How To Manage Peroneal Tendon Subluxation
In 2009, Raikin reported on 14 patients with intrasheath subluxation diagnosed with dynamic ultrasound.47 He performed a posterior open trapdoor flap of the fibula at the level of the retromalleolar groove and used a rotary burr to deepen the groove. He repaired the flap with non-absorbable sutures through drill holes in the anterior fibula. American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot scores were improved over 33 months from 61 points to 93 points and nine of 14 patients reported excellent results.
Shawen and Anderson have also described and popularized indirect deepening procedures.25 The authors introduced the idea of a solid core drill bit and sequentially reaming the posterior cancellous fibula until one can use a tamp to deepen the groove 3 to 8 mm. This procedure is advantageous because it avoids an open osteotomy and surgeons can perform it with a low learning curve. It is imperative to confirm the drill is within the fibula and not in the lateral gutter, which one can avoid by first using a cannulated drill and guide wire.
Ogawa and colleagues performed a similar procedure on 15 patients and reported statistically significant poorer outcomes in patients requiring additional peroneal tendon repair versus isolated peroneal subluxation.48 Similarly, Saxena and Ewen reported on a cohort of 31 athletic patients who showed a tendency for a longer return to activity with additional peroneus brevis tear repairs.49 Again, multiple anatomic studies have shown a concave retromalleolar groove to be common and we have a low threshold for groove deepening.2,5
The literature is abundant with level III and IV studies on this topic. Given the complexity and paucity of peroneal subluxation cases, there has only been a grade I recommendation for the procedures described.50
A Closer Look At The Authors’ Surgical Technique
Our preferred technique for direct superior peroneal retinaculum repair with groove deepening involves a sharp excision of a 1 to 2 mm cuff of retinaculum at the posterolateral border of the fibula.51 Debride the peroneal tendons and repair them as necessary with absorbable sutures. Resect any atypical bulky, low-lying peroneus brevis muscle belly by electrocautery to prevent bleeding.
At this time, assess the retromalleolar groove for shape and bring the tendons through passive range of motion to evaluate for subluxation with circumduction and eversion of the ankle. With the tendons retracted, make a sharp periosteal incision at the tip of the fibula, lateral to the calcaneofibular ligament. Then insert a 3.5 mm solid drill in parallel to the retromalleolar groove and ream the distal fibula proximally about 2 to 3 cm. Then use a small curette to further debride and soften the fibrocartilage of the groove. Proceed to utilize a small, flat tamp to deepen the groove until attaining a desired depth (approximately 6 to 8 mm) to prevent dislocation.
Once the retinaculum is amenable to direct repair, resect the posterolateral border of fibula with a rongeur to allow for a fresh, bleeding bed. Then sharply elevate a lateral periosteal flap to assist in suture repair and perform a pants-over-vest suture repair technique, reinforcing the superior peroneal retinaculum with absorbable sutures. Take care to avoid inadvertently suturing the tendons when repairing the superior peroneal retinaculum.