The October 2024 Foot & Ankle Roundup. 360. looks at: Hemiarthroplasty for hallux rigidus; Fixed or mobile-bearing ankle arthroplasty? A meta-analysis; Bone grafting for periprosthetic bone cysts following total ankle arthroplasty; Diabetic foot ulcer after first-ray amputation; Early motion after ankle surgery: the path to faster recovery?; Are podiatrists and orthopaedic surgeons approaching zone 2 fifth metatarsal fractures in the same way?

Aims

This study evaluated the effect of treating clinician speciality on management of zone 2 fifth metatarsal fractures.

This study evaluates patient reported outcome measurement information system (PROMIS) scores after total hip arthroplasty (THA) and total ankle arthroplasty (TAA) in matched cohorts, while simultaneously evaluating implant survivorship and 90-day hospital utilization. It is hypothesized that while both procedures would yield similar PROMIS score improvements, THA would demonstrate superior mid-term implant survivorship. Primary THA and TAA patients from 2015–2022 with minimum one-year follow-up were retrospectively reviewed. After applying exclusion criteria, 2,092 THAs and 478 TAAs were included for analysis. Demographics, pre- and post-operative patient reported outcome measures (PROMs), revision surgeries, ED visits, and re-admissions were collected. THA and TAA patients were then propensity score matched at 2:1 ratio for age, sex, race, BMI, ASA, and comorbidities, resulting in a final cohort of 844 THAs and 455 TAAs for comparison. There were similar pre-operative PROMIS Pain Interference (PI) scores between THA and TAA, with both showing improvement at six weeks. However, THA patients exhibited lower PI scores at one year (53.0 versus 54.0; p=0.009). Pre-operative PROMIS Physical Function (PF) was worse in THA patients but showed greater improvement compared to TAA patients at both six weeks (p<0.001) and one year (p<0.001). Pre-operative PROMIS depression scores were similar and improved similarly in both groups. Joint-specific PROMs (HOOS for THA and FAAM for TAA) improved in both cohorts. THA demonstrated superior survivorship free of all-cause revision at five years compared to TAA (95% versus 77%; p<0.0001). Patients undergoing THA or TAA experienced significant improvements in their general and joint-specific PROMs post-operatively. However, patients undergoing THA demonstrated higher PROMIS PI and PF scores at one-year when compared to TAA, as well as improved survivorship. Generic PRO instruments enable comparison of medical treatments in different anatomic sites to the patients overall health

The August 2024 Foot & Ankle Roundup. 360. looks at: ESWT versus surgery for fifth metatarsal stress fractures; Minimally invasive surgery versus open fusion for hallux rigidus; Diabetes and infection risk in total ankle arthroplasty; Is proximal medial gastrocnemius recession useful for managing chronic plantar fasciitis?; Fuse the great toe in the young!; Conservative surgery for diabetic foot osteomyelitis; Mental health and outcome following foot and ankle surgery

Aims. Retrospective review of a consecutive series of 1,168 total ankle replacements (TAR) performed at Wrightington, to analyse modes of failure and clinical outcomes following TAR failure. Methods. All patients undergoing TAR between November 1993 – June 2019 were collated (4–25 year follow-up; mean 13.7 years). 6 implants were used (300 STAR, 100 Buechal Pappas, 509 Mobility, 118 Zenith, 41 Salto and 100 Infinity). 5 surgeons, all trained in TAR, performed the surgery. Modes of failure were collated and clinical and radiological outcomes recorded for the revisional surgery following failure of the TAR. Results. 156 (13.4%) TARs failed (47STAR 15.6%, 16BP 16%, 77Mobility 15.1%, 6Salto 14.6%, 10Zenith 8.5% and 0Infinity 0%). Mean time to failure 5.8 years (0.1- 21.4 years). The 4 most common modes of failure were 44.9% aseptic loosening, 11.5% gutter pain, 10.9% infection and 10.3% recurrent edge loading. 50 underwent conversion to tibiotalocalcaneal (TTC) fusion with nail with 9 (18%) failing to fuse. 31 underwent revision TAR with 2 (6.5%) subsequently failed. 22 underwent ankle fusion with 10 (45%) failing to fuse. 21 underwent polyethylene exchange of which 8 (38%) had further poly failure. 20 (12.8%) were managed conservatively, 2 (1.3%) required below knee amputation and 6 were listed but lost to follow-up. 81 of the 1168 (7%) consecutive cohort were lost to follow-up. Conclusions. 13.4% of the TAR cohort have failed at average follow-up 13.7 years. There was no difference in failure modes across the implant designs. Whilst the fixed bearing has the shortest follow-up, it may be performing better as there have been no failures so far. Prior to October 2016, most revisions were to fusion (TTC 18% failure rate, ankle 45% failure rate), whereas post 2016, 57% patients elected for revision TAR (6.5% failure)

One assumed function of Total Ankle Replacement (TAR) is that by maintaining ankle joint motion we can protect the other hind foot joints from further degredation. 1. However, there is no work to our knowledge that compares hindfoot outcomes between TAR and arthrodesis. Sokolowski et al. found that 68% of TAR patients had no radiological progression of subtalar arthritis after TAR, and 4% went on to fusion. 2. However, no evaluation of the other hindfoot joints was made and no comparison made to other treatment. We performed a retrospective review of all patients at our centre who had had a TAR or ankle arthrodesis since 2002. Case notes and imaging were reviewed and all instances of hindfoot treatment (injections or surgical procedures) noted. Patients were excluded who had no documentation, were followed up at other hospitals, had prior hindfoot fusion, or were having staged surgeries at the time of index treatment. Chi squared analysis was used to compare the cohorts. 214 arthrodesis cases and 302 TAR were eligible. The average age was 57. Average time to follow up was 13 years (4–21). At the time of abstract submission 107 sets of notes had been reviewed fully. Full analysis will be performed by conference. 14% of TAR patients went on to have further procedures to the hindfoot joints while 35% of arthrodesis patients had further procedures (p=0.014). There was also a significant difference in the number of patients progressing to fusion of a further hindfoot joint between groups (TAR- 4%, arthrodesis- 20%, p=0.01). These data suggest that TAR are protective of symptomatic change of hindfoot joints. Patients with TAR had fewer hindfoot fusions than those with arthrodesis and also fewer procedures of any form, including injections

Background. Ankle and hindfoot fusion in the presence of large bony defects represents a challenging problem. Treatment options include acute shortening and fusion or void filling with metal cages or structural allograft, which both have historically low union rates. Impaction grafting is an alternative option. Methods. A 2 centre retrospective review of consecutive series of 32 patients undergoing hindfoot fusions with impaction bone grafting of morselised femoral head allograft to fill large bony void defects was performed. Union was assessed clinically and with either plain radiography or weightbearing CT scanning. Indications included failed total ankle replacement (24 patients), talar osteonecrosis (6 patients) and fracture non-union (2 patients). Mean depth of the defect was 29 ±10.7 mm and mean maximal cross-sectional area was 15.9 ±5.8 cm. 2. Tibiotalocalcaneal (TTC) arthrodesis was performed in 24 patients, ankle arthrodesis in 7 patients and triple arthrodesis in 1 patient. Results. Mean age was 57 years (19–76 years). Mean follow-up of 22.8 ±8.3 months. 22% were smokers. There were 4 tibiotalar non-unions (12.5%), two of which were symptomatic. 10 TTC arthrodesis patients united at the tibiotalar joint but not at the subtalar joint (31.3%), but only two of these were symptomatic. The combined symptomatic non-union rate was 12.5%. Mean time to union was 9.6 ±5.9 months. One subtalar non-union patient underwent re-operation at 78 months post-operatively after failure of metalwork. Two (13%) patients developed a stress fracture above the metalwork that healed with non-operative measures. There was no bone graft collapse with all patients maintaining bone length. Conclusion. Impaction of morselised femoral head allograft can be used to fill large bony voids around the ankle and hindfoot when undertaking arthrodesis, with rapid graft incorporation and no graft collapse despite early loading. This technique offers satisfactory union outcomes without the need for shortening or synthetic cages

Background. Patients who undergo either primary or revision total ankle replacement (TAR) expect improvements in pain, function and quality of life. The goal of this study was to measure the functional outcome improvements and the difference in patient-reported outcomes in patients undergoing primary total ankle replacements compared to revision TAR. Methods. A single-center prospective cohort study was undertaken between 2016 and 2022. All patients were followed up for a minimum of 6 months. Patients undertook the Manchester Oxford Foot Questionnaire (MoxFQ) and EQ-5D health quality questionnaires pre-operatively, at 6 months and yearly for life. The Mann Whitney test was undertaken for statistical analysis. Results. A total of 165 primary and 71 revision ankle replacements were performed between 2016 and 2022. The mean age was 71 years for primary replacements and 69 years for revisions. The INFINITY was utilized in the majority of primary total ankle replacements. Revision replacements were either the INBONE II or INVISION and they were most often revising the MOBILITY implant. The main indication for revision was aseptic loosening (83%). Other causes included infection, malalignment and insert wear. The overall MoxFQ improved by a mean of 46.5 for primaries and 40.2 for revisions. The EQ-5D score also showed overall improvements with the mean difference in mobility increasing by 1.6. Conclusion. Both primary and revision ankle replacements result in improved functional scores at 6 months, 1 year and 2 years. In this cohort with the implants used, both primary and revision ankle replacements demonstrate similar improvements in functional scores

Background. Total Ankle Replacement (TAR) is an established treatment option for end-stage ankle arthritis. We analysed at minimum, 10-year patient-reported and clinical outcomes of 156 TARs from a single centre. We specifically compared outcomes between patients under 60 and over 60 at time of surgery. Methods. Data was collected retrospectively from our departmental patient database. It included all patients who underwent a TAR by a single surgeon between 2006 and 2010 and patients were divided into those under 60 and those over 60 at the time of surgery. Patient reported outcomes (PROMs), including WOMAC, SF-36 and patient satisfaction scores and complications were analysed preoperatively and at one, two, five and over 10 years postoperatively. Results. There were 156 patients included in this analysis, 61 were under 60 (mean age 50.29) and 95 were over 60 (mean age 69.12). A total of 12 patients had revision surgery, (nine in the under 60 group) and 52 patients were deceased at the time of analysis (10 in the under 60 group). At one year the over 60 group had less pain and better functional scores (p=0.02, p=0.017). At two, five and ten years there was no statistical difference in pain and function between groups. At two years the over 60s reported less stiffness and quicker return to activities of daily living (p=0.007, p=0.001). However, at five and 10 years there was no statistical difference in any domain. Conclusions. This study demonstrates that age does not correlate with a significant difference in pain or functional outcomes in patients who have TAR, at over 10 years follow up. The higher revision rates in the younger group may correlate with higher functional demand and lower mortality rate

Despite advancements, revision rates following total ankle replacement (TAR) are high in comparison to other total joint replacements. This explant analysis study aimed to investigate whether there was appreciable metal particulate debris release from various contemporary TARs by describing patterns of material loss. Twenty-eight explanted TARs (9 designs: 3 fixed and 6 mobile bearing), revised for any reason, were studied. The articulating surfaces of the metal tibial and talar components as well as the polyethylene insert were assessed for damage features using light microscopy. Based on the results of the microscopic analysis, scanning electron microscopy with energy dispersive X-ray spectroscopy was performed to determine the composition of embedded debris identified, as well as non-contacting 3D profilometry. Pitting, indicative of material loss, was identified on the articulating surfaces of 54% of tibial components and 96% of talar components. Bearing constraint was not found to be a factor, with similar proportions of fixed and mobile bearing metal components showing pitting. More cobalt-chromium than titanium alloy tibial components exhibited pitting (63% versus 20%). Significantly higher average surface roughness (Sa) values were measured for pitted areas in comparison to unpitted areas of these metal components (p<0.05). Additionally, metallic embedded debris (cobalt-chromium likely due to pitting of the tibial and talar components or titanium likely from loss of their porous coatings) was identified in 18% of polyethylene inserts. The presence of hard 3. rd. body particles was also indicated by macroscopically visible sliding plane scratching, identified on 79% of talar components. This explant analysis study demonstrates that metal debris is released from the articulating surfaces and the coatings of various contemporary TARs, both fixed and mobile bearing. These findings suggest that metal debris release in TARs may be an under-recognised issue that should be considered in the study of painful or failed TAR moving forwards

Objective. The purpose of this study was to determine the outcomes of revision ankle replacements, using the Invision implant and impaction allograft for massive talar dome defects following primary ankle replacement failure. Outcomes were assessed in terms of bone graft incorporation; improvement in patient reported outcome measures (PROMs); and survivorship of the revision ankle arthroplasty. Methods. A retrospective review of prospectively collected data identified eleven patients who had massive bone cysts and underwent revision of a failed primary total ankle replacement to the Invision revision system, combined with impaction grafting using morselized femoral head allograft. These revisions occurred at a single high volume ankle arthroplasty centre. Computed tomography (CT) scans were used to assess bone graft incorporation and the Manchester-Oxford Foot Questionnaire (MOXFQ) and EQ-5D scores were used pre and post operatively to assess PROMs. Results. The mean follow up was 18 months (12–48months). In all eleven patients, improvement was reported in the post-operative MOXFQ and EQ-5D scores. CT scans showed bone graft incorporation in all cases. None of the patients have required further surgery and are continue to do well clinically at latest follow up. Conclusions. In the short term, this study confirms revision ankle replacements with the Invision prosthesis and impaction with morselized femoral head allograft is a suitable revision option for primary ankle replacement failure with massive talar bone loss. Long term follow up continues of these complex patients

Ankle fusion (AF), a durable intervention for ankle arthritis, has been the management of choice but restricts mobility. Recently, total ankle replacement (TAR) has been offered to patients looking to maintain mobility. The aim was to compare the biomechanics of AF and TAR while walking on inverted and everted slopes which create a greater demand for complex foot mobility than level walking. A ten-camera motion detection setup captured trials as patients walked in both directions over a 5⁰ lateral slope with embedded force plates. Moments (Nm/Kg) across the knee and ankle were exported from Visual 3D in the sagittal and frontal plane, and data were reported as means with 95% confidence intervals. 15 patients were recruited (6 TAR, 9 AF). The median age, follow-up and BMI was 67 years, 4 years and 35.8 kg/m² in AF, and 73 years, 7 years and 28.1 kg/m² in TAR, respectively. During inverted slope walking (4 TAR, 7 AF), abduction moments across (i) the knee: TAR 0.38 (0.37–0.39) vs AF 0.37 (0.27–0.52) and (ii) the ankle: TAR 0.20 (0.13–0.27) vs AF 0.25 (0.18–0.32), and extension moments across (i) the knee: TAR 0.68 (0.38–0.97) vs AF 0.85 (0.69–1.01) and (ii) the ankle: TAR 1.46 (1.30–1.62) vs AF 1.30 (1.08–1.52). During everted walking (5 TAR, 7 AF), abduction moments across (i) the knee: TAR 0.41 (0.30–0.52) vs AF 0.46 (0.27–0.66) and (ii) the ankle: TAR 0.24 (0.11–0.38) vs AF 0.26 (0.18–0.33), and extension moments across (i) the knee: TAR 0.76 (0.54–0.99) vs AF 0.93 (0.72–1.14) and (ii) the ankle: TAR 1.39 (1.19–1.59) vs AF 1.26 (1.04–1.48). There were no differences in abduction moments during inverted or everted slope walking. However, patients with AF had increased extension moments across the knee, particularly on inverted slopes, suggesting that AF creates a greater demand for knee compensation than TAR

Background. The literature on the outcome of revision total ankle arthroplasty (TAA) remains limited. We aim to report the clinical and radiological outcomes of revision TAA at a high-volume centre in the UK. Methods. Retrospective review of 28 patients that underwent 29 revision TAA procedures using INBONE II prosthesis. Demographic, radiological, and patient reported outcome measures data were analysed. Results. The mean (range) duration from primary TAA to revision was 87.5 (16–223) months. The main indication for the revision was aseptic loosening of the primary TAA (82.8%). Additional procedures were required in 75.9% of patients. At mean (range) follow-up of 40 (24- 60) months, the infection, re-operation, and implant survival rates were 6.9%, 6.9% and 96.5% respectively. A significant postoperative improvement in the component alignment radiographic measures was observed. Osteolysis, subsidence, loosening and heterotopic ossification rates were comparable to other reports and did not influence the clinical outcome. A significant improvement was observed in the MOXFQ (all domains) and the EQ-5D (three domains) at 24 months postoperatively. Conclusions. Revision TAA using INBONE II was associated with good short-term survival and improvement in the postoperative scores at 2 years. Maintenance of the postoperatively improved alignment was documented at follow up. The relatively high survival rate in this series supports the notion that revision TAA is a satisfactory option for failed primary TAA

Introduction. This is a multi-centre, prospective, observational study of 503 INFINITY fixed bearing total ankle arthroplasties. We report the minimum two-year results of this prosthesis which was introduced to the UK Market in 2014 and is now the most used ankle arthroplasty in the National Joint Registry of England and Wales. Methods. Patients were recruited from 11 centres in the United Kingdom between June 2016 and November 2019. Demographic, radiographic, and functional outcome data (Ankle Osteoarthritis Scale, Manchester Oxford Foot Ankle Questionnaire and Euroquol 5D-5L) were collected preoperatively, at 6 months, 1 year and 2 years and 5 years. The average age was 67.8 (range 23.9 to 88.5) and average BMI 29.3 (18.9 to 48.0). The COFAS grading system was used to stratify deformity. There were 261 (51.9%) COFAS Type 1, 122 (24.2%) COFAS Type 2, 31 (6.2%) COFAS 3 and 89 (17.7%) COFAS type 4. 38 patients (7.6%) presented with inflammatory arthritis. 99 (19.7%) implantations utilised patient specific instrumentation. Complications and reoperations were recorded as adverse events. Radiographs were assessed for lucencies, cysts and/or subsidence. Results. The mean follow up was 34.2 months (range 24–64). 15 patients have died, 8 withdrawn and 3 lost to follow up. 8 implants (1.6%) have been revised. According to the Glazebrook classification there were low grade complications in 6.6%, medium grade in 1.4% and high grade in 1.6%. There have been an additional 13 non revision re-operations (2.6%) at the latest follow up. There was a significant (p < 0.01) improvement across all functional outcome scores at a minimum of 2yr follow up. Discussion and conclusion. This large cohort has shown a low early revision rate and high functional outcomes with a low-profile fixed bearing prosthesis

The June 2024 Foot & Ankle Roundup³⁶⁰ looks at: First MTPJ fusion in young versus old patients; Minimally invasive calcaneum Zadek osteotomy and the effect of sequential burr passes; Comparison between Achilles tendon reinsertion and dorsal closing wedge calcaneal osteotomy for the treatment of insertional Achilles tendinopathy; Revision ankle arthroplasty – is it worthwhile?; Tibiotalocalcaneal arthrodesis or below-knee amputation – salvage or sacrifice?; Fusion or replacement for hallux rigidus?.

Introduction. We report the functional outcome and survivorship of the Hintegra Total Ankle Replacement (TAR), in consecutive cases by multiple surgeons in a single UK institution. Between 2010–2014 the Hintegra TAR held 7.1% UK market share and surgeons should be aware of failure mechanisms. Methods. We conducted a retrospective review of prospectively collected data for 70 consecutive Hintegra TAR cases in a single institution between 2010–2014. Data collected included patient demographics, complications, reoperations, patient reported outcome measures (PROMS: AOS, MOX-FQ, pain VAS) and patient satisfaction. Results. The 70 patients (54 male/ 16 female) had an average age of 69 (range 48–84 years). Mean follow up was 76 months (range 60–04), 10 patients died during the follow up. Implant survivorship was 81.4% at most recent follow up. The commonest radiographic finding was periprosthetic cysts (n=28, 40%), size range (7–40mm), location of cysts: isolated talus (n=14), isolated tibia (n=6), mixed (n=8). 10 failed TARs were revised to Inbone TAR at a mean of 48 months (range 9–69). 3 Failed TARs were revised to arthrodesis (2 tibiotalar fusions, 1 hindfoot nail). 11 patients required reoperation with implant retention: 8 periprosthetic cyst debridement and grafting at a mean of 61 months (range 27–91), 1 lateral gutter debridement and 1 periprosthetic fracture ORIF. PROMS data was available for all patients. Overall patients showed marked improvement in functional outcome scores between pre-operative and final follow up questionnaires. Mean pre-op AOS: 62, MOX-FQ: 68 and pain VAS: 67.5 with mean final follow up scores of: AOS: 35, MOX-FQ: 36 and pain VAS: 30. Conclusion. Our experience demonstrates improved PROMS following ankle arthroplasty for patients with a mean follow up of 6.4 years. Implant survivorship is similar to other TAR studies. We have identified a high incidence of periprosthetic cysts and would recommend ongoing surveillance of these patients

Introduction. Day Case Surgery (defined as same day discharge) is a priority within the National Health Service and has been shown to provide beneficial outcomes for patients and hospitals. We report our experience developing a Day Case Programme for Total Ankle Replacement (TAR). Methods. Prior to the introduction of a Day Case Programme, average length of stay following TAR in our unit was 3.5 days. Stakeholders were consulted about ways in which same day discharge could be facilitated. Patients' post-operative pain charts were reviewed prior to the introduction of this programme. Inclusion criteria included non-complex surgery (anticipated tourniquet < 2hrs), friend or relative support and pre-operative walking-aid assessment. An enhanced recovery protocol included long-acting popliteal block and dexamethasone. Patients were discharged with opiate analgesia and written pain instructions. Patients were asked to complete a pain and satisfaction questionnaire. Patient Reported Outcome Measures (PROMs) were recorded. Results. From September 2017 to April 2019 21 of 70 patients underwent TAR as a Day Case. Mean age was 67 years (43-85 years). Complications included two delayed wound healings and one representation on day three with urinary retention. No patients reported post-operative nausea or vomiting, 60% did not use Oramorph at home. Average Visual Analogue Score for pain was 23/100 on day one and 21/100 day three post-operatively. There was no significant difference in pre-operative or overall change in MOXFQ, VAS or EQ5D PROMS. Conclusions. Early results suggest that Day Case Total Ankle Replacements are safe. Appropriate patient selection is necessary. Day Case Surgery relies on support and communication between multiple teams to organise and run effectively

Revision options for a failed Total ankle arthroplasty (TAA) have historically been limited to complex hindfoot fusions, bespoke ankle arthroplasty revision or amputation. The patient outcomes of these procedures has been felt to be poor. The introduction of the INBONE-II and INVISION ankle arthroplasty revision systems has created a range of revision arthroplasty options, with the possibility of improved patient outcomes. We aim to report on the early results of 20 sequential revision TAA. All patients undergoing revision TAA with INBONE-II or INVISION had prospective collection of pre-operative and post-operative MOx-FQ and EQ-5D scores. Between September 2013 and June 2019 23 patients underwent revision TAA with mean time from implantation of 35 months (6 to 74). Those with greater than 1 year follow-up had scores included. Other outcomes included radiographic assessment for loosening and revision. 13 patients had INBONE-II and 10 INVISION. None required revision at the time of review. Pre-operative MOx-FQ averaged 40.6 (13.4 pain, 21 walking, 6.2 social). Post-operative MOx-FQ averaged 17.4 (6.2 pain, 8.1 walking, 3.1 social). Average EQ-5D improved from 8 to 6.6 and average EQ-VAS from 60 to 80. On radiograph review one patient had radiolucent lines around their INBONE-II stem evident at 1 year. This had not progressed by 4 years total follow-up. Another patient had uncoupling of part of the stem of her INBONE-II but had not required revision. This was attributed to surgeon error. Revision TAA using the INBONE-II and INVISION systems shows promising early results relating to loosening and revision and good maintained improvement in MOx-FQ and EQ-5D scores. This provides further evidence that patients with a failed TAA can safely have revision rather than having to commit to complex ankle/hindfoot fusion. This provides surgeons with flexibility particularly in those patients with other hindfoot arthritis or arthrodesis

Introduction. Total ankle replacement (TAR) is performed for post-traumatic arthritis, inflammatory arthropathy, osteoarthritis and other indications. The Scottish Arthroplasty Project (SAP) began collection of data on TAR in 1997. In this study, using data from the SAP, we look at trends in the use and outcomes of TAR in Scotland. Methods. We identified 499 patients from the SAP who underwent TAR between 1997 and 2015 with imaging available on the National Picture Archiving and Communication System (PACS). We identified, and looked at trends in, implant type over the following time periods: 1998–2005; 2006–2010 and 2011–2015. Age, gender, indication and outcomes for each time period were examined and also trends with implant type over time. Results. There were 499 primary TAR procedures with an overall incidence of 0.5/10. 5. population per year. Eight different implants were identified with significant changes in the numbers of each type used over time. The peak incidence of TAR was in the 6th decade. The mean age of patients undergoing TAR from 59 years in 1997–2005, to 65 years in 2011–15 (p< 0.0001). The percentage of patients with inflammatory arthropathy was 52% in 1997–2005, compared with 10% in 2011–2015. Subsequent arthrodesis and infection rates appeared to be higher during the first time period. The female to male ratio also changed over time. The incidence of TAR increased overall during the study period (r= 0.9, p=< 0.0001). This may be due to a broadening range of indications and patient selection criteria, in turn due to increased surgeon experience and the evolution of implant design. Conclusion. This study examines a large number of TARs from an established arthroplasty registry. The rate of TAR has increased significantly in Scotland from 1997 to 2015. Indication and patient age has changed over time and this could potentially impact outcomes after ankle replacement

Background. The importance of total ankle replacement (TAR) implant orientation in the axial plane is poorly understood with major variation in surgical technique of implants on the market. Our aims were to better understand the axial rotational profile of patients undergoing TAR. Methods. In 157 standardised CT Scans of end-stage ankle arthritis patients planning to undergo primary TAR surgery, we measured the relationship between the knee posterior condylar axis, the tibial tuberosity, the transmalleolar axis(TMA) and the tibiotalar angle. The foot position was measured in relation to the TMA with the foot plantigrade. The variation between medial gutter line and the line bisecting both gutters was assessed. Results. The mean external tibial torsion was 34.5±10.3°(11.8–62°). When plantigrade the mean foot position relative to the TMA was 21±10.6°(0.7–38.4°) internally rotated. As external tibial torsion increased, the foot position became more internally rotated relative to the TMA(pearson correlation 0.6;p< 0.0001). As the tibiotalar angle became more valgus, the foot became more externally rotated relative to the TMA(pearson correlation −0.4;p< 0.01). The mean difference between the medial gutter line and a line bisecting both gutters was 4.9±2.8°(1.7°-9.4°). More than 51% of patients had a difference greater than 5°. The mean angle between the medial gutter line and a line perpendicular to the TMA was 7.5°±2.6°(2.8°-13.7°). Conclusion. There is a large variation in rotational profile of patients undergoing TAR, particularly between the medial gutter line and the transmalleolar axis. Surgeon designers and implant manufacturers need to develop consistent methods to guide surgeons towards judging appropriate axial rotation of their implanton an individual basis. We recommend careful clinical assessment and CT scanspre-operatively to enable the correct rotation to be determined