Abstract
The lateral meniscus is more variable than the medial meniscus morphologically in size, thickness, shape, and mobility. The most common lateral meniscal variant is discoid in shape, which implies greater coverage of the tibia and usually increased thickness. Variants can be normal in shape but hypermobile due to abnormal insertions called unstable menisci, or abnormal in shape, such as ring-shaped meniscus. Other anomalies of the lateral meniscus include hypoplasias, abnormal insertions, and double-layered lateral meniscus.
The underlying causes of lateral meniscal abnormalities are multifactorial. Several theories try to explain the etiology of the variant lateral meniscus. Some authors favor a failure of formation due to phylogenetic incompletion; whereas others favor a congenital origin. Furthermore, different theories have been proposed that suggest a wide range of abnormalities leading to unstable meniscus presenting with similar symptoms often resulting in the “snapping knee” syndrome.
Since it was first described, several classifications were proposed using clinical, radiologic, and arthroscopic findings. Although most of these classifications are descriptive, newer systems focus on influencing treatment.
Discoid menisci are more prone to mechanical trauma because of their thickness, relatively bad vascularization, decreased amount of collagen fibers, and weak attachments to the posterior capsule. Therefore discoid menisci are associated with an increased incidence of tears. The most common tear pattern is degenerative horizontal cleavage tear.
Many stable lateral meniscal variants are asymptomatic and are found incidentally. The most common symptoms, which usually occur during childhood and adolescence, are a clunking sound with flexion of the knee, pain, decreased range of motion, joint line tenderness, sensation of a foreign object within the knee, quadriceps atrophy, and effusion. Lateral meniscal variation can be associated with other musculoskeletal anomalies. Osteochondral lesion of the lateral femoral condyle, high fibular head, fibular muscular defects, hypoplasia of the lateral femoral condyle with lateral joint-space widening, hypoplasia of the lateral tibial spine, abnormally shaped lateral malleolus of the ankle, and enlarged inferior lateral geniculate artery are examples of such anomalies.
The treatment options for the various lateral meniscal variants include observation, partial meniscectomy with or without reattachment, total meniscectomy, and for a normally shaped unstable lesion reattachment to the adjacent capsule. In order to properly choose the treatment method for the lateral meniscal variant, one must consider the age and activity level of the patient, the anatomy of the lesion, the duration and extent of the symptoms, and the amount of joint destruction. One must realize that the patient with a lateral meniscal variant usually has an abnormal knee at the outset. It must be kept in mind that there may be no good treatment option; rather, the only choice may be the lesser of two evils.
It is suggested that there is a need for early diagnosis and greater caution in the treatment of discoid lateral menisci. When evaluating the treatment outcome, Ikeuchi rating system and Lysholm knee scale are frequently used. Heightened awareness of the clinician to the possibility of discoid meniscus, its variable presentations and complications, and management considerations may improve therapeutic outcome.
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References
Achour, N.A., Tlili, K., Souei, M.M., Gamaoun, W., Jemni, H., Dali, K.M., Dahmen, J., Hmida, R.B.: Le menisque discoide chez l’enfant: aspects echographiques. J. Radiol. 87, 35–40 (2006)
Aglietti, P., Bertini, F.A., Buzzi, R., Beraldi, R.: Arthroscopic meniscectomy for discoid lateral meniscus in children and adolescents: 10-year follow-up. Am. J. Knee Surg. 12, 83–87 (1999)
Ahn, J.H., Shim, J.S., Hwang, C.H., Oh, W.H.: Discoid lateral meniscus in children: clinical manifestations and morphology. J. Pediatr. Orthop. 21(6), 812–816 (2001)
Ahn, J.H., Lee, Y.S., Ha, H.C., Shim, J.S., Lim, K.S.: A novel magnetic resonance imaging classification of discoid lateral meniscus based on peripheral attachment. Am. J. Sports Med. 37(8), 1564–1569 (2009)
Aichroth, P.M., Patel, D.V., Marx, C.I.: Congenital discoid lateral meniscus in children: a follow up study and evaluation of management. J. Bone Joint Surg. Br. 73, 932–939 (1991)
Albertsson, M., Gillquist, J.: Discoid lateral menisci: a report of 29 cases. Arthroscopy 4, 211–214 (1988)
Andrish, J.: Meniscal injuries in children and adolescents: diagnosis and management. J. Am. Acad. Orthop. Surg. 4, 231–237 (1996)
Arnold, M.P., Kampen, A.V.: Symptomatic ring-shaped lateral meniscus. Arthroscopy 16, 852–854 (2000)
As?k, M., Sen, C., Taser, Ö.F., Alturfan, A.K., Sözen, Y.V.: Discoid lateral meniscus: diagnosis and results of arthroscopic treatment. Knee Surg. Sports Traumatol. Arthrosc. 11(2), 99–104 (2003)
Atay, öA, Aydingöz, Ü., Doral, M.N., Tetik, O., Leblebicio?lu, G.: Symptomatic ring-shaped lateral meniscus: magnetic resonance imaging and arthroscopy. Knee Surg. Sports Traumatol. Arthrosc. 10, 280–283 (2002)
Atay, Ö.A., Doral, M.N., Leblebicio?lu, G., Tetik, O., Aydingöz, U.: Management of discoid lateral meniscus tears: observations in 34 knees. Arthroscopy 19(4), 346–352 (2003)
Atay, Ö.A., Pekmezci, M., Doral, M.N., Sargon, M.F., Ayvaz, M., Johnson, D.L.: Discoid meniscus: an ultrastructural study with transmission electron microscopy. Am. J. Sports Med. 35(3), 475–478 (2007). Epub 23 Jan 2007
Baratz, M.E., Fu, F.H., Mentago, R.: Meniscal tears: the effect of menisectomy and of repair on intra-articular contact areas and stress in the human knee. Am. J. Sports Med. 14, 270–274 (1986)
Bellier, G., Dupont, J.Y., Larrain, M., Caudron, C., Carlioz, H.: Lateral discoid menisci in children. Arthroscopy 5, 52–56 (1989)
Bin, S.I., Kim, J.C., Kim, J.M., Park, S.S., Han, Y.K.: Correlation between type of discoid lateral menisci and tear pattern. Knee Surg. Sports Traumatol. Arthrosc. 10, 218–222 (2002)
Burk Jr., D.L., Mitchell, D.G., Rifkin, M.D., Vinitski, S.: Recent advances in magnetic resonance imaging of the knee. Radiol. Clin. N. Am. 28, 379–393 (1990)
Casscells, S.W.: Gross pathological changes in the knee joint of the aged individual: a study of 300 cases. Clin. Orthop. 132, 225–232 (1978)
Clark, C.R., Ogden, J.A.: Development of the menisci of the human knee joint: morphological changes and their potential role in childhood meniscal injury. J. Bone Joint Surg. Am. 65, 538–547 (1983)
D’Lima, D.D., Copp, S.N., Colwell Jr., C.W.: Isolated lateral ring meniscus. Case report. Am. J. Knee Surg. 8(3), 117–118 (1995)
Davidson, D., Letts, M., Glasgow, R.: Discoid meniscus in children: treatment and outcome. Can. J. Surg. 46(5), 350–358 (2003)
Dickason, J.M., Del Pizzo, W., Blazina, M.E., Fox, J.M., Friedman, M.J., Snyder, S.J.: A series of ten discoid medial menisci. Clin. Orthop. 168, 75–79 (1982)
Dickhaut, S.C., DeLee, J.C.: The discoid lateral-meniscus syndrome. J. Bone Joint Surg. Am. 64, 1068–1073 (1982)
Fairbank, T.J.: Kneejoint changes after meniscectomy. J. Bone Joint Surg. Br. 30-B, 664–670 (1948)
Fujikawa, K., Iseki, F., Mikura, Y.: Partial resection of the discoid meniscus in the child’s knee. J. Bone Joint Surg. Br. 63, 391–395 (1981)
Good, C.R., Green, D.W., Griffith, M.H., Valen, A.W., Widmann, R.F., Rodeo, S.A.: Arthroscopic treatment of symptomatic discoid meniscus in children: classification, technique, and results. Arthroscopy 23(2), 157–163 (2007)
Hamada, M., Shino, K., Kawano, K., Araki, Y., Matsui, Y., Doi, T.: Usefulness of magnetic resonance imaging for detecting intrasubstance tear and/or degeneration of lateral discoid meniscus. Arthroscopy 10(6), 645–653 (1994)
Hayashi, L.K., Yamaga, H., Ida, K., Miura, T.: Arthroscopic meniscectomy for discoid lateral meniscus in children. J. Bone Joint Surg. Am. 70, 1495–1500 (1988)
Hong, C.N.: A ring-shaped lateral meniscus. Am. J. Knee Surg. 12, 109–110 (1999)
Ikeuchi, H.: Arthroscopic treatment of the discoid lateral meniscus: technique and long-term results. Clin. Orthop. 167, 19–28 (1982)
Irani, R.N., Karasick, D., Karasick, S.: A possible explanation of the pathogenesis of osteochondritis dissecans. J. Pediatr. Orthop. 4, 358–360 (1984)
Johnson, R., Beynnon, B.: Chapman’s Orthopaedic Surgery, 3rd edn, Lippincott, Williams & Wilkins, Philadelphia, 22, 2247–2269 (2001)
Johnson, R.G., Simmons, E.H.: Discoid medical meniscus. Clin. Orthop. 167, 176–179 (1982)
Jordan, M.R.: Lateral meniscal variants: evaluation and treatment. J. Am. Acad. Orthop. Surg. 4, 191–200 (1996)
Kaplan, E.B.: Discoid lateral meniscus of the knee joint. Bull. Hosp. Joint Dis. 16, 111–124 (1955)
Kerr, R.: Radiologic case study: discoid lateral meniscus. Orthopedics 8, 1142–1147 (1986)
Kim, J.M., Bin, S.I.: Meniscal allograft transplantation after total meniscectomy of torn discoid lateral meniscus. Arthroscopy 22(12), 1344–1350 (2006)
Kim, S.J., Jeon, C.H., Koh, C.H.: A ring shaped lateral meniscus. Arthroscopy 11, 738–739 (1995)
Kim, S.J., Kim, D.W., Min, B.H.: Discoid lateral meniscus associated with anomalous insertion of the medial meniscus. Clin. Orthop. 315, 234–237 (1995)
Kim, S.J., Yoo, J.H., Kim, H.K.: Arthroscopic one-piece excision technique for the treatment of symptomatic lateral discoid meniscus. Arthroscopy 12(6), 752–755 (1996)
Kim, S.J., Lee, Y.T., Choi, C.H., Kim, W.D.: A partially duplicated discoid lateral meniscus. Arthroscopy 14, 518–521 (1998)
Kim, Y.G., Ihn, J.C., Park, S.K., Kyung, H.: An arthroscopic analysis of lateral meniscal variants and comparison with MRI findings. Knee Surg. Sports Traumatol. Arthrosc. 14, 20–26 (2006)
Kroiss, F.: Die Verletzungen der Kniegelenkoszwischenknorpel und ihrer Verbindungen. Beitr. Klin. Chir. 66, 598–801 (1910)
Kurosawa, H., Koide, S., Nakajima, H.: Results of meniscectomy. Orthop. Surg. 27, 825–832 (1976)
Le Minor, J.M.: Comparative morphology of the lateral meniscus of the knee in primates. J. Anat. 170, 161–171 (1990)
Lee, D.H., Kim, T.H., Kim, J.M., Bin, S.I.: Results of subtotal/total or partial meniscectomy for discoid lateral meniscus in children. Arthroscopy 25(5), 496–503 (2009)
Manzione, M., Pizzutillo, P.D., Peoples, A.B., Schweizer, P.A.: Meniscectomy in children: a long-term follow-up study. Am. J. Sports Med. 11, 111–115 (1983)
Middleton, D.S.: Congenital discshaped lateral meniscus with snapping knee. Br. J. Surg. 24, 246–255 (1936)
Mitsuoka, T., Shino, K., Hamada, M., Horibe, S.: Osteochondritis dissecans of the lateral femoral condyle of the knee joint. Arthroscopy 15, 20–26 (1999)
Mizuta, H., Nakamura, E., Otsuka, Y., Kudo, S., Takagi, K.: Osteochondritis dissecans of the lateral femoral condyle following total resection of the discoid lateral meniscus. Arthroscopy 17, 608–612 (2001)
Monllau, J.C., Leon, A., Cugat, R., Ballester, J.: Ring-shaped lateral meniscus. Arthroscopy 14, 502–504 (1998)
Najafi, J., Bagheri, S., Lahiji, F.A.: The value of sonography with micro convex probes in diagnosing meniscal tears compared with arthroscopy. J. Ultrasound Med. 25, 593–597 (2006)
Nathan, P.A., Cole, S.C.: Discoid meniscus: a clinical and pathologic study. Clin. Orthop. 64, 107–113 (1969)
Neuschwander, D.C., Drez Jr., D., Finney, T.P.: Lateral meniscal variant with absence of the posterior coronary ligament. J. Bone Joint Surg. Am. 74, 1186–1190 (1992)
Noble, J.: Lesions of the menisci: autopsy incidence in adults less than fifty-five years old. J. Bone Joint Surg. Am. 59, 480–483 (1977)
Pellacci, F., Montanari, G., Prosperi, P., Galli, G., Celli, V.: Lateral discoid meniscus: treatment and results. Arthroscopy 8, 526–530 (1992)
Picard, J.J., Constantin, L.: Radiological aspects of the discoid meniscus. J. Radiol. Électrol. Méd. Nucl. 45, 839–841 (1964)
Raber, D.A., Friederich, N.F., Hefti, F.: Discoid lateral meniscus in children: long-term follow-up after total meniscectomy. J. Bone Joint Surg. Am. 8, 1579–1586 (1998)
Rao, P.S., Rao, S.K., Paul, R.: Clinical, radiologic, and arthroscopic assessment of discoid lateral meniscus. Arthroscopy 17(3), 275–277 (2001)
Rosenberg, T.D., Paulos, L.E., Parker, R.D., Harner, C.D., Gurley, W.D.: Discoid lateral meniscus: case report of arthroscopic attachment of a symptomatic Wrisberg-ligament type. Arthroscopy 3(4), 277–282 (1987)
Ryu, K.N., Kim, I.S., Kim, E.J., Ahn, J.W., Bae, D.K., Sartoris, D.J., Resnick, D.: MR imaging of tears of discoid lateral menisci. AJR Am. J. Roentgenol. 171(4), 963–967 (1998)
Shahriaree, H.: O’Conner’s Textbook of Arthroscopic Surgery, pp. 318–321. Lippincott, Philadelphia (1992)
Silverman, J.M., Mink, J.H., Deutsch, A.L.: Discoid menisci of the knee: MR imaging appearance. Radiology 173, 351–354 (1989)
Smillie, I.S.: The congenital discoid meniscus. J. Bone Joint Surg. Br. 30, 671–682 (1948)
Smith, C.F., Van Dyk, G.E., Jurgutis, J., Vangsness Jr., C.T.: Cautious surgery for discoid menisci. Am. J. Knee Surg. 12(1), 25–28 (1999)
Sugawara, O., Miyatsu, M., Yamashita, I., Takemitsu, Y., Onozawa, T.: Problems with repeated arthroscopic surgery in the discoid meniscus. Arthroscopy 7, 68–71 (1991)
Suzuki, S., Mita, F., Ogishima, H.: Double-layered lateral meniscus: a newly found anomaly. Arthroscopy 7(3), 267–271 (1991)
Tegner, Y., Lysholm, J.: Rating systems in the evaluation of knee ligament injuries. Clin. Orthop. 198, 43–49 (1985)
Terashima, T., Ohkoshi, Y., Yamamoto, K., Ebata, W., Nagasaki, S., Nishiike, J., Hashimoto, T., Yamane, H.: The pathogenesis of osteochondritis dissecans in the lateral femoral condyle associated with lateral discoid meniscus injury. Biennial congress of International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports Medicine (ISAKOS), Hollywood, 3–7 April 2005
Tetik, O., Doral, M.N., Atay, O.A., Leblebicio?lu, G., Türker, S.: Partial deficiency of the lateral meniscus. Arthroscopy 19(5), E42 (2003)
Vandermeer, R.D., Cunningham, F.K.: Arthroscopic treatment of the discoid lateral meniscus: results of long-term followup. Arthroscopy 5(2), 101–109 (1989)
Washington III, E.R., Root, L., Liener, U.C.: Discoid lateral meniscus in children. Long-term follow-up after excision. J. Bone Joint. Surg. 77-A(9), 1357–1361 (1995)
Watanabe, M., Takeda, Ikeuchi, H.: Atlas of Arthroscopy, 3rd edn, pp. 75–130. Igaku-Shoin, Tokyo (1979)
Watson-Jones, R.: Specimen of internal semilunar cartilage as a complete disc. Proc. R. Soc. Med. 23, 588 (1930)
Woods, G.W., Whelan, J.M.: Discoid meniscus. Clin. Sports Med. 9, 695–706 (1990)
Yaniv, M., Blumberg, N.: The discoid meniscus. J. Child. Orthop. 1, 89–96 (2007)
Yoshida, S., Ikata, T., Takai, H., Kashiwaguchi, S., Katoh, S., Takeda, Y.: Osteochondritis dissecans of the femoral condyle in the growth stage. Clin. Orthop. Relat. Res. 346, 162–170 (1998)
Young, R.: The external semilunar cartilage as a complete disc. In: Cleland, J., Mackay, J., Young, R. (eds.) Memoirs and Memoranda in Anatomy, p. 179. Williams & Norgate, London (1889)
Zaman, M., Leonard, M.A.: Meniscectomy in children: results in 59 knees. Injury 12, 425–428 (1981)
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Atay, Ö.A., Atay, Ö.A., Yilgör, İ.Ç., Yilgör, İ.Ç., Doral, M.N., Doral, M.N. (2012). Lateral Meniscal Variations and Treatment Strategies. In: Doral, M. (eds) Sports Injuries. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-15630-4_38
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