Kellgren–Lawrence scoring system underestimates cartilage damage when indicating TKA: preoperative radiograph versus intraoperative photograph

Introduction The Kellgren–Lawrence score helps the orthopedic surgeon to classify the severity of knee osteoarthritis (OA) before total knee arthroplasty (TKA). There might be a discrepancy between subjective complaints of the patients and radiologically visible changes of the knee joint in many cases. In this context, we performed a prospective clinical study to compare the preoperative degree of knee OA using the Kellgren–Lawrence score with the intraoperative extent of cartilage damage during primary TKA.