A prospective audit of knee arthroscopy: a study of the accuracy of clinical diagnosis and therapeutic value of 325 knee arthroscopies.

A prospective audit of 321 patients (325 knees) placed on the waiting list for arthroscopy revealed an accuracy of the preoperative diagnosis of 57%. The accuracy of consultants was 71% and the other grades of staff was 49%. The operation treated a pathological lesion and was considered to be therapeutic in 154 knees (47%); an operation was more likely to be therapeutic when the preoperative diagnosis was correct (132 knees) than when the diagnosis was incorrect (22 knees). Attention to establishing an accurate preoperative diagnosis and close supervision of the waiting lists by consultants will reduce the number of non-therapeutic arthroscopies.