Objectives: The most common reason for reoperation following arthroscopic hip surgery is conversion to total hip arthroplasty (THA). The purpose of this study was to identify clinical and radiographic risk factors for early conversion to THA. Methods: Data were prospectively collected on all hip arthroscopy patients from January 2009 through December 2011. Inclusion criteria for the study group were patients undergoing hip arthroscopy for a labral tear who eventually converted to THA. Patients were then compared to a control group of patients who underwent hip arthroscopy for a labral tear and did not convert to THA during the same period. Exclusion criteria were patients with previous hip conditions such as Legg-Calves-Perthes, slipped capital femoral epiphysis, pigmented villonodular synovitis, and avascular necrosis. A bivariate analysis of 41 preoperative and intraoperative variables was performed. Results: A total of 792 patients met inclusion and exclusion criteria. A total of 72 (9%) converted to THA. The control group consisted of 720 patients who did not convert to THA. Bivariate analysis demonstrated that the study group had significantly higher means or frequencies than the control group for the following variables: male gender, age at time of surgery, BMI, back pain, previous back surgery, Tönnis grade above 0, acetabular inclination angle, alpha angle, Seldes combined-type labral tear, labral tear size, chondral injury, traction time, labral debridement (versus repair), number of anchors used repair or reconstruction, and capsular release (versus repair). The study group had significantly lower means or frequencies than the control group for the following variables: preoperative patient reported outcome scores, crossover sign, lateral center edge angle, and psoas release. A statistically significant difference in average joint space was not observed. Conclusion: Multiple risk factors are possible preoperative and intraoperative risk factors for conversion to THA following hip arthroscopy. The clinician and patient should be aware of these variables.
Labral Injury: Radiographic Predictors at the Time of Hip Arthroscopy
Purpose The purpose of this study was to investigate the influence of multiple demographic and radiographic findings on the size of labral tears identified at the time of hip arthroscopy. Methods Data were prospectively collected for patients treated with arthroscopic labral repair or debridement from February 2008 to August 2011. Preoperative radiographic and demographic data were collected for 392 patients during the study period. Exclusion criteria included revision surgery and previous hip conditions. An anteroposterior pelvic view, 45° Dunn view, and false‐profile view were used to measure Tönnis grade, neck‐shaft angle, alpha angle, lateral center edge angle (LCEA), anterior center edge angle (ACEA), acetabular inclination, and the extent of crossover sign when present. At the time of surgery, labral tear size and location were documented for all patients, using traditional acetabular clock face nomenclature for sizing. A multiple linear regression analysis was then performed to assess the correlation of radiographic and demographic findings with the size of the labral tear. Results Regression analysis displayed statistical significance for sex ( P < .0001), age ( P < .0001), and alpha angle ( P = .005) with labral tear size. For female patients, Tönnis grade ( P = .0004) and neck‐shaft angle ( P = .004) correlated with labral tear size. This model accounted for only 26% of variation in labral tear size. Conclusions Preoperative risk factors for the extent of labral tear size are male sex, increasing age, and increasing alpha angle. Labral tears were larger in female patients with higher Tönnis grades and lower neck‐shaft angles. Measurements of acetabular coverage and version showed no correlation with labral tear size. The majority of labral tear size variation was not accounted for in this model. Level of Evidence Level IV, therapeutic case series.