Ligament Reconstruction for Ankle Instability
By Dr Ooi Lai Hock
Introduction
One of the most common major elective foot and ankle operation is ligament reconstruction for ankle instability secondary to repeated ankle sprains. There are many surgical techniques in orthopaedic textbooks and literature to ankle instability surgically. For example, there are more than 10 ways to treat this condition surgically. In my experience and hands, I find that the most reliable and reproducible surgical technique is the modified Bostrom-Evans ligament reconstruction for ankle instability.
I will describe the technique and advantages of the ligament reconstruction below. I will also provide you with the results and pictures of patients under my care. In the surgical technique, immediate full weight bearing with an orthotic is allowed. This is a vast change from other techniques whereby patients are kept in a cast and not allowed to weight-bear for weeks. Nearly all patients find this extremely important as it is certainly more convenient and acceptable.
Ligament Reconstruction for Ankle Instability
The modified Bostrom-Evans ligament reconstruction is a reliable technique which reduces the recurrence of ankle instability. I have modified the technique with the use of a bioabsobable interference screw to anchor the harvested tendon graft to reconstruct the lateral ligaments and this enhances immediate post-operative stability.
Surgical Technique
The technique uses a small incision over the lateral aspect of the ankle. The patient is able to ambulate full weight bearing nearly immediately after surgery with an air cast boot
 Skin incision 5-6cm |
 Plication of the anteiror talofibular ligament |
 Full weight bearing immediately after surgery in an air cast |
 Bioabsorbable screw |
 Peroneus brevis used as tendon graft to reconstruct the calcaneofibular ligament |
 Cosmetic wound healing |
Advantages
- Immediate stability allows for full weight bearing with an air cast boot after surgery.
- No cast needed at all.
- Mild pain post-op (Pain scores typically 1-3/10 with analgesia).
- Small cosmetic scar (usually 5-6cm) with minimal wound problems.
Results
Mean scores for the Foot & Ankle Outcome Score (FAOS) and American Orthopaedic Foot & Ankle Society (AOFAS) Hindfoot scores in 15 patients in one series showed a significant improvement over time in the table below.
References:
- KW Lai, LH Ooi. Use of biodegradable interference screw in ankle lateral ligament reconstruction. Presented at 31st Singapore Orthopaedic Association (2008) & 39th Malaysian Orthopaedic Association Annual Scientific Meetings (2009).
