Clinical and Radiographic Outcomes after Total Ankle Arthroplasty and Suture Tape Augmentation for Ankle Arthritis Combined with Ankle Instability

CATEGORY: Ankle Arthritis; Ankle; Sports INTRODUCTION/PURPOSE: End-stage ankle arthritis is commonly seen in combination with various forms of ligamentous instability. Correction of the ankle arthritis and meticulous ligament balancing is key to a successful outcome after a total ankle replacement. In particular, with varus or multidirectional instability, ligament repair or reconstruction can be performed with a combination of suture and/or suture anchors if there is adequate biologic tissue remaining for repair. To date there has been no study to report on the isolated use of suture tape to correct residual intraoperative lateral ankle instability and talar tilt after total ankle replacement. The purpose of this study is to evaluate the clinical and radiographic outcomes after this combined surgical procedure. METHODS: This was a single institution, retrospective study involving 36 patients that underwent a primary total ankle arthroplasty surgery in combination with a lateral ankle ligament reconstruction using a suture tape construct (InternalBrace(TM), Arthrex, Naples, FL). Retrospective review of prospectively collected information from patient charts of three foot and ankle fellowship trained surgeons were evaluated at preoperative, 6-months, 1-year and 2-years postoperative for various demographics as well as VAS pain and FAAM scores. Postoperative complications including revision surgery, hardware failure, or persistent instability were also recorded. In addition, preoperative radiographs were compared to 1-year and final follow up (mean, 26 months; range, 13-90 months) radiographs for correction of the coronal deformity. Analysis involved a 1-way repeated Friedman test with post hoc Wilcoxon signed-rank tests. P values are adjusted using the Bonferroni multiple testing correction method. Assumptions for normality were checked through normal quantile-quantile (QQ) plots. RESULTS: At two years postoperative, VAS pain (p<0.001) and FAAM functional scores (p<0.001) were significantly improved from preoperative. Additionally, both VAS pain (p=0.026, p-0.043) and FAAM scores (p=0.00142, p<0.001) significantly improved at each time point (6-months, 1-year) compared to preoperative. On weight bearing mortise view radiographs, the mean preoperative talar tilt angle was 11.9 (range, 1.4-25.7) degrees of varus. At 1-year and 2-years postoperative the mean talar tilt angles were significantly improved from preoperative at 1.1 and 0.7 degrees, respectively (p<0.001, p<0.001)). The correction was significantly improved and maintained at final follow up of at least 2 years. There were no significant differences between 1-year and 2-year talar tilt measurements (p=1.00). There were three complications requiring revision surgery. Two were for component loosening and the third was for a deep infection. CONCLUSION: Combined ankle arthritis and instability can be a challenging problem for foot and ankle surgeons. This study demonstrated that the use of suture tape to reconstruct the lateral ankle ligament complex after total ankle replacement provides and maintains adequate correction of any residual coronal deformity at a final follow up of at least two years.