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.
Tsai
Kai-Jow
KJ
Department of Orthopaedic Surgery, Cathay General Hospital, Taipei, Taiwan. tsaikj@ms2.hinet.net
Chiang
Hongsen
H
Jiang
Ching-Chuan
CC
D000293:Adolescent; D000328:Adult; D016118:Anterior Cruciate Ligament / Q000473:pathology / Q000601:surgery; D000070598:Anterior Cruciate Ligament Injuries; D001182:Arthroscopy; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000175:diagnosis / Q000473:pathology / Q000601:surgery / Q000628:therapy; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010329:Patella / Q000637:transplantation; D019651:Plastic Surgery Procedures; D012421:Rupture / Q000175:diagnosis / Q000473:pathology / Q000601:surgery / Q000628:therapy; D013710:Tendons / Q000637:transplantation; D014182:Transplantation, Autologous; D019564:Unnecessary Procedures