Meniscus ======== * Eric Wooltorton Meniscus: from the Greek *meniskos*, the diminutive of *mene* (moon).1 Two of these semi-lunar cartilages occupy each knee. Once described as muscle remnants and ascribed few functions, the menisci are now known to transmit tibio–femoral load, absorb shock, prevent synovial impingement, lubricate the joint and assist the surfaces in gliding over one another.2 ![Figure1](http://www.cmaj.ca/https://www.cmaj.ca/content/cmaj/166/1/70/F1.medium.gif) [Figure1](http://www.cmaj.ca/content/166/1/70/F1) Figure. **MRI of the knee. This coronal view demonstrates a tear (arrow) in the medial meniscus of a 59-year-old jogger. Also seen are the medial femoral condyle (M), the lateral femoral condyle (L) and the tibia (T).** Photo by: Courtesy: Dr. Lloyd Sly ![Figure2](http://www.cmaj.ca/https://www.cmaj.ca/content/cmaj/166/1/70/F2.medium.gif) [Figure2](http://www.cmaj.ca/content/166/1/70/F2) Figure. **Arthroscopic view of the edges of a medial meniscal tear, separated here by a surgical instrument, before their resection.** Photo by: Courtesy: Dr. Bill Smyth Meniscal injuries are common in intense athletic activities involving twisting, jumping and sudden deceleration — 2 of the 22 Olympic athletes admitted to Atlanta hospitals during the 1996 Olympic Games had meniscal tears3 — but can also occur through more benign mechanisms, presumably because of age-related meniscal degeneration.2 Symptoms of a meniscal tear can include “popping,” catching, locking and buckling of the knee, mild synovitis and joint line pain. Physical assessment for meniscal damage often includes the McMurray test.4 On its own, the McMurray test has limited sensitivity and specificity5 and is subject to a fair degree of interrater variability.6 In one study, 24 of 200 patients with a positive McMurray test result (12%) had paradoxical findings: a positive McMurray result on the unaffected side of the knee.7 MRI is often used in the diagnosis of meniscal tears, but it is an imperfect diagnostic tool. In one series of asymptomatic adults, MRI findings consistent with meniscal tears were found in 12 of 74 (16%) people.8 In 1806 the Lichtleiter, one of the earliest illuminated viewing devices, was invented to inspect vaginas, rectums and bladders.9 In 1918, Professor Kenji Takagi of Tokyo University used a cystoscope to inspect the knee of a cadaver, and in the 1950s, Dr. Masaki Watanabe, a former student of Takagi, developed the first truly functional arthroscopes. At the 1964 Tokyo Olympics, Canadian team orthopedic surgeon Robert Jackson started studying Watanabe's techniques and is credited with bringing arthroscopy to North America.10 Arthroscopy offered reduced pain and healing times in comparison with arthrotomy. In its 40th anniversary issue, *Sports Illustrated* named Jackson as one of the 40 people “who have most significantly altered or elevated the world of sports in the last four decades,”11 along with such notables as Wayne Gretzky, Muhammad Ali and Michael Jordan. There were 30 597 arthroscopies in Canada in 1999/2000 (Canadian Institute for Health Information: unpublished data), making it one of the most commonly performed orthopedic procedures in Canada. **Eric Wooltorton** *CMAJ* ## References 1. 1. Fortune R. *The words of medicine: sources, meanings, and delights.* Springfield (IL): Charles C. Thomas; 2001. p. 80. 2. 2. Rath E, Richmond JC. The menisci: basic science and advances in treatment. Br J Sports Med 2000;34:252-7. [FREE Full Text](http://www.cmaj.ca/lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiRlVMTCI7czoxMToiam91cm5hbENvZGUiO3M6ODoiYmpzcG9ydHMiO3M6NToicmVzaWQiO3M6ODoiMzQvNC8yNTIiO3M6NDoiYXRvbSI7czoxOToiL2NtYWovMTY2LzEvNzAuYXRvbSI7fXM6ODoiZnJhZ21lbnQiO3M6MDoiIjt9) 3. 3. Keim ME, Williams D. Hospital use by Olympic athletes during the 1996 Atlanta Olympic Games. Med J Aust 1997;167:603-5. [PubMed](http://www.cmaj.ca/lookup/external-ref?access_num=9418801&link_type=MED&atom=%2Fcmaj%2F166%2F1%2F70.atom) 4. 4. McMurray TP. The semilunar cartilages. Br J Surg 1942;29:407. [CrossRef](http://www.cmaj.ca/lookup/external-ref?access_num=10.1002/bjs.18002911612&link_type=DOI) [Web of Science](http://www.cmaj.ca/lookup/external-ref?access_num=000188111300011&link_type=ISI) 5. 5. Fowler PJ, Lubliner JA. The predictive value of five clinical signs in the evaluation of meniscal pathology. Arthroscopy 1989;5:184-6. [CrossRef](http://www.cmaj.ca/lookup/external-ref?access_num=10.1016/0749-8063(89)90168-0&link_type=DOI) [PubMed](http://www.cmaj.ca/lookup/external-ref?access_num=2775390&link_type=MED&atom=%2Fcmaj%2F166%2F1%2F70.atom) 6. 6. Dervin GF, Stiell IG, Wellas GA, Rody K, Grabowski J. Physicians' accuracy and interrator reliability for the diagnosis of unstable meniscal tears in patients having osteoarthritis of the knee. Can J Surg 2001; 44(4): 267-74. [PubMed](http://www.cmaj.ca/lookup/external-ref?access_num=11504260&link_type=MED&atom=%2Fcmaj%2F166%2F1%2F70.atom) [Web of Science](http://www.cmaj.ca/lookup/external-ref?access_num=000170279700010&link_type=ISI) 7. 7. Kim SJ, Min BH, Han DY. Paradoxical phenomena of the McMurray test. An arthroscopic investigation. Am J Sports Med 1996;245(1):83-7. 8. 8. Boden SD, Davis DO, Dina TS, Stoller DW, Brown SD, Vailas JC, et al. A prospective and blinded investigation of magnetic resonance imaging of the knee. Abnormal findings in asymptomatic subjects. Clin Orthop 1992;282: 177-85. [PubMed](http://www.cmaj.ca/lookup/external-ref?access_num=1516310&link_type=MED&atom=%2Fcmaj%2F166%2F1%2F70.atom) 9. 9. Bush RB, Leonhardt H, Bush IV, Landes RR. Dr. Bozzini's lichtleiter. A translation of his original article. Urology 1974;3(1):119-23. [CrossRef](http://www.cmaj.ca/lookup/external-ref?access_num=10.1016/S0090-4295(74)80080-4&link_type=DOI) [PubMed](http://www.cmaj.ca/lookup/external-ref?access_num=4591409&link_type=MED&atom=%2Fcmaj%2F166%2F1%2F70.atom) 10. 10. Andrews JR, Timmerman LA, editors. *Diagnostic and operative arthroscopy*. Philadelphia: WB Saunders; 1997. 11. 11. Hoffer R. Arthroscopic surgery for athletes. Sports Illus 1994;81:138-9.