Primary Total Ankle Research Articles

Impact of Body Mass Index on Complication Rates Following Primary Total Ankle Arthroplasty

Category: Ankle; Ankle Arthritis Introduction/Purpose: Recent literature has indicated higher body mass index (BMI) to be of concern for poorer outcomes following total ankle arthroplasty. The purpose of this study is to evaluate the impact of implementing BMI cutoff points on 6-month postoperative outcomes following total ankle arthroplasty (TAA). Methods: The Nationwide Readmissions Database (NRD) was queried from 2015-2020 to identify 5,865 patients undergoing primary elective TAA with a reported BMI range via ICD-10 diagnosis. Our cohort consisted of patients with BMI ≥30 kg/m2, stratified into groups by 5 BMI point intervals. Preoperative demographics, comorbidities, postoperative outcomes, and total length of stay (LOS) were analyzed between cohorts. Multivariate regression analyses were conducted to control for predictors of adverse postoperative outcomes other than BMI. Results: When stratifying by preoperative BMI, higher BMI was associated with significantly lower age (p <.001) and rate of smoking (p <.001), and higher rate of female sex (p <.001), Medicaid insurance (p <.001), higher CCI score (p <.001), among other comorbidities. Multivariate regression analysis of 180-day postoperative outcomes, controlling for demographic and comorbidity differences, found that preoperative BMI 40-44.9 and ≥45 kg/m2 was significantly predictive of increased risk of any complication (44-44.9: OR=1.843; p<.001)(45+: OR=1.960; p<.001), adverse discharge (44-44.9: OR=1.217 p=.015)(45+: OR=2.030; p<.001), and extended stay greater than 4 days (44-44.9: OR=1.653; p<.001)(45+: OR=2.171; p<.001), with BMI ≥45 kg/m2 also being significantly predictive of 65% increased risk of readmission (OR=1.655; p=.004). Conclusion: Higher BMI in TAA is associated with an increased risk of any postoperative complication, adverse discharge, and extended LOS. Specifically, a BMI cutoff of 40kg/m2 would serve to prevent 38.6% of the 963 obese patients experiencing complications following TAA. While our results suggest that implementing a strict BMI cutoff would serve to reduce complications substantially, it will also prevent a large number of patients from undergoing a complication-free surgery that will ultimately serve to reduce pain and increase function. Instead, we suggest physicians consider a BMI cutoff in concert with other comorbidity factors that may affect surgical outcomes following TAA.

Association of Radiographic Soft Tissue Thickness with Revision Total Ankle Arthroplasty Following Primary Total Ankle Arthroplasty: A Minimum of 5-year Follow-up

Category: Ankle; Ankle Arthritis Introduction/Purpose: The incidence of primary total ankle arthroplasty (TAA) is rising, with a corresponding increase in revision surgeries. Despite this, research on risk factors for revision TAA following primary TAA remains limited. Radiographic soft-tissue thickness has been explored as a potential predictor for outcomes in hip, knee, and shoulder arthroplasty, but its role in TAA has not been assessed. This study aimed to assess the predictive value of radiographic soft tissue thickness for identifying patients at risk of requiring revision surgery following primary TAA. Methods: A retrospective study was conducted on 323 patients who underwent primary TAA between 2003 and 2019. Radiographic measurements of soft tissue thickness were obtained from preoperative lateral weightbearing radiographs. Clinical variables including age, gender, body mass index (BMI), American Society of Anesthesiologists (ASA) classification, diabetes, smoking status, primary diagnosis, and implant type were recorded. Logistic regression analysis was used to assess the predictive value of soft tissue thickness and BMI for revision TAA. Results: The rate of revision surgery was 4.3% (14 out of 323 patients). Patients requiring revision had significantly greater tibial-tissue (3.54 vs. 2.48 cm; p=0.02) and talus-tissue (2.79 vs. 2.42 cm; p=0.02) thickness compared to those who did not require revision. Both the Tibial-Tissue thickness (Odds Ratio: 1.16 [1.12-1.20]; p < 0.01) and the Talus-Tissue thickness (Odds Ratio: 1.10 [1.05-1.15]; p < 0.01) measurements were significant predictors of revision TAA in multivariable logistic regression models. In contrast, BMI was not a significant predictor of revision TAA. The two metrics demonstrated excellent interrater reliability. Conclusion: Greater soft tissue thickness, as measured radiographically, was a better predictor of revision TAA compared to BMI. These findings suggest that radiographic soft tissue thickness may be a valuable tool for assessing the risk of the need for revision TAA following primary TAA. Further research is needed to validate these findings and explore the potential impact on clinical practice. Figure 1. Radiographical Assessment of Tissue Thickness The figure illustrates the method for obtaining the radiographic measurements on weightbearing lateral radiographs. (A) A line was drawn from the posterior distal tibia to the anterior distal tibia (Red Line), and the distance of the parallel segment extending from the anterior cortex of the tibia to the end of the soft tissue shadow was measured to determine the Tibial-Tissue thickness. A line was drawn from the lateral process of the talus to the head/neck junction of the talus (Yellow Line), and the distance of the parallel segment, extending from the head/neck junction of the talus to the end of the soft tissue shadow, was measured to determine the Talus-Tissue thickness.

A COMPARISON OF FUNCTIONAL OUTCOME SCORES FOR PRIMARY AND REVISION ANKLE ARTHROPLASTIES

BackgroundPatients 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.MethodsA 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.ResultsA 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.ConclusionBoth 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.

MANAGEMENT OF FAILED TOTAL ANKLE ARTHROPLASTY AND MASSIVE BONE CYSTS USING IMPACTION BONE GRAFTING AND THE INVISION TOTAL ANKLE REVISION SYSTEM

ObjectiveThe 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.MethodsA 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.ResultsThe 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.ConclusionsIn 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.

Association of Radiographic Soft Tissue Thickness With Revision Total Ankle Arthroplasty Following Primary Total Ankle Arthroplasty: A Minimum of 5-year Follow-up.

The incidence of primary total ankle arthroplasty (TAA) is rising, with a corresponding increase in revision surgeries. Despite this, research on risk factors for revision TAA following primary TAA remains limited. Radiographic soft tissue thickness has been explored as a potential predictor for outcomes in hip, knee, and shoulder arthroplasty, but its role in TAA has not been assessed. This study aimed to assess the predictive value of radiographic soft tissue thickness for identifying patients at risk of requiring revision surgery following primary TAA. A retrospective study was conducted on 323 patients who underwent primary TAA between 2003 and 2019. Radiographic measurements of soft tissue thickness were obtained from preoperative radiographs. Two novel radiographic measures of soft tissue thickness were developed and assessed (tibial tissue thickness and talus tissue thickness). Clinical variables including age, gender, body mass index (BMI), American Society of Anesthesiologists (ASA) classification, diabetes, smoking status, primary diagnosis, and implant type were recorded. Logistic regression analysis was used to assess the predictive value of soft tissue thickness and BMI for revision TAA. The rate of revision surgery was 4.3% (14 of 323 patients). Patients requiring revision had significantly greater tibial tissue (3.54 vs 2.48 cm; P = .02) and talus tissue (2.79 vs 2.42 cm; P = .02) thickness compared with those not requiring revision. Both the tibial tissue thickness (odds ratio 1.16 [1.12-1.20]; P < .01) and the talus tissue thickness (odds ratio: 1.10 [1.05-1.15]; P < .01) measurements were significant predictors of revision TAA in multivariable logistic regression models. However, BMI was not a significant predictor of revision TAA. The two metrics demonstrated excellent interrater reliability. Greater soft tissue thickness was a better predictor of revision TAA compared with BMI. These findings suggest that radiographic soft tissue thickness may be a valuable tool for assessing the risk of the need for revision TAA following primary TAA. Further research is needed to validate and explore the potential impact on clinical practice. Level III, comparative study.

Does Timing of Subtalar Arthrodesis Affect Reoperation or Revision Rates for Total Ankle Arthroplasty?

Introduction/Purpose: The incidence of primary total ankle arthroplasty (TAA) in the treatment of end-stage ankle arthritis has increased substantially over the last decade. TAA may be performed alone or in conjunction with additional procedures including subtalar (ST) or triple arthrodesis as end-stage ankle arthritis is often associated with degenerative disease affecting neighboring joints. Prior literature has demonstrated that the ipsilateral hindfoot arthrodesis may increase the risk for revision after TAA and that simultaneous ST arthrodesis with TAA could result in significant short term clinical and radiologic improvements. However, there is limited research comparing staged versus simultaneous hindfoot arthrodesis with concomitant TAA. The purpose of this study is to compare the reoperation rates after TAA with simultaneous hindfoot arthrodesis versus staged hindfoot arthrodesis followed by TAA. Methods: Patients who underwent primary TAA from 2015-2022 were identified in the PearlDiver database using international classification of diseases (ICD) and current procedural (CPT) codes. Patients were only selected if they contained 1-year database follow-up after the index TAA. Patients were sorted into three cohorts: (1) primary TAA without any history of hindfoot arthrodesis (control), (2) those with staged hindfoot arthrodesis prior to TAA, and (3) those with hindfoot arthrodesis at the same time as TAA. Demographic characteristics including age, gender, and Charlson Comorbidity Index (CCI) were assessed for each cohort. The 1-year rate of reoperation and revision were the primary outcomes of this study. Univariate analysis using chi- square tests and student T-tests were performed to analyze any differences in patient demographics, comorbidities, and complications. Multivariate analysis using logistic regression was subsequently conducted to account for any confounding variables and covariates. Results: 9,912 patients underwent TAA without prior hindfoot arthrodesis, 297 patients underwent TAA with prior hindfoot arthrodesis and 174 with hindfoot arthrodesis concurrently with TAA. The incidences of reoperation (OR 3.52, 12.6% vs. 3.9%, P&lt;0.001) and revision (OR 3.66, 4.0% vs. 1.1%, P=0.001) were higher in the simultaneous cohort when compared to the control. However, there were no statistically significant differences in rates of reoperation (OR 0.96, 4.0% vs. 3.9%, P= 0.891) or revision (OR 1.94, 2.4% vs. 1.1 %, P= 0.095) when comparing staged hindfoot arthrodesis to the control. Conclusion: Patients undergoing concurrent hindfoot arthrodesis with TAA had a 3.5 times higher odds of reoperation and revision when compared to the control. Patients undergoing staged procedures did not demonstrate a difference in revision or reoperation rates when compared to the control. Staged hindfoot arthrodesis and TAA may be an effective option in treating complex end-stage ankle and hindfoot arthritis whereas a simultaneous approach may lead to higher rates of complications.

Survival and risk assessment in revision arthroplasty of the ankle.

Implant failure has become more common as the number of primary total ankle arthroplasties (TAAs) performed has increased. Although revision arthroplasty has gained attention for functional preservation, the long-term results remain unclear. This study aimed to assess the long-term outcomes of revision TAA using a mobile-bearing prosthesis in a considerably large cohort; the risk factors for failure were also determined. This single-centre retrospective cohort study included 116 patients (117 ankles) who underwent revision TAA for failed primary TAA between July 2000 and March 2010. Survival analysis and risk factor assessment were performed, and clinical performance and patient satisfaction were evaluated preoperatively and at last follow-up. The mean duration from initial revision TAA to last follow-up was 15.0 years (SD 3.0; 11.2 to 20.5). The cumulative survival rates of the revised ankles were 81% (95% confidence interval (CI) 74% to 88%), 74% (65% to 82%), and 70% (61% to 79%) at five, ten, and 15 years, respectively. Comorbidities prior to primary TAA, aseptic loosening, instability, or grafting of cysts were found to be the most common risk factors for secondary revision. The median value for preoperative pain, as assessed using the visual analogue scale, declined from 6 (interquartile range (IQR) 5 to 8) to 2 (IQR 0 to 5) (p < 0.001) and the mean American Orthopaedic Foot and Ankle Society ankle-hindfoot score improved from 43 (SD 17) preoperatively to 70 (SD 20) (p < 0.001) at last follow-up. Revision TAA offers acceptable survival rates after 15 years; it therefore offers a valuable option for treatment of implant failure in carefully selected cases. Although patient-reported outcomes improve substantially, the degree of improvement reported following primary TAA is not achieved.

Nationally Representative Trends in Incidence of Procedures Done Concomitantly With Primary and Revision Total Ankle From 2012 to 2020

Background As new literature emerges and practice patterns fluctuate, there is a significant potential for variation with regard to adjunctive procedures performed with primary total ankle arthroplasty (pTAA) and revision total ankle arthroplasty (rTAA). Our study aims to evaluate yearly trends in the incidence of concomitant procedures and compare the incidence of adjunctive procedures between pTAA and rTAA. Methods The 2012-2020 American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was queried for all pTAA and rTAA. The number of concurrent procedures was compared between pTAA and rTAA and compared across years available in the most current version of the NSQIP database (2012-2020). Results Patients undergoing pTAA had a higher mean age than patients undergoing rTAA (64 vs 61 years; P &lt; .001), and patients undergoing rTAA had higher wound class (P &lt; .001), indicating higher levels of contamination. Concurrent procedures were performed significantly less frequently with pTAA than rTAA (mean procedures 0.82 vs 1.30; P &lt; .001). Removal of deep implants was more commonly coded with rTAA than pTAA (9.0% vs 17.7%; P &lt; .001). Gastrocnemius recession was more frequently performed with pTAA than rTAA (10.4% vs 3.0%; P = .001). Conclusion As pTAA and rTAA increase in incidence throughout the United States, there is increased importance on furthering our understanding of these procedures. This study provides a nationally representative analysis of adjunctive procedures with pTAA and rTAA from 2012 to 2020. Generally, more adjunctive procedures are performed with rTAA versus pTAA, confirming the high complexity of rTAA. Levels of Evidence: Level III

Younger Patients Undergoing Total Ankle Arthroplasty Experience Higher Complication Rates and Worse Functional Outcomes.

Although many patients with posttraumatic ankle arthritis are of a younger age, studies evaluating the impact of age on outcomes of primary total ankle arthroplasty (TAA) have revealed heterogenous results. The purpose of the present study was to determine the effect of age on complication rates and patient-reported outcomes after TAA. We retrospectively reviewed the records of 1,115 patients who had undergone primary TAA. The patients were divided into 3 age cohorts: <55 years (n = 196), 55 to 70 years (n = 657), and >70 years (n = 262). Demographic characteristics, intraoperative variables, postoperative complications, and patient-reported outcome measures were compared among groups with use of univariable analyses. Competing-risk regression analysis with adjustment for patient and implant characteristics was performed to assess the risk of implant failure by age group. The mean duration of follow-up was 5.6 years. Compared with the patients who were 55 to 70 years of age and >70 years of age, those who were <55 years of age had the highest rates of any reoperation (19.9%, 11.7%, and 6.5% for the <55, 55 to 70, and >70-year age groups, respectively; p < 0.001), implant failure (5.6%, 2.9%, and 1.1% for the <55, 55 to 70, and >70-year age groups, respectively; p = 0.019), and polyethylene exchange (7.7%, 4.3%, and 2.3% for the <55, 55 to 70, and >70-year age groups, respectively; p = 0.021). Competing-risk regression revealed a decreased risk of implant failure for patients who were >70 of age compared with those who were <55 years of age (hazard ratio [HR], 0.21 [95% confidence interval (CI), 0.05 to 0.80]; p = 0.023) and for patients who were 55 to 70 years of age compared with those who were <55 years of age (HR, 0.35 [95% CI, 0.16 to 0.77]; p = 0.009). For all subscales of the Foot and Ankle Outcome Score (FAOS) measure except activities of daily living, patients who were <55 years of age reported the lowest (worst) mean preoperative and postoperative scores compared with those who were 55 to 70 years of age and >70 years of age (p ≤ 0.001). Patients who were <55 years of age had the highest mean numerical pain score at the time of the latest follow-up (23.6, 14.4, 12.9 for the <55, 55 to 70, and >70-year age groups, respectively; p < 0.001). Studies involving large sample sizes with intermediate to long-term follow-up are critical to reveal age-related impacts on outcomes after TAA. In the present study, which we believe to be the largest single-institution series to date evaluating the effect of age on outcomes after TAA, younger patients had higher rates of complications and implant failure and fared worse on patient-reported outcome measures. Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

A Systematic Review of Outcomes of Total Ankle Arthroplasty with INBONE II

Category: Ankle Arthritis; Ankle Introduction/Purpose: The INBONE II is a fixed-bearing implant with a stemmed tibial component commonly used for total ankle arthroplasty (TAA). Despite its frequent use and previously reported outcomes within individual clinical studies, no study has systematically reviewed outcomes of TAA with this implant. The purpose of this study was to perform a systematic review of the literature and report on outcomes of TAA with the INBONE II. Methods: A systematic review of the literature was performed according to the Preferred Reporting Items for Systematic Review and Meta-analyses (PRISMA) guidelines. Databases searched included PubMed, Google Scholar, SCOPUS and CINAHL from database date of inception through February 28th, 2023. Clinical studies of INBONE II outcomes in peer reviewed journals were included. Outcomes included were survivorship, patient reported outcome measures (PROMs), and complications. Outcome results were compiled using weighted averages when possible. This review of 26 articles included 808 patients with 667 primary TAA and 141 revision TAA. Results: Survivorship, with failure defined as metal component revision, was 97.8% at an average follow-up of 49 months (range, 14-85.4 months) and 94.2% at an average follow-up of 25.7 months (range, 9.1-47.5) months for primary and revision TAA respectively. Complication rates for primary TAA included: 3.8% intra-operative fractures, 2.5% post-operative fractures, 1.8% deep infection, 8.0% wound complications, 1.6% rate of poly exchange, and 1.6% nerve injuries. Revision TAA complication rates included: 12.3% intra-operative fractures, 6.9% wound complications, 3.3% deep infections, and a 5.5% incidence of nerve injury. Average PROMs for primary TAA included: AOFAS American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot score improved 41 points, visual analog scale (VAS) scores decreased 5.9, and patient satisfaction of 92.6%. Revision TAA PROMs were not consistently reported. Conclusion: This study is the largest compilation of INBONE II outcomes and survivorship. Primary and revision TAA with the INBONE II results in satisfactory improvement in PROMs and low complication rates. The overall survivorship is 97.8% and 94.2% at an average follow-up of 49 months (range, 14-85.4 months) and 25.7 months (range, 9.1-47.5) for primary and revision total ankle arthroplasty respectively. These findings support continued use of this implant in primary and revision TAA.

Early Survivorship, Clinical and Radiographic Outcomes Following Primary and Revision Total Ankle Arthroplasty using a Modular Augmented Revision (INVISION) Implant

Category: Ankle Arthritis; Ankle Introduction/Purpose: As the number of total ankle replacements (TAR) performed annually increases, there is an increased demand for implants that can be used in revision scenarios when primary TARs fail. As indications for TAR expand, there is increased reliance on modular systems to treat challenging conditions including bone loss, avascular necrosis, and instability. The INVISION Total Ankle Arthroplasty System (Wright Medical Technology/Stryker, Memphis, TN), released in 2018, includes modular augmented tibial trays and talar plates of varied heights to compensate for bone loss. There is limited data on early survivorship and clinical outcomes of the INVISION. This novel study aims to determine the early implant survivorship, complications, patient-reported outcomes (PROMIS), and radiographic outcomes of the INVISION implant used in both the primary and revision arthroplasty setting. Methods: This study is a single-institution retrospective review of adult patients who underwent primary or revision TAR with the INVISION implant with minimum 2-year follow-up. Demographics, reason for use of INVISION, surgical data, complications, pre- operative and 2 year post-operative radiographic data, and pre-operative and 2-year post-operative patient-reported outcome scores were collected. The primary outcome was survivorship (retention of both tibial/talar components at final follow-up). Secondary outcomes were reoperation (return to OR with retention of both tibial and talar components), radiographic complications (peri-implant lucency, cysts, or subsidence), and patient-reported outcomes (PROMIS pre-operative and 2-year post-operative). PROMIS scores were collected across the following domains: physical function, pain interference, pain intensity, global mental health, and depression score. Results: Twenty-six patients (primary=7; revision=19) underwent INVISION TAR (mean age 62 years, weight 81.kg, BMI 29.3 kg/m2, 15/26 male) with mean follow-up 3.5 years. Reason for INVISION primary TAR included tibial (n=1) or talar (n=5) bone loss, and take-down fusion (n=1); INVISION revision TAR was used for tibial (n=6) or talar (n=7) component subsidence, recurrent tibiotalar malalignment (valgus=1, varus=3), and post-infection bone loss (n=2). Two-year implant survivorship was 100%. There were 2 reoperations (7.7%): 1 gutter debridement and 1 irrigation, debridement and polyethylene exchange for infection. Two-year follow-up PROMIS domains improved significantly (p &lt; 0.05) from pre-operative in both the primary (pain interference, pain intensity) and revision cohorts (pain interference, pain intensity, global physical function). Two-year radiographic follow-up yielded 1 tibial peri-implant lucency and 1 tibial cyst. Conclusion: In this single-institution series, there was excellent short-term survivorship of the INVISION TAR implant with no failures in primary or revision cases. There were significant improvements in patient-reported outcomes scores. There were low rates of peri-implant lucencies and cysts. The results of this study support the use of the INVISION implant in both the complex primary and revision TAR setting. INVISION may offer an alternate surgical solution to fusion, custom printed cage implants, and total talus replacement in this complex patient population. Further research and follow-up data are warranted to report the longer-term outcomes and survivorship of this implant.

2023 Roger A. Mann Award Winner: Younger Patients Undergoing Total Ankle Arthroplasty Experience Higher Complication Rates and Worse Functional Outcomes Scores

Category: Ankle Arthritis; Ankle Introduction/Purpose: Although many patients with postraumatic ankle arthritis are of a younger age, studies evaluating the impact of age on outcomes of primary total ankle arthroplasty (TAA) reveal heterogenous results. The purpose of this study is to determine the effect of age on complication rates and patient reported outcomes after TAA. Methods: This was a retrospective study of 1,185 primary TAA divided into 3 age cohorts (Age &lt; 55, n=219; Age55-70, n=688; Age&gt;70, n=278). Patient demographics, intraoperative variables, postoperative complications, and patient reported outcome measures were compared among groups using univariable analyses. Multivariable Cox regression was performed to assess risk for implant failure by age group. Mean follow-up was 5.7 years. Results: Compared to Age55-70 and Age&gt;70 groups, Age &lt; 55 patients had the lowest mean ASA score (2.2 vs 2.4 vs 2.5; p&lt; 0.001) and highest rates of all complications (33.8% vs 23.1% vs 19.8%; p=0.001), implant failure (9.1% vs 6.0% vs 3.2%; p=0.022), and component removal (5.0% vs 2.8% vs 1.1%; p=0.030). Univariable and multivariable cox regression analysis revealed decreased risk for implant failure for Age&gt;70 compared to Age &lt; 55 patients (HR: 0.43 [95%CI: 0.19-0.94], p=0.034; and HR: 0.42 [95%CI: 0.18-0.95], p=0.038, respectively). Across the AOFAS Hindfoot and all FAOS subscales, Age &lt; 55 group reported the lowest (worst) mean pre and postoperative scores (p &lt; 0.001). The age &lt; 55 group had the highest mean VAS score at final follow-up (22 vs 14 vs 14; p&lt; 0.001). Conclusion: Studies involving large sample sizes with mid-to long-term follow up are critical to reveal age-related impacts on outcomes after TAA. Younger patients had higher rates of complications and implant failure and fared worse on patient reported outcome measures in the largest single-institution series to date evaluating the effect of age on outcomes in TAA.

Increased Hospital Length of Stay for Obesity Class II and III Patients After Primary Total Ankle Arthroplasty: A NSQIP Analysis

Category: Ankle Arthritis Introduction/Purpose: Obesity is a well-established risk factor for complications after total hip and knee arthroplasty. The incidence of total ankle arthroplasty (TAA) continues to grow, but few studies have evaluated TAA outcomes in patients with obesity. The present study sought to measure the impact of obesity on TAA outcomes using a national database. Methods: The 2012-2020 National Surgical Quality Improvement Program (NSQIP) database was queried for primary TAA (CPT:27002). 1,610 patients were identified and stratified by preoperative body mass index (BMI): non-obese (18 5-29.9kg/m2, n=760), obesity class I (30.0-34.9kg/m2, n=455), and class II and III (&gt;35.0kg/m2, n=395). Preoperative and perioperative patient data, operative time, hospital length of stay (LOS), and 30-day complications were compared using univariable statistics. Multivariable analyses controlling for patient characteristics were employed to measure the effect of obesity on operative time and LOS. Results: Compared to the non-obese group, obesity class II and III patients were younger (61.9 versus 65.6 years;p &lt; 0.001), more female (57.2% versus 42.0%;p &lt; 0.001), higher ASA class (p &lt; 0.001) and had more comorbidities such as hypertension, diabetes, and dyspnea (p &lt; 0.001). Mean preoperative albumin was lower (p=0.013) and white blood count was higher (p &lt; 0.001) in the obesity class II and III group. Home discharge rate was lowest in class II and III patients (88.6%;p=0.017). Multivariable regression revealed longer hospital LOS for obesity class II and III (μ=0.21; p=0.005) relative to the non-obese group. Obesity group was not associated with operative time or 30-day readmissions and reoperations. Conclusion: Obesity class II and III patients undergoing TAA had more comorbidities and longer hospital LOS compared to lower BMI patients. Despite the well-established association between obesity and postoperative complications after hip and knee arthroplasty, the present NSQIP analysis of 1,610 TAA patients did not find a greater burden of acute complications among patients with obesity.

Fusion after a failed primary total ankle arthroplasty.

When a total ankle arthroplasty (TAA) fails, it can be converted to a fusion or a revision arthroplasty. Despite the increasing numbers of TAAs being undertaken, there is little information in the literature about the management of patients undergoing fusion following a failed TAA. The primary aim of this study was to analyze the survival of fusions following a failed TAA using a large dataset from the National Joint Registry (NJR). A data linkage study combined NJR and NHS Digital data. Failure of a TAA was defined as a fusion, revision to a further TAA, or amputation. Life tables and Kaplan-Meier graphs were used to record survival. Cox proportional hazards regression models were fitted to compare the rates of failure. A total of 131 patients underwent fusion as a salvage procedure following TAA. Their mean age was 65.7 years (SD 10.6) and 73 (55.7%) were male. The mean follow-up was 47.5 months (SD 27.2). The mean time between TAA and fusion was 5.3 years (SD 2.7). Overall, 32 (24.4%) underwent reoperations other than revision and 29 (22.1%) failed. Of these 24 (18.3%) underwent revision of the fusion and five (3.8%) had a below-knee amputation. No patients underwent conversion to a further TAA. Failure usually occurred in the first three postoperative years with one-year survival of fusion being 96.0% (95% confidence interval (CI) 90.7 to 98.3) and three-year survival in 69 patients being 77.5% (95% CI 68.3 to 84.4). Salvage fusion after a failed TAA shows moderate rates of failure and reoperations. Nearly 25% of patients required revision within three years. This study is an extension of studies using the same methodology reporting the failure rates and risk factors for failure, which have recently been published, and also one reporting the outcome of revision TAA for a failed primary TAA, using the same methodology, which will shortly be published.

Fixed Bearing in Primary Total Ankle Replacement Is Associated with Reduced Revision Rates

Category: Ankle Arthritis; Ankle Introduction/Purpose: The revision rate for total ankle replacement (TAR) in Australia has decreased over the past 6-years, coinciding with an increased use in fixed bearing prostheses. This study aimed to determine if the use of fixed bearing prostheses or surface coating are associated with lower revision rates. Methods: Data from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) included primary cementless TAR procedures performed for any diagnosis from January 2015-December 2021. Procedures were grouped by insert mobility (fixed &amp; mobile) and surface coating (HA &amp; non HA). The time to first revision was summarised using Kaplan-Meier estimates of survivorship, with hazard ratios (HR) obtained from Cox proportional hazards models including age, gender, insert mobility and surface coating. Results: There were 1,865 primary cementless TAR procedures of which 1,467 (78.7%) were fixed bearing and 398 (21.3%) mobile bearing. HA coating was used in 422 (28.8%) of fixed bearing procedures and 336 (84.4%) of mobile bearings. The cumulative percent revision (CPR) at 6 years was 4.1% for fixed bearing and 9.8% for mobile bearing TAR procedures. When the effects of insert mobility and bearing surface were considered separately, fixed bearings had a significantly lower revision rate compared to mobile bearings (HR=0.48), but there was no significant difference between HA and non HA coatings (HR = 1.18). When analysed by insert mobility and surface coating, mobile bearing HA prostheses had a significantly higher revision rate than fixed bearing prostheses with either coating. Conclusion: Analysis of 1,865 primary cementless TAR procedures shows that fixed bearing prostheses have significantly lower rates of revision than mobile bearing prostheses even when adjusting for surface coating.

Early outcomes of the Exactech Vantage fixed-bearing total ankle replacement.

The Vantage Total Ankle System is a fourth-generation low-profile fixed-bearing implant that has been available since 2016. We aimed to describe our early experience with this implant. This is a single-centre retrospective review of patients who underwent primary total ankle arthroplasty (TAA) with a Vantage implant between November 2017 and February 2020, with a minimum of two years' follow-up. Four surgeons contributed patients. The primary outcome was reoperation and revision rate of the Vantage implant at two years. Secondary outcomes included radiological alignment, peri-implant complications, and pre- and postoperative patient-reported outcomes. There were 168 patients (171 ankles) included with a mean follow-up of 2.81 years (2 to 4.6) and mean age of 63.0 years (SD 9.4). Of the ten ankles with implant failure (5.8%), six had loosening of the tibial component. In the remaining four failed implants, one was due to periprosthetic joint infection (PJI), one was due to loosening of the talar component, and two were due to loosening of both the tibial and talar components. Seven patients underwent reoperation: irrigation and debridement for superficial infection (n = 4); bone grafting for cysts (n = 2); and open reduction internal fixation (n = 1). Asymptomatic peri-implant lucency/subsidence occurred in 20.1% of ankles, with the majority involving the tibial component (n = 25). There were statistically significant improvements in PROMs in all domains. Short-term results of this implant demonstrate early survival comparable to the reported survivorship of similar low-profile, non-stemmed implants. Radiological lucency occurred more commonly at the tibial component, and revisions occurred primarily due to loosening of the tibial component. Further research is needed to evaluate longer-term survivorship.

A Propensity Score Matched Exploration of Infection in Primary Total Ankle Arthroplasty.

Infection is a serious complication of primary total ankle arthroplasty (TAA) and can lead to implant failure and revision surgery. Various demographic, comorbidity, and surgical factors have been associated with an increased risk of infection. However, the evidence base remains limited, and further research is needed regarding infection in TAA. This study aims to analyze risk factors of infection and explore outcomes following infected TAA. A retrospective cohort study was conducted using data from a single institution from 2002 to 2022. Patients who underwent primary TAA and had subsequent infection were identified through annual registry surveillance and matched using propensity score matching (PSM) based on various demographic, comorbidity, and surgical factors. Demographics were compared between the matched groups using Mann-Whitney U test and Fisher exact test. The outcomes following infection were identified and summarized using descriptive statistics. A total of 1863 patients who underwent primary TAA were identified, and 19 were diagnosed with an infection. The identifiable overall infection rate was 1.0%. After PSM, there were no significant differences in the difference in age, gender, BMI, and smoking status between the infected and control cohort. There was a statistically significant increase in the rate of diabetes in the infected cohort. The subsequent surgical intervention resulted in limb salvage in 18 (94.7%) cases. Out of the total number of cases, 2-stage revision to total ankle replacement was performed in 7 cases, whereas revision to arthrodesis and isolated polyethylene exchange were each carried out in 4 cases. One patient had to undergo amputation; however, at the time of the most recent follow-up, all patients were found to be free of infection. This study demonstrated high rates of a history of smoking and diabetes in the infected TAA cohort. The diabetes rate in the infected group was significantly higher than the noninfected controls. Two-stage revision to total ankle replacement was performed in 7 cases, and revision to arthrodesis and isolated polyethylene exchange were each carried out in 4 cases. Overall, a high rate of limb salvage was reported. Level III, case-control study.

Pulmonary Embolism, Mortality, and Medical Complications Following a Total Ankle Replacement: A Systematic Review and Meta-analysis.

There is sparse data on the incidence of thromboembolic and medical complications following total ankle replacements. The aim of this systematic review was to determine the risk of deep vein thrombosis and pulmonary embolism as well as mortality and medical complications following ankle replacements. A systematic review was undertaken using all levels of evidence following PRISMA guidelines. Of the 1657 articles identified, 25 met the inclusion criteria. The inclusion criteria were a primary total ankle replacement with the recording of medical complications and/or thromboembolic events and/or mortality data. Two reviewers independently reviewed all articles. Quantitative methods were used to pool the percentages with complications across studies. The pooled percentage with reported symptomatic deep vein thrombosis across 18 studies was 0.07% (95% CI 0.001%-0.59%). The pooled percentage with reported postoperative pulmonary embolism across 8 studies was 0.01% (95% CI 0.001%-0.03%). The pooled postoperative reported mortality was 0.06% (95% CI 0.001%-0.24%). Other medical complications had low incidences. Our study indicates rates of reported thromboembolic events of less than 1 in 1000. Notably the level of evidence analyzed was mainly Level III and IV, likely underestimating the true incidence of these events because of recall and medical record limitations, and we had insufficient information on usage of chemoprophylaxis among these patients. Level IV, systematic review based on all levels of evidence including case series.

How Does a Novel In Situ Fixed-bearing Implant Design Perform in Revision Ankle Arthroplasty in the Short Term? A Survival, Clinical, and Radiologic Analysis.

Given the growing number of primary total ankle replacements (TAR), an increase in the number of patients undergoing subsequent revisions might be expected. Achieving a stable and balanced ankle while preserving the remaining bone stock as much as possible is crucial for success in revision TAR. Most reported techniques rely on bulky implants with extended fixation features. Since 2018, we have used a novel, three-component ankle prosthesis for revision that is converted in situ to a fixed-bearing, two-component ankle prosthesis once the components have found their position according to an individual's anatomy. The results of this novel concept (fixation, revision, pain, or function) have not, to our knowledge, been reported. What are the short-term results with this new revision TAR design, in terms of (1) repeat revision surgery, (2) patient-reported outcomes on the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, (3) pain according to the VAS, and (4) radiographic signs of fixation? Between February 2018 and February 2020, we performed 230 TAR surgeries (in 206 patients) for any indication in our clinic. The novel semiconstrained, uncemented Hintermann Series H2 © implant was used in 96% (220 of 230) of procedures (201 patients). Fifty-four percent (119 of 220) of these were converted from an existing TAR to H2, which was the focus of the present study. However, only 45% (54 of 119) of these conversions to H2 were eligible for analysis. These patients had a mean age of 63 ± 12 years, and 43% (23 of 54) were women. The median (range) follow-up time was 3.2 years (2.0 to 4.3). The H2 design allows in situ conversion to a fixed-bearing system, with minimal bone resection. It achieves translational and rotational stability while preserving function and supporting the periarticular soft tissues. We defined repeat revision as exchange of one or both metal components, ankle fusion, or amputation and assessed it using a cumulative incidence survivorship estimator. Factors potentially associated with revision were assessed using Cox regression analyses. Clinical and radiologic outcomes were assessed preoperatively and at the most recent follow-up interval. Clinical outcomes included pain on the VAS (average pain during normal daily activity during the past seven days) and AOFAS score. Radiologic outcomes were the tibial articular surface angle, tibiotalar surface angle, talar tilt angle in the coronal plane, and AP offset ratio in the sagittal plane, as well as radiolucent lines and radiographic signs of loosening, defined as change in position greater than 2° of the flat base of the tibia component in relation to the long axis of the tibia, subsidence of the talar component into the talus greater than 5 mm, or change in position greater than 5° relative to a line drawn from the top of the talonavicular joint to the tuberosity of the calcaneus, as seen on plain weightbearing radiographs. The cumulative incidence of repeat revision after 1 and 2 years was 5.6% (95% CI 0% to 11%) and 7.4% (95% CI 0% to 14%), respectively. With the numbers available, no clinical factors we analyzed were associated with the risk of repeat revision. The median values of all assessed clinical outcomes improved; however, not all patients improved by clinically important margins. The median (range) AOFAS ankle-hindfoot score increased (from 50 [16 to 94] to 78 [19 to 100], difference of medians 28; p < 0.01), and the median pain on the VAS decreased (from 5 [0 to 9] to 2 [0 to 9], difference of medians 3; p < 0.01) from before surgery to follow-up at a minimum of 2 years. Radiographically, lucency was seen in 12% (6 of 49 patients) and loosening was seen in 8% (4 of 49). One of these patients showed symptomatic loosening and was among the four patients overall who underwent revision. We could not assess risk factors for repeat revision because of the low number of events (four). The investigated new in situ fixed-bearing ankle design achieved overall better short-term results than those reported in previous research. Destabilization of the ankle joint complex, soft tissue insufficiency, and possible changes of the joint configuration need an optimal solution in revision arthroplasty. The studied implant might be the answer to this complex issue and help surgeons in the perioperative decision-making process. However, a relatively high percentage of patients did not achieve a clinically important difference. Observational studies are needed to understand long-term implant behavior and possibly to identify ankles benefiting the most from revision. Level IV, therapeutic study.

Metal allergy and the use of custom implants in primary total ankle replacement

PurposePatients with metal allergy often go undiagnosed prior to surgery. This can lead to a high rate of complications, especially with orthopedic implants which can be highly variable in the composition of metals used in their production. The purpose of this technique guide is to highlight the use of pre-operative allergy testing in patients with known history of metal allergy, emphasize the proper steps in identifying a potential metal sensitivity reaction, and to report in literature the success of primary custom printed total ankle arthroplasty implants manufactured without the use of traditional metal compositions. Technique guidePatients often have undergone treatment in the past, but nevertheless, discussion about all treatment options, both conservative and surgical should be addressed. The author's preference is to maintain motion in the ankle joint if safe and reasonable. Often times patients will be unaware of metal allergy unless they have had prior reaction, usually from a previous orthopedic surgery. In the cases where the patient does report previous hypersensitivity reaction to metals, referral should then be made to an Allergist for comprehensive metal patch testing or lymphocyte transformation testing. Once the metal limitations are identified, orthopedic industry partner with custom printing capabilities is then contacted. Working with engineers, ankle implants free of offending metals are able to be manufactured. Analysis & discussionTo the author's knowledge, very few cases of metal sensitivity to total ankle replacement exist in the literature. The author's experience to date has shown favorable results when metal allergy is identified, particularly in patients with known history of metal allergy. With proper pre-operative planning and industry partner, good outcomes can be achieved in patients with metal allergy undergoing primary total ankle arthroplasty.