Deltoid Ligament Release in Total Ankle Arthroplasty: The Effects on Coronal Stability and the Longitudinal Arch of the Foot.

Abstract

BackgroundTotal ankle arthroplasty (TAA) with severe varus deformity may be associated with medial soft tissue contractures. The long-term consequences of deltoid ligament release are unknown in the setting of coronal plane deformity correction during TAA. We examined the impacts of TAA with concomitant deltoid ligament release to achieve and maintain coronal alignment, and subsequent effects on longitudinal arch stability.MethodsA retrospective review of 399 consecutive TAA performed with either INFINITY, INBONE II, or INVISION arthroplasty systems identified 32 patients who underwent concomitant complete deltoid ligament release. All patients had a preoperative intra-articular varus deformity >10 degrees and minimum follow-up of 2 years. Preoperative and postoperative radiographs quantified Meary's angle, calcaneal pitch, and tibiotalar tilt. Implant revision, unplanned reoperations, magnitude of coronal plane correction, and longitudinal arch stability were the primary interests.ResultsTwenty-five ankles met inclusion criteria with a median follow-up of 3.5 (range, 2 to 6.7) years and 92% implant survivorship. Seven ankles were excluded secondary to insufficient follow-up but revealed no complications. Median preoperative coronal alignment improved from 20.0 (range, 10.9 to 32.6) to 1.6 (range, -1.2 to 8.0) degrees varus (P < .001). Median preoperative calcaneal pitch increased from 19.1 (range, 12.0 to 37.1) to 20.8 (range, 14.0 to 26.9) degrees (P = .48). Median preoperative Meary's angle increased from -0.5 (range, -17.3 to 29.8) to 2.4 (range, -10.0 to 23.0) degrees (P = .77).ConclusionSevere varus deformity is not a contraindication to TAA. Complete release of the contracted deltoid ligamentous complex may be beneficial to achieve neutral coronal alignment and intra-articular balance of varus deforming forces during TAA. Despite being a critical stabilizer of the nonpathologic ankle and foot, deltoid ligament release performed in conjunction with TAA did not appear to accelerate clinical medial ankle instability, valgus talar tilt, or radiographic progressive collapsing foot deformity.Level of Evidence:Therapeutic, Level III: Retrospective.