diagnosis
The injured knee should be compared with the contralateral knee (1)
In the acute setting, possible associated injuries such as multi ligament injuries or knee dislocation should be ruled out (1).
Examination of the knee for ACL tears involves the following:
- Lachman's test - sensitivity of 60% to 100%; mean 84%
- anterior drawer test - sensitivity of 9% to 93%; mean 62%
- pivot shift test - sensitivity of 27% to 95% mean 62% (1,2)
Imaging
- plain x-ray
- should be the first imaging study in patients with suspected ACL injury
- findings may include ligament injury and associated fractures
- MRI
- provides excellent soft tissue detail of the site of ACL injury
- helps in evaluating associated
- meniscal tears - seen in approximately 60 to 75% of ACL injuries
- collateral ligament injuries - seen in upto 46% of ACL injuries
- bone bruises, occult fractures, chondral injuries (1,2)
Reference:
- (1) Alford JW, Bach BR. Examination through familiarity with basics and a systemic approach. Managing ACL tears:Evaluation and diagnosis. The journal of musculoskeletal medicine 2004
- (2) Cimino F, Volk BS, Setter D.Anterior cruciate ligament injury: diagnosis, management, and prevention. Am Fam Physician. 2010;82(8):917-22.