Acute anterolateral rotatory instability of the knee
Norwood, L.A.; Andrews, J.R.; Meisterling, R.C.; Glancy, G.L.
Journal of Bone and Joint Surgery. American Volume 61(5): 704-709
1979
ISSN/ISBN: 0021-9355 PMID: 582318 Document Number: 140637
Consecutive knees [36] with acute anterolateral rotatory instability were reviewed to document the ligamentous and meniscal injuries and to evaluate the value of the jerk test and anterior drawer test in diagnosing anterolateral rotatory instability. At surgery, the anterior cruciate ligament and the midthird of the lateral capsular ligament were torn in 21 knees; the lateral capsular ligament alone in 6 knees; the anterior cruciate ligament alone in 4 knees; the anterior cruciate ligament lateral capsular ligament and fibers of the iliotibial tract in 3 knees; and the anterior cruciate ligament and iliotibial tract fibers in 2 knees. The lateral meniscus tear was the sole meniscal injury in 14 knees and the medial meniscus tear was the sole meniscal injury in 5 knees. Both the medial and the lateral menisci were torn in 6 knees, and 11 knees had no meniscal injury. The anterior drawer test, done with the tibia in neutral rotation, was the most sensitive test for anterolateral rotatory instability and was prevented by hamstring spasm. The jerk test was frequently guarded against by the patient, and was positive on the initial examination in only 9 of 36 knees. The anterior drawer test was positive in 14 of 36 knees on initial examination. Each test was markedly positive at examination under anesthesia prior to surgery. Four knees with acute anteromedial rotatory instability had unexpected anterolateral instability demonstrated on examination under anesthesia prior to surgical repair of the acute medial compartment injury. Knees with acute anteromedial rotatory instability should also be examined for anteriolateral rotatory instability under anesthesia prior to surgical repair of the medial ligaments.