Arthroscopic assessment of cartilage repair: a validation study of 2 scoring systems

Purpose: This study tested the validity and reliability of the International Cartilage Repair Society (ICRS) cartilage repair assessment and the Oswestry Arthroscopy Score (OAS), which have been designed to assess repair of articular cartilage. Type of Study: Prospective validation study of arthroscopic cartilage repair scores. Methods: Arthroscopic videos were assessed by a panel of orthopaedic surgeons specializing in cartilage repair. Scoring was repeated after a 2-month interval. Scorers also answered a questionnaire to assess the face and content validity of the scoring systems. Validity of the 2 systems was compared and reliability and repeatability were measured. Pearson's correlation coefficient was used to measure equivalence reliability. The interclass correlation coefficient (ICC) was used to assess the repeatability and inter-rater reliability of each score, and internal consistency was assessed with Cronbach's alpha. Results: Face and content validity are acceptable for both scores. There is good agreement (equivalence reliability) between the scores (Pearson's correlation coefficient, r =.88; P 0.7 for each score. Cronbach's alpha was 0.91 for ICRS and 0.82 for OAS, indicating better internal consistency for the ICRS score. Conclusions: The ICRS and OAS arthroscopic scores have been validated for the assessment of cartilage repair and both have been found to be statistically reliable and repeatable. The ICRS score does not allow for graft hypertrophy and may overscore in this situation, whereas the OAS includes assessment of graft stiffness. Both scores show satisfactory stability and repeatability. Internal consistency is adequate for both scores, although it is higher for the ICRS score. Both the ICRS and OAS arthroscopic scores are effective tools in the evaluation of cartilage repair. Level of Evidence: Level III, diagnostic study of nonconsecutive patients (no consistently applied reference gold standard)