Brostrom-Like Procedure Augmented with Swivelock Internal Brace for the Reconstruction of Chronic Medial Ankle Ligament Complex

Abstract

Category: Midfoot/Forefoot Introduction/Purpose: The medial ligaments and joint capsules appear to stretch or rupture under the increasing stress following a tear of the PTT in patients with flat foot often leading to pain, swelling and dysfunctional foot. This study assesses the efficacy of a Brostrom like procedure augmented with Swivelock Internal Brace for the reconstruction of chronic medial ankle ligament complex. Methods: A retrospective study was performed reviewing 15 flat foot patients who presented with pronounced hindfoot pronation collapse of the medial longitudinal arch after injury. The procedures included exploration and direct repair of PTT, deltoid ligament and spring ligament. Our modification included Swivelock Internal Brace enhanced reconstruction of deltoid and spring ligaments, after calcaneal medializing osteotomy. Other additional procedures such as FDL transfer, subtalar arthroereisis and Cotton osteotomy were performed as needed (Fig.1). Weight bearing X-rays of the foot, AOFAS-AH and SF36 scoring were taken before and after surgery. Results: There were 8 males and 7 females among the 15 patients. The age was 29.8±10.1 years old. The follow-up time period was 32.6±11.4 months. Both the AOFAS-AH (52.8±15.2 to 90.4±7.5 and SF-36 (55.4±12.6 to 91.2±6.3 scores improved significantly (p<0.001). Comparing preoperative to postoperative standing radiographs, there was significant improvement in the AP talar first metatarsal angle (25.6±18.4 to 9.5±7.8 degrees（P<0.001), lateral talar first metatarsal angle (18.3±8.4 to +2.6±4.5 degrees（P<0.001）and moment arm on the Saltzman view (+15.2mm±10.8 to +2.5±3.6mm（P=0.003） (Fig.2). No recurrence of pronation deformity or foot arch collapse was observed after surgery. Conclusion: The medial ankle ligaments were attenuated and under the increasing stress following a tear of the PTT in patients of flat foot. Direct repair of the ligaments after rupture usually resulted in low strength and high recurrence. Simultaneous reconstruction of medial ankle ligaments with Swivelock internal brace maintained long term medial ankle stability and the longitudinal arch. This technique protects the repaired tendon and decreased the need for FDL transfer, potentially permitted earlier rehabilitation and improved function compared to traditional techniques.