Presence of Subfibular Ossicle Does Not Affect the Outcome of Arthroscopic Modified Broström Procedure for Chronic Lateral Ankle Instability

SLR - September 2019 - Thanh Hoa Bui

Reference: Kim WJ, Lee HS, Moon SI, Kim HS, Yeo ED, Kim YH, Seok Park E, Lee YK. Presence of Subfibular Ossicle Does Not Affect the Outcome of Arthroscopic Modified Broström Procedure for Chronic Lateral Ankle Instability. Arthroscopy. 2019 Mar;35(3):953-960.

Scientific Literature Review

Reviewed By: Thanh Hoa Bui, DPM
Residency Program: Hoboken University Medical Center – Hoboken, NJ

Podiatric Relevance: Subfibular ossicles (SFO) can be found in normal population but present in higher incidence with patients with chronic lateral ankle instability (CLAI), implying a correlation. When CLAI patients with SFO associated with pain or instability have failed conservative treatment, surgical intervention is indicated. However the optimal technique for SFO treatment in CLAI patients remains unclear. A possible surgical option for CLAI patients and SFO is to perform arthroscopic modified Brostrom procedure (MBP) with the excision of SFO. The purpose of this article is to evaluate the clinical and radiological outcomes of all-inside, arthroscopic MBP used to treat CLAI according to SFO status.

Methods: This is a Level IV retrospective comparative study of patients who underwent arthroscopic MBP from January 2013 to September 2016 by a single experienced surgeon. Patients included had a follow up greater or equal to 12 months. The 125 patients who met inclusion criteria were divided into two groups: the SFO group (26 ankles) and the non-SFO group (99 ankles). Patients were evaluated preoperatively, at six and 12 months postoperatively. The American Orthopedic Foot and Ankle Society ankle-hindfoot, and visual analog scale were used to clinically evaluate patients. Radiographically, anteroposterior, lateral, and stress radiographs were used to evaluate SFO size and talar tilt.

Results: Final AOFAS scores had improved when compared preoperatively in SFO and NSFO groups. The VAS scores also improved in both groups; however, the differences between two groups were not significant. The final talar tilt improved in both the final follow-up in the SFO group and NSFO group. Neither the preoperative nor final talar tilt angle differed between two groups. The angle did not differ between the SFO and NSFO group.

The SFO size was divided into small and large subgroups. The AOFAS and VAS scores did not differ at the final follow-up; all scores improved (AOFAS and VAS score in small and large ossicle subgroup). Neither the preoperative nor the final talar tilt angle differed between the subgroups. The change in angle did not different between the subgroups. The main finding is that that the outcomes of the SFO and NFSO groups did not different significantly, however improvements existed.

Conclusions: The main limitation to this study was that there was no comparison between arthroscopic MBP with SFO excision to arthroscopic MBP without SFO excision with an SFO. However, this study provided valuable information. Authors concluded that outcomes after MBP and SFO excision, despite the size, were the same as those of BMP alone in patients without SFOs with successful clinical and radiographic outcomes at the final follow up visit. And all-inside arthroscopic MBP is reliable treatment method for CLAI patients regardless of SFO status.

When SFO are present, especially if large in size, another possible surgical technique is ossicular osteosynthesis, however this surgeon excised all SFO when present, despite of size, with improved outcomes. If a patient presents with CLAI and SFO, arthroscopic MBP with SFO excision is viable option in which ossicular osteosynthesis may be unnecessary.