Measuring Outcomes in Knee Articular Cartilage Pathology

Measuring outcomes following treatment of knee articular cartilage lesions is crucial to determine the natural history of disease and the efficacy of treatments. Outcome assessments for articular cartilage treatments can be clinical (based on failure, lack of healing, reoperation, need for arthroplasty), radiographic (X-ray, MRI), histologic, or patient reported and functional. The purpose of this review is to discuss the application and properties of patient-reported outcomes (PROs) with a focus on articular cartilage injuries and surgery in the knee. The most frequently used and validated PROs for knee articular cartilage studies include: the Knee injury and Osteoarthritis and Outcome Score, International Knee Documentation Committee Subjective Knee Form, and Lysholm score as knee-specific measures; the Marx Activity Rating Scale and Tegner Activity Scale as activity measures; and EQ-5D and SF-36/12 as generic quality-of-life measures. Incorporating these validated PROs in studies pertaining to knee articular cartilage lesions will allow researchers to fully capture clinically relevant outcomes that are most important to patients.