Correction of foot malalignment after old talar neck fracture

Abstract

Category: Hindfoot Introduction/Purpose: Posttraumatic talar neck mal-union often results in varus hindfoot and adducted forefoot. That leads to a deformed stiff foot and peri-talar osteoarthritis, causing pain, altered gait and dysfunctions. This study analyzed the adopted corrective methods and their clinical and radiographic outcomes. Methods: This study retrospectively reviewed 18 cases of symptomatic malaligned foot as a result of old talar neck fracture, who undertook corrective surgeries during the period from Sept.2009 to Oct. 2016. The average time interval between the injury and the corrective surgery was 23.8±33.5 months. Procedures including ORIF of talus, lateralizing calcaneal osteotomy, subtalar arthrodesis and opening osteotomy of medial talus were selected for the correction and reconstruction of foot deformity. The follow-up time after surgery was 29.5±18.5months. The angle of first metatarsal axis and talar axis (FMT) was measured on the A-P view of foot. The distance between the lowest point of calcaneus and the tibial axis (Moment Arm, MoA) and the angle between the lateral wall of calcaneus and tibial axis (hindfoot alignment angle, HAA) were measured on the hindfoot alignment view of foot. VAS score, AOFAS-AH score and SF-36 scores were compared before and after surgery. Results: The FMT angle increased from -6.8±5.7 degrees before surgery to +1.8±2.6 degrees after surgery (p<0.05); The MoA increased from -3.1±2.4 cm before surgery to +0.5±1.0 cm after surgery (p<0.05); The HAA increased from -19.6±8.3 degrees before surgery to -3.8±4.1 degrees after surgery (p<0.05) 。 The VAS score decreased from 6.5±2.3 before surgery to 1.0±1.2 after surgery (p<0.05). The AOFAS-AH score increased from 54.5±16.2 before surgery to 88.6±12.3 after surgery (p<0.05). The SF-36 score increased from 48.7±10.5 before surgery to 85.4±9.2 after surgery (p<0.05). The osteotomy and arthrodesis sites were healing well judging from the X-ray and CT images. Conclusion: The correction and reconstruction of deformed foot resulted from old mal-united talar fracture poses a difficult clinical problem. The major principle is to correct the varus hindfoot and adducted forefoot. Selected Combined procedures including ORIF of talus, calcaneal lateralizing osteotomy, subtalar arthrodesis and medial talar opening osteotomy are recommended to restore normal alignments and functions.