Continuous Passive Motion after Hip Arthroscopy for Femoroacetabular Impingement: A Prospective, Comparative Trial


      Though continuous passive motion (CPM) devices are often used in post-operative rehabilitation protocols after surgical treatment of symptomatic femoroacetabular impingement (FAI), no prospective, controlled data currently exists about whether or not these devices provide measureable benefit to patients after hip arthroscopy. The aim of this prospective, comparative study is to investigate whether or not CPM devices objectively benefit patients in the early post-operative period.


      In this IRB-approved study at a tertiary care academic medical center, surgical and post-operative medications and rehabilitation protocols between 2 surgeons were standardized. One surgeon used CPM in his rehabilitation protocol while the other surgeon did not. Consented subjects answered questions regarding pre-operative pain, function, and psychological status included the International Hip Outcome Tool (iHOT-12), visual analog scale (VAS) pain, pain medication usage, Patient Health Questionnaire (PHQ-8), and Pain Catastrophizing Scale (PCS). At the two-week and six-week post-operative visits, patients recorded average pain felt over the preceding 2 weeks. At the 6-week visit, patients also completed the iHOT-12. Pre-operative predictors with univariate p-values less than 0.15 were incorporated into multivariable linear regression models.


      In a complete case analysis of 40 and 29 patients having reached the 2-week and 6-week post-operative marks, respectively, patients prescribed CPM devices had statistically significantly greater pain reduction at 6 weeks (normalized pain reduction of 76% vs. 33%, p=0.0048) and greater improvement in hip function score at 6 weeks (normalized iHOT-12 score increase of 143% vs. 50%, p=0.0088). No factors achieved significance at 2 weeks post-operative.


      This is the first study to investigate the impact of CPM inclusion in short-term post-operative rehabilitation outcomes after hip arthroscopy for symptomatic FAI. Including CPM in post-operative rehabilitation was associated with significantly improved pain and function by 6 weeks post-operative.