Comparison of treatment outcomes for patients with chronic lateral ankle instability with subtle cavus foot: Is calcaneal osteotomy an essential procedure?

Background: Chronic lateral ankle instability (CLAI), frequently resulting from ankle sprains, is often associated with undiagnosed hindfoot varus deformities, specifically subtle cavus foot (SCF). While ligament reconstruction remains the standard treatment for CLAI with SCF, there is ongoing debate regarding the need for adjunctive calcaneal osteotomy to correct the underlying malalignment. Our study aims to evaluate the clinical efficacy and necessity of minimally invasive calcaneal osteotomy combined with arthroscopic modified Broström procedure in patients with CLAI with SCF.

Materials and methods: A retrospective analysis of 102 patients with CLAI and SCF was conducted from November 2016 to November 2022. Patients undergoing arthroscopic modified Broström procedure were assigned to the control group, while those receiving arthroscopic modified Broström procedure with minimally invasive calcaneal osteotomy were placed in the experimental group. General data and complications were documented. Preoperative and postoperative imaging included calcaneal pitch angle, Meary's angle, arch height, and calcaneus valgus angle. Clinical outcomes were measured using the American Orthopedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Score and visual analogue scale (VAS).

Results: A total of 81 patients with 2-year follow-up were included, with 46 in the experimental group and 35 in the control group. Significant differences in imaging indicators were observed in the experimental group at all follow-up points (P < 0.001), while no significant changes were noted in the control group (P > 0.05). Both groups demonstrated improvements in AOFAS and VAS scores (P < 0.001), with differences between 3- and 24-month follow-up (P < 0.001). Significant differences in imaging indicators and AOFAS scores were found between groups at both follow-up intervals (P< 0.01). The complication rate was 6.52% in the experimental group and 11.43% in the control group.

Conclusions: For patients with CLAI with SCF, arthroscopic modified Broström procedure with minimally invasive calcaneal osteotomy is an effective treatment that minimizes bone and soft tissue damage. Our study suggests that it is necessary to correct hindfoot alignment while stabilizing the ankle joint to enhance function and reduce recurrence of chronic ankle instability.

Level of evidence: Level III, retrospective comparative study.