OBJECTIVETo study the examination,surgical opportunity and surgery methods of lost instability of traumatic dislocation of the knee joint.

METHODSSixty-three patients (48 males and 15 females,ranging in age from 16 to 75 years,with an average of 36.6 years) were checked, treated and followed up from January 2001 to April 2006. According to classification of Wascher for knee dislocation, there was 1 case of KD-I, 13 KD-II, 17 KD-III, 18 KD-IV, 14 KD-V. Stability of the knee was evaluated by physical and radiological examinations, of which 53 patients were treated with open surgery, 4 patients were treated with arthroscope, 4 patients were treated with arthroscope and open surgery, 1 patient was treated with amputation, 1 patient was treated with total knee arthroplasty.

RESULTSThe detection rate of MRI was 100% (39/39), stress radiography was 100% (19/19), arthroscpoe was 93.3% (14/15). According to Lysholm Criteria for knee joint function,the preoperative Lysholm score in old traumatic group was 37.17 +/- 5.33, fresh traumatic group was 37.41 +/- 5.38. The postoperative Lysholm score in old traumatic group was 67.33 +/- 14.72, fresh traumatic group was 82.45 +/- 12.13 (Z = -3.061, P = 0.002).

CONCLUSIONMRI stress radiography and arthroscope do well for the evaluation of stability of the knee. Instable traumatic dislocation of the knee joint must be operated promptly. Fresh instable dislocations of knee prefer repair,old instable dislocations of knee prefer reconstruction.