Primary Ankle Arthroplasty Research Articles

Restoration of Talar Height, Alignment, and Implant Survival after Revision Total Ankle Arthroplasty with Minimum 2-Year Follow-up

Category:Ankle Arthritis; Ankle; OtherIntroduction/Purpose:With the introduction of improved implants and long-term outcome data, total ankle arthroplasty (TAA) is becoming an increasingly common surgical treatment for end-stage ankle osteoarthritis. However, the treatment of a failed primary TAA remains a significant challenge. Ankle arthrodesis as a salvage procedure results in high rates of non-union and collapse. Revision arthroplasty is an alternative to arthrodesis, but there is little published data on the outcomes of revision total ankle arthroplasty (RTAA). This study presents 2-year outcomes after RTAA using a modular prosthesis and metal/cement augmentation to reconstitute talar height, as well as restore sagittal and coronal alignment.Methods:A retrospective review was performed on 23 patients who underwent RTAA after failed primary TAA. Demographic data, talar height, coronal and sagittal alignment, and range of motion pre-revision and at most recent follow up were recorded. Failure was defined as need for revision surgery during the follow up period. Radiographic measurements were performed on weight bearing lateral and AP radiographs. For Agility implants, measurement on weight-bearing computed tomography (WBCT) was required. The measurement methodology was performed on both radiographs and WBCT for validation and measurements were consistent across all implants.Results:Patient follow-up ranged from 2 to 3.9 years, with a mean of 2.56 years. 17 of 22 RTAA did not require further revision. Of the five failures, one was due to deep infection, four to subsidence of the talar component. For the 17 successful revisions, average pre-operative coronal malalignment was 3.8◦ (range 7.4◦ varus to 15◦ valgus), and average post-operative malalignment improved to 2.6◦ (range 0◦ varus to 7.9◦ valgus), but this difference was not statistically significant (p=.09). Average pre-operative sagittal malalignment was 8.7◦ (range 20.7◦ plantarflexion to 20.1◦ dorsiflexion), and average post-operative malalignment improved to 3.6◦ (range 8.3◦ plantarflexion to 9.3◦ dorsiflexion), which was statistically significant (p=.01). Talar height improved by 3.9mm (p< 0.001), and range of motion from 16.9◦ to 25.0◦ (p,0.001).Conclusion:At a minimum of two years of follow up, revision arthroplasty shows improved alignment, talar height, and range of motion. While the failure rate remains significantly higher than primary ankle arthroplasty, it is comparable or superior to that of conversion to arthrodesis. The complexity of RTTA varies greatly due to surgical risk, soft tissue quality, and residual bone stock amongst other factors, which limits the generalizability of this patient cohort. RTAA is a viable option for the salvage of failed primary TAA, with functional and radiographic improvements shown at mid-term follow-up.

Patient-Reported Outcomes Before and After Primary and Revision Total Ankle Arthroplasty.

Studies examining the clinical outcomes of revision total ankle arthroplasty (TAA) are sparse. Revision TAA surgery has become more common with availability of revision implants and refinement of bone-conserving primary implants. In this study, patient-reported results and clinical outcomes were analyzed for a cohort of patients who underwent both primary and revision TAA at a single high-volume institution. We retrospectively reviewed prospectively collected data on 29 patients with failed primary total ankle arthroplasty. Cases of isolated polyethylene exchange, infection, or extra-articular realignment procedures were excluded. Patient-reported outcome (PRO) measures and clinical results were reviewed in this longitudinal study. Fifteen patients (51.7%) underwent revision of just the talar and polyethylene components while 13 patients (44.8%) underwent revision of all components. The most common cause was talar subsidence (51.7%). The average time to revision was 3.9 years with a follow-up of 3.2 years after revision, and 3 (10.3%) revision arthroplasties required further surgery; 2 required conversion to arthrodesis and 1 required second revision TAA. Improvements in PROs were better after primary than revision TAA. Clinical and patient-reported results of revision ankle arthroplasty after metal component failure improved significantly but never reached the improvements seen after primary ankle arthroplasty. In our series, 10.3% of revision TAAs required a second revision TAA or arthrodesis surgery. Therapeutic Level III, comparative series.

Revision Surgery for Metal Component Failure in Total Ankle Arthroplasty

Category: Ankle Arthritis Introduction/Purpose: Metal component failure in total ankle arthroplasty(TAA) is difficult to treat. Traditionally, to an arthrodesis has been advocated. Revision TAA surgery has become more and more common with availability of revision implants and refinement of bone conserving primary implants. It this study, patient reported results and clinical outcomes are analyzed for patients undergoing revision total ankle arthroplasty. Methods: We retrospectively reviewed prospectively collected data on 45 patients (cases) with a mean age of 63.7 +/-10.2 years who developed loosening or collapse of either major metal component in the primary total ankle arthroplasty. Cases of isolated polyethylene exchange, infection, or extra-articular realignment procedures were excluded. Prospectively collected patient reported outcomes measures including the American Orthopaedic Foot and Ankle Society(AOFAS) hindfoot score, Visual Analog Scale (VAS), Short Form 36 (SF-36), Short Musculoskeletal Function Assessment (SMFA), and the Foot and Ankle Outcomes Score (FAOS) questionnaires were collected. Clinical data was collected through thorough review of the electronic medical record to identify clinical failure defined as explant and second revision or conversion to arthrodesis or amputation. Results: The causes of failure of primary TAA in this study were aseptic loosening of both components (40%), talar component subsidence/loosening (37.7%), tibial loosening (8.8%), coronal talar subluxation (8.8%) and talar malrotation (2.2%). Twenty-four patients (53.3%) underwent revision of all components, nineteen (42.2%) just the talar and polyethylene components, and two (4.4%) the tibial and polyethylene components. The average time to revision was 5.56 years +/- 5.71 with a follow-up of 3.02 years +/- 1.25 after revision. Ten (22.2%) revision arthroplasties required further surgery; five required conversion to arthrodesis and five required second revision TAA. VAS scores, SF36 scores, SMFA scores, AOFAS Hindfoot scores, and FAOS all improved after revision surgery but took 2 years to reach scores comparable to 1 year after primary TAA. Conclusion: Clinical and patient reported results of revision ankle arthroplasty after metal component failure were comparable to those after primary ankle arthroplasty. In our series, 22.2% of revision TAAs required a second revision TAA or arthrodesis surgery. Various prosthesis performed similarly when used in revision scenarios. Patients recovered faster from primary ankle arthroplasty when compared to revision ankle arthroplasty but all scores were comparable by the two-year follow-up visit after revision arthroplasty surgery.

Infected Total Ankle Arthroplasty

Infections in total ankle arthroplasty are a serious complication, about which there is little information in the current literature. This is a retrospective review of infected total ankle arthroplasty at one institution from 1995 to 2012. Risk factors were compared between patients with infected total ankle arthroplasty and age- and sex-matched patients who did not have infection (control patients) within the same time period. 966 patients with total ankle arthroplasty were reviewed, and 29 cases of infected total ankle arthroplasty (3.2%) were identified. The incidence of infection in primary ankle arthroplasty was 2.4% and in revision arthroplasty was 4%. Risk factors for infection in our cohort included diabetes, prior ankle surgery, and wound healing problems more than 14 days postoperatively. No significant difference was found between groups with respect to risk factors including smoking, body mass index, and operative time. At latest follow-up, none of the patients had signs of persistent infection. Operative intervention of infected total ankle arthroplasty resulted in limb salvage in 79% of cases (a 21% amputation rate). At final follow-up, 65.5% of cases were infection-free with retained arthroplasty. This was achieved by irrigation and debridement alone, 1-stage fusion, and most often 2-stage revision. The final outcome was fusion in 3 of 29 cases (10.3%). Given the morbidity of infected ankle arthroplasty, careful consideration should be made about performing arthroplasty in patients with multiple prior surgeries and comorbidities that predispose to wound-healing difficulties. Level III, retrospective comparative study.