Progress on study of factors influencing the prognosis and complications of surgery for discoid meniscus injury in children / 中国骨伤

The discoid meniscus is a common congenital meniscal malformation that is prevalent mainly in Asians and often occurs in the lateral discoid meniscus. Patients with asymptomatic discoid meniscus are usually treated by conservative methods such as observation and injury avoidance, while patients with symptoms and tears need to be treated surgically. Arthroscopic saucerization combined with partial meniscectomy and meniscus repair is the most common surgical approach., and early to mid-term reports are good. The prognostic factors are the patient's age at surgery、follow-up time and type of surgery. Some patients experience complications such as prolonged postoperative knee pain, early osteoarthritis, retears and Osteochondritis dissecans. The incidence of prolonged postoperative knee pain was higher and the incidence of Osteochondritis dissecans was the lowest. Retears of the lateral meniscus is the main reason for reoperation.

Observation for curative effect of different surgical arthroscopy on treatment for the discoid meniscus injury in knee joint / 中国医学装备

Objective:To observe the curative effect of different surgical arthroscopy on treatment for the discoid meniscus injury in knee joint.Methods: The clinical data of 78 patients with discoid meniscus injury who received treatment of arthroscopic minimally invasive surgical were retrospectively studied. 42 patients were complete discoid meniscus injury, and 36 patients were incomplete discoid meniscus injury in the 78 cases. The 42 patients with discoid meniscus injury of complete type were divided into observation 1 group (22 cases) and observation 2 group (20 cases), and the 36 patients with discoid meniscus injury of incomplete type were divided into control 1 group (19 cases) and control 2 group(17 cases). The patients of observation 1 group and control 1 group were treated with complete resection operation, and the patients of observation 2 group and control 2 group were treated with partial resection arthroplasty. The knee physiological function of all patients before and after treatment were assessed by using Lysholm knee function score and the subjective assessment table of International Knee Joint Documentation Committee (IKDC) for knee, and the curative effects of each group was compared.Results: After treatment, the Lysholm and IKDC scores of 4 groups significantly increased than that of before treatment(P<0.05), and the Lysholm and IKDC scores of observation 1 group was significantly higher than that of observation 2 group (t=9.193,t=9.065,P<0.05). But there was no statistically significant difference between the control 1 group and control 2 group about Lysholm and IKDC scores (t=0.874, t=0.891,P>0.05). The excellent rate of the observation 2 group was significantly lower than that of observation 1 group(x2=5.292,P<0.05), while the difference of the excellent rate between the control 1 group and the control 2 group was no statistically significant (x2=0.734,P>0.05).Conclusion: All of patients with discoid meniscus injury of knee joint receives different surgical treatment under arthroscopy can obtain good effect, but the curative effect of patients with discoid meniscus injury of complete type who receives completely excision is significantly better than that of who receives partial resection arthroplasty.

Observation for curative effect of different surgical arthroscopy on treatment for the discoid meniscus injury in knee joint / 中国医学装备

Objective:To observe the curative effect of different surgical arthroscopy on treatment for the discoid meniscus injury in knee joint.Methods: The clinical data of 78 patients with discoid meniscus injury who received treatment of arthroscopic minimally invasive surgical were retrospectively studied. 42 patients were complete discoid meniscus injury, and 36 patients were incomplete discoid meniscus injury in the 78 cases. The 42 patients with discoid meniscus injury of complete type were divided into observation 1 group (22 cases) and observation 2 group (20 cases), and the 36 patients with discoid meniscus injury of incomplete type were divided into control 1 group (19 cases) and control 2 group(17 cases). The patients of observation 1 group and control 1 group were treated with complete resection operation, and the patients of observation 2 group and control 2 group were treated with partial resection arthroplasty. The knee physiological function of all patients before and after treatment were assessed by using Lysholm knee function score and the subjective assessment table of International Knee Joint Documentation Committee (IKDC) for knee, and the curative effects of each group was compared.Results: After treatment, the Lysholm and IKDC scores of 4 groups significantly increased than that of before treatment(P<0.05), and the Lysholm and IKDC scores of observation 1 group was significantly higher than that of observation 2 group (t=9.193,t=9.065,P<0.05). But there was no statistically significant difference between the control 1 group and control 2 group about Lysholm and IKDC scores (t=0.874, t=0.891,P>0.05). The excellent rate of the observation 2 group was significantly lower than that of observation 1 group(x2=5.292,P<0.05), while the difference of the excellent rate between the control 1 group and the control 2 group was no statistically significant (x2=0.734,P>0.05).Conclusion: All of patients with discoid meniscus injury of knee joint receives different surgical treatment under arthroscopy can obtain good effect, but the curative effect of patients with discoid meniscus injury of complete type who receives completely excision is significantly better than that of who receives partial resection arthroplasty.

Curative effect of arthroscopic surgery on knee joint disease in children / 中华实用儿科临床杂志

Objective To analyze the clinical characteristics of children with knee joint diseases and discuss the curative effect of arthroscopy.Methods Eighty-nine children with knee joint diseases in Department of Orthopedics,the First Affiliated Hospital of Xinxiang Medical University from October 2012 to October 2015 were selected,and they were given knee arthroscopic surgery according to the disease types and characteristics,such as meniscal suture,suture plus angioplasty and synovectomy etc.All the symptoms,signs and the joint functions were recorded preoperatively and postoperatively.At the end of follow-up,surgical results were analyzed according to Lysholm score and International Knee Documentation Committee Knee evaluation form (IKDC) classification standard.Results The patients with discoid meniscus tear were the most,accounting for 55.55％ (55/99 knees).All patients were followed up for 6-30 months(the average time was 21 months) to find that all symptoms were relieved or disappeared within 1 year after operation.The outcome was evaluated according to the Tegner knee function:76 knees (76.76％) were markedly effective,16 knees (16.16％) were effective,6 knees (6.06％) were invalid and 1 knee (1.01％) was poor,and the excellent rate was 92.92％.The curative effect was evaluated according to Lysholm knee function score and IKDC score at the last follow-up.The Lysholm score in preoperation [(52.46 ± 4.79) scores] improved to (96.52 ± 3.97) scores in postoperation,and the difference was significant (t =-36.24,P ＜ 0.05);the IKDC score in preoperation [(46.52 ± 10.25) scores] improved to (90.67-± 5.89) scores in postoperation,and the difference was significant (t =-50.69,P ＜ 0.05).There was no joint infection,blood vessel or nerve damage and so on.Conclusions Meniscus tear is common in children with knee joint diseases,and most common is discoid lateral meniscus tear,and arthroscopy can have satisfactory outcome,with no obvious complications.Therefore,arthroscopic surgery is an ideal method for surgical treatment of children with knee joint disease.

Bilaterally Simultaneous Medial and Lateral Discoid Menisci / 대한정형외과학회잡지

Most discoid menisci are lateral and medial discoid meniscus is very rare. Several articles have reported on bilateral lateral discoid menisci as well as bilateral medial discoid menisci, and a few articles have reported simultaneous medial and lateral discoid menisci in the same knee. Only one case of simultaneous medial and lateral discoid menisci, bilaterally, has been reported. We present another case of a male patient with bilaterally simultaneous medial and lateral discoid menisci, diagnosed with magnetic resonance imaging and arthroscopy. The patient was treated by arthroscopic partial meniscetomy.

Treatment of discoid meniscus injury by arthroscopic surgery / 中国综合临床

Objective To investigate the bettertherapeutic method and clinical efficacy of discoid meniscus injury under arthroscope.Methods Forty-one patients with discoid meniscus injury were selected as our subjects from Nov.2011 to Feb.2013,who were treated by arthroscopic surgery and performed with meniscus plasty.Thirt-eight patients were received ultra Fast-fix meniscal repair system.Joint function exercises were performed on bed within 1 month after operation.Incomplete weight bearing were performed after 1 month postoperation.After 3 month postoperation,they were permitted for full weight bearing.Results All patients were treated successfully with surgery and no postoperative complications occurred.The patients were followed up from 3.0 to 18.0 months and average was 10.5 months.The preoperative Lysholm scores were(68.28 ±8.04)) lower than that at the postoperation (88.17 ± 7.49)) and the difference were significant (t =11.59,P ＜ 0.05).Furthermore,according to Ikeuchi criterion,the outcomes were 28 cases with excellent,10 cases with good and 3 cases with general rank.Conclusion Discoid meniscus plasty and suture under arthroscope is proved to be a better approach with less trauma,recovery quickly and fewer complications.It should be a preferred method for discoid meniscus injury.

Ressonância magnética na avaliação das variações anatômicas meniscais e da anatomia ligamentar perimeniscal: potenciais causas de erro de interpretação / Magnetic resonance imaging in the assessment of meniscal anatomic variants and of the perimeniscal ligamentous anatomy: potential interpretation pitfalls

O conhecimento adequado das variações anatômicas meniscais e das estruturas perimeniscais é essencial para uma avaliação adequada dos exames de ressonância magnética do joelho, tanto no diagnóstico das lesões meniscais quanto para se evitar uma série de possíveis erros diagnósticos. Este artigo revê variações anatômicas que alteram o tamanho, a forma e a estabilidade meniscais e que incluem os vários tipos de menisco discoide, outras variações morfológicas meniscais menos frequentes e o ossículo meniscal. Também é revisada a anatomia de estruturas perimeniscais, principalmente ligamentares, que incluem os ligamentos meniscocapsulares, intermeniscais, meniscofemorais e extensões meniscoligamentares.

The knowledge of meniscal anatomic variants and of the normal perimeniscal structures is essential to understand magnetic resonance imaging studies of the knee, both for the diagnosis of meniscal lesions and to avoid potential interpretation pitfalls. The present article reviews anatomic variants that change the size, shape and stability of the menisci, including the different types of discoid menisci, other less frequent meniscal malformations and the meniscal ossicle. Additionally, the anatomy of perimeniscal structures, particularly those including the meniscocapsular, intermeniscal, meniscofemoral ligaments and other menisco-ligamentous structures is reviewed.

Comparison of Clinical Results for Repairing Lateral Discoid Meniscus Tear between the Contouring Surgery Group and the Additional Repair Group

PURPOSE: We aimed to compare the clinical results of treating lateral discoid meniscus tear between the contouring surgery group and the additional repair group. MATERIALS AND METHODS: We evaluated 60 cases (58 patients) with lateral discoid meniscus tear and who were arthroscopically treated between September 2003 and February 2007 and we followed them for at least two years. The sixty cases were divided into two groups: thirty-two cases underwent contouring surgery (Group A) and twenty-eight cases underwent contouring surgery and repair (Group B). The duration of symptoms, the tear patterns and clinical results between the two groups were investigated. RESULTS: The most frequent types of tear pattern were longitudinal and central hole tears in group A, while complex tear was most common in group B. The mean duration of the symptoms was 5.6 months (range: 1~24) in group A and 16.6 months (range: 1~84) in group B, which was statistically significant (p=0.025). Based on Ikeuchi's grading, the proportions with good or excellent outcomes were not different between the two groups (p=0.12). However, group A had a larger proportion of excellent outcomes (p=0.031) than group B. CONCLUSION: The contouring surgery and additional repair group had a significant longer duration of symptoms, a more complex tear pattern and less excellent results than did the contouring group.

MRI Classification and Manifestations of Discoid Meniscus / 中国医学影像学杂志

Purpoes: To discuss the MRI manifestation and classification of discoid lateral meniscus and improve the accuracy of MRI diagnosis for discoid meniscus.Materials and Methods: 70 cases of discoid meniscus verified by arthroscopy were divided into impuberal group(n=30) and adult group (n =40).Following three quantitative parameters were measured.The meniscal width and tibial plateau width on the coronal slice showing the inttercondyloid spine( a),the number of the spine showing butterfly change when the layer thickness was 4mm(b) and the maximum width showing butterfly change on the sagittal slice(c).The discoid meniscus were classified as slab type (n=33),wedge type(n = 19),hypertrophied - horn type(n= 18) according to their shape.Results:69 cases had torn in different extent,a>or =20% (P0.05).Significant difference in the incidence of each type existed in c(Por = 20% is the most reliable criterion to diagnose discoid meniscus.Using b as the criterion of discoid meniscus is easy to occur missed diagnosis,c in the wedge type is bigger than the one in the hypertrophied type.Age can impact the classification of discoid meniscus.

Menisco discoideo medial sintomático / Symptomatic medial discoid meniscus

A discoid meniscus is shaped like a disc and has a thicker cut section, compared with that of the normal semilunar meniscus. Lateral discoid meniscus are very rare, while the medial equivalent is extremely rare. We report two patients with a symptomatic torn medial discoid meniscus. Both patients were successfully treated with arthroscopic partial resection. Only one of the patients had a certified unilateral disease, because he underwent contralateral knee arthroscopy previously, for a meniscal tear in a normally shaped medial meniscus. A review of the available literature regarding this condition is also presented.

Un menisco discoideo presenta grosor aumentado y forma de disco, en lugar de la configuración semilunar normal. Su variante lateral es poco frecuente, siendo aún más inhabitual el compromiso del menisco medial. Se presentan dos pacientes con lesión sintomática de menisco discoideo medial. Ambos pacientes fueron tratados exitosamente mediante resección parcial artroscópica. En sólo uno de los pacientes se descartó patología bilateral, ya que éste había sido sometido previamente a artroscopia de rodilla contralateral por lesión meniscal medial en menisco de configuración normal. Se presenta además una revisión de la literatura disponible acerca de esta patología.

Treatment Result of Preserving Peripheral Rim of Torn Lateral Discoid Meniscus

PURPOSE: To evaluate the clinical results of preserving the peripheral rim of meniscus in the injuries of lateral discoid meniscus. MATERIALS AND METHODS: We analyzed 38 patients, 40 knees. Mean follow-up period was 17.4 months and mean age was 34.9 years old(10~62). We classified the lesion according to Watanabe and Ahn(classifying the type of tear according to arthroscopic finding). Clinical results were analyzed by Ikeuchi's clinical grading system and the Lysholm knee scoring scale. Radiographic evaluations were analyzed with plain radiographs. The common clinical results were pain in 40 cases(100%), locking in 16. Radiological degenerative arthritis changes were 31 persons(33 cases, 82.5 %) by simple initial X-ray. The common radiological changes were hypoplasia of lateral femoral condyle in 29 cases (72.5%), widening of lateral joint space in 26. RESULTS: Partial meniscectomy was undergone in 14 patients(15 cases) and partial meniscectomy with meniscal repair was undergone in 24 patients(25 cases). The patients were categorized using Watanabe's classification: complete, 25 cases(62.5%) and incomplete, 15 cases(37.5%). There were longitudinal tears(type 2) in 15 cases(37.5%), complex tears(type 7) in 12 cases. The mean Lysholm score was improved from 56.7 points to 86 points postoperatively after the partial meniscectomy, and from 62.7 points to 88 points after the partial menisccectomy with meniscal repair, which were not statistically significant(p>0.05). According to Ikeuchi's grading system, 11 cases(73.3%) had either excellent or good ratings in the partial menisectomy and 21 cases(84%) in the partial menisectomy with meniscal repair, which were not statistically significant(p>0.05). CONCLUSION: We believe that preserving peripheral meniscus by using partial menisectomy and partial menisectomy with meniscus repair lead to good function and satisfactory results.

Experience of Arthroscope Treatment to the Knee Discoid / 医学研究杂志

Objective To observe the effect of arthroscopic meniscectomy to treat discoid lateral meniscus tear.Methords From Oct.2003 to Aug.2006,28 patients who with discoid meniscus injury are treated by the arthroscope in Taizhou municipal hospital,including 22 male patients and 6 female patients,age from 16 years old to 45 years old,average is 28.5 years old.Results The patients are tracked from 2 to 24 moths,average is 9 months.The results are devided into 4 grades:excellent,good,general and bad by the Ikeuchi standerd.The excellent results are 17 patients and the good results are 7 patients and general results are 4 patients.All without complication and be 85.7 percent in all the patients.Conclusion Arthroscopic meniscectomy should be a preferred method for discoid lateral menisci tear,due to its minimal invasion,possibility of early mobilization,a lower complication rate,and preservation of more meniscus structure and function.If the operation is combined with standard rehabilitation training,the effects can beenhanced.

Arthroscopic meniscoplasty in horizontal tear of discoid lateral meniscus / 中国矫形外科杂志

[Objective]To evaluate efficacy and method of arthroscopic meniscoplasty for horizontal tear of discoid lateral meniscus in a short follow-up term. [Method]A series of 27 patients (27 knees) (mean age 32 years, range 6 years to 42 years) who underwent arthroscopic evaluation and treatment of a discoid lateral meniscus between 2002 and 2006 was reviewed. All the patients who were selected had the horizontal type of tear. Of those discoid menisci classified intraoperatively (n=27), 85.2% (n=23) were complete discoid lateral menisci and 14.2% (n=4) were incomplete discoid lateral menisci. No Wrisberg type was noted. Arthroscopic meniscoplasty was performed in all cases. The horizontal tear meant meniscus was divided into two leaves. The auther removed the unstable leaf to the peripheral rim and preserved the stable one. Arthroscopic meniscoplasty was performed in the stable leaf.[Result]All the patients were evaluated at follow-up according to the Lysholm knee Scoring Scale. At follow-up, patients were reviewed to recognize possible of retear and requirement of arthroscopic revision. The knee score of these patients improved from 72.48?4.64 points preoperatively to 92.18?4.52 points postoperatively. Recurrence of tear or requirement of arthroscopic revision was not noted at the final follow-up. [Conclusion]Arthroscopic meniscoplasty of the horizontal tear of discoid meniscus is an effective method.

Arthroscopic Analysis of Lateral Meniscal Variants

PURPOSE: We classified lateral meniscal variants according to types and tear pattern, and compared MR images with arthroscopic findings. MATERIALS AND METHODS: We reviewed 164 consecutive cases (158 patients) of arthroscopic examination for lateral meniscal variants during last ten years. We classified lateral meniscal variants into four types of arthroscopic appearance by modified Watanabe 's classification, and into six tear patterns by modifying O 'Connor 's classification. RESULTS: Regarding four types, 131 cases were complete; 25, incomplete; 4, Wrisberg, and 4, ringshaped. Six tear patterns were as follows: 33 simple horizontal, 21 complicated horizontal, 37 longitudinal, 27 central, 14 complex, and 12 radial. Among 31 cases with central tear or ring-shaped meniscus, we reviewed 25 MR images. Fifteen (60%) MRI 's were interpreted as displaced meniscal tear(bucket handle tear), 7 (28%) as discoid meniscal tear, and other 3 (12%) as simple tear: misinterpretation rate was 72%. Twelve patients (13 cases, 7.9%) had osteochondritis dissecans of lateral femoral condyle: nine patients (10 cases) of them had central tear, two patients (2 cases) had simple horizontal tear, and one patient (1 case) had ring-shaped meniscus. CONCLUSION: MR findings of ring-shaped meniscus or central tear should be differentiated from displaced meniscal tear(bucket-handle tear) considering history of trauma.

Arthroscopic treatment of discoid meniscus injury / 中华创伤骨科杂志

Objective To observe the effect of arthroscopic meniscectomy to tr eat discoid lateral meniscus tear. Methods From July 1999 to June 2003, arthrosc opic meniscectomy was conducted for 49 menisci of 45 patients with discoid later al meniscus tear. 41 patients had unilateral injury, and 4 bilateral. 32 knees w ere complete injury and 17 incomplete. The discoid lateral meniscus tear account ed for nearly one third of the patients with meniscus tear who received arthrosc opic meniscectomy at the same time. Arthroscopic partial meniscectomy was done f or 44 knees, total meniscectomy for 5 knees and meniscus suture for 3 knees. Aft er operation the rehabilitation training programs, including straight-leg-rais ing exercise and range-of-motion exercise, were carried out. Results The opera tions for the 45 cases were successful and there was no complication. 40 patient s were followed up. Before operation, the mean Lysholm -Ⅱscore was 55 points ( 40 to 71 points). After a mean follow-up period of 39 months, the mean Lysholm -Ⅱscore was 88 points (60 to 100 points). The excellent and good results were obtained in 85.3%of the patients. Conclusions Arthroscopic meniscectomy should be a preferred method for discoid lateral menisci tear, due to its minimal invas ion, possibility of early mobilization, a lower complication rate, and preservat ion of more meniscus structure and function. If the operation is combined with s tandard rehabilitation training, the effects can be enhanced.

Long Term Results After Resection of the Discoid Meniscus in Children / 대한정형외과학회잡지

PURPOSE: We retrospectively reviewed the long term results of arthroscopic resection of the discoid meniscus in children and evaluated postoperative clinical symptoms and radiological changes. MATERIALS AND METHOD: The results of arthroscopic surgery in 27 symptomatic discoid menisci of 22 patients who were under 15 years old at the time of operation (average; 11 year 9 month old) were evaluated. Average follow-up period was 9 years 4 months (5 years-18 years 1 months). Clinical results were analyzed according to Ikeuchi's clinical grading system and radiological degenerative changes were classified according to Fairbank at the last follow-up. RESULTS: According to Ikeuchi's grading system, excellent results were obtained in 10 cases (37.0%), good in 12 cases (44.4%), fair in 5 cases (18.5%). No radiological change was observed in 1 case (3.7%), 1 radiological sign in 5 cases (18.5%), 2 radiological signs in 13 cases (48.1%) and more than 3 radiological signs in 8 cases (29.6%) in the last follow-up radiograph. No correlation between clinical results and radiological changes. CONCLUSION: Arthroscopic resection of discoid meniscus in children was effective at relieving symptoms over a follow up of more than 5 years, though radiological degenerative changes occurred. We recommend that follow up is resuired to determine whether the clinical results of knees in middle or older age groups will worsen.

Midterm follow-up of symptomatic discoid meniscus after arthroscopic surgery / 第三军医大学学报

Objective To evaluate the effect of arthroscopic reshaping procedures on symptomatic discoid meniscus and compare the outcomes between children and adults. Methods The medical records of those who had undergone arthroscopic reshaping procedures for symptomatic discoid meniscus between January 1997 to December 2000 were reviewed. Results Fifty-four patients had been followed up more than 7 years, including 38 children and 16 adults. The average Lysholm score increased from (65.0?10.0) preoperatively to (72.0?10.0) postoperatively. The average 8.2-year follow-up showed no obvious clinical symptoms and signs or osteoarthritis in children. Fourteen knees in adults were found osteoarthritis on X-ray film, of which 6 showed the symptoms and signs of osteoarthritis. Conclusion The midterm efficacy of arthroscopic surgery for symptomatic discoid menisci and the occurrence of postoperative osteoarthritis are related to age and injury course.

Arthroscopic treatment of symptomatic discoid lateral meniscus / 第三军医大学学报

Objective To observe the effect of arthroscopic meniscectomy for symptomatic discoid lateral meniscus and the importance of early treatment. Methods Arthroscopic meniscectomy was performed on 29 patients (31 knees) with symptomatic discoid lateral meniscus. Partial meniscectomy was performed on 27 knees, subtotal meniscectomy on 4 knees with tear on the edge of meniscus. Results The operations on all 31 knees were successful without complications. The mean Lysholm score was 95.6 (87-100) during the follow-up, which was significantly higher than that before the operation (65.7, range 36-78; P

Arthroscopic Reshaping of Discoid Meniscus with Local Anaesthesia and Radiofrequency / 中国运动医学杂志

Objective To study the effect of arthroscopic plasty of discoid meniscus with local anaesthesia and radiofrequency. Methods From Aug. 2000 to Aug.2002, arthroscopic plasty of discoid lateral meniscus with local anaesthesia and radiofrequency was performed on twenty-six joints in twenty-three patients including 12 male and 11 female, their average age was 25 years(13～14 yrs). The procedure of discoid meniscus reshaping in 23 cases was to produce the similar appearance to the normal lateral meniscus. Unstable leaf of the horizontally torn meniscus was removed, while the stable one was preserved. In 6 cases,the tear of edge rim was not only reshaped but also insider-out sutured. Results 21 cases were followed-up for average 11 months (from 5 months to 2 5 years).There was no pain snap and lock, the joint function is normal in 21 cases and 23 knees. Based on Ikeuch knee functional scales,16 cases were rated as excellent, 3 good and 2 fair. Conclusion Arthroscopic radiofrequency meniscus plasty is of importance in avoiding total meniscectomy. The procedures were safety and less traumatic.

Prevalence of Lateral Discoid Meniscus / 대한정형외과학회잡지

PURPOSE: Lateral discoid meniscus is a well known disease entity with an uneventfully high incidence in Koreans and Japanese. However, the reported incidence had been obtained mainly by using arthroscopy. The purpose of this study was to determine the prevalence of discoid lateral meniscus obtained by arthroplasty, unrelated to arthroscopic surgery. MATERIALS AND METHODS: We studied the prevalence of lateral discoid meniscus in 465 cases of total knee replacement arthroplasty, after disregarding patients with any possibility of an affecting lateral meniscus. To conduct the comparison, we measured the incidence of lateral discoid meniscus in 423 arthroscopy cases, performed during study period, and in 1,364 of our arthroscopy cases. RESULTS: We found 18 discoid lateral menisci during 465 total knee replacement arthroplasties, Therefore, its prevalence of lateral discoid meniscus was 3.9%. but 38 cases (9.0%) out of 423 arthroscopy cases, and 145 cases (10.6%) out of 1,364 arthroscopy cases were diagnosed as a lateral discoid meniscus. We also founded that 50% of lateral discoid meniscus cases were bilateral. CONCLUSION: We suspect that the prevalence of lateral discoid meniscus is similar in the Korean and Western populations. However, due to different lifestyles and ethnicity, Koreans might experience in one discomfort and confront a treatment, and thus the reported prevalence of discoid lateral meniscus is higher in Koreans.