The acutely locked knee--is a manipulation worth while?

Over a 10-year period, 85 consecutive patients presented to the Accident and Emergency Department with an acutely locked knee and were all treated by manipulation under anaesthesia. Out of 69 patients who could be adequately followed up, 46 (67 per cent) subsequently required arthrotomy for an internal derangement. In 41 of these patients there was a bucket-handle tear of a meniscus. Twenty-three patients (33 per cent) made a full recovery from manipulation alone. In view of the high incidence of correctable lesions, immediate arthroscopy and, if necessary, definitive operation would be a better treatment for the acutely locked knee.