Abstract
Background
Cartilage lesions in chronic lateral ligament deficiency are common with the incidence rates mentioned in the previous literature up to 30%. However, other intra-articular pathologies in the unstable ankle have received little attention. Anterolateral impingement associated with synovitis and scarring is a less recognised feature in the treatment of chronic instability. The aim of our study was to ascertain the incidence of chondral and anterolateral impingement lesions in the symptomatic lateral ligament complex deficiency.
Methods
We performed a retrospective study of all consecutive patients who underwent modified Brostrom repair for symptomatic recurrent instability of the ankle. All patients underwent a MRI scan prior to surgery. Arthroscopy was performed in all the patients before lateral ligament reconstruction. Seventy seven patients with 78 ankles were included in the study. Patients who had previous ankle surgery or inflammatory arthropathy were excluded. Data was obtained from clinical and radiological records. Arthroscopic findings were recorded in detail during the surgery.
Results
The mean age was 29.8 years (Range 18.2 – 58 yrs). There were 44 females and 34 males in the study. The incidence of chondral lesions were 11.5% (9 out of 78 ankles). The commonest site for chondral defect was the anteromedial talar dome. The incidence of anterolateral impingement which required arthroscopic debridement was 48.7% (38 ankles). A further 10 ankles revealed non-specific synovitis and scarring which was debrided. The sensitivity and specificity of the MRI scans in the assessment of chondral lesions is 91% and 100%.
Conclusion
The incidence of chondral lesions in chronic ankle instability is lower than previously published literature. However, soft tissue impingement lesions have a much higher incidence and require debridement. Arthroscopic examination and debridement of impingement prior to lateral ligament reconstruction of the ankle is quintessential in the management of chronic anterolateral instability.
