Ligament stabilization improved clinical and radiographic outcomes for individuals with chronic ankle instability and medial ankle osteoarthritis.

PURPOSE

Chronic ankle instability with a long symptom duration is often accompanied by medial compartment ankle osteoarthritis (OA). However, the outcomes of individuals after ligament stabilization have rarely been reported. The radiographic and clinical outcomes after ligament stabilization in individuals with chronic ankle instability and medial compartment OA were investigated.

METHODS

The study investigated 27 ankles with chronic ankle instability and medial compartment OA that underwent lateral ankle ligament reconstruction from 2007 to 2015 with a follow-up period of at least 1 year. Ligament stabilization was performed via either the modified Broström procedure (MBP) or lateral ankle reconstruction (LAR) using semitendinosus tendon allografts.

RESULTS

The median instability duration was 60 (range 12-480) months, and the median follow-up period was 39 (range 12-108) months. The preoperative Takakura ankle OA stage was predominantly stage I (20 patients (74.1%)), followed by stage II (five patients (18.5%)). Ankle MRI (20 ankles) revealed medial cartilage denudation in three cases (15%), cartilage thinning in nine cases (45%), osteophyte formation in ten cases (50%), and loose body formation in six cases (30%). According to the arthroscopic results, the modified Outerbridge grade was two in nine cases and four in ten cases, so these grades were the most common (37.5% and 41.7%, respectively). The MBP was performed in 14 patients, and LAR was performed in 13 patients (52% and 48%, respectively); the bone marrow stimulation procedure was performed in 15 patients (55%). The visual analogue scale score decreased from 6.0 (SD 1.6) preoperatively to 1.8 (SD 1.6) postoperatively (p = 0.000). The American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score improved from 61.9 (SD 14.2) to 89.7 (SD 6.2), and the Karlsson-Peterson score improved from 54.7 (SD 13.9) to 88.3 (SD 9.0) (p = 0.000). There were no serious complications, and all patients were satisfied.

CONCLUSIONS

Ligament stabilization with arthroscopic procedures for individuals with chronic ankle instability and medial ankle OA yielded significant functional outcomes with high patient satisfaction, even without radiographic improvement.

LEVEL OF EVIDENCE

IV.