Risk Factors for Conversion of Hip Arthroscopy to Total Hip Arthroplasty: A Large Closed-Cohort Study

Abstract

Purpose To evaluate risk factors for conversion of hip arthroscopy to total hip arthroplasty (THA) within 2 years in a closed patient cohort. Methods This study was a case series of consecutive hip arthroscopy procedures from September 2008 to November 2018 in the electronic medical record of Kaiser Permanente Northern California. Patients were included with minimum 2-year follow-up or if they had conversion to THA within 2 years (the primary outcome) regardless of follow-up time. Patient characteristics at the time of the index arthroscopy were extracted; characteristics of patients who experienced the outcome event versus those who did not were compared by use of multivariable logistic regression models and receiver operating characteristic (ROC) curves. Results The mean follow-up time was 4.9 years (median 4.6, range 0.6 to 11.6). The mean age was 37.2 years (range 10 to 88), and 57% were female. During the follow-up period, 82 patients underwent a THA within 2 years of their arthroscopies (5.3%, 95% confidence interval 4.3% to 6.5%) after a median time of 9 months (interquartile range 5.9 to 14.4) after the initial arthroscopy. Increasing age was highly predictive of early THA conversion (area under the ROC curve = 0.78, P < .001). Although other predictors showed significant bivariable associations with early failure, body mass index (BMI), race, sex, and prior arthroscopy did not add meaningful independent predictive information. Conclusions The risk of conversion to THA within 2 years after hip arthroscopy increased substantially with patient age at the time of the procedure. BMI, race, sex, and prior arthroscopy were not important independent predictors of conversion beyond the information contained in patient age. Level of Evidence Level IV, therapeutic case series.

Association Between Comorbid Depression and Rates of Postoperative Complications, Readmissions, and Revision Arthroscopic Procedures After Elective Hip Arthroscopy

“…Kester et al 19 and West et al 36 identified patient age, female sex, and index procedure performed by a low-volume surgeon as risk factors for undergoing revision hip arthroscopy within 2 years. Although studies have associated these and other numerous risk factors with early conversion from hip arthroscopy to THA, 1 , 32 previous studies to our knowledge have not reported an association between depression and revision hip arthroscopy.…”

Outcomes After Primary Hip Arthroscopy in Athletes Older Than 40 Years Compared With Nonathletes

“…Hip arthroscopy in patients older than 40 years should be approached with extreme caution, as increasing age has been strongly associated with poorer outcomes and higher rates of failure. 2,16,19,23,49,50 However, recent evidence brings this age-associated paradigm into question. Two recent systematic reviews on hip arthroscopy in patients older than 40 years came to parallel conclusions.…”

What the papers say

“…The authors [ 4 ] from California, USA, evaluated the risk factors for conversion of hip arthroscopy to THA within 2 years in a closed patient cohort. This study was a case series of consecutive hip arthroscopy procedures from September 2008 to November 2018 in the electronic medical record of Kaiser Permanente Northern California.…”