaishya, Editor-in-Chief, Journal of Orthopaedics at raju.vaishya@gmail.com. Submission checklist You can use this list to carry out a final check of your submission before you send it to the journal for review. Please check the relevant section in this Guide for Authors for more details. Ensure that the following items are present: One author has been designated as the corresponding author with contact details: • E-mail address • Full postal address All necessary files have been uploaded: Manuscript: • Include keywords • All figures (include relevant captions) • All tables (including titles, description, footnotes) • Ensure all figure and table citations in the text match the files provided • Indicate clearly if color should be used for any figures in print Graphical Abstracts / Highlights files (where applicable) Supplemental files (where applicable) Further considerations 42 • Manuscript has been 'spell checked' and 'grammar checked' • All references mentioned in the Reference List are cited in the text, and vice versa • Permission has been obtained for use of copyrighted material from other sources (including theInternet) • A competing interests statement is provided, even if the authors have no competing interests todeclare • Journal policies detailed in this guide have been reviewed • Referee suggestions and contact details provided, based on journal requirements For further information, visit our Support Center. BEFORE YOU BEGIN Ethics in publishing Please see our information on Ethics in publishing. Studies in humans and animals If the work involves the use of human subjects, the author should ensure that the work described has been carried out in accordance with The Code of Ethics of the World Medical Association (Declaration of Helsinki) for experiments involving humans. The manuscript should be in line with the Recommendations for the Conduct, Reporting, Editing and Publication of Scholarly Work in Medical Journals and aim for the inclusion of representative human populations (sex, age and ethnicity) as per those recommendations. The terms sex and gender should be used correctly. Authors should include a statement in the manuscript that informed consent was obtained for experimentation with human subjects. The privacy rights of human subjects must always be observed. All animal experiments should comply with the ARRIVE guidelines and should be carried out in accordance with the U.K. Animals (Scientific Procedures) Act, 1986 and associated guidelines, EU Directive 2010/63/EU for animal experiments, or the National Research Council's Guide for the Care and Use of Laboratory Animals and the authors should clearly indicate in the manuscript that such guidelines have been followed. The sex of animals must be indicated, and where appropriate, the influence (or association) of sex on the results of the study. Declaration of interest All authors must disclose any financial and personal relationships with other people or organizations that could inappropriately influence (bias) their work. Examples of potential competing interests include employment, consultancies, stock ownership, honoraria, paid expert testimony, patent applications/registrations, and grants or other funding. Authors must disclose any interests in two places: 1. A summary declaration of interest statement in the title page file (if double anonymized) or the manuscript file (if single anonymized). If there are no interests to declare then please state this: 'Declarations of interest: none'. 2. Detailed disclosures as part of https://service.elsevier.com/app/home/supporthub/publishing/ https://www.elsevier.com/about/policies/publishing-ethics#Authors https://www.wma.net/policies-post/wma-declaration-of-helsinki-ethical-principles-for-medical-research-involving-human-subjects/ https://www.wma.net/policies-post/wma-declaration-of-helsinki-ethical-principles-for-medical-research-involving-human-subjects/ http://www.icmje.org/recommendations/ http://www.icmje.org/recommendations/ http://www.icmje.org/recommendations/ https://www.who.int/gender-equity-rights/understanding/gender-definition/en/ https://www.nc3rs.org.uk/arrive-guidelines https://ec.europa.eu/environment/chemicals/lab_animals/legislation_en.htm https://ec.europa.eu/environment/chemicals/lab_animals/legislation_en.htm https://ec.europa.eu/environment/chemicals/lab_animals/legislation_en.htm https://grants.nih.gov/grants/olaw/guide-for-the-care-and-use-of-laboratory-animals.pdf https://grants.nih.gov/grants/olaw/guide-for-the-care-and-use-of-laboratory-animals.pdf https://grants.nih.gov/grants/olaw/guide-for-the-care-and-use-of-laboratory-animals.pdf 43 a separate Declaration of Interest form, which forms part of the journal's official records. It is important for potential interests to be declared in both places and that the information matches. More information. Submission declaration Submission of an article implies that the work described has not been published previously (except in the form of an abstract, a published lecture or academic thesis, see 'Multiple, redundant or concurrent publication' for more information), that it is not under consideration for publication elsewhere, that its publication is approved by all authors and tacitly or explicitly by the responsible authorities where the work was carried out, and that, if accepted, it will not be published elsewhere in the same form, in English or in any other language, including electronically without the written consent of the copyrightholder. Use of inclusive language Inclusive language acknowledges diversity, conveys respect to all people, is sensitive to differences, and promotes equal opportunities. Content should make no assumptions about the beliefs or commitments of any reader; contain nothing which might imply that one individual is superior to another on the grounds of age, gender, race, ethnicity, culture, sexual orientation, disability or health condition; and use inclusive language throughout. Authors should ensure that writing is free from bias, stereotypes, slang, reference to dominant culture and/or cultural assumptions. We advise to seek gender neutrality by using plural nouns ("clinicians, patients/clients") as default/wherever possible to avoid using "he, she," or "he/she." We recommend avoiding the use of descriptors that refer to personal attributes such as age, gender, race, ethnicity, culture, sexual orientation, disability or health condition unless they are relevant and valid. When coding terminology is used, we recommend to avoid offensive or exclusionary terms such as "master", "slave", "blacklist" and "whitelist". We suggest using alternatives that are more appropriate and (self-) explanatory such as "primary", "secondary", "blocklist" and "allowlist". These guidelines are meant as a point of reference to help identify appropriate language but are by no means exhaustive or definitive. Reporting sex- and gender-based analyses Reporting guidance For research involving or pertaining to humans, animals or eukaryotic cells, investigators should integrate sex and gender-based analyses (SGBA) into their research design according to funder/ sponsor requirements and best practices within a field. Authors should address the sex and/or gender dimensions of their research in their article. In cases where they cannot, they should discuss this as a limitation to their research's generalizability. Importantly, authors should explicitly state what definitions of sex and/or gender they are applying to enhance the precision, rigor and reproducibility of their research and to avoid ambiguity or conflation of terms and the constructs to which they refer (see Definitions section below). Authors can refer to the Sex and https://service.elsevier.com/app/answers/detail/a_id/286/supporthub/publishing/ https://www.elsevier.com/about/policies/publishing-ethics#Authors https://www.elsevier.com/about/policies/publishing-ethics#Authors https://www.elsevier.com/about/policies/publishing-ethics#Authors https://doi.org/10.1186/s41073-016-0007-6 44 Gender Equity in Research (SAGER) guidelines and the SAGER guidelines checklist. These offer systematic approaches to the use and editorial review of sex and gender information in study design, data analysis, outcome reporting and research interpretation - however, please note there is no single, universally agreed-upon set of guidelines for defining sex and gender. Definitions Sex generally refers to a set of biological attributes that are associated with physical and physiological features (e.g., chromosomal genotype, hormonal levels, internal and external anatomy). A binary sex categorization (male/female) is usually designated at birth ("sex assigned at birth"), most often based solely on the visible external anatomy of a newborn. Gender generally refers to socially constructed roles, behaviors, and identities of women, men and gender-diverse people that occur in a historical and cultural context and may vary across societies and over time. Gender influences how people view themselves and each other, how they behave and interact and how power is distributed in society. Sex and gender are often incorrectly portrayed as binary (female/male or woman/man) and unchanging whereas these constructs actually exist along a spectrum and include additional sex categorizations and gender identities such as people who are intersex/have differences of sex development (DSD) or identify as non-binary. Moreover, the terms "sex" and "gender" can be ambiguous—thus it is important for authors to define the manner in which they are used. In addition to this definition guidance and the SAGER guidelines, the resources on this page offer further insight around sex and gender in research studies. Author contributions For transparency, we encourage authors to submit an author statement file outlining their individual contributions to the paper using the relevant CRediT roles: Conceptualization; Data curation; Formal analysis; Funding acquisition; Investigation; Methodology; Project administration; Resources; Software; Supervision; Validation; Visualization; Roles/Writing - original draft; Writing - review & editing. Authorship statements should be formatted with the names of authors first and CRediT role(s) following. More details and an example. Changes to authorship Authors are expected to consider carefully the list and order of authors before submitting their manuscript and provide the definitive list of authors at the time of the original submission. Any addition, deletion or rearrangement of author names in the authorship list should be made only before the manuscript has been accepted and only if approved by the journal Editor. To request such a change, the Editor must receive the following from the corresponding author: (a) the reason for the change in author list and (b) written confirmation (e-mail, letter) from all authors that they agree with the addition, removal or rearrangement. In the case of addition or removal of authors, this includes confirmation from the author being added or removed. Only in exceptional circumstances will the Editor consider the addition, deletion or rearrangement of authors after the manuscript has been accepted. While the Editor considers the request, https://doi.org/10.1186/s41073-016-0007-6 https://doi.org/10.1186/s41073-016-0007-6 https://doi.org/10.3897/ese.2022.e86910 https://www.elsevier.com/authors/policies-and-guidelines/edi#SAGER https://www.elsevier.com/authors/journal-authors/policies-and-ethics/credit-author-statement 45 publication of the manuscript will be suspended. If the manuscript has already been published in an online issue, any requests approved by the Editor will result in a corrigendum. Article Transfer Service This journal is part of our Article Transfer Service. This means that if the Editor feels your article is more suitable in one of our other participating journals, then you may be asked to consider transferring the article to one of those. If you agree, your article will be transferred automatically on your behalf with no need to reformat. Please note that your article will be reviewed again by the new journal. More information. Reporting clinical trials Randomized controlled trials should be presented according to the CONSORT guidelines. At manuscript submission, authors must provide the CONSORT checklist accompanied by a flow diagram that illustrates the progress of patients through the trial, including recruitment, enrollment, randomization, withdrawal and completion, and a detailed description of the randomization procedure. The CONSORT checklist and template flow diagram are available online. Copyright Upon acceptance of an article, authors will be asked to complete a 'Journal Publishing Agreement' (see more information on this). An e-mail will be sent to the corresponding author confirming receipt of the manuscript together with a 'Journal Publishing Agreement' form or a link to the online version of this agreement. Subscribers may reproduce tables of contents or prepare lists of articles including abstracts for internal circulation within their institutions. Permission of the Publisher is required for resale or distribution outside the institution and for all other derivative works, including compilations and translations. If excerpts from other copyrighted works are included, the author(s) must obtain written permission from the copyright owners and credit the source(s) in the article. Elsevier has preprinted forms for use by authors in these cases. Author rights As an author you (or your employer or institution) have certain rights to reuse your work. More information. Elsevier supports responsible sharing Find out how you can share your research published in Elsevier journals. https://www.elsevier.com/authors/article-transfer-service http://www.consort-statement.org/ http://www.consort-statement.org/ https://www.elsevier.com/about/policies/copyright https://www.elsevier.com/about/policies/copyright/permissions https://www.elsevier.com/__data/assets/word_doc/0007/98656/Permission-Request-Form.docx https://www.elsevier.com/about/policies/copyright https://www.elsevier.com/about/policies/copyright https://www.elsevier.com/about/policies/copyright https://www.elsevier.com/authors/journal-authors/submit-your-paper/sharing-and-promoting-your-article 46 Role of the funding source You are requested to identify who provided financial support for the conduct of the research and/or preparation of the article and to briefly describe the role of the sponsor(s), if any, in study design; in the collection, analysis and interpretation of data; in the writing of the report; and in the decision to submit the article for publication. If the funding source(s) had no such involvement, it is recommended to state this. Open access Please visit our Open Access page for more information. Language (usage and editing services) Please write your text in good English (American or British usage is accepted, but not a mixture of these). Authors who feel their English language manuscript may require editing to eliminate possible grammatical or spelling errors and to conform to correct scientific English may wish to use the English Language Editing service available from Elsevier's Author Services. Submission Our online submission system guides you stepwise through the process of entering your article details and uploading your files. Editable article files (e.g., Word, LaTeX) are mandatory to use in the peerreview process and typeset your article for final publication. All correspondence, including notification of the Editor's decision and requests for revision, is sent by e-mail. Submit your article Please submit your article via https://www.editorialmanager.com/JOO/default.aspx. Suggesting reviewers Please submit the names and institutional e-mail addresses of several potential reviewers. You should not suggest reviewers who are colleagues, or who have co-authored or collaborated with you during the last three years. Editors do not invite reviewers who have potential competing interests with the authors. Further, in order to provide a broad and balanced assessment of the work, and ensure scientific rigor, please suggest diverse candidate reviewers who are located in different countries/ regions from the author group. Also consider other diversity attributes e.g. gender, race and ethnicity, career stage, etc. Finally, you should not include existing members of the journal's editorial team, of whom the journal are already aware. Note: the editor decides whether or not to invite your suggested reviewers. PREPARATION Manuscripts must conform to the instructions given below: https://www.elsevier.com/journals/journal-of-orthopaedics/0972-978X/open-access-options https://webshop.elsevier.com/language-editing-services/language-editing/ https://webshop.elsevier.com/language-editing-services/language-editing/ 47 General Type the manuscript using 'Times New Roman' font, size 12 in double space throughout. Please arrange the manuscript as follows: Title page, Abstract, Introduction, Methods, Results, Discussion, and References. Number all pages consecutively, beginning with the title page. All figures and Tables must be referred to in the manuscript. Consult a recent issue of the Journal for details. Only the Title page should bear the names and addresses of the author(s). Editorials, perspective and review articles are generally by invitation. However if you are interested in writing a review/perspective, you can send an email to the editor with the topic and a short summary of contents to be included. The editor will convey his decision in 7-10 days' time. Length of articles Text of original articles should be between 2000 and 3500 words. The article should not ordinarily contain more than 3 tables, 2 figures and 25 references. Case Reports are accepted only if they can be converted into 'What is your diagnosis?' format (please consult a recent issue of the Journal). Briefly, the format consists of case report of about 500 words, a diagnostic image followed by the actual diagnosis/answer and discussion (250 words) and upto 5 references. Letters discussing or criticizing material published recently in the Journal, brief presentations of data, or those pertaining to issues of relevance to health policy, practice of medicine, or the like, are welcome. These should not exceed 500 words, 1 table and 5 references. Queries For questions about the editorial process (including the status of manuscripts under review) or for technical support on submissions, please visit our Support Center. Peer review This journal operates a double anonymized review process. All contributions will be initially assessed by the editor for suitability for the journal. Papers deemed suitable are then typically sent to a minimum of two independent expert reviewers to assess the scientific quality of the paper. The Editor is responsible for the final decision regarding acceptance or rejection of articles. The Editor's decision is final. Editors are not involved in decisions about papers which they have written themselves or have been written by family members or colleagues or which relate to products or services in which the editor has an interest. Any such submission is subject to all of the journal's usual procedures, with peer review handled independently of the relevant editor and their research groups. More information on types of peer review. Double anonymized review This journal uses double anonymized review, which means the identities of the authors are concealed from the reviewers, and vice versa. More information is available on our website. To facilitate this, please include the following separately: https://service.elsevier.com/app/home/supporthub/publishing/ https://www.elsevier.com/reviewers/what-is-peer-review https://www.elsevier.com/reviewers/what-is-peer-review https://www.elsevier.com/reviewers/what-is-peer-review 48 Title page (with author details): This should include the title, authors' names, affiliations, acknowledgements and any Declaration of Interest statement, and a complete address for the corresponding author including an e-mail address. Anonymized manuscript (no author details): The main body of the paper (including the references, figures, tables and any acknowledgements) should not include any identifying information, such as the authors' names or affiliations. Use of word processing software It is important that the file be saved in the native format of the word processor used. The text should be in single-column format. Keep the layout of the text as simple as possible. Most formatting codes will be removed and replaced on processing the article. In particular, do not use the word processor's options to justify text or to hyphenate words. However, do use bold face, italics, subscripts, superscripts etc. When preparing tables, if you are using a table grid, use only one grid for each individual table and not a grid for each row. If no grid is used, use tabs, not spaces, to align columns. The electronic text should be prepared in a way very similar to that of conventional manuscripts (see also the Guide to Publishing with Elsevier). Note that source files of figures, tables and text graphics will be required whether or not you embed your figures in the text. See also the section on Electronic artwork. To avoid unnecessary errors you are strongly advised to use the 'spell-check' and 'grammar- check' functions of your word processor. Article structure Subdivision - numbered sections Divide your article into clearly defined and numbered sections. Subsections should be numbered 1.1 (then 1.1.1, 1.1.2, ...), 1.2, etc. (the abstract is not included in section numbering). Use this numbering also for internal cross-referencing: do not just refer to 'the text'. Any subsection may be given a brief heading. Each heading should appear on its own separate line. Introduction State the objectives of the work and provide an adequate background, avoiding a detailed literature survey or a summary of the results. Material and methods Provide sufficient details to allow the work to be reproduced by an independent researcher. Methods that are already published should be summarized, and indicated by a reference. If quoting directly from a previously published method, use quotation marks and also cite the source. Any modifications to existing methods should also be described. https://www.elsevier.com/authors/journal-authors/submit-your-paper 49 Theory/calculation A Theory section should extend, not repeat, the background to the article already dealt with in the Introduction and lay the foundation for further work. In contrast, a Calculation section represents a practical development from a theoretical basis. Results Results should be clear and concise. Discussion This should explore the significance of the results of the work, not repeat them. A combined Results and Discussion section is often appropriate. Avoid extensive citations and discussion of published literature. Conclusions The main conclusions of the study may be presented in a short Conclusions section, which may stand alone or form a subsection of a Discussion or Results and Discussion section. Appendices If there is more than one appendix, they should be identified as A, B, etc. Formulae and equations in appendices should be given separate numbering: Eq. (A.1), Eq. (A.2), etc.; in a subsequent appendix, Eq. (B.1) and so on. Similarly for tables and figures: Table A.1; Fig. A.1, etc. Essential title page information • Title. Concise and informative. Titles are often used in information-retrieval systems. Avoid abbreviations and formulae where possible. • Author names and affiliations. Please clearly indicate the given name(s) and family name(s) of each author and check that all names are accurately spelled. You can add your name between parentheses in your own script behind the English transliteration. Present the authors' affiliation addresses (where the actual work was done) below the names. Indicate all affiliations with a lowercase superscript letter immediately after the author's name and in front of the appropriate address. Provide the full postal address of each affiliation, including the country name and, if available, the e-mail address of each author. • Corresponding author. Clearly indicate who will handle correspondence at all stages of refereeing and publication, also post-publication. This responsibility includes answering any future queries about Methodology and Materials. Ensure that the e-mail address is given and that contact details are kept up to date by the corresponding author. • Present/permanent address. If an author has moved since the work described in the article was done, or was visiting at the time, a 'Present address' (or 'Permanent address') may be indicated as a footnote to that author's name. The address at which the author actually did the work must be retained as the main, affiliation address. Superscript Arabic numerals are used for such footnotes. 50 Title page In animal studies, the title should state the species; all other titles will refer to human studies. State names of authors (including first names), the departments and the institution where the work was done. Please do not add your academic qualifications, designation etc. State contribution of each author clearly. A short, running title, not exceeding 40 characters, should be provided. Please provide the name, postal address with PIN code, facsimile number and E-mail address of the author to whom communications and proofs are to be sent. Acknowledgements, if any, may be mentioned on this page. Abstract A concise and factual abstract is required. The abstract should state briefly the purpose of the research, the principal results and major conclusions. An abstract is often presented separately from the article, so it must be able to stand alone. For this reason, References should be avoided, but if essential, then cite the author(s) and year(s). Also, non-standard or uncommon abbreviations should be avoided, but if essential they must be defined at their first mention in the abstract itself. Keywords Immediately after the abstract, provide a minimum of 3 keywords to maximum of 12 keywords, using American spelling and avoiding general and plural terms and multiple concepts (avoid, for example, 'and', 'of'). Be sparing with abbreviations: only abbreviations firmly established in the field may be eligible. These keywords will be used for indexing purposes. Abbreviations Define abbreviations that are not standard in this field in a footnote to be placed on the first page of the article. Such abbreviations that are unavoidable in the abstract must be defined at their first mention there, as well as in the footnote. Ensure consistency of abbreviations throughout the article. Acknowledgements Collate acknowledgements in a separate section at the end of the article before the references and do not, therefore, include them on the title page, as a footnote to the title or otherwise. List here those individuals who provided help during the research (e.g., providing language help, writing assistance or proof reading the article, etc.). Formatting of funding sources List funding sources in this standard way to facilitate compliance to funder's requirements: 51 Funding: This work was supported by the National Institutes of Health [grant numbers xxxx, yyyy]; the Bill & Melinda Gates Foundation, Seattle, WA [grant number zzzz]; and the United States Institutes of Peace [grant number aaaa]. It is not necessary to include detailed descriptions on the program or type of grants and awards. When funding is from a block grant or other resources available to a university, college, or other research institution, submit the name of the institute or organization that provided the funding. If no funding has been provided for the research, it is recommended to include the following sentence: This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Units Follow internationally accepted rules and conventions: use the international system of units (SI). If other units are mentioned, please give their equivalent in SI. Math formulae Please submit math equations as editable text and not as images. Present simple formulae in line with normal text where possible and use the solidus (/) instead of a horizontal line for small fractional terms, e.g., X/Y. In principle, variables are to be presented in italics. Powers of e are often more conveniently denoted by exp. Number consecutively any equations that have to be displayed separately from the text (if referred to explicitly in the text). Footnotes Footnotes should be used sparingly. Number them consecutively throughout the article. Many word processors can build footnotes into the text, and this feature may be used. Otherwise, please indicate the position of footnotes in the text and list the footnotes themselves separately at the end of the article. Do not include footnotes in the Reference list. Artwork Electronic artwork General points • Make sure you use uniform lettering and sizing of your original artwork. • Embed the used fonts if the application provides that option. • Aim to use the following fonts in your illustrations: Arial, Courier, Times New Roman, Symbol, oruse fonts that look similar. • Number the illustrations according to their sequence in the text. • Use a logical naming convention for your artwork files. • Provide captions to illustrations separately. • Size the illustrations close to the desired dimensions of the published version. • Submit each illustration as a separate file. 52 • Ensure that color images are accessible to all, including those with impaired color vision. A detailed guide on electronic artwork is available. You are urged to visit this site; some excerpts from the detailed information are given here. Formats If your electronic artwork is created in a Microsoft Office application (Word, PowerPoint, Excel) then please supply 'as is' in the native document format. Regardless of the application used other than Microsoft Office, when your electronic artwork is finalized, please 'Save as' or convert the images to one of the following formats (note the resolution requirements for line drawings, halftones, and line/halftone combinations given below): EPS (or PDF): Vector drawings, embed all used fonts. TIFF (or JPEG): Color or grayscale photographs (halftones), keep to a minimum of 300 dpi. TIFF (or JPEG): Bitmapped (pure black & white pixels) line drawings, keep to a minimum of 1000 dpi. TIFF (or JPEG): Combinations bitmapped line/half-tone (color or grayscale), keep to a minimum of 500 dpi. Please do not: • Supply files that are optimized for screen use (e.g., GIF, BMP, PICT, WPG); these typically have alow number of pixels and limited set of colors; • Supply files that are too low in resolution; • Submit graphics that are disproportionately large for the content. Color artwork Please make sure that artwork files are in an acceptable format (TIFF (or JPEG), EPS (or PDF) or MS Office files) and with the correct resolution. If, together with your accepted article, you submit usable color figures then Elsevier will ensure, at no additional charge, that these figures will appear in color online (e.g., ScienceDirect and other sites) in addition to color reproduction in print. Further information on the preparation of electronic artwork. Figure captions Ensure that each illustration has a caption. Supply captions separately, not attached to the figure. A caption should comprise a brief title (not on the figure itself) and a description of the illustration. Keep text in the illustrations themselves to a minimum but explain all symbols and abbreviations used. https://www.elsevier.com/authors/author-schemas/artwork-and-media-instructions https://www.elsevier.com/authors/author-schemas/artwork-and-media-instructions https://www.elsevier.com/authors/author-schemas/artwork-and-media-instructions 53 Tables Please submit tables as editable text and not as images. Tables can be placed either next to the relevant text in the article, or on separate page(s) at the end. Number tables consecutively in accordance with their appearance in the text and place any table notes below the table body. Be sparing in the use of tables and ensure that the data presented in them do not duplicate results described elsewhere in the article. Please avoid using vertical rules and shading in table cells. References Number the references in the order in which they first appear in the text and identify the reference numbers in the text in superscript. References must be placed at the end of the manuscript. Please use recent references as much as possible. The responsibility for accuracy of references lies with the respective authors. The Journal is in agreement with the International Committee of Medical Journal Editors (http://www.icmje.org). The general arrangement, abbreviations of Journal names and punctuations followed are as per the Uniform Requirements for Manuscripts submitted to Biomedical Journals (http://www.icmje.org). Please pay attention to the style of references and punctuations as follows: Journal article List all authors when six or less as shown in the example below: Tallon D, Chard J, Dieppe P. Exploring the priorities of patients with osteoarthritis of the knee. Arthritis Care and Res 2000;13:312–9. When there are seven or more authors, list only the first six and add et al. Boo