盘状半月板MRI分型及其表现分析

目的:探讨盘状半月板MRI表现及其分型特点,提高盘状半月板MRI诊断率.材料和方法:将70例行MRI检查并经关节镜证实的盘状半月板分为未成年组、成年组.对全部病例冠状面髁间棘层面半月板宽度与胫骨平台宽度之比(板面比)、矢状面层厚4mm扫描"领结样"改变层数及"领结样"改变最宽层面前后径宽度进行测量、分析.根据盘状半月板MRI表现分为板型、楔型、肥角型.结果:70例盘状半月板中未成年组30例、成年组40例,板型33例、楔型19例、肥角型18例,69例发生不同程度撕裂.整组病例板面比≥20%(P<0.01),各型年龄分布无显著性差异(P>0.05),各型矢状面"领结样"改变最宽层面不全相同(P<0.05).结论:板面比≥20%诊断盘状半月板最可靠,矢状面层厚4mm扫描"领结样"改变层数≥3诊断盘状半月板易发生漏诊,矢状面"领结样"改变最宽层面楔型较肥角型大,年龄可影响盘状半月板分型.     

膝关节盘状半月板类型及损伤的MRI分析

目的探讨外侧盘状半月板的MRI分型特征及不同类型盘状半月板撕裂的发生率.资料与方法将89例MRI表现典型的外侧盘状半月板分作两组,即未成年组和成年组,其中未成年组35例(36膝),4～17岁(平均13.2岁);成年组54例(57膝),18～74岁(平均42.0岁).将盘状半月板分作板型、楔型、肥角型.分析不同类型的盘状半月板合并半月板撕裂的发生率.结果未成年组板型26膝、楔型4膝、肥角型6膝;成年组板型36膝、楔形15膝、肥角型6膝.两组盘状半月板类型的发生比率无显著性差异(P＞0.10).无论未成年组或成年组均以板型常见.不同类型盘状半月板发生撕裂的比率有显著性差异(P＜0.005),肥角型全部显示半月板撕裂,板型盘状半月板撕裂比率高于楔型.结论无论成年组或未成年组的盘状半月板多见于外侧,其盘状半月板类型的分布两组间无显著差异.而不同类型的盘状半月板合并半月板撕裂的概率是有差异的,因此,MRI检查对临床确定治疗盘状半月板的方案很有帮助.     

MRI对军事训练致盘状半月板损伤的临床应用价值

目的:探讨MRI对军事训练致膝关节盘状半月板损伤的临床应用价值。方法:回顾性分析36例武警部队军人盘状半月板资料,其中33例经关节镜证实盘状半月板撕裂,33例撕裂病例均有明确的军事训练致伤史,观察盘状半月板形态、大小及信号改变,判断盘状半月板及其损伤分型。结果:36例盘状半月板,均发生在外侧。36例中,板型21例,楔型9例,肥角型6例。33例盘状半月板发生撕裂,以关节镜为诊断标准,MRI诊断膝关节盘状半月板准确率为100%,MRI诊断盘状半月板水平撕裂、斜行撕裂、纵行撕裂、放射状撕裂、桶柄状撕裂及复杂撕裂的准确性分别为91.7%、94.4%、100%、97.2%、91.7%、94.4%。结论:MRI对军事训练致盘状半月板撕裂能清晰显示、准确分型,对临床治疗方案的制定有重要的指导作用,具有较高的临床应用价值。     

膝关节盘状半月板及撕裂的MRI诊断

目的 探讨盘状半月板的MRl分型及其撕裂的MRI诊断.方法 对55例(57膝)经手术或关节镜证实且有完整MRI资料的盘状半月板进行回顾性分析,观察盘状半月板的形态、大小及信号改变,包括半月板宽度和厚度的测量.结果 57膝盘状半月板,56膝发生在外侧,只1膝在内侧.57膝中,板型34膝,楔型15膝,肥角型8膝,其中46膝盘状半月板发生撕裂、7膝伴有变性.结论 盘状半月板多见于外侧,且常并发半月板撕裂或变性.     

膝关节盘状半月板的MRI诊断

目的　探讨膝关节盘状半月板的MRI表现以及MRI诊断盘状半月板的标准。材料与方法　对 2 6例经手术或关节镜证实的盘状半月板和 3 0例健康志愿者的膝关节进行MRI检查 ,对正常及盘状半月板的形态、大小及信号改变进行对照观察 ,包括半月板宽度和厚度的测量。结果　 2 6例盘状半月板中 ,2 5例为外侧盘状半月板 ,只有 1例为内侧盘状半月板 ,18例为厚板型 ,8例为楔型。冠状面上 ,盘状半月板体部平均宽度及厚度明显大于正常半月板 ,分别为 2 3 .4mm、11.5mm (P <0 .0 5 )和 3 .2mm、0mm(P <0 .0 1)。但盘状半月板边缘厚度与对侧半月板厚度差超过 2mm者只有 6例。矢状面上 ,连续 3层或 3层以上显示盘状半月板的前后角相连形成“领结”样改变 ,而正常半月板只有 2层有此表现。 2 6例盘状半月板中 ,2 4例并发半月板变性或撕裂。结论　盘状半月板多见于外侧半月板。盘状半月板特征性的MR表现是盘状半月板明显较正常半月板厚、大 ,MRI检查易于诊断。盘状半月板常并发半月板变性或撕裂。     

The value of MRI in the diagnosis of injury of discoid meniscus

目的:探讨MRI对膝关节盘状半月板及其损伤的诊断价值.方法:回顾性分析89例(151个膝关节)盘状半月板及其损伤的MRI、关节镜及手术资料.结果:89例盘状半月板中,88例(150个膝关节)为外侧盘状半月板,1例(1个膝关节)为内侧盘状半月板,表现为半月板增大、增宽、增厚,矢状面上可见≥3个层面前后角相连,冠状面髁闻棘层面半月板宽度>15 mm.本组中81例(138个膝关节)伴半月板损伤,发生率为91.40%,MRI表现为半月板不同程度变性或撕裂.与膝关节镜及手术对照,MRI图像对半月板损伤诊断的特异度为92.31%、敏感度为99.28%,对I～Ⅱ级半月板损伤诊断的符合率为95.00%;对Ⅲ级半月板损伤诊断的符合率为98.98%.结论:MRI能准确判断盘状半月板类型及其损伤的范围和程度,是诊断盘状半月板及其损伤的最佳检查方法.     

MRI对膝关节盘状半月板及其损伤的诊断价值

目的:探讨MRI对膝关节盘状半月板及其损伤的诊断价值。方法:回顾性分析89例(151个膝关节)盘状半月板及其损伤的MRI、关节镜及手术资料。结果:89例盘状半月板中,88例(150个膝关节)为外侧盘状半月板,1例(1个膝关节)为内侧盘状半月板,表现为半月板增大、增宽、增厚,矢状面上可见≥3个层面前后角相连,冠状面髁间棘层面半月板宽度>15mm。本组中81例(138个膝关节)伴半月板损伤,发生率为91.40%,MRI表现为半月板不同程度变性或撕裂。与膝关节镜及手术对照,MRI图像对半月板损伤诊断的特异度为92.31%、敏感度为99.28%;对Ⅰ～Ⅱ级半月板损伤诊断的符合率为95.00%;对Ⅲ级半月板损伤诊断的符合率为98.98%。结论:MRI能准确判断盘状半月板类型及其损伤的范围和程度,是诊断盘状半月板及其损伤的最佳检查方法。     

盘状半月板MRI表现（附56例分析）

目的分析56例盘状半月板MRI表现,以提高盘状半月板诊断正确率.材料和方法经手术、关节镜确诊的56例盘状半月板,对其MR图像不同层面进行测量,参照Crues等有关半月板损伤行MRI分级.结果56例盘状半月板形态学分型凹透镜型29例,厚板型10例,簸箕型5例,后角肥大型8例,不完全型4例,其中央薄弱部分以粉碎性撕裂为主,周缘厚实部分以退变为主,MRI诊断与手术对比总符合率为89.3%;结论对各种盘状半月板的认识有助于提高MRI诊断盘状半月板的正确率,并对外科手术有指导意义.     

膝关节半月板囊肿的MRI特点

目的 探讨半月板囊肿的MRI特点及流行病学特点.方法 对489例膝关节半月板囊肿的发病率、性别、年龄、囊肿的大小、分布、性状及合并半月板撕裂等进行统计,分析半月板囊肿分型与半月板撕裂、撕裂类型及年龄的关系.结果 半月板囊肿的发病率为1.92％,男、女性别无明显差异.内、外侧半月板囊肿的发生比率为1:2.15;外侧半月板囊肿多发生于前角、体部,内侧多发生在后角;根据半月板囊肿的MRI表现分为4型:半月板旁型、半月板内型、滑膜型和混合型;本组病例中合并半月板撕裂者占94.7％,滑膜型半月板囊肿合并半月板撕裂比率明显低于其他类型;半月板囊肿分型与半月板撕裂类型无统计学相关,各型半月板囊肿均以水平撕裂最多见.本组半月板囊肿按年龄分为≤19岁、20～50岁、≥51岁3组,年龄与半月板囊肿分型无统计学相关,在各年龄阶段,半月板旁型半月板囊肿最多见.结论 半月板囊肿多发生于外侧半月板,外侧半月板囊肿多见于前角、体部,内侧多见于后角,常合并半月板撕裂;滑膜型半月板囊肿合并半月板撕裂比率明显低于其他类型;各型半月板囊肿均以水平撕裂最多见;在各年龄阶段,半月板旁型半月板囊肿最多见.     

盘状半月板的MRI诊断

目的探讨盘状半月板及损伤的MRI表现及诊断标准。方法回顾性分析40例盘状半月板测量方法;盘状半月板分型及损伤诊断标准。结果本组40例均为外侧盘状半月板。24例为厚板型,16例为楔型。38个合并不同程度半月板损伤,损伤率95%。结论MRI检查是诊断盘状半月板的首选方法;半月板与相应层面胫骨平台横径之比(板/面比)超过40%是诊断盘状半月板必要的标准。     

Epidemiologic, clinical and arthroscopic study of the discoid meniscus variant in Greek population

This retrospective study was aimed to investigate the epidemiologic, clinical and arthroscopic features of discoid meniscus variant in Greek population. We reviewed the cases of 2,132 patients who underwent knee arthroscopy between 1986 and 2004 and diagnosis of discoid lateral meniscus was established in 39 patients with mean age of 31.7 ± 9.4 years old. Incidence of the discoid lateral meniscus variant was recorded at rate of 1.8% presenting no significant differences according to patient gender or lesion body side. Regarding the type of discoid dysmorphy, 23 cases attributed to complete type, 15 were incomplete and in one case, Wrisberg type was observed. Predictive values of the most commonly recorded physical signs in the clinical diagnosis of the discoid meniscus were analysed. Comparative evaluation of the long-term results of arthroscopic partial meniscectomy performed in patients with intact or torn discoid lateral meniscus and torn normally shaped lateral meniscus was carried out using Lysholm and IKDC scoring systems. Also, we investigated any correlation between dysmorphy type and tear pattern analysing the arthroscopic findings. Results demonstrated that the discoid meniscus lesion represents an atypical clinical entity in adults and no significant predictive value of the signs encountered in the clinical examination of the patients with discoid meniscus was observed. Clinical outcome after arthroscopic partial meniscectomy regarding the intact discoid meniscus group was superior in comparison with that of torn discoid meniscus cases. On other hand, no difference in the result of partial meniscectomy between discoid and normal lateral meniscus tear groups was found. No statistically significant relationship between the type of discoid menisci and tear pattern or incidence rate of concomitant intraarticular lesions was confirmed.     

Discoid meniscus

The discoid meniscus is probably a congenital deviation that usually occurs laterally. The Watanabe classification consists of complete, incomplete, or Wrisburg ligament types. Complete and incomplete discoid menisci normally require treatment only when a tear occurs. The Wrisburg ligament type lacks a posterior capsular attachment. The preferred treatment is repair of the posterior capsular disruption with saucerization of the remaining meniscus.     

Correlation between type of discoid lateral menisci and tear pattern

This study analyzed the relationship between type of discoid lateral menisci and tear pattern. There were 108 consecutive cases (103 patients) with discoid lateral meniscus tear treated by arthroscopy. Regarding type of discoid meniscus (Watanabe's classification), 38 cases were "complete" and 70 cases "incomplete." There was no Wrisberg type. Tear patterns were classified into simple horizontal, complicated horizontal, longitudinal, radial, degenerative, and complex tear. The relationship between tear pattern and type of discoid menisci was statistically highly significant. Simple horizontal tear was found only in the complete type of case, and radial, degenerative, and complex tears were found only in the incomplete type of case. In the longitudinal tear, however, we found no correlation between tear pattern and type of discoid meniscus. In addition, the extent of meniscal resection was dependent on the tear pattern. Subtotal or total meniscectomy was performed significantly more frequently in longitudinal and complex tears. In radial and degenerative tears only partial meniscectomy was carried out. Complicated horizontal tears showed no difference in extent of resection. Among the 13 cases of simple horizontal tears partial meniscectomy was performed in 12 cases. These findings about relationship between the type of discoid menisci and tear pattern could be useful in planning operation and deciding extent of resection.     

Comparison of the insertion of the posterior horn of the lateral meniscus: discoid versus non-discoid

Purpose

The purpose of this study was to compare the insertion sites of the posterior horn between discoid and non-discoid lateral meniscus using magnetic resonance imaging (MRI).

Methods

Two hundred and twenty-seven patients who had MRI scans before surgery and underwent arthroscopy were enroled in this study. A coronal view showing the narrowest width of the midbody of the lateral meniscus was chosen to measure the widths of the entire tibial plateau and the midbody of the lateral meniscus. Considering the ratio of the meniscal width to the tibial plateau width, the patients were divided into non-discoid, incomplete discoid, and complete discoid groups. On a coronal view accurately showing the insertion of the posterior horn of the lateral meniscus, a distance between the peak of the lateral tibial eminence and the centre of the insertion of the posterior horn, and a width of the lateral tibial plateau between the lateral edge of the tibial plateau and the peak of the lateral tibial eminence were measured.

Results

The insertion centre of the posterior horn was located more medially in the incomplete and complete discoid groups than in the non-discoid group (p = 0.003, 0.010, respectively). When individual differences in the knee size were corrected, the insertion centre of the posterior horn in the incomplete discoid and complete discoid groups was located more medially than in the non-discoid group (p = 0.009, 0.003, respectively).

Conclusion

The insertion centre of the posterior horn of the lateral meniscus is located more medially to the apex of the lateral tibial eminence in the discoid group than in the non-discoid group. This finding needs to be considered for an accurate position of the posterior horn of lateral meniscus during the lateral meniscal allograft transplantation.

Level of evidence

IV.

     

Pullout failure strength of the posterior horn of the medial meniscus with root ligament tear

Purpose

To evaluate the reparability of the posterior horn of the medial meniscus with root ligament tear by measuring the actual pullout failure strength of a simple vertical suture of an arthroscopic subtotal meniscectomized posterior horn of the medial meniscus.

Methods

From November 2009 to May 2010, nine posterior horns of the medial meniscus specimens were collected from arthroscopic subtotal meniscectomy performed as a treatment for root ligament rupture of the posterior horn of the medial meniscus. Simple vertical sutures were performed on the specimens, and pullout failure load was tested with a biaxial servohydraulic testing machine (Model 8874; Instron Corp., Norwood, MA, USA). The degree of degeneration, extrusion, and medial displacement of the medial meniscus were evaluated with magnetic resonance imaging (MRI). The Kellgren–Lawrence classification was used in standing plain radiography, and mechanical alignment was measured using orthoroentgenography. Tear morphology was classified into ligament proper type or meniscoligamentous junctional type according to the site of the torn root ligament of the posterior horn of the medial meniscus during arthroscopy.

Results

The mean pullout failure strength of the posterior horn of the medial meniscus was 71.6 ± 23.2 N (range, 41.4–107.7 N). The degree of degeneration of the posterior horn of the medial meniscus on MRI showed statistically significant correlation with pullout failure strength and Kellgren–Lawrence classification. Pullout failure strength showed correlation with mechanical alignment and Kellgren–Lawrence classification (P < 0.05).

Conclusions

The measurement of pullout failure strength of the posterior horn of the medial meniscus with root ligament tear showed a degree of repairability. The degree of degeneration of the posterior horn of the medial meniscus on MRI showed a significant correlation with the pullout failure strength. The pullout failure strength was also not only correlated with the degree of degeneration of the posterior horn of the medial meniscus, but also with mechanical alignment and Kellgren-Lawrence classification, which represent bony degenerative change.     

后角肥大型盘状半月板的动态MRI研究

目的 通过后角肥大型盘状半月板的动态分析,探讨后角肥大型盘状半月板的形成原因.资料与方法 总共40例患者分为两组,一组为后角肥大型盘状半月板,另一组为随即选取的板型或凹面镜型盘状半月板.首先对所有患者进行膝关节伸直位MR扫描,再令患者适当活动膝关节,然后膝关节维持在屈曲30°位进入磁体扫描.分别观察前后两次扫描半月板的形态变化,并测量半月板后缘的最大厚度.结果 20例后角肥大型盘状半月板患者中,有9例在活动后半月板发生了明显的形态变化,最大厚度明显降低,转变为板型或凹面镜型盘状半月板.而板型或凹面镜型盘状半月板没有发生明显形态变化.两组病例在伸直位向屈曲位变化时半月板后缘的最大厚度的改变量间差异有统计学意义(P<0.01).结论 后角肥大型盘状半月板可能是板型或凹面镜型盘状半月板变形后的一种表现.     

Discoid menisci of the knee: MR imaging appearance

Discoid menisci of the knee are not uncommon, and the criteria for arthrographic diagnosis and the clinical symptoms are well known. Although enlarged menisci have been recognized at magnetic resonance (MR) imaging, there are no criteria for the MR imaging diagnosis. The authors describe 29 discoid menisci imaged by means of MR. A discoid meniscus was said to be present if three or more 5-mm-thick contiguous sagittal images demonstrated continuity of the meniscus between the anterior and posterior horns. High-resolution coronal images allowed more graphic depiction of the abnormally wide meniscus. In approximately one-third of the cases in which coronal images were obtained, the measurable height difference between the discoid and the opposite meniscus was greater than or equal to 2 mm. Arthroscopic correlation (obtained in 10 cases) revealed that six cases of discoid meniscus were diagnosed correctly with MR imaging, although one meniscus was considered discoid at MR imaging but was not considered discoid at arthroscopy. Of three discoid menisci seen to be torn at arthroscopy, two were seen to be torn at MR imaging.