Heterotopic Ossification Following Total Ankle Arthroplasty With Fourth-Generation Prostheses

The significance of heterotopic ossification following total ankle arthroplasty: a systematic review and meta-analysis

PURPOSE

The purpose of this systematic review and meta-analysis was to evaluate the prevalence and clinical significance of heterotopic ossification (HO) following total ankle replacement (TAR).

METHODS

During August 2023, the PubMed, Embase and Cochrane library databases were systematically reviewed to identify clinical studies reporting HO following TAR. Data regarding surgical characteristics, pathological characteristics, subjective clinical outcomes, ankle range of motion, radiographic outcomes, reoperation rates were extracted and analysed.

RESULTS

Twenty-seven studies with 2639 patients (2695 ankles) at a weighed mean follow-up time of 52.8 ± 26.9 months were included. The pooled prevalence rate was 44.6% (0.25; 0.66). The implant with the highest rate of HO was the INBONE I (100%) and BOX (100%) implants. The most common modified Brooker staging was grade 1 (132 patients, 27.0%). Random effects models of standardized mean differences found no difference in American orthopedic foot and ankle society (AOFAS) scores, visual analog scale scores (VAS) and ankle range of motion (ROM) between patients with HO and patients without HO. Random effects models of correlation coefficients found no correlation between AOFAS, VAS and ROM and the presence of HO. The surgical intervention rate for symptomatic HO was 4.2%.

CONCLUSION

This systematic review and meta-analysis found that HO is a common finding following TAR that is not associated with inferior clinical outcomes. Surgical intervention was required only for moderate-to-severe, symptomatic HO following TAR. This study is limited by the marked heterogeneity and low level and quality of evidence of the included studies. Further higher quality studies are warranted to determine the precise prevalence and impact of HO on outcomes following TAR.

LEVEL OF EVIDENCE III

Results of Total Ankle Arthroplasty Versus Ankle Arthrodesis

No differences have been found between total ankle arthroplasty (TAA) and ankle arthrodesis (AA) with respect to patient-reported outcome measures (PROMs), although both interventions were shown to improve PROMs with respect to the preoperative situation. That is, both interventions (AA and TAA) were effective in improving preoperative symptoms. On the other hand, 2-year complication rates were higher after AA (27%) than after TAA (16%); however, infection rates were similar (4%). The published revision rate after AA is 16% versus 11% after TAA. In short, TAA and AA appear to offer the same PROMs, but TAA has a lower rate of complications (except for infection) and revisions.

Radiographic Comparison of Heterotopic Ossification After Primary Total Ankle Arthroplasty in Fourth-Generation Implants

Level III: Retrospective comparative.

Total Ankle Arthroplasty With Anatomic Lateral Ankle Stabilization (ATLAS) in Moderate and Severe Pre-operative Varus Alignment

The purpose of the present study was to assess the early clinical and radiographic outcomes for patients who underwent TAA and Anatomic Lateral Ankle Stabilization (ATLAS) using synthetic graft for instability in moderate and severe preoperative varus alignment. Seven ankles with moderate or severe varus alignment underwent TAA with a 3^rd generation prothesis (INBONE-2) and ATLAS using synthetic graft between September 2018 and February 2019 at a single institution, and were at least 1 year postoperative (mean 13.3 months, range 12-15). Medical records and charts were reviewed for revisions, reoperations, and complications. Weightbearing radiographs were assessed using tibiotalar alignment parameters preoperatively, and during the latest follow-up. Survivorship for INBONE-2 with ATLAS was 100%; recurrent instability was not observed. Symptomatic talonavicular joint arthritis was recorded for a single patient 12 months postoperatively; no revisions, or reoperations were performed. Coronal alignment improved significantly from 17.7 ± 9.3 (range, 10.1-33.6) to 2.3 ± 1.2 (range, 0.9-4.4) degrees (p < .006), and all ankles achieved neutral alignment in a single stage. Regarding sagittal alignment, 2 ankles (28.5%) were translated anteriorly and the rest were neutral (71.5%) preoperatively. Significant posterior translation was observed and during the latest follow-up, 4 ankles were neutral (57.1%) and 3 posterior (42.9%) (p < .009). Satisfactory outcomes were observed at a minimum of 1-year follow-up for patients with moderate or severe varus alignment who underwent TAA with INBONE-2 and ATLAS. ATLAS may afford advantages over previously described repair techniques. Comparative studies between the Brostrum-Gould and ATLAS are warranted.