MENISCAL INJURY

tive tears tend to have less mechanical problems.

Special functional tests for internal derangement The description and use of these tests has been described in several previous issues of sportEX medicine and therefore won’t be repeated here (see sportEX medicine issue 14 (p11), issue 7 (p8-9 in detail, p14)).

Collateral ligament injury is diagnosed by performing the abduction or adduction stress tests in 30 degrees of flexion for the medial and lateral ligaments respec- tively (Fig 6.). More significant injury may result in medial joint laxity in extension. There are a myriad of tests for integrity of cruciate ligaments and the menisci, which have resulted in a number of papers to determine sensitivity and specificity of the individual tests against subsequent

Anterior drawer test Specificity range 23% to 100% with mean of 67% Sensitivity range 9% to 93% with a mean of 62%

Lachman test Specificity only reported in 1 paper (10) as 100% Sensitivity range 60% to 100% with mean of 84%

Pivot shift test Specificity not reported Sensitivity range 27% to 95% with a mean of 38%

Box 3: Sensitivity and specificity of 3 tests for ACL injury

McMurray test Mean sensitivity 53% Mean specificity 59%

Apley compression test 1 study (11) Sensitivity 16% Specificity not tested

Joint effusion 1 study (12) Sensitivity 35% Specificity 100%

Box 4: Sensitivity and specificity of 3 tests for meniscal injuries

12 SportEX

Summary of examination ● Alignment of femur, tibia and patella in standing and walking ● Range of active and passive flexion and extension ● Is there a fluid wave or ballottement of the patella to indicate effusion? ● Joint line tenderness ● Lachman test supine and prone ● Anterior drawer test ● Posterior drawer test or posterior sag ● Lateral pivot shift ● McMurray test

arthroscopy. There have been problems with some of the study designs, particu- larly in performing clinical laxity tests in a consistent manner to minimise inter and intra observer error.

Three studies report on full examination for ACL injuries without specifying exami- nation techniques (6-8). The sensitivity for ACL injures was more than 82% and the specificity was more than 94%. A number of other studies have identified the specific examination manoeuvres, anterior drawer test, Lachman and pivot shift, although it is not clear from a num- ber of the papers whether examination took place under anaesthetic (see shaded box on the left).

My personal preference for examination of the ACL is a ‘reverse Lachman test’. This was taught to me by a physiotherapist (the author of the next article) and is a Lachman test in prone lying, when the hamstrings are much more relaxed and forward translation of the tibia on the femur is easily felt.

There are a number of studies that have also investigated the diagnostic accuracy of the examination for meniscal injuries, using arthroscopy as the reference stan- dard. Five reported results from a combi- nation of examination techniques, with mean sensitivity of 77% and mean speci- ficity of 15%.

Imaging Conventional arthrography can demon- strate meniscal tears, but MRI has super- seded this because it is non-invasive, more accurate and can demonstrate dis- placed meniscal fragments, insubstance meniscal changes, parameniscal cysts and other changes. Pre-operative diagnosis based on good clinical examination suggests that there is little cost benefit to

performing MRI, and the role of imaging is to help exclude other pathology such as osteochondral fracture, which can mimic or accompany an injured meniscus.

Surgical colleagues may request imaging in order to help decide between primary meniscal repair and partial menisectomy, although this decision is frequently left until arthroscopy. The goal is to preserve meniscal tissue whenever possible, and tears involving the outer two thirds of a meniscus may be candidates for repair.

Summary Meniscal tears can occur in isolation or combination with other pathology. They can be of a traumatic or degenerative nature, and may be asymptomatic or cause mechanical problems. A history of mechanical dysfunction such as locking or clicking in association with effusion, joint line tenderness and positive McMurray’s suggests arthroscopic intervention may be indicated.

References 1. Cunningham LS, Kelsey JL. Epidemiology of musculoskeletal impairments and associated disability. Am J public Health. 1984;74:574- 579. 2. Wright V, Helliwell PS. Undergraduate educa- tion in musculoskeletal diseases. Br J Rheumatol. 1992;31:279-280. 3. Shrive NG, O’Connor JJ, Goodfellow JW. Loadbearing in the knee joint. Clin Orthop. 1978;131:279-287. 4. Rath E, Richmond JC. The menisci: basic sci- ence and advances in treatment. Br J Sports Med. 2000;34:252-257. 5. Boden SD, Davis DO, Dina TS, et al. A prospective and blinding investigation of mag- netic resonance imaging of the knee; abnormal findings in asymptomatic subjects. Clin Orthop. 1992;282:177-185. 6. Simonsen O, Jensen J, Mouritsen P, Lauritsen J. The accuracy of clinical examination of injury to the knee joint. Injury. 1984;16:96-101. 7. O’Shea KJ, Murphy KP, Heekin RD, Herzwurm PJ. The diagnostic accuracy of history, physical examination and radiographs in the evaluation