Magnetic resonance imaging of anterior cruciate ligament rupture

BACKGROUND: Magnetic resonance (MR) imaging is a useful diagnostic tool for the assessment of knee joint injury. Anterior cruciate ligament repair is a commonly performed orthopaedic procedure. This paper examines the concordance between MR imaging and arthroscopic findings. METHODS: Between February, 1996 and February, 1998, 48 patients who underwent magnetic resonance (MR) imaging of the knee were reported to have complete tears of the anterior cruciate ligament (ACL). Of the 48 patients, 36 were male, and 12 female. The average age was 27 years (range: 15 to 45). Operative reconstruction using a patellar bone-tendon-bone autograft was arranged for each patient, and an arthroscopic examination was performed to confirm the diagnosis immediately prior to reconstructive surgery. RESULTS: In 16 of the 48 patients, reconstructive surgery was cancelled when incomplete lesions were noted during arthroscopy, making reconstructive surgery unnecessary. The remaining 32 patients were found to have complete tears of the ACL, and therefore underwent reconstructive surgery. Using arthroscopy as an independent, reliable reference standard for ACL tear diagnosis, the reliability of MR imaging was evaluated. The true positive rate for complete ACL tear diagnosis with MR imaging was 67%, making the possibility of a false-positive report of "complete ACL tear" inevitable with MR imaging. CONCLUSIONS: Since conservative treatment is sufficient for incomplete ACL tears, the decision to undertake ACL reconstruction should not be based on MR findings alone

The Coronal Plane High Tibial Osteotomy. Part II: A Comparison of Axial Rotation with the Opening Wedge High Tibial Osteotomy

The amount of axial rotation in the tibia caused by high tibial osteotomy is relatively unknown. The authors hypothesize that the coronal plane high tibial osteotomy, a novel technique used to treat varus malalignment, alters the axial rotation of the tibia less than the opening wedge high tibial osteotomy. Eight, embalmed, stripped cadaveric tibia–fibula constructs with intact interosseous membranes were randomized to either opening wedge or coronal plane high tibial osteotomies. Sequential valgus corrections of 5°, 10°, and 15° were performed. The Qualisys Track Manager motion capture system was used to measure axial rotation. Student’s t test was used to compare axial rotation between the two groups. A p value of 0.05 was determined to be significant. The coronal plane technique produced rotations about the tibial axis that were statistically significantly smaller than those of the opening wedge technique for all correction angles (1.2° internal rotation (IR) vs 16° external rotation (ER), respectively, at 5° correction; p = 0.02) (3.5° IR vs 21.2° ER at 10° correction; p = 0.04) (4.5° IR vs 23.0° ER at 15° correction; p = 0.01). The coronal plane high tibial osteotomy alters axial rotation of the tibia significantly less than the opening wedge high tibial osteotomy