Use of an Extended-Length Tibial Tray in Total Ankle Arthroplasty: Rate of Subsidence, Loosening, Heterotopic Bone Formation, and Clinical Outcomes.

BACKGROUND: Total ankle arthroplasty (TAA) has continued to increase in popularity as a treatment for ankle arthritis. Despite popularity, continual updates to implant designs strive for improved outcomes which has led to different implant design changes including an extended-length tibial tray to offer more distal tibia cortical coverage. The purpose of this study was to compare radiographic findings (tibial component subsidence, tibial component loosening, heterotopic ossification [HO]) and patient-reported outcome measures (PROMs) between 2 age-, gender-, and body mass index-matched TAA groups.

METHODS: This study was a retrospective review of TAA patients matched into 2 groups: group 1 patients received the extended tibial tray implant, and group 2 received the standard tibial tray implant. Pre- and postoperative lateral radiographs and PROMs (Veterans-RAND 12 [VR-12] Item Health Survey, Ankle Osteoarthritis Scale [AOS], visual analog scale [VAS], and patient satisfaction) were analyzed.

RESULTS: Seventy-eight patients were allocated to each group. The mean age was 66.7 years in group 1 and 66.9 years in group 2, with a mean follow-up of 44.6 months and 50.7 months, respectively. There were no significant differences between the groups for pre- and postoperative PROMs. Group 1 had higher patient satisfaction with overall care (95.4 vs 89.8, P = .019). Radiographically, the rate of HO formation was significantly lower in group 1 (38.5% vs 62.8%, P < .001), and group 1 also had greater plantarflexion (P = .096) and significantly less dorsiflexion (P = .008).

CONCLUSION: Results appear to indicate that using TAA implants with an extended-length tibial tray is associated with more complete distal tibia cortical coverage, a numerically lower but statistically nonsignificant rate of tibial component subsidence, less heterotopic ossification formation, a trend toward greater postoperative plantarflexion, and higher patient satisfaction with overall care.

LEVEL OF EVIDENCE: Level III, retrospective cohort study.