A retrospective review of dorsal locking compression plating for hallux metatarsophalangeal joint arthrodesis Dr. Olivia Antos 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, 2021 i Declaration I, Olivia Antos, declare that this research report 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. 12th day of November 2021 ii Dedication This research report is dedicated to my daughter, Liana who gives my life meaning and my husband, Nabil Khan for all his love and support. I would also like to thank my sister, Sylvia Antos-Hanney for being my biggest fan and my parents, Wanda and Kazimierz Antos who believe in my dreams as much as I do. iii Abstract Purpose: In this retrospective study the primary aim was to radiographically evaluate the arthrodesis rate of the hallux metatarsophalangeal joint (MTPJ) using a dorsal compression plate without the use of additional fixation devices. The secondary aim was to assess patient satisfaction by using the self-reported foot and ankle score (SEFAS), comparing pre and post operative scores. Methods: 32 patients (38 feet) who underwent hallux metatarsophalangeal joint arthrodesis using only a dorsal compression plate between January and December 2016 were assessed. Standardised weight bearing radiographs of the foot were taken at six weeks postoperatively to assess for union. Patient satisfaction was evaluated by comparing self-reported foot and ankle score pre and post operatively. Results: 27 patients (32 feet) met the inclusion criteria for this study. Five of these patients had bilateral hallux metatarsophalangeal joint arthrodesis surgery. Of these, 87.5% were female and 12.5% were male. The mean age at the time of operation was 62 years (SD = 10.4). Radiographic union was seen in 29 (90.6%) feet at six weeks post surgery. The self- reported foot and ankle score demonstrated significant improvement from a preoperative score of 29 to a postoperative score of 41 at three year follow up. Conclusion: The sole use of a dorsal compression plate demonstrated a union rate of 90.6% and an improved SEFAS score postoperatively, which yielded good to excellent results in patients who had undergone arthrodesis of the hallux metatarsophalangeal joint. These results are comparable to those where the gold standard for hallux metatarsophalangeal joint arthrodesis has been used. The use of the dorsal compression plate eliminates the need for an additional compression screw thus decreasing costs of implants, theatre time and x-ray exposure. Level of evidence: IV iv Acknowledgements I would like to express my sincere gratitude to Professor N. Saragas for his guidance and input, as well as allowing me access to his patient’s files so I could conduct this study. I would also like to thank Dr. Andrew Strydom for his guidance and valuable input throughout this research project. v Table of contents Declaration ............................................................................................................................... i   Dedication ............................................................................................................................... ii   Abstract .................................................................................................................................. iii   Acknowledgements .............................................................................................................. iv   Table of contents ................................................................................................................... v   List of Figures ...................................................................................................................... vii   List of Tables ....................................................................................................................... viii   Nomenclature ........................................................................................................................ ix   CHAPTER 1 ............................................................................................................................. 1   INTRODUCTION AND LITERATURE REVIEW ...................................................................... 1 1.1 Background………...……………………………………………………………………………1 1.2 Literature Review……………………………………………………………………………….2 1.3 Study aims and objectives……………………………………………………………………..4 CHAPTER 2 ............................................................................................................................. 5   METHODOLOGY ..................................................................................................................... 5   2.1   Research Question ...................................................................................................... 5   2.2   Research Design ......................................................................................................... 5   2.3   Materials and Methods ................................................................................................. 5   2.4   Selection criteria .......................................................................................................... 6   2.5 Data Collection ............................................................................................................. 6   2.6   Data Analysis ............................................................................................................... 7   2.7 Surgical technique ....................................................................................................... 8   CHAPTER 3 ........................................................................................................................... 10   RESULTS .............................................................................................................................. 10   vi CHAPTER 4 ........................................................................................................................... 15   DISCUSSION ......................................................................................................................... 15   4.1 Recommendations ........................................................................................................ 17 4.2 Limitations……………………………………………………………...……………………..17 CHAPTER 5 ........................................................................................................................... 18   CONCLUSION ....................................................................................................................... 18   Appendices ........................................................................................................................... 19   Appendix A: Ethics Approval .................................................................................................. 19   Appendix B: Title Change ...................................................................................................... 21 Appendix C: Hospital permission letters………………………………………………………. …23 Appendix D: Data collection sheets………………………………………………………………..26 Appendix E: Self-reported foot and ankle score…………………………………………...….... 27 Appendix F: Data spread sheet………………………………………………………………..…..28 Appendix G: Plagiarism/turn-it-in report cover page .............................................................. 31 Appendix H: Turn-it-in letter of motivation………………………………………………………...32 Appendix I: References………………………………………………………………………..…...33 vii List of Figures Chapter 3 Figure 3.1…………………………………………………………………………………12 Figure 3.2…………………………………………………………………………………12 Figure 3.3…………………………………………………………………………............13 viii List of Tables Table 3.1………………………………………………………………………………….....10 Table 3.2 ……………………………………………………………………………………13 ix Nomenclature AOFAS: American Orthopaedic Foot and Ankle Society AP: Antero-posterior ES: Effect size LCP: Locking compression plate MTPJ: Metatarsophalangeal joint SD: Standard deviation SEFAS: Self-reported foot and ankle score SRM: Standardised response mean 1 CHAPTER 1 INTRODUCTION AND LITERATURE REVIEW 1.1 Background The hallux metatarsophalangeal joint (MTPJ) is a specialised joint containing a sesamoid mechanism. The metatarsal head has a convex cartilaginous surface, which articulates with the concave proximal phalanx. The collateral ligaments connect with the sesamoid ligaments. The hallux is moved by four groups of muscles and tendons: dorsally by the extensor hallucis longus and brevis, plantarly the flexor hallucis longus and brevis, medially by abductor hallucis and laterally by adductor hallucis 1. The hallux MTPJ forms one of the crucial tripod structures of the foot, supporting about one third of the body weight. The main stabilisers of the joint are the capsule-ligamentous structures and therefore conditions affecting their integrity would lead to instability, abnormal motion and weight distribution. Therefore, disruption of the normal biomechanics leads to joint degeneration, pain and deformity. Hallux metatarsophalangeal joint (MTPJ) arthrodesis is a successful procedure with good results 2, 3. It provides good alignment correction of the first ray as well as pain relief from an arthritic hallux MTPJ. Indications for hallux MTPJ arthrodesis include: 4 • Severe hallux valgus deformity (Hallux valgus angle greater than 40°) not amenable to joint preserving procedures • Degenerative joint disease resulting from inflammatory arthritides, autoimmune and crystal deposition conditions that are not responding to at least six months of conservative treatment • Advanced hallux rigidus (osteoarthritis) • As a salvage procedure for failed arthroplasty and joint preserving procedures • Deformities due to muscle imbalances caused by neurological conditions (cerebral vascular accident, head injury, cerebral palsy) 2 Contra indications: • Early osteoarthritis where joint preserving techniques are preferred • Active infections • Poor soft tissue envelope (poor skin status) • Poor peripheral circulation The gold standard for the construct used while performing an arthrodesis of the hallux MTPJ is a compression screw across the hallux MTPJ with a dorsal locking plate 5, however the available small surface area can make lag screw placement difficult. The hypothesis for this study is that the use of a contoured dorsal locking compression plate across the prepared surface should result in comparable arthrodesis rates. To date, there is one study that has looked at success rates of hallux MTPJ arthrodesis using a contoured dorsal locking compression plate alone 6. Therefore, this study presents a case series where a contoured dorsal locking compression plate was used alone for arthrodesis of the hallux MTPJ. 1.2 Literature review Hallux MTPJ arthrodesis was first described for hallux valgus deformity by Broca in 1852 and then by Clutton in 1894 with satisfactory results 2. Since then various procedures have been described to achieve better arthrodesis rates and alignment of the hallux. Hallux MTPJ arthrodesis is a highly successful procedure showing union rates of up to 100% 3, 7, 8, 9, 10, 11. Conditions involving the hallux MTPJ can be managed in various ways and may include resection interposition arthroplasty, proximal phalanx or metatarsal head resurfacing hemiarthroplasty, total joint replacement or arthrodesis 12. Compared to excision arthroplasty, arthrodesis is the most reliable surgical procedure as it is predictable, results in a better weight bearing capacity 13 and avoids complications such as instability, cock up deformity of the first ray and first ray shortening 14. The disadvantages of arthroplasty of the hallux MTPJ are that it causes significant stiffness and early component loosening resulting in high failure rates which require revision surgery, often a salvage arthrodesis procedure 15. Hallux MTPJ arthrodesis has been widely described as a treatment for end stage arthritis with the aim of eliminating pain and obtaining a stable plantigrade toe 16. Studies have confirmed 3 that arthrodesis of the hallux MTPJ increases weight bearing on the medial column thereby restoring medial column stability and protecting the lesser MTPJ’s and plantar fat pad by reducing transfer metatarsalgia 16, 17. Further studies have also shown that eliminating motion at the hallux MTPJ causes no observable change in the gait pattern of patients that have undergone the procedure 16. The main determinants of outcome after arthrodesis are: • Choice of fixation 18 • Method of joint surface preparation 19 • Positioning of the hallux 20 • Patient factors (co-morbidities and social habits) 21, • Effective protection and good rehabilitation Various fixation devices are available to achieve arthrodesis of the hallux MTPJ, including screws, plates, wires, staples, external fixators 5, 22, 23, 24, 25 or a combination. Arthrodesis rates of up to 90 - 100% have been achieved with plate fixation 26 by using either locking or non-locking options that are pre contoured 3, 8, 10, 11, 27. Some studies have shown that compression plates achieve higher arthrodesis rates as compared to locked plates 28, 29. Screws have also been used as a means in achieving arthrodesis of the hallux MTPJ 28. Cross configuration screws have been used alone with arthrodesis rates of up to 95% 20. Screws can be combined with K-wire fixation or can be used with a dorsal neutralisation plate. Other fixation methods such as K-wires, K-wires with loops and staples have been used in the past but they have been shown to be biomechanically less stable 24, 31. The combination of a lag screw across the MTPJ with a dorsal neutralisation plate has been shown to be the most stable construct 5, 18, 32 and is widely recommended as the fixation of choice in the arthrodesis of the hallux MTPJ. The rate of hallux MTPJ arthrodesis depends on the preparation technique of the bony surfaces 33, 34. Joint surface preparation can be achieved using planar cuts 33, curettage of cartilage using burrs 33 as well as cup and cone reamers 20, 34, 35. Procedures that preserve bone length as well as convexity/concavity of the opposing surfaces have been shown to produce better arthrodesis rates and outcomes 19, 35. 4 Planar cuts are a quicker option for bony preparation but have the disadvantage of causing bone shortening if the desired position is not obtained and requires further resection 17. Cup and cone reamers provide a larger surface area for arthrodesis 19. They have the advantage of providing reproducible results 36 and allows for multi-planar alignment 17 as well as being biomechanically more stable 19. Commercially available cup-and-cone reamers have the advantage of being user-friendly and lead to predictable results 35. Percutaneous arthrodesis has been advocated for and results have been comparable to open arthrodesis with improved postoperative American Orthopaedic Foot and Ankle Society (AOFAS) score 37. However, it has a steep learning curve and the risk of over resection of the metatarsal head, which may result in shortening and poor positioning. The three-dimensional position of the toe is an important factor determining the outcome of the arthrodesis 17. The best position has been reported to be neutral rotation, dorsiflexion depending on the medial longitudinal arch height and approximately 5° of valgus depending on the position of the lesser toes and the amount of hallux valgus interphalangeus. Varus is not acceptable 19, 30, 31, 38, 39, 40. Dorsiflexion of the hallux MTPJ is determined intra operatively by pushing the foot on a flat sterile tray to simulate weight bearing. It ranges from 4° to 8° depending on the degree of arch height, but more importantly the hallux needs to clear the ground with walking and the tip of the toe must be able to touch the ground when it flexes at the interphalangeal joint 39. Most frequent complications include malalignment, nonunion, malunion, need for hardware removal, arthritis of adjacent joints (interphalangeal arthrosis), osteonecrosis and osteitis 41. Outcomes following arthrodesis include improved weight bearing, stability during gait 42, and decreasing pain from the arthritic joint and pressure from bunion removal. Recent hallux arthrodesis studies show good functional medium-term outcomes, with improved AOFAS scores and patient satisfaction rates 43, 44. 1.3 Study aim and objectives The primary aim was to radiographically evaluate the arthrodesis rate of the hallux MTPJ using a dorsal locking compression plate without additional lag screw fixation. 5 The secondary aim was to assess patient satisfaction by using the self-reported foot and ankle score (SEFAS) functional scoring tool. The overall study objective is to assess the rate of arthrodesis of the hallux MTPJ using the contoured dorsal compression locking plate alone and comparing the arthrodesis rate to that of other implants that have been used in the literature. CHAPTER 2 METHODOLOGY 2.1 Research Question Is the fusion rate using a dorsal locking compression plate comparable to the preferred method of a compression screw and dorsal neutralisation plate in hallux MTPJ arthrodesis? 2.2 Research Design This research design was a cross sectional study comprising a retrospective review of radiographs and clinical notes as well as assessing patient satisfaction using the SEFAS score. 2.3 Materials and Methods The records of 32 patients who had hallux MTPJ arthrodesis using a dorsal compression plate between January and December 2016 at the Netcare Linksfield Hospital were reviewed. Ethical approval was obtained from the Human Research Ethics Committee (Medical) of the University of the Witwatersrand before data collection commenced. There were 32 patients (38 feet) that were operated in 2016 and of these six were bilateral. There were incomplete records for five patients (six feet) and these were excluded from this study. Twenty-seven patients (32 feet) were included in this study. Demographics as well as medical comorbidities and social habits were documented (Table 3.1). Standardised weight bearing radiographs of the foot were taken at six weeks postoperatively and assessed for union. Union was defined as bony bridging between the phalanx and metatarsal seen in both antero-posterior (AP) and lateral X-ray views 27. The radiographs 6 were taken with the X-ray beam one metre from the cassette centred on the midfoot with a 15° inclination cephalad according to an international standardised protocol on weight bearing radiographs 1. The SEFAS score has been validated specifically for foot and ankle surgery 45. The SEFAS questionnaire was completed by 22 of the 27 patients who had undergone MTPJ arthrodesis at the time of data collection, which was three years post surgery. 2.4 Selection criteria Patient selection criteria Inclusion criteria: • Patients ≥ 18 years of age • Patients who underwent a hallux MTPJ arthrodesis between January and December 2016 Exclusion criteria • Revision hallux MTPJ arthrodesis • Incomplete records 2.5 Data Collection The researcher assessed the X-rays and commented on whether there was radiographic evidence of arthrodesis across the hallux MTPJ. The patients were contacted telephonically three years postoperatively, consent was obtained and patient satisfaction was assessed using the SEFAS score. The SEFAS sores were compared for preoperative and postoperative values. The questionnaire was conducted in English. Each patient received a unique study number thereby maintaining patient confidentiality. An excel spreadsheet with the following variables was used to collect the data (see Appendix A): 7 -­‐ Patient number -­‐ Gender and age -­‐ Co morbidities/social habits -­‐ Union: Yes/No -­‐ SEFAS score 2.6 Data Analysis 2.6.1 Study sampling For the present study sample size calculation for cross sectional studies formula 46 was used: n = !!∗!(!!!) !! where: n = sample size, z = standard normal variate (at 5% margin of error it is 1.96), p = expected proportion or prevalence/rate based on previous similar studies and d = margin of error (we used 5%, for a 95% confidence interval). The proportion (p) (arthrodesis rate) from the largest single-surgeon patient series reported to determine arthrodesis rate for the hallux MTPJ using the recommended construct was used. In this study an arthrodesis rate of 98% was achieved 40 hence the optimum sample size for the present study was calculated to be 30 feet. 2.6.2 Data interpretation and statistical analysis Data analysis was conducted using STATA version 14. Descriptive analysis was conducted to describe the study participants. For continuous variables such as age, the Shapiro Wilk test was used to determine the distribution of the data and the appropriate central tendency measure (i.e. mean (SD)/ median (IQR)) to report. For categorical variables frequency tables were computed. To evaluate the arthrodesis rate of the hallux MTPJ using a dorsal compression plate, frequency tables were computed to count the proportion of hallux MTPJ’s that were considered to have fused. To compare the fusion rate using the dorsal LCP and the fusion rate using the recommended construct 40, a chi-squared test was used. In terms of the SEFAS questionnaire, responsiveness is the extent to which a questionnaire is able to detect changes over time or due to an intervention such as surgery 47. Of the 27 8 patients that were included in this study, only 22 completed the SEFAS scores pre and post operatively. To test responsiveness effect size (ES) and standardised response means (SRM) were calculated. ES is calculated as the difference between the means before and after intervention divided by the standard deviation (SD) of the same measure before treatment 47. SRM is calculated as the difference between the means before and after treatment divided by the SD of the change. For both, ES and SRM, values of 0.2, 0.5 and 0.8 were regarded as small, moderate and large effects, respectively 47. 2.6.3 Data processing The data for the study was entered into an Excel spreadsheet prior to entering it into STATA version 14 for analysis. To process the data in preparation for analysis, the data was checked for errors in recording, duplicates and missing values. 2.6.4 Data analysis Descriptive analysis was conducted for the demographic characteristics of the patients. A Shapiro Wilk test was used to determine the distribution of the continuous variables. The null hypothesis for a Shapiro Wilk test is that the data is normal; hence, a p-value of less than 0.05 indicates that the data is skewed. For skewed data medians and interquartile ranges (IQR) were reported, for normal data means and standard deviations (SD) were reported. To determine the arthrodesis rate of the hallux MTPJ using a dorsal compression plate, frequency tables were computed to count the proportion of hallux MTPJ’s that were considered to have fused. To compare the arthrodesis rate using the dorsal LCP and the recommended construct 40, a proportions test was used. 2.7 Surgical technique Patients were positioned supine. A thigh tourniquet was used in all cases. A medial incision was made over the hallux MTPJ and dissection continued through the medial capsule. The joint was adequately exposed for preparation. The joint surfaces were denuded of cartilage down to subchondral cancellous bone using power conical reamers. The subchondral bone was fenestrated to promote bone marrow elements leaking into the fusion site. The hallux was reduced in neutral rotation, appropriate dorsiflexion relative to the height of the medial longitudinal arch and physiological valgus. The position was held with a K-wire and checked 9 under fluoroscopy. The reduction was fixed with a contoured dorsal locking compression plate (Paragon 28 Gorilla® MTP Plating System or the Tornier MAXLOCK™ EXTREME™ System). The surgical site was irrigated and closure performed in a routine layered manner. Patients were instructed to follow a post-operative protocol of strict high elevation for the first two weeks, followed by heel weightbearing in an assistive wedge-heel post-operative shoe for another four weeks. 10 CHAPTER 3 RESULTS The table below summarises the demographics, co morbidities and social habits of the patients who had a hallux MTPJ arthrodesis. (Table 3.1) Table 3.1: Demographic characteristics of study patients (N=32) CHARACTERISTICS TOTAL NUMBER OF PATIENTS (n=27) Age (years) Mean (SD) 62 ± 10.4 Gender N (%) Male 4 (12.5%) Female 28 (87.5) No of Comorbidities None 6 (22%) One 7 (26%) Two 7 (26%) Three 7 (26%) Smoking (Yes/No) 11 Yes 1 (3%) No 31 (97%) Alcohol Use (Social/No) Social 16 (50%) No 16 (50%) Side of Surgery (L/R) Left Foot 8 (30%) Right Foot 14 (52%) The mean age at the time of operation was 62 years (SD = 10.4). Of the 27 patients included in the study, the majority were female (refer to Figure 3.1). Fourteen feet (52%) had surgery on the right foot (refer to Figure 3.2). Seven patients had one comorbidity, seven patients had two, seven patients had three and six had no comorbidities. Of the seven with one comorbidity, all had united at six weeks whereas of the seven patients with two comorbidities, one patient had delayed union. Two patients with three comorbidities had delayed union. These comorbidities included diabetes, asthma, breast cancer, gout, rheumatoid arthritis, epilepsy and hypercholesterolaemia. 12 There was however no difference with respect to gender, side of operation, smoking status and alcohol consumption (p>0.05) when comparing those feet that showed radiographic union at six weeks and those that had a delayed union. Le%   30%   Right   52%   Bilateral   18%   87.50%   12.50%   Female   Male   Figure 3.1: Gender distribution Figure 3.2: Side of surgery 13 Radiographic union (refer to Figure 3.1) was seen in 29 (90.6%) feet at six weeks. Neither of the three patients with a delayed union smoked cigarettes. Figure 3.3: Graph showing radiographic union achieved at six weeks post surgery The SEFAS questionnaire was completed by 22 patients and demonstrated improvement between preoperative assessment (mean score of 29) and postoperative follow-up (mean score of 41) indicating that functional scores improved following arthrodesis of the hallux MTPJ. The mean difference (12) between preoperative and postoperative assessment is shown in Table 3.2. Table 3.2: SEFAS score improvement Pre-Op Mean (SD) Post-Op Mean (SD) Mean Difference (SD) ES SRM SEFAS 29 (11.15) 41 (7.83) 12 1.07 0.94 90.63%   0.00%   10.00%   20.00%   30.00%   40.00%   50.00%   60.00%   70.00%   80.00%   90.00%   100.00%   Union  at  six  weeks   Arthrodesis  on  X-­‐rays   14 Three feet demonstrated moist wounds and three feet had residual swelling at their two week follow up. At six weeks follow up all wounds had healed and there were no further complications. 15 CHAPTER 4 DISCUSSION Hallux MTPJ arthrodesis is considered to be the gold standard for the treatment of many conditions that cause chronic pain and disability of the hallux as well as transfer metatarsalgia and keratosis of the lesser toes. Arthrodesis has been shown to provide a stable first ray, thereby eliminating painful motion and increasing weight-bearing distribution of the forefoot 3. The success rate of hallux MTPJ arthrodesis varies widely, reported to be between 80-100% 40. The combination of a lag screw across the MTPJ with a dorsal neutralisation plate has been shown to be the most stable construct 5, 18, 32 and is widely recommended as the construct of choice in the arthrodesis of the hallux MTPJ. Historically, many complications were reported with the use of small fragment plates such as skin irritation and pressure symptoms 36 which led to the development of low profile, pre contoured dorsal plates with locking and non-locking screw options. The use of locking plates in hallux MTPJ arthrodesis, however, is gaining popularity due to the evolution of the dorsal plate 6 and the results in the current study are comparable to other devices used in hallux MTPJ arthrodesis as reported in the literature. Good clinical outcomes are directly related to surgical technique and device used for internal fixation 48. In the current study radiological arthrodesis was achieved at six weeks in 90.63% of the feet operated. Thirteen feet that showed radiographic union at six weeks had two or more co morbidities. Three feet went onto a delayed union (united at nine and ten weeks) and of these patients two had more than one comorbidity. There may be an association between patient comorbidities and arthrodesis rate however this cannot be concluded from this series and would require further studies. None of the three patients who showed radiographic union beyond six weeks were smokers, nonetheless there is evidence in the literature that demonstrates an association between patients who smoke and complications of delayed union as well as wound healing 21, 49. 16 Meijer et al. recently published a study reviewing the use of a dorsal locking plate without making use of additional compression screw fixation across the MTPJ 6. The results showed a radiological union rate of 97% and an overall low complication rate of 5% that included non- union and infection. These figures are in keeping with those that are stated in the literature. Grondal et al. in their study of 22 cases showed the non-union rate for two crossed compression screws was 7.5% with the recommendation that the crossed screws should cross distal to the joint line 50, 51, 52. Satisfactory interfragmentary compression has not been adequately achieved with the use of isolated dorsal plating, with retrospective studies revealing a non-union rate of 9.9% 35, 51, 53. Polini et al. in 2003 recommended that the dorsal plate should be combined with an inter- fragmentary screw, making it twice as strong as two crossed screws from a biomechanical aspect 5, 32. This has been shown by Sharma et al. to have a low non-union rate of 3.9% 54. In our series the arthrodesis rate was 90.6%, which is comparable to previous studies. In a study by Hunt et al. comparing locked versus non-locked plates in the arthrodesis of the hallux MTPJ it was shown that there was a trend towards higher rates of non-union in patients where a titanium dorsal locked plate was used. The authors speculated that the reason for this maybe a decreased ability to obtain compression across the arthrodesis site with the locked plate construct as well as inferior rigidity of the titanium plate that was used. It is critical to obtain interfragmentary compression to achieve arthrodesis 28. In the current study, a titanium alloy (TI-6AL-4V) locking compression plate was used. It has excellent mechanical properties including superior biocompatibility, high strength and fracture toughness, excellent corrosion resistance and a Young’s modulus of elasticity similar to cortical bone 55. This plate has an oblong compression slot proximally to allow for compression of the MTPJ surface as well as locking screw options. Joint surface preparation is one of the many important factors for achieving good results with MTPJ arthrodesis. The literature describes various methods that have been used including planar cuts, peg-and-socket or more spherical cup-and-cone techniques 17. Peg-and-socket techniques provide innate stability but are technically demanding to perform, lose bone stock and result in shortening of the first ray 56, 57, 58, 59. Planar cuts are a quicker option for bony preparation but have the disadvantage of causing bone shortening if the desired position is not obtained and requires further resection 17. Curtis et al. reported greater 17 stiffness with the cup and cone method of joint preparation as compared with planar excision 19 as this provides surfaces that are adaptable, cater for precise positioning of the hallux MTPJ, create a larger surface area for arthrodesis and are biomechanically superior 17, 19, 38. In the current study, the surgeon uses meticulous methods for joint preparation including drilling of the proximal and distal surfaces for the release of bone marrow elements into the arthrodesis site, which aids in union across this site. In this series the SEFAS score improved post operatively as compared to the pre operative assessment. This is in keeping with Maffuli et al. who demonstrated improved satisfaction with the AOFAS score in their series 43, 44. 4.1 Recommendations Based on the results from this study the following recommendations are made: • Successful arthrodesis requires meticulous preparation of joint surfaces and careful surgical technique with regards to fixation. • The use of a dorsal compression locking plate for MTPJ arthrodesis has shown good arthrodesis rates as well as functional outcomes. In this study, arthrodesis rate at six weeks was 90.63% and by ten weeks all patients had achieved arthrodesis of the hallux MTPJ. It can thus be recommended that a dorsal compression locking plate can be used without the need for an interfragmentary screw. • Future prospective randomised studies on the use of the dorsal compression locking plate are required. • A larger cohort of patients should be used for future study purposes. 4.2 Limitations The limiting factor of this study was the small sample group as well as the fact that there was no control group. The patient records are from a single surgeon in the sub specialty of foot and ankle and therefore these results may not be fully reproducible. Only 22 patients participated in the SEFAS questionnaire thereby limiting numbers and not providing a true reflection of patient satisfaction. 18 A follow up study that includes multiple surgeons, a larger sample size as well as a control group may further strengthen the indications for using a contoured dorsal locking compression plate for hallux MTPJ arthrodesis. CHAPTER 5 CONCLUSION Arthrodesis of the MTPJ is a commonly performed procedure for a variety of indications. Many fixation combinations have been used, however this study demonstrates that with the evolution of dorsal locking plates, a contoured dorsal locking compression plate can be used alone in the arthrodesis of the hallux MTPJ with good results. Although all cases ultimately united, the results in this study show that using the contoured dorsal locking compression plate alone may require more time to union in ten percent of patients. Patient satisfaction improved post operatively as was shown by the SEFAS score. Many factors play an important role in the arthrodesis rate of the hallux MTPJ including meticulous joint preparation and hallux positioning. Due to the limitations of this study, further large patient-based studies are necessary to advocate for the use of a contoured dorsal locking compression plate alone and to identify other factors which may affect union time in this construct. 19 Appendices Appendix A: Ethics approval 20 21 Appendix B: Title Change 22 23 Appendix C: Hospital permission letters 24 25 26 Appendix D: Data Collection sheets Patient 1 Patient demographics Age Gender Co morbidities Social habits Yes No Smoking Ethanol use Arthrodesis on X-rays (Y/N) Yes No SEFAS score 27 Appendix E: SEFAS score 28 Appendix F: Data spread sheet Patient number Age Gender Co morbidities Smoking Patient 1 78 F AF, cholesterol CCF No Patient 2 27 F Macrodactyly R big toe No Patient 3 73 F None No Patient 4 58 F Diabetic, HPT, Bronchiectasis No (previous smoker) Patient 5 65 F Prediabetic, breast ca, asthmatic No Patient 6 57 M HPT No Patient 7 67 F Breast Ca 2012 (HRT) No Patient 8 73 F HPT, prev DVT No Patient 9a 54 F Rheumatoid Arthritis, Diabetic No Patient 9b 54 F Rheumatoid Arthritis, Diabetic No Patient 10 77 F HPT, GORD No Patient 11 61 F None No Patient 12 73 F Gout, HPT No Patient 13a 66 M Gout, cardiac bypass surgery (open heart) No Patient 13b 66 M Gout, cardiac bypass surgery (open heart) No Patient 14a 29 F None Yes (18/day 11 years) Patient 14b 29 F None Yes (18/day 11 years) Patient 15 61 F Gout, Diabetic, Hypothyroidism No Patient 16a 61 F HPT No Patient 16b 61 F HPT No Patient 17 61 F Rheumatoid arthritis, Epileptic, Cholesterol No Patient 18 48 F Diabetic, Cholesterol, HPT Yes (15/day fpr 10 years) Patient 19 69 F Gout, HPT No Patient 20a 56 F Hypothyroidism No Patient 20b 56 F Hypothyroidism No Patient 21 57 M Rheumatoid arthritis No Patient 22 67 F None No Patient 23 49 F Rheumatoid arthritis No Patient 24 67 F Throat ca with radiation 20 years ago, hypothyroidism, Diabetic No Patient 25 Patient 26 75 M HPT No Patient 27 66 F Gout, hypothyroidism, No Patient 28 68 F HPT No Patient 29 48 F None No Patient 30 68 F Hypothyroidism, GORD, Cholesterol No Patient 31a 68 F None No Patient 31b 68 F None No Patient 32 54 F Rheumatoid arthritis, Hypothyroidism, Cholesterol No (previous smoker) 29 Patient number Alcohol use Date of surgery Side of surgery Date of x-rays Patient 1 No 18.01.2016 L foot 03.03.2016 Patient 2 No 03.02.2016 R foot 22.03.2016 Patient 3 No 24.02.2016 R foot 08.04.2016 Patient 4 No 25.02.2016 R foot No x-rays Patient 5 Social 29.02.2016 R foot 14.04.2016 Patient 6 Social 29.02.2016 L foot 14.04.2016 Patient 7 Social 31.03.2016 L foot 13.05.2016 Patient 8 No 31.03.2016 R foot 17.05.2016 Patient 9a No 04.04.2016 L foot 20.05.2016 Patient 9b No 10.10.2016 R foot 29.11.2016 Patient 10 No 07.04.2016 L foot 20.05.2016 Patient 11 No 13.04.2016 L foot 27.05.2016 Patient 12 No 18.04.2016 R foot 30.05.2016 Patient 13a No 05.05.2016 R foot 17.06.2016 Patient 13b No 05.05.2016 L foot 17.06.2016 Patient 14a Social 30.05.2016 R foot No x-rays Patient 14b Social 30.05.2016 L foot No x-rays Patient 15 Social 04.06.2016 R foot 12.07.2016 Patient 16a Social 11.07.2016 R foot 26.08.2016 Patient 16b Social 11.07.2016 L foot 26.08.2016 Patient 17 No 27.07.2016 R foot 09.09.2016 Patient 18 Social 15.08.2016 R foot 04.10.2016 Patient 19 Social 05.09.2016 R foot 18.10.2016 Patient 20a No 07.09.2016 R foot 27.10.2016 Patient 20b No 07.09.2016 L foot 27.10.2016 Patient 21 No 14.09.2016 L foot No x-rays Patient 22 Social 19.09.2016 R foot 01.11.2016 Patient 23 Social 21.09.2016 L foot 08.11.2016 Patient 24 No 29.09.2016 L foot 21.11.2016 Patient 25 Patient 26 Social 05.10.2016 R foot 21.11.2016 Patient 27 No 26.10.2016 R foot 12.12.2016 Patient 28 Social 07.11.2016 R foot 22.12.2016 Patient 29 social 10.11.2016 R foot 29.12.2016 Patient 30 No 21.11.2016 R foot No x-rays Patient 31a Social 23.11.2016 R foot 05.01.2017 Patient 31b Social 23.11.2016 L foot 05.01.2017 Patient 32 Social 30.11.2016 L foot 13.01.2017 30 Patient number Arthrodesis on X-rays Complications SEFAS pre SEFAS post Patient 1 Yes None 28 31 Patient 2 Yes None 40 41 Patient 3 Yes None 44 46 Patient 4 Yes Moist wound, healed 10 38 Patient 5 No (union at 10 weeks) None 25 48 Patient 6 Yes None 18 31 Patient 7 Yes Moist wound, healed 29 47 Patient 8 Yes None 29 41 Patient 9a Yes None 39 18 Patient 9b Yes None 35 26 Patient 10 Yes None No answer Patient 11 Yes None 40 45 Patient 12 Yes None 34 47 Patient 13a Yes None No answer Patient 13b No (union at 10 weeks) None Patient 14a Yes None 34 47 Patient 14b Yes None 27 47 Patient 15 Yes None No answer Patient 16a Yes None No answer Patient 16b Yes None Patient 17 No (union at 9 weeks) None No answer Patient 18 Yes Residual swelling 2/52 7 46 Patient 19 Yes None 48 48 Patient 20a Yes None 17 39 Patient 20b Yes None 14 38 Patient 21 Yes None 29 41 Patient 22 Yes None No participation Patient 23 Yes None 20 45 Patient 24 Yes Moist wound, healed 24 48 Patient 25 Excluded Patient 26 Yes None No answer Patient 27 Yes Residual swelling 1/52 35 44 Patient 28 Yes None No answer Patient 29 Yes Residual swelling 1/52 32 42 Patient 30 Yes None 48 48 Patient 31a Yes None No answer Patient 31b Yes None Patient 32 Yes None 19 33 31 Appendix G: Plagiarism/turn-it-in report cover sheet 32 Appendix H: Turn-it-in letter of motivation 33 Appendix I: References 1. Coughlin MJ,Saltzman LC,Anderson BR.Mann’s Surgery of the foot and ankle.9th ed: Elsevier Health Sciences; 2014. 2. Clutton HH. The treatment of hallux valgus. St Thomas Rep 22:1-12, 1984. 3. Yee G, Lau J. Current concepts review: hallux rigidus. Foot Ankle Int 2008;29(6): 637– 46. 4. Coughlin MJ. Arthrodesis of the first metatarsophalangeal joint. OrthopRev.1990; 19: 177-86. 5. Politi J, Hayes J, Njus G, et al. First metatarsal-phalangeal joint arthrodesis: a biomechanical assessment of stability. Foot Ankle Int 2003; 24(4):332-7. 6. Meijer JG, Grabe JC, Greyling P. The outcome of first metatarsophalangeal joint arthrodesis using a locking compression plate. SA Orthop J 2020; 19 (4) 7. Maher AJ, Metcalfe SA. First MTP joint arthrodesis for the treatment of hallux rigidus: Results of 29 consecutive cases using the foot health status questionnaire validated measurement tool. Foot 2008; 18:123-130. 8. Hyer CF, Scott RT, Swiatek M. A Retrospective Comparison of four plate constructs for first Metatarsophalangeal Joint: Static Plate, Static Plate with Lag Screw, Locked Plate, and Locked Plate with Lag Screw. J Foot Ankle Surg 2012; 51:285-287. 9. Hyer CF, Morrow S. Successful Arthrodesis of the First Metatarsophalangeal Joint in patients with Inflammatory and Non inflammatory Arthritis: A comparative Analysis. J Foot Ankle Surg 2014; 53:291-294. 10. Coughlin MJ, Shurnas PS. Hallux rigidus: grading and long-term results operative treatment. J Bone Joint Surg Am 2003;85-A(11):2072–88. 11. Brodsky JW, Passmore RN, Pollo FE, et al. Functional outcome of arthrodesis of the first metatarsophalangeal joint using parallel screw fixation. Foot Ankle Int 2005;26: 140–6. 12. Erdil M, Elmadag NM, Polat G, Tuncer N, Bilsel K, Ucan V, Erkocak OF, Sen C. Comparison of Arthrodesis, Resurfacing Hemiarthroplasty, and Total Joint Replacement in the Treatment of Advanced Hallux Rigidus. J Foot Ankle Surg 52 (2013) 588-593 13. Henry APJ, Waugh W. The use of foot prints in assessing the results of operations for hallux valgus: a comparison of Keller’s operation and arthrodesis. J Bone Joint Surg Am 1975; 57(4):478–81. 14. Lau JT, Daniels TR. Outcomes following cheilectomy and interpositional arthroplasty in 34 hallux rigidus. Foot Ankle Int 22:462-470, 2001. 15. Gibson JNA, Thomson CE. Arthrodesis or total replacement Arthroplasty for hallux rigidus: A randomized controlled trial. Foot Ankle Int. 2005; 26:680-690. 16. Mann RA, Oates JC. Arthrodesis of the first metatarsophalangeal joint. Foot Ankle 1980;1(3): 159-66. 17. Wood EV, Walker CR, Hennessy MS. First Metatarsophalangeal Arthrodesis for Hallux Valgus. Foot Ankle Clin N AM 2014. 18. Rongstad DJ, Miller GJ, Vadergriend RA et al. A biomechanical comparison of four fixation methods of first metatarsophalangeal joint arthrodesis. Foot Ankle Int 1994; 15: 415-9 19. Curtis MJ, Myerson M, Jinnah RH, Cox QG, Alexander I. Arthrodesis of the first metatarsophalangeal joint: a biomechanical study of internal fixation techniques. Foot Ankle 1993;14 (7):395–9. 20. Fanous RN, Ridgers S, Sott AH. Minimally invasive arthrodesis of the first metatarsophalangeal joint for hallux rigidus. Foot and Ankle Surg 2014; 20:170-173. 21. Krannitz KW, Fong HW, Fallat LM, et al. The effect of cigarette smoking on radiographic bone healing after elective foot surgery. J Foot Ankle Surg 2009; 48 (5): 525-7 22. Mann RA, Coughlin MJ. Adult hallux valgus. In: Coughlin MJ, Mann RA, editors. Surgery of the foot and ankle. 7th ed. Philadelphia: Mosby; 1999. p. 150-269. 23. Yu GV, Shook JE. Arthrodesis of the first metatarsophalangeal joint. In: Banks A, et al., editors. McGlamry’s comprehensive textbook of foot and ankle surgery. Philadelphia: Lippincott Williams and Wilkins; 2001. P. 581-606. 24. Choudhary RK, Theruvil B, Taylor GR. First metatarsophalangeal arthrodesis: a new technique of internal fixation by using memory compression staples. J Foot Ankle Surg 2004;43 (5):312-7. 25. Fadel GE, Rowley DI, Abboud RJ. Hallux metatarsophalangeal joint arthrodesis: various techniques. Foot 2002; 12(2): 88-96. 26. Mandell D, Karbassi J, Zhou H, Burroughs B, Aurigemma P, Patel AR. A locking compression plate versus the gold-standard non-locking plate with lag screw for first metatarsophalangeal fusion: A biomechanical comparison. The Foot 34 (2018) 69-73. 27. Coughlin MJ, Abdo RV. Arthrodesis of the first metatarsophalangeal joint with Vitallium plate fixation. Foot Ankle Int 1994; 15 (1): 18-28. 35 28. Hunt KJ, Ellington JK, Anderson RB, et al. Locked versus nonlocked plate fixation for hallux MTP arthrodesis. Foot Ankle Int 2011;32(7):704–9. 29. Hunt KJ, Barr CR, Lindsey DP, et al. Locked versus nonlocked plate fixation for first metatarsophalangeal arthrodesis: a biomechanical investigation. Foot Ankle Int 2012;33(11):984–90. 30. Ettl V, Radke S, Gaertner M, Walther M. Arthrodesis in the treatment of hallux rigidus. Int Orthop 27(6):382–385, 2003. 31. Patil S, Chojnowski A, Albert J. A retrospective analysis of first metatarsophalangeal joint fusions. Foot Ankle Surg 11(2):113–116, 2005. 32. Buranosky DJ, Taylor DT, Sage RA, et al. First metatarsophalangeal joint arthrodesis: quantitative mechanical testing of six-hole plate versus crossed screw fixation in cadaveric specimens. J Foot Ankle Surg 2001;40:208–13. 33. Weil LS. First metatarsophalangeal joint arthrodesis. In: Chang T, editor. Master techniques in podiatric surgery: the foot and ankle. Philadelphia: Lippincott Williams and Wilkins; 2005. p. 119–28. 34. Myerson MS. Reconstructive foot and ankle surgery. Philadelphia: Elsevier Saunders; 2005. p. 365–80. 35. Goucher NR, Coughlin MJ. Hallux metatarsophalangeal joint arthrodesis using dome- shaped reamers and dorsal plate fixation: a prospective study. Foot Ankle Int 2006;27(11):869–76. 36. Coughlin MJ. Arthrodesis of the first metatarsophalangeal joint with mini-fragment plate fixation. Orthopaedics 1990; 13(9): 1037-44. 37. Bauer T, Lortat-Jacob A, Hardy P. First metatarsophalangeal joint percutaneous arthrodesis. J Orthop Traumatol (2010) 96: 567-573. 38. Kelikian AS. Technical considerations in hallux metatarsophalangeal arthrodesis. Foot Ankle Clin 2005; 10 (1): 167-90. 39. Harper MC. Positioning of the Hallux for first metatarsophalangeal joint arthrodesis. Foot Ankle Int 1997; 18 (12): 827. 40. Kumar S, Pradhan R, Rosenfield PF. First metatarsophalangeal Arthrodesis Using a Dorsal Plate and a Compression Screw. Foot Ankle Int 2010; 31: 797-801. 41. Roukis TS. Nonunion after arthrodesis of the first metatarsophalangeal joint: a systematic review. J Foot Ankle Surg 2011; 50(6): 710-3. 36 42. DeFrino PF, Brodsky JW, Pollo FE, et al. First metatarsophalangeal arthrodesis: a clinical, pedographic and gait analysis study. Foot Ankle Int 2002;23(6): 496-502. 43. Maffuli N, Papalia R, Palumbo A, et al. Quantitative review of operative management of hallux rigidus. Br Med Bull 2011;98: 75-98. 44. McNeil DS, Baumhauer JF, Glazebrook MA. Evidence-based analysis of the efficacy for operative treatment of hallux rigidus. Foot Ankle Int 2013:34: 15-32. 45. Coster M, Karlsson MK, Nilsson J, Carlsson A. Validity, reliability, and responsiveness of a self-reported foot and ankle score (SEFAS). Acta Orthopaedica 2012; 83 (2): 197- 203. 46. Charan J, Biswas T. How to calculate sample size for different study designs in medical research. Indian journal of psychological medicine. 2013 Apr; 35(2): 121. 47. Dariusch A, Katharina K, Christoph S, Bertil B, Christian L and Dietmar K. Reliability, validity and responsiveness of the German self-reported foot and ankle score (SEFAS) in patients with foot or ankle surgery. BMC Musculoskeletal Disorders 2017 18:409. 48. Fuhrmann RA. First metatarsophalangeal arthrodesis for hallux rigidus. Foot Ankle Clin N Am 16 (2001) 1-12. 49. Cobb TK, Gabrielsen TA, Campbell DC, et al. Cigarette smoking and non union after ankle arthrodesis. Foot Ankle Int 1994; 15 (2):64-7. 50. Grondal L, Stark A. Fusion of the first metatarsophalangeal joint, a review of techniques and considerations. Presentation of our results in 22 cases. The Foot 2005;15:86–90 51. Hyer CF, Glover JP, Berlet GC, et al. Cost comparison of crossed screws versus dorsal plate construct for first metatarsophalangeal joint arthrodesis. J Foot Ankle Surg 2008;47:13–8. 52. Jarde ́ O, Laya Z, Olory B, et al. Arthrodesis of the first metatarsophalangeal joint using convex and concave drills: a report on 50 cases. Acta Orthop Belg 2005; 71:76–82. 53. Ellington JK, Jones CP, Cohen BE, et al. Review of 107 hallux MTP joint arthrodesis using dome-shaped reamers and a stainless-steel dorsal plate. Foot Ankle Int 2010;31:385–90. 54. Sharma H, Bhagat S, Deleeuw J, et al. In vivo comparison of screw versus plate and screw fixation for first metatarsophalangeal arthrodesis: does augmentation of internal compression screw fixation using a semi-tubular plate shorten time to clinical and radiologic fusion of the first metatarsophalangeal joint (MTPJ)? J Foot Ankle Surg 2008;47:2–7. 37 55. Neto M, Hall D, Frisch N, Fischer A, Jacobs J, Pourazal R. Is TI-6AL-$V alloy always the same in orthopaedic implants? JBJS Vol. 103 B, No. Supp 1 56. Harrison M, Harvey F. Arthrodesis of the first metatarsophalangeal joint for hallux valgus and rigidus. J Bone Joint Surg Am 1963; 45:471-80. 57. Humbert JL, Bourbonnie`re C, Laurin CA. Metatarsophalangeal fusion for hallux valgus: indications and effect on the first metatarsal ray. Can Med Assoc J 1979;120(8):937–41, 956. 58. Mckeever DC. Arthrodesis of the first metatarsophalangeal joint for hallux valgus, hallux rigidus, and metatarsus primus varus. J Bone Joint Surg Am1952;34(1):129–34. 59. Moynihan FJ. Arthrodesis of the metatarso-phalangeal joint of the great toe. J Bone Joint Surg Br 1967;49(3):544–51.