Are There Gender Differences in Outcomes of Surgery for Chronic Ankle Instability?
The authors of a recently published study hypothesized that clinical and radiographic outcomes would be significantly different in male and female patients undergoing a modified Brostrum procedure. Were they right?
Kenneth J. Mroczek, MD
Xu HX, Choi MS, Kim MS, Park KS, Lee KB. Gender differences in outcome after modified brostrum procedure for chronic lateral ankle instability. FAI 2016;37:64-69.
Xu et al retrospectively reviewed the records of 155 patients (94 males, 61 females) who underwent a modified Brostrum procedure for chronic lateral ankle instability. The procedure involved primarily repairing the anterior talofibular and calcaneofibular ligaments with the Gould modification of reinforcing the repair with the inferior extensor retinaculum.
The authors hypothesized that clinical and radiographic outcomes would be different between male and female patients. Their inclusion criteria for the study were:
- Symptoms greater than 6 months
- Failure of non-operative treatment
- No past history of an ankle fracture
- No previous ankle surgery
There were no differences between groups in mean age, symptom duration, and follow-up duration, while a significant difference was found in BMI: The male group had a higher BMI than the female group (24.9 vs. 23.4). The mean follow-up duration of all the patients was 42.8 months.
Clinical outcomes were assessed with Karlsson and AOFAS ankle-hindfoot scores. Talar tilt and anterior talar translation were measured for radiographic outcomes.
There were no statistical differences in any of the measured outcomes between groups:
- The mean preoperative Karlsson scores were 53.6 for males and 54.9 for females, with the scores improving postoperatively to 93.2 and 92.2, respectively.
- The mean AOFAS ankle-hindfoot scores also improved from 62.4 to 93.7 for males and 63.6 to 92.3 for females.
- The mean talar tilt and anterior talar translation similarly improved for male and female patients.
Additional procedures the patients underwent included arthroscopic synovectomies, osscile excisions, removal of loose bodies, spur excision, and microfracture or drilling for ostoechondral injuries. No significant differences in these procedures were observed between the 2 groups.
There were no statistical differences in complication rates between male and female patients.
This is the first study to analyze gender in the outcomes of a modified Brostrum procedure for chronic lateral ankle instability.
The authors hypothesized that there would be a difference between male and female patients based on the observation of poorer results for females in several studies on rotator cuff repair and anterior cruciate ligament reconstruction. They believed the expected variation would be due to differences in:
- Activity demands
- Muscle strength
- Neuromuscular coordination
- Joint laxity
- Hormonal influences on ligaments
Their hypothesis proved to be incorrect as no differences in clinical or radiographic outcomes were seen between male and female patients in their cohort.
Ankle instability usually responds to non-operative treatment centered on bracing and physical therapy. For a small subset of patients who develop chronic instability that fails such treatment, the procedure of choice is a modified Brostrum lateral ligament reconstruction.
Although there are many described procedures, direct repair of the ligaments is preferred as the primary procedure. Many of the other described procedures involve sacrificing part of the peroneal tendons, which can weaken an important dynamic ankle stabilizer and/or act as a checkrein procedure limiting range of motion.
The lack of influence of gender on the outcome of this preferred primary procedure for chronic lateral ankle instability is encouraging. Furthermore, the clinical and radiographic outcomes were good.
There are limitations to this study: It was retrospective, and it failed to measure pre- and postoperative sports activity participation.
Kenneth J. Mroczek, MD, is an Assistant Professor of Orthopaedic Surgery and Chief of the Division of Foot and Ankle Surgery, Department of Orthopaedic Surgery, NYU Langone Medical Center – Hospital for Joint Diseases, New York, New York.