Arthroscopic modified Brostrom operation allows faster recovery in chronic ankle instability

The modified Brostrom operation (MBO) has found widespread use in the therapy of lateral chronic ankle instability (CAI). However, alternative surgical techniques like the open reconstruction using a periosteal flap (RPF) are still an important part of the surgical treatment of lateral CAI. Both procedures differ in terms of the reconstruction material used and the surgical procedure.

Moritz Mederake et al conducted a study to compare the arthroscopic MBO and the RPF. The article has been published in – "Archives of Orthopaedic and Trauma Surgery" journal.

The authors retrospectively analysed 25 patients with lateral CAI after a tear of the anterior talofibular ligament (ATFL). 14 patients received arthroscopic MBO and 11 patients received RPF. They compared the postoperative outcome between both groups with respect to subjective instability, the number of ankle sprains, pain, complications and follow-up operations as well as the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score.

Surgical techniques:

Arthroscopic MBO:

It was performed using the Arthrex Broström Repair implant system (Arthrex Inc. Naples, Florida, USA). Viewing from the anteromedial aspect of the joint a debridement is performed with special attention paid to the preparation of the anterior aspect of the distal fibula with the anatomical origin of the ATFL. Through the anterolateral portal onto the inferior aspect of the fibula a SutureTak drill guide and drill bit are used to create two bone tunnels 5 mm and 10 mm proximal to the tip of the distal fibula. These two drill holes are armed with a 3 mm Biocomposite SutureTak anchor. 15 mm ventrodistally from the tip of the fibula 4 exit points for the suture are marked. Using a Micro SutureLasso, all four sutures are shuttled through the marked points. In the next step, all four sutures are passed subcutaneously through the anterolateral arthroscopic portal. While holding the foot in slight eversion, the sutures are fastened down to the fibula thus sewing the inferior extensor retinaculum to the periosteum of the lateral malleolus.

RPF:

The skin incision is located anterior to the distal fibula curving in the posterior direction distally at the lateral malleolus. Then two periosteal flaps from the fibula are prepared and elevated from proximal to distal. The next step is to make two drillholes at the tip of the fibula in the direction of the attachments of the ATFL and the CFL. The two periosteal flaps are now pulled through the drill holes. The insertion sites of the ATFL and the CFL have to be exposed and a cortical bone block of 10 × 10 mm is then removed. The dorsal flap is fixed in slight equinus of the foot. It is directed deep to the peroneal tendons and held under tension. The fixation with the cortical block at the prepared site of insertion of the CFL is made by a staple. Fixation of the anterior flap is made in the same way at the prepared site of insertion of the ATFL, but in a neutral position with the hindfoot in valgus at the subtalar joint.

Key findings of the study were:

• Both surgical procedures resulted in a significant improvement in pain, in subjective instability, in the reduction in the frequency of ankle sprains and improvement in the AOFAS ankle-hindfoot score one year postoperatively.

• Three months postoperatively, the values for pain and instability of the MBO group were significantly better compared to the RPF. One year after the operation, these differences were evened out.

• Also in terms of complications and follow-up operations, no significant difference was found between the two procedures.

The authors concluded that – "The MBO and the RPF are surgical techniques that yield a comparable clinical outcome one year postoperatively. Pain, function, instability and the frequency of ankle sprains improve significantly with both procedures and do not differ significantly from one another. The arthroscopic MBO appears to have the advantage of faster recovery through significantly faster pain reduction and improvement of instability. From our point of view, RPF can be seen as a good alternative therapy, which can be carried out if the MBO is not technically feasible or available."

Further reading:

Arthroscopic modifed Broström operation versus open reconstruction with local periosteal fap in chronic ankle instability. Moritz Mederake, Ulf Krister Hofmann, Ingmar Ipach. Archives of Orthopaedic and Trauma Surgery (2022) 142:3581–3588 https://doi.org/10.1007/s00402-021-03949-2