The use of continuous passive motion following knee cartilage defect surgery: a systematic review

We evaluated the clinical evidence of using continuous passive motion postoperatively after treating articular cartilage lesions of the knee. We hypothesized that postoperatively, the use of continuous passive motion improves the outcomes of cartilage restoration procedures. Multiple medical databases (MEDLINE, EMBASE, CINAHL, PubMed, Sport-Discus, and Cochrane) were searched for Level I through IV evidence with specific study inclusion and exclusion criteria. The following key words were searched: microfracture, mosaicplasty, OATS, ACI, osteochondral autograft, osteochondral allograft, autologous chondrocyte implantation, autologous chondrocyte transplantation, CPM, continuous passive motion, motion therapy, postoperative knee rehabilitation, cartilage, knee. All studies were independently reviewed by the authors and the references were checked for any missed articles. Four Level III studies were identified that met inclusion criteria for our hypothesis. No randomized, controlled studies were identified. A meta-analysis could not be performed as a result of the heterogeneity of the procedures and outcome measures. Definitive conclusions regarding the benefits of continuous passive motion postoperatively in knee cartilage surgery could not be made secondary to this heterogeneity. Continuous passive motion is commonly used postoperatively following cartilage surgery. Unfortunately, the clinical evidence (only 4 studies) to support the use of continuous passive motion is lacking despite an overwhelming abundance of basic science support and the common clinical practice of continuous passive motion implementation postoperatively in knee cartilage restoration procedures. There is a great need for well-conducted, high-level evidence studies to address this void in our literature.