Total Ankle Replacement Research Articles

Avascular Necrosis of the Talus: Diagnosis, Treatment, and Modern Reconstructive Options.

Talar avascular necrosis (AVN) is a devastating condition that frequently follows type III and IV talar neck fractures. As 60% of the talus is covered by hyaline cartilage, its vascular supply is limited and prone to trauma, which may eventually lead to AVN development. Early detection of AVN (Hawkins sign, MRI) is crucial, as it may prevent the development of the irreversible stages III and IV of AVN. Alertness is advised regarding non-obvious conditions that may cause this complication (sub chondroplasty, systemic lupus erythematosus, diabetes mellitus). Although, in stages I-II, AVN may be treated with non-surgical procedures (ESWT therapy, non-weight bearing) or joint-sparing techniques (core drilling, bone marrow aspirate injections), stages III-IV require more advanced procedures, such as joint-sacrificing procedures (hindfoot arthrodesis/ankle arthrodesis), or replacement surgery, including total talar replacement (TTR) or combined total ankle replacement (TAR). The advancement of 3D-printing technology and increased access to implant manufacturing are contributing to a rise in the production rates of third-generation total talar prostheses. As a result, there is a growing frequency of alloplasty procedures and combined total ankle replacement (TAR) surgeries. By performing TTR as opposed to deses, the operator avoids (i) delayed union, (ii) a shortening of the limb, (iii) a lack of mobility, and (iv) the stiffening of adjacent joints, which are the main disadvantages of joint-sacrificing procedures. Simultaneously, TTR and combined TAR offer (i) a brief period of weight-bearing restriction, (ii) quick pain relief, and (iii) preservation of the length of the limb. Here, we summarize the most up-to-date knowledge regarding AVN diagnosis and treatment, with a special focus on the role of TTR.

Influence of Tibial Component Design Features and Interference Fit on Implant-Bone Micromotion in Total Ankle Replacement: A Finite Element Study.

Implant survivorship in uncemented total ankle replacement (TAR) is dependent on achieving initial stability. This is because early micromotion between the implant and bone can disrupt the process of osseointegration, leading to poor long-term outcomes. Tibial implant fixation features are designed to resist micromotion, aided by bony sidewall retention and interference fit. The goal of this study was to investigate design-specific factors influencing implant-bone micromotion in TAR tibial components with interference fit. Three implant designs with fixation features representative of current TAR tibial components (ARC, SPIKES, KEEL) were virtually inserted into models of the distal tibias of 2 patients with end-stage ankle arthritis. Tibia models were generated from deidentified patient computed tomography scans, with material properties for modeling bone behavior and compaction during press-fit. Finite element analysis (FEA) was used to simulate 2 fixation configurations: (1) no sidewalls or interference fit, and (2) sidewalls with interference fit. Load profiles representing the stance phase of gait were applied to the models, and implant-bone micromotions were computed from FEA output. Sidewalls and interference fit substantially influenced implant-bone micromotions across all designs studied. When sidewalls and interference fit were modeled, average micromotions were less than 11 µm, consistent across the stance phase of gait. Without sidewalls or interference fit, micromotions were largest near either heel strike or toe-off. In the absence of sidewalls and interference fit, the amount of micromotion generally aligned inversely with the size of implant fixation features; the ARC design had the largest micromotion (~540 µm average), whereas the KEEL design had the smallest micromotion (~15 µm). This study presents new insights into the effect of TAR fixation features on implant-bone micromotion. With sidewalls and interference fit, micromotion is predicted to be minimal for implants, whereas with no sidewalls and no interference fit, micromotion depended primarily on the implant design. This study presents new insights into the effect of TAR primary fixation features on implant-bone micromotion. Although design features heavily influenced implant stability in the model, their influence was greatly diminished when interference fit was introduced. The results of this study show the relative importance of design features and interference fit in the predicted initial stability of uncemented TAR, potentially a key factor in implant survivorship.

Traumatic Periprosthetic Fractures Following Total Ankle Replacement A Systematic Review and Proposed Classification

Total ankle replacements (TAR) are increasingly utilized, but postoperative traumatic periprosthetic fractures remain a rare yet challenging complication. This systematic review aims to address the gap in literature by proposing a comprehensive classification system for these fractures, considering implant stability, fracture location, and surrounding bone quality. A systematic review identified 13 cases from 9 studies meeting inclusion criteria. Fractures were categorized using the proposed Hill-Brown classification: Type A (talus or fibula), Type B (distal tibial component), and Type C (diaphysis/proximal tibial metaphysis). Implant stability was a key factor, with Type B fractures further classified as B1 (stable), B2 (unstable with adequate bone stock), and B3 (unstable with poor bone stock). Most fractures occurred at or near the distal tibial component (Type B), with implant stability largely dependent on fracture location and bone quality. Surgical fixation, particularly minimally invasive plate osteosynthesis (MIPO) with locking plates, was the preferred treatment for stable implants, showing low complication rates. Unstable implants often required revision TAR or conversion to arthrodesis. Surgical intervention is recommended following all traumatic periprosthetic fractures in the setting of a TAR. Bone quality, particularly in patients with rheumatoid arthritis or osteoporosis, significantly impacted treatment decisions. Our findings emphasize the importance of fracture location, implant stability, and bone quality in managing these fractures. Future multicenter studies are necessary to validate this classification system and refine treatment protocols. Level of Evidence: Level III

Female sex as a negative predictor of outcomes of ankle arthrodesis: a retrospective comparative monocentric study

BackgroundEnd-stage post-traumatic osteoarthritis of the ankle joint may require arthrodesis if conservative treatment fails and a decision against total ankle replacement is made. We aimed to compare the sex-specific differences in outcomes and objectify them using validated specific scores.MethodsBetween 2010 and 2021, 221 patients underwent ankle arthrodesis at our institution, including 143 men (MAA) and 78 women (FAA). In addition to demographic data, the aetiology of osteoarthritis, the Foot Function Index (FFI-D), the Olerud-Molander Score (OMAS), and the Short Form-12 questionnaire (SF-12) were collected in this monocentric study. The mean follow-up time was 5.8 years. End-stage osteoarthritis was mostly due to ankle fractures as a result of sprains, falls, and road traffic accidents.ResultsPost-operatively, the mean FFI-D for pain was 17.3 (MAA: 14.7; FAA 22.2) and 43.9 for function (MAA: 41.1; FAA 49.5); the mean OMAS was 58.2; and the mean SF-12 physical component score was 42.5. Women achieved significantly worse results in all scores; only the mental component summary of the SF-12 did not differ between the sexes (p > 0.05). Approximately 34% of women stated that the result in terms of gait pattern was worse than expected (MAA 16.1%; p < 0.05). Again, significantly more men stated that the result was better than expected (MAA: 48.3%; FAA: 31.5%, p < 0.05).ConclusionsThe fact that the clinical results were significantly worse in women after ankle arthrodesis should be considered when determining the indication. However, the expectations of men and women also need to be individually adjusted.

Increased Activity Level Following Total Ankle Replacement Results in Improved Patient Reported Outcomes

While evidence highlights increased activity levels following total ankle replacement (TAR), the correlation between postoperative activity changes and ankle-surgery-specific patient-reported outcomes is unexplored. This retrospective cohort study investigates the effect of activity level changes on patient-reported outcomes, including the Manchester-Oxford Foot Questionnaire (MOXFQ) and patient satisfaction following TAR. Patient records from a single center performing TARs between January 2014 and February 2023 were reviewed alongside patient questionnaires completed preoperatively and at a mean follow-up of 44±31 months postoperatively (range 6-134 months). Activity participation pre- and postoperatively was assessed and correlated with MOXFQ scores. Data from 89 patients was available for analysis (mean age 72.3±8.9 years [range, 48-92]). Postoperatively, 31 patients (35%) increased, 42 (47%) maintained, and 16 (18%) decreased their activity levels. The mean time to return to regular activity was 23.4 weeks. Preoperative MOXFQ scores were similar across all groups (increased: 74.03±14.00; maintained: 73.6±13.9; decreased: 77.0±15.5; p=0.71). All groups showed significant improvements in MOXFQ scores from preoperative to postoperative assessments (p<0.05). Patients with increased activity levels showed greater MOXFQ improvements (-61.6±19.0) compared to those with decreased activity levels (-38.3±26.6) (p<0.01). Following TAR, 82% of patients maintained or increased their activity levels. Patients with increased postoperative activity exhibited superior improvements in MOXFQ scores. These findings underscore the importance of promoting physical activity for optimal outcomes following TAR. Level of Clinical EvidenceLevel 3, retrospective cohort study.

Total ankle arthroplasty in valgus ankle osteoarthritis

The valgus total ankle replacement (TAR) presents a considerable challenge and tests the skill and ingenuity of even the most accomplished foot and ankle surgeon. Coronal plane deformity used to be considered a relative contra-indication for TAR, however with implant innovation and greater surgical understanding, the indications for TAR in deformity continue to expand. Success requires a bespoke approach to each patient to ensure that intra- and extraarticular deformities and imbalance are adequately addressed to avoid TAR failure. The overall goal in TAR surgery is achieving a well aligned and stable ankle with a well aligned and stable foot below. This article presents some of our strategies to achieve this when considering TAR in the valgus ankle.10.1016/j.fuspru.2024.08.002

Design of functionally graded porous lattice structure tibial implant for TAR

Use of porous lattice structures and functionally graded (FG) implants in orthopaedic applications has emerged as a promising solution to reduce stress shielding. However, there is a notable research gap in examining the effects of post-operative scenarios within the lattice pores and different porosity distribution laws in functionally graded porous lattice structure (FGPLS) implants on the biomechanical performance of tibial implant for total ankle replacement (TAR). The objective of the study is to investigates the effects of both post-operative tissues and various porosity distribution laws on the biomechanical performance of tibial implant for TAR and proposes a new design strategy. CAD models for lattice structures at various porosities were developed to incorporate the effects of post-operative tissues such as fibrous tissue, cartilage, immature bone, and mature bone. The pore spaces of these lattice structures were assumed to be filled with the post-operative ingrowth tissues. The lattice structure and these tissues together form the Representative volume element (RVE), whose effective properties were calculated using Asymptotic homogenization (AH) technique. Equations linking mechanical properties and porosity were established and used to assign mechanical properties to macro-FE models of FGPLS tibial implants based on three different power laws i.e. n = 0.1,1 and 5. Macro-FE models for intact and implanted tibia bones were developed using homogeneous properties of cortical bone and heterogeneous cancellous bone properties. The proximal part of the tibia was fixed, and a compressive load was applied through the anterior nodes of the meniscal bearing to represent dorsiflexion loading during normal walking. The Finite Element Analysis (FEA) was utilized to investigate the biomechanical performance of these implanted models in terms of stress distribution in the tibia bone and implant-bone micromotion. A comparison was made between models with solid metallic implants and those with FGPLS implants. Additionally, models with varying post-operative tissues in the pore space were compared, as well as models with different porosity variation laws were also compared. Results demonstrated that models implanted with FGPLS implants having porosity variation based on power law n = 0.1 showed increased bone stress and micromotion compared to those with solid metallic implants. Specifically, in models with FGPLS implants with porosity variation based on a power law of n = 0.1, the bone area with stress ranging from 2–5 MPa increased significantly in the periprosthetic region compared to models with solid metallic implants. The bone stress value for the majority of the region above the medial and lateral peg increased from 1–2 MPa to 2–5 MPa. Although there was a slight increase in micromotion values, they remained below the acceptable threshold of 50 µm. Models with porosity variations based on power laws n = 1 and n = 5 exhibited similar bone stress and micromotion results as solid metallic implants. Additionally, no significant difference in bone stresses was observed for different stages of bone ingrowth at pore space. These findings indicate that both the porous structure and porosity distribution within the implant significantly influence the biomechanical performance of tibial implants for TAR. So, it can be concluded that FGPLS implants with power law n = 0.1 are effective in reducing stress shielding and supporting the long-term survival of TAR by increasing bone stress and reducing the chances of aseptic loosening due to implant induced adaptive bone remodelling.

Preoperative planning of total ankle prosthesis – What are we aiming at?

IntroductionAnkle osteoarthritis poses significant challenges, affecting patients’ quality of life and often necessitating surgical intervention. Total ankle replacement (TAR) has emerged as an effective treatment, in patients with post-traumatic arthritis. Precise preoperative planning is crucial for achieving optimal outcomes in TAR procedures. This article explores the use of advanced imaging techniques, virtual modeling, and surgical strategies in preoperative planning for TAR. MethodsThe preoperative planning process involves thorough patient assessment, including clinical examination and imaging studies such as Weight Bearing CT scans (WBCT) and MRI. Classification systems like the Canadian Orthopedic Foot & Ankle Society (COFAS) classification help guide treatment decisions and staging of procedures. Virtual foot/ankle models derived from WBCT scans enable accurate assessment of deformities and facilitate precise implant positioning. DiscussionOptimal TAR outcomes rely on restoring normal ankle anatomy and function while addressing associated deformities and pathology. Precise alignment, joint congruency, and rotational positioning of implant components are Important considerations. Virtual planning allows for simulation of implant placement and axis correction, aiding surgical decision-making and predicting outcomes. However, it has limitations in predicting soft tissue effects and final implant size. ConclusionPreoperative planning plays a important role in TAR procedures, understanding optimal implant placement. Advanced imaging modalities, classification systems, and virtual modeling techniques enhance surgical precision. Continued refinement of preoperative planning strategies is essential for further advancing TAR outcomes and patient satisfaction.10.1016/j.fuspru.2024.07.001

Deep learning-based automated angle measurement for flatfoot diagnosis in weight-bearing lateral radiographs

This study aimed to develop and evaluate a deep learning-based system for the automatic measurement of angles (specifically, Meary’s angle and calcaneal pitch) in weight-bearing lateral radiographs of the foot for flatfoot diagnosis. We utilized 3960 lateral radiographs, either from the left or right foot, sourced from a pool of 4000 patients to construct and evaluate a deep learning-based model. These radiographs were captured between June and November 2021, and patients who had undergone total ankle replacement surgery or ankle arthrodesis surgery were excluded. Various methods, including correlation analysis, Bland–Altman plots, and paired T-tests, were employed to assess the concordance between the angles automatically measured using the system and those assessed by clinical experts. The evaluation dataset comprised 150 weight-bearing radiographs from 150 patients. In all test cases, the angles automatically computed using the deep learning-based system were in good agreement with the reference standards (Meary’s angle: Pearson correlation coefficient (PCC) = 0.964, intraclass correlation coefficient (ICC) = 0.963, concordance correlation coefficient (CCC) = 0.963, p-value = 0.632, mean absolute error (MAE) = 1.59°; calcaneal pitch: PCC = 0.988, ICC = 0.987, CCC = 0.987, p-value = 0.055, MAE = 0.63°). The average time required for angle measurement using only the CPU to execute the deep learning-based system was 11 ± 1 s. The deep learning-based automatic angle measurement system, a tool for diagnosing flatfoot, demonstrated comparable accuracy and reliability with the results obtained by medical professionals for patients without internal fixation devices.

Age Influence on Total Ankle Arthroplasty Outcomes: A Systematic Review

Total ankle arthroplasty has gained popularity as advancing technology has resulted in higher survivorship and lower complication rates. In the past, total ankle replacement candidates have been reserved for patients greater than 50 years old with low physical demands and minimal deformity. However, with newer designs, surgeons have begun to expand their patient inclusion criteria. The purpose of this study was to analyze current literature comparing patient outcomes among total ankle replacement patients over and under age 50. A systematic review of the literature was performed comparing the impact of age to total ankle replacement outcomes. 159 articles were reviewed. Seven studies met our inclusion criteria and therefore were included in the synthesis. No statistically significant difference in outcomes was determined for the younger and older age groups in regard to reoperation, complications, and implant survivorship (p = .412, .955, .155, respectively). However, the statistical model is underpowered given the limited number of studies. While the findings of this study infer that total ankle replacement outcomes are not significantly different among older and younger age groups, further research in this area is needed.

Effect of Preoperative Coronal Plane Alignment on Actual Versus Predicted Alignment Using Patient Specific Instrumentation in Total Ankle Replacement

Alignment in total ankle replacement is important for success and implant survival. Recently there has been the introduction and adoption of patient specific instrumentation for implantation in total ankle replacement. Current literature does not evaluate the effect of preoperative deformity on accuracy of patient specific instrumentation. A retrospective radiographic analysis was performed on 97 consecutive patients receiving total ankle replacement with patient specific instrumentation to assess the accuracy and reproducibility of the instrumentation. Subgroup analysis evaluated the effect of preoperative deformity. All surgeries were performed by fellowship trained foot and ankle surgeons without industry ties to the implants used. Preoperative and postoperative films were compared to plans based on computerized tomography scans to assess how closely the plan would be implemented in patients. Overall postoperative coronal plane alignment was within 2° of predicted in 87.6% (85 patients). Similarly, overall postoperative sagittal plane alignment was within 2° of predicted in 88.7% (86 patients). Tibial implant size was accurately predicted in 81.4% (79 patients), and talus implant size was correct in 75.3% (73 patients). Patients with preoperative varus deformity had a higher difference between predicted and actual postoperative alignment compared to valgus deformity (1.1° compared to 0.3°, p=0.02). A higher average procedure time was found in varus patients, and more adjunctive procedures were needed in patients with varus or valgus deformity, but these were not significant, p>0.5. Surgeons can expect a high degree of accuracy when using patient specific instrumentation overall, but less accurate in varus deformity.

An evaluation of the total ankle replacement in the modern era: a narrative review.

Total ankle replacement has become an increasingly popular surgical procedure for treatment of end-stage ankle arthritis. Though ankle arthrodesis has historically been considered the gold standard treatment, advancements in implant design, functional outcomes, and survivorship have made total ankle replacement a compelling alternative. Particularly, in the past 20 years, total ankle replacement has undergone tremendous innovation, and the field of research in this procedure continues to grow. In this review, we aim to summarize the history, evolution, advancements, and future directions of total ankle replacement as described through implant design, indications, surgical procedures, complications, and outcomes. Literature searches were conducted in PubMed to identify relevant articles published prior to March 2023 using the following keywords: "total ankle replacement", "total ankle arthroplasty", and "total ankle". Total ankle replacement has demonstrated significant improvements in surgical technique, implant design, survivorship, and clinical and functional outcomes in the modern era. The procedure reports high patient satisfaction, low complication rates, and improved functional abilities that challenge the current gold standard treatment for ankle arthritis. Though there are areas of improvement for total ankle replacement, the procedure demonstrates promising outcomes for patients with end-stage ankle arthritis to improve pain and functional abilities. Research studies continue to explore various the facets of total ankle replacement, including outcomes, risk factors, novel techniques and modalities, and complications, to direct future innovation and to optimize patient results.

What is the Total Ankle Arthroplasty Experience of Podiatric Foot and Ankle Surgery Fellows? A National Survey

In 2011, the Council of Podiatric Medical Education, the accrediting body of the American Podiatric Medical Association, approved the conversion of all Podiatric Residencies to 3-year surgical programs. In 2012, there were 12 podiatric fellowships recognized by the American College of Foot and Ankle Surgeons. To date, there are 53 programs listed under the college's website. As podiatric fellowships expand further research is needed to identify advantages and difficulties of fellowship training. One of the most salient topics is Total Ankle Replacement. Our primary aim was to obtain current fellow survey data to formulate improved outcomes of Total Ankle Arthroplasty and enhance our understanding of podiatric reconstructive foot and ankle surgery fellowship training programs. Invitation was administered by email and 73.6% of active reconstructive 2023-24 American College of Foot and Ankle Surgeons post-graduate fellows responded. Fellowship total ankle replacement case volume was significantly greater than residency (p = 0.037). Completion of 0-5 total ankle replacement(s) was 30.8%, and greater than 30 in 17.9% of fellows. Fifty nine percent reported feeling “comfortable” or “very comfortable” with total ankle arthroplasty. Patient specific instrumentation was used in a majority of cases by 66.7% of programs. Over three fourths (79.8%) of fellows stated they planned on performing TAR as an attending surgeon after their fellowship. Despite its limitations, we hope our survey data can aid graduating and previous fellows and add to the body of knowledge for future TAR educational programs and industry involvement. As podiatric fellowships continue to transform, so too must our research efforts to track progress.

Outcomes of cobalt-chrome 3D-printed total talus replacement with and without combined total ankle replacement

BackgroundCollapse of the talus and peri-talar arthritis pose treatment challenges due to the anatomy and location of the talus as a keystone of the foot and ankle. Custom 3D-printed total talus replacement (TTR) and combined total ankle total talus replacement (TATTR) have emerged as treatment options for these pathologies. However, the safety and efficacy of these implants is unknown due to the limited number of cases and short follow-up durations. MethodsThis was a retrospective study to assess surgical outcomes of patients who underwent a TTR and TATTR with or without subtalar fusion. Patient demographics, intraoperative parameters, device related surgical and non-surgical events, imaging and clinical evaluations, and patient reported outcome (PRO) measures were compiled. ResultsA total of 38 patients received a custom 3D-printed implant with mean follow-up time of 22.1 (range: 12–45) months. In this cohort, 7 (18.4 %) required secondary surgery and 3 (7.9 %) required implant removal. Multivariate logistic regression revealed that patient diagnosis of depression was a significant predictor of secondary surgery with an OR 17.50 (p = 0.037). Significant postoperative improvements were observed in the talocalcaneal height (p = 0.005) and talar declination angle (p = 0.013) for the TATTR group. VAS and PROMIS pain interference (PI) scores demonstrated an initial significant improvement in pain, but this improvement did not maintain significance at most recent follow-up. However, there was a significant increase in the PROMIS physical function (PF) scores (p = 0.037) at most recent follow-up. ConclusionThese results demonstrate that TTR and TATTR provide significant improvement in post-operative radiographic foot and ankle alignment and physical function at the two-year timepoint. PRO findings suggest that patients are more active after surgery. Surgeons considering proceeding with either of these procedures should counsel patients about pain and functional outcomes as well as realistic expectations in patients with depression. Level of evidenceLevel 3

Reconstruction of unstable ankle charcot deformity using a 3-D printed titanium porous block and hindfoot nail – A case report

Charcot neuroarthropathy (CN) of the ankle joint can cause marked bone resorption of the talus resulting in severe deformity and instability. The utilisation of a 3-D printed bespoke titanium porous block that allows the use of an intramedullary calcaneo-tibial nail is an attractive option in such cases that has been reported for use in post-trauma deformities, following tumour resections, in avascular necrosis of talus and for revision of failed total ankle replacements, however has not previously been reported for Charcot ankle reconstructions. We present a novel case and surgical technique illustrating the use of a 3-D printed titanium porous block and hindfoot nail for reconstruction of a deformed and unstable Charcot hindfoot.

Additional Procedures at the Time of Total Ankle Replacement Do Not Increase Risk of Short-term Complications: A Matched Cohort Analysis.

This retrospective cohort study compared short-term complication rates following total ankle arthroplasty (TAA), alone or with concomitant procedures. Secondary independent risk factors were also examined as they related to postoperative outcomes. The American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) database was queried using Current Procedural Terminology (CPT) codes to identify patients who underwent TAA (27702) between 2010 to 2021. Patients were divided into cohorts based on the presence or absence of ancillary procedures. Propensity score matching was employed to account for demographic differences, and statistical analyses were performed to compare short-term complication rates between matched cohorts. A total of 2225 patients were identified, with 1432 (64.4%) receiving TAA alone and 793 (35.6%) with ancillary procedure(s). After matching, 793 patients were included in each cohort. The ancillary cohort had longer operative times (P < .001) and length of hospital stay (LOS) (P < 0.001). Rates for extended LOS were significantly higher in the ancillary cohort than in the simple cohort (P = .01). No other complications varied significantly between cohorts, including the incidence of any adverse event (AAE). American Society of Anesthesiologists classification of 4 was found to be an independent risk factor for development of AAE (odds ratio [OR] = 1.091, P = .04). Matched subgroup analysis excluding tendon lengthening as a concomitant procedure found that the ancillary cohort still had longer operative time (P < .001) and LOS (P < .05) than patients undergoing simple TAA. Without significant difference in rates of AAE other than extended LOS, the relative safety of ancillary TAA appears similar to that of TAA alone. Such knowledge can help inform surgical decision-making and assuage safety concerns for patients requiring additional corrective procedures at the time of TAA. Level III, retrospective comparative study.

Outcome after total ankle replacement or ankle arthrodesis in end-stage ankle osteoarthritis on the basis of german-wide data: a retrospective comparative study over 10 years

BackgroundIn symptomatic end-stage osteoarthritis of the ankle joint, total ankle replacement and ankle arthrodesis are the two primary surgical options for patients for whom conservative treatment fails. Published revision rates are often biased and difficult to compare. In this study, unplanned reoperation rates and revision rates were determined for both surgical interventions based on a large dataset, and risk factors for unplanned reoperations were identified.MethodsGerman-wide health data of the largest German health-care insurance carrier between 2001 and 2012 were retrospectively analyzed, and unplanned reoperation rates within 10 years were determined for index surgeries conducted in 2001 and 2002. Unplanned reoperation rates within 5 years for index surgeries conducted in 2001/2002 were compared to index surgeries conducted in 2006/2007. Multivariate logistic regression was used to identify risk factors for unplanned reoperations.ResultsAfter ankle arthrodesis, 19% (95% confidence interval [CI], 16–22%) of 741 patients needed to undergo an unplanned reoperation within ten years. After total ankle replacement, the unplanned reoperation rate was 38% [95% CI, 29–48%] among 172 patients. For initial surgeries conducted at a later date, unplanned reoperation rates within five years were 21% [95% CI, 19–24%] for 1,168 ankle arthrodesis patients and 23% [95% CI, 19–28%] for 561 total ankle replacement patients. Significant risk factors for unplanned reoperations after ankle arthrodesis in the initial cohort were age < 50 years (odds ratio [OR] = 4.65 [95% CI 1.10;19.56]) and osteoporosis (OR = 3.72 [95% CI, 1.06;13.11]); after total ankle replacement, they were osteoporosis (OR = 2.96 [95% CI, 1.65;5.31]), Patient Clinical Complexity Level (PCCL) grade 3 (OR = 2.19 [95% CI, 1.19;4.03]), PCCL grade 4 (OR = 2.51 [95% CI, 1.22;5.17]) and diabetes mellitus (OR = 2.48 [95% CI, 1.33;4.66]). Kaplan-Meier analyses including 1,525 ankle arthrodesis patients and 644 total ankle replacement patients revealed an average unplanned reoperation-free time of approximately 17 years for both procedures.ConclusionsSimilar revision rates and unplanned reoperation rates for both procedures in the later-date cohort can likely be attributed to a learning curve for surgeons as well as advances in implant design. This analysis of billing health insurance data supports an increase in total ankle replacement surgeries.

Postoperative Medial Malleolar Fractures in Total Ankle Replacement Are Associated With Decreased Medial Malleolar Width and Varus Malalignment: A Case-Control Study.

There are limited data regarding risk factors associated with periprosthetic medial malleolar fractures in total ankle arthroplasty (TAA). This case-control study aimed to identify the risk factors and analyze the effect of prophylactic screw fixation in preventing a medial malleolar fracture after TAA. A case-control study was conducted on 149 patients who underwent primary TAA. Twenty patients with postoperative medial malleolar fractures >4 weeks postoperatively (cases) were identified. An additional 129 patients (controls) were randomly selected from the TAA database. Radiographic evaluation included tibial component coronal alignment and postoperative medial malleolar width. Demographics and radiographic variables were compared between cohorts. Logistic regression was used to investigate the association between medial malleolar fracture and postoperative coronal alignment, medial malleolar width, and prophylactic fixation of the medial malleolus. Mean (SD) medial malleolar width was significantly smaller in the fracture cohort (8.52 mm [1.6]) than in the control group (11.78 mm [1.74]) (P < .001). Mean (SD) tibial component coronal alignment was 92.17 degrees (2.77) in the fracture cohort and 90.21 degrees (1.66) in the control group (P = .002). Regression analysis identified a significant negative association between postoperative medial malleolar width and the probability of fracture (OR = 0.06, 95% CI 0.01, 0.26, P < .001). Varus malalignment of the tibial component was positively associated with the probability of fracture (OR = 1.90, 95% CI 1.27, 2.86, P = .002). Prophylactic screw fixation resulted in more than 90% reduction in the odds of a fracture (OR = 0.04, 95% CI 0.01, 0.45, P = .01). ROC curve analysis determined a medial malleolar width of 10.3 mm as a potential threshold for predicting fracture. Decreased medial malleolar width and postoperative varus malalignment were associated with an increased risk of postoperative medial malleolar fracture. Therefore, surgeons should consider prophylactic screw fixation in patients with a medial malleolar width <10.3 mm or at risk of postoperative varus deformity.

ARE TOTAL ANKLE ARTHROPLASTIES MORE PROTECTIVE OF THE HINDFOOT JOINTS THAN ANKLE ARTHRODESIS? A 13-YEAR AVERAGE RETROSPECTIVE REVIEW OF 516 CASES

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 degredation1. 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 fusion2. 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.

WHAT HAPPENS AFTER FAILED TOTAL ANKLE ARTHROPLASTY?

AimsRetrospective 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.MethodsAll 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.Results156 (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.Conclusions13.4% 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).