[The value of the radiologic Lachman test in anterior cruciate ligament ruptures].

A radiologic Lachman test of both knees was performed in 35 patients with surgically verified tears of the anterior cruciate ligament (ACL). We found a mean anterior drawer of 3.2 mm for uninjured joints, 4.5 mm for isolated ACL-tears and 10.8 mm for complex ACL-injuries. Sensitivity of the radiological Lachman test was 95% for complex ACL-injuries as only 23% in case of isolated ACL-ruptures. Failure of diagnosis due to clinical investigation in case of ACL-ruptures could not be proved by means of radiological Lachman-test. Technical requirements and radiation exposure are further disadvantages. Clinically doubtful cases of acute knee injuries should therefore be investigated with other diagnostic procedures.