In vivo ankle kinetics after surgical management of concurrent chronic ankle instability and osteochondral lesions of the talus.

Background: Ankle joint moment and reaction force alteration after surgical treatment of chronic ankle instability (CAI) and osteochondral lesions of the talus (OLT) remains unknown.

Research Question: The current study aimed to investigate the in vivo kinetic effects of surgical management on patients with CAI and OLT and conduct a comparison with healthy subjects.

Methods: Eight patients with concurrent CAI and OLT were assessed in a stair descent setting prior to surgical management and one-year postoperatively. For inverse dynamic analysis, ground reaction forces and trajectories of skin markers were imported to AnyBody Modelling System to calculate the ankle joint reaction force and external ankle moment. One-dimensional statistical parametric mapping was performed for the comparison of ankle kinetic curves during gait cycle among healthy subjects, patients before surgery and patients after surgery.

Results: Preoperative patients displayed increased dorsiflexion moment compared with healthy subjects during 38.2 %-40.9 % of the gait cycle and during 38.1 %-41.1 % of the gait cycle with postoperative patients. Preoperative patients showed an increased anterior shear force compared with healthy subjects during 42.2 %-43.7 % of the gait cycle, and 42.8 %-43.2 % of the gait cycle with postoperative patients. Patients exhibited an increased maximal medial force preoperatively and postoperatively compared with healthy subjects (p < 0.001).

Significance: One-stage surgical treatment of CAI and OLT can decrease the excessive dorsiflexion moment and anterior force of the ankle joint. Excessive medial force of the ankle joint was partially decreased postoperatively, but it still significantly increased compared with that of healthy subjects. Such a finding may be attributed to impaired peroneal activation and requires additional rehabilitative treatment.