Factors correlating with patients' satisfaction after undergoing cartilage repair surgery-data from the German Cartilage Registry (KnorpelRegister DGOU).

Subjective patient satisfaction is the most relevant parameter for assessing the success of treatment after orthopaedic surgery. The aim of the present study was to correlate patient-reported outcome parameters (i.e., absolute KOOS, KOOS increase) and revision-free survival with patient's satisfaction. Furthermore, the study aimed on the identification of pre-operative factors that are associated with patient's satisfaction after the surgery.For the present study, 6305 consecutive patients from the German Cartilage Registry (KnorpelRegister DGOU) were analyzed. Patient characteristics and outcome were correlated with patients' satisfaction after a follow-up of three years by Spearman correlation. P values < 0.05 were considered statistically significant.Mean age was 37 ± 12.5 years, 59.7% patients were male, and 40.3% female. Most patients (46.7%) were treated with an autologous chondrocyte implantation (ACI). The strongest correlation of subjective satisfaction and the subscore quality of life (r = 0.682; p < 0.001) was found, whereas the post-operative increase in KOOS from the pre-operative value showed only a moderate correlation (r = 0.520; p < 0.001). There was also a significant correlation with the absolute KOOS value (r = 0.678; p < 0.001), the subscores pain (r = 0.652; p < 0.001), quality of life (r = 0.682; p < 0.001), and sports (r = 0.633; p < 0.001), whereas symptoms (r = 0.504, p < 0.001) and activities of daily life (r = 0.601; p < 0.001) showed a weaker correlation. Pain also correlated highly significant with the patient satisfaction 24 months after surgery (r = - 0.651, p < 0.001). The correlation between satisfaction after the 2nd and 3rd year (r = 0.727; p < 0.001) is stronger than correlation after six months and three years (r = 0.422, p < 0.001). All pre-operative parameters show a very weak correlation (r < 0.1).The use of standardized measuring instruments (KOOS and Pain) is a relevant outcome parameter in science and clinical practice, whereas absolute values represent satisfaction better than the individual increase. The subscores "pain," "quality of life," and "sports" represent satisfaction better than the subscores "symptoms" and "activity of daily life." Early satisfaction has only a moderate predictive value for satisfaction after 3 years, which is of great practical relevance in particular for the assessment of potential treatment failures. It is remarkable to note that a revision surgery is only very mildly associated with increased dissatisfaction. Pre-operative factors are not reliable prediction factors for post-operative patient satisfaction.