Development of a Predictive Algorithm for Symptomatic Hip Abductor Tears in Patients Undergoing Primary Hip Arthroscopy
Background: Patients presenting with lateral hip pain may pose a difficult diagnostic challenge, as pain can be due to various causes.
Purpose/hypothesis: The purpose was to identify risk factors and predictors for symptomatic hip abductor tears in a cohort of patients undergoing primary hip arthroscopy for femoroacetabular impingement syndrome. We hypothesized that body mass index (BMI), female sex, age, and presence of chondral damage would be significant predictors of hip abductor pathologies.
Study design: Cohort study (diagnosis); Level of evidence, 3.
Methods: Data were prospectively collected and retrospectively reviewed. Patients were included if they underwent primary hip arthroscopy between March 2009 and December 2019. Patients with Tönnis grade >1, previous hip conditions, incomplete radiographic data, or open procedures were excluded. All demographic variables, intraoperative measurements, and radiographic measurements were assessed using a bivariate analysis. A stepwise logistic regression was used to determine predictive variables.
Results: In total, 255 hips with a hip abductor tear that underwent hip arthroscopy and 2106 hips without a tear that underwent hip arthroscopy were included. The stepwise logistic regression successfully created a predictive model using age, sex, BMI, lateral joint space, and alpha angle as variables. The efficiency of the predictive model was 90.7%, with an area under the curve of 0.894. The odds of having a hip abductor tear were 7.41 times higher in females (odds ratio [OR], 7.41; 95% CI, 4.61-11.9). Each additional year of age was associated with a 13.7% (OR, 1.137; 95% CI, 1.12-1.16) increase in the odds of having a tear. Similarly, with each 1-unit increase in BMI, the odds of having a tear increased by 3.4% (OR, 1.034; 95% CI, 1.01-1.06).
Conclusion: This study successfully created a predictive model that identified female sex (OR, 7.41), increasing age (OR, 1.137 for each year), and increased BMI (OR, 1.034 for each unit of BMI) as significant independent predictors of the presence of hip abductor tears in patients undergoing hip arthroscopy for femoroacetabular impingement syndrome. This model can be used in support of physical examination and imaging suggestive of hip abductor pathology to preoperatively identify the probability of a symptomatic hip abductor tear in these patients.