Complications in medial meniscus suture: a cadaveric study

The aim of this study was to examine the possibility of complications in medial meniscus repair using an inside-out suturing device. Anatomical cadaveric study. Six fresh frozen cadaveric lower limbs were used. The posterior horn of the medial meniscus was sutured using three vertical stitches. An anatomical dissection was subsequently performed to check for any possible effects upon the structures of the medial aspect of the knee. In addition, an incision was made in a safety zone in order to ascertain whether it was possible to carry out the suture without affecting the aforementioned structures. No vascular or nervous structures were pierced by the needle. On knotting, it was found that a number of different structures had become trapped: the sartorial tendon was affected in each of the specimens used. In four cases, the saphenous vein was trapped by some of the knots. The saphenous nerve was trapped in four instances. Once this had been established, a small accessory incision was made to provide access to a safety zone, where suture can be performed without affecting any neurovascular or tendinous structures. Inside-out suture of the posterior meniscal horn carries a high incidence of entrapment of the neurovascular structures of the medial aspect of the knee. The sartorial tendon is constantly affected. Such complications can easily be avoided by entering the safety zone via a small auxiliary incision. This study provides evidence that complications affecting the peripheral structures of the medial aspect of the knee may arise during inside-out suture of the posterior horn of the medial meniscus and proposes a simple method of averting them.     

Immunolocalization of types I, II, and X collagen in the tibial insertion sites of the medial meniscus

The medial meniscus of the rabbit knee joint attaches to the tibial plateau via anterior and posterior insertions. Intact meniscal tibial insertions are essential for meniscal function. In the present study the distributions of types I, II, and X collagen in meniscal tibial insertions were investigated by indirect immunohistochemistry in a rabbit model. Four tissue zones were histologically identified in the anterior insertion site, including the ligamentous zone, uncalcified and calcified fibrocartilaginous zones and bone; the ligamentous zone was not observed in the posterior insertion site. Labeling for type I collagen was found to be strong in the ligament tissue and bone, and weak in the fibrocartilages which were also labeled for type II collagen. Tissues positive for different types of collagen overlapped and formed an irregular interface with various angles and depths, especially at the interface between the calcified fibrocartilage and bone. Positive labeling for type X collagen was identified only in the calcified fibrocartilage zone. The coexistence of types I and II collagen in the meniscal tibial insertions may indicate that this structural unit is subjected to both compressive and tensile loads. Type X collagen may play a role in maintaining the calcifying status of this tissue zone, so that its mechanical stiffness is kept between that of uncalcified fibrocartilage and hard bone. Restoration of the insertional structure including the distinct collagen distribution should be considered for a functional meniscal substitution. Received: 22 June 1999/Accepted: 27 September 1999     

MRI超短回波时间序列评价膝关节半月板的研究进展

半月板是膝关节的重要结构,MRI超短回波时间（UTE）序列相比传统MRI序列能够直接采集短T₂/T₂*信号,不仅能够定量测量半月板,还能够显示半月板胶原纤维及钙化成分,区分半月板红白区,以及评估半月板pH值等。简要介绍UTE序列,并就其在半月板中的研究进展予以综述。     

MRI和关节镜诊断膝半月板损伤的比较研究

目的 :探讨膝关节半月板损伤MRI和关节镜下的不同表现及其对半月板损伤的诊断意义。方法 :回顾性分析 10 2个半月板损伤的MRI表现和关节镜下图像。根据MRI信号改变将半月板损伤分为Ⅰ级、Ⅱ级、Ⅲ级 ,并与关节镜下所见对比 ,分别加以研究。结果 :根据MRI信号强度改变 ,10 2个膝关节中Ⅰ级损伤 3 4个 ,Ⅱ级损伤 2 7个 ,Ⅲ级损伤 41个。与关节镜检结果对比 ,MRI诊断半月板撕裂的敏感度 90 .0 % ,特异度 91.9% ,符合率 91.2 %。结论 :MRI在半月板损伤的诊断中具有极高价值 ,对指导患者的治疗具有重要的临床意义。     

Mid-term clinical results of medial meniscus repair with the meniscus arrow in the unstable knee

The medial meniscus is a secondary stabilizer to anterior tibial translation and provides significant stability, especially in an ACL-deficient knee. The purpose of this study is to evaluate the clinical outcome of medial meniscus repair in the unstable knee. Between 1997 and 2002, 11 patients, with a mean age of 25.8 years (range 15–39 years), underwent all-inside medial meniscus repair, using the Meniscus Arrow, for unstable medial meniscus tear in ACL-deficient knees. For various reasons none of these patients underwent ACL reconstruction. The average follow-up was 73 months (range 52–91 months). There were three failures (27.3%) defined as the need for reoperation and partial meniscectomy. The mean Tegner activity score decreased from 6.75 (pretrauma) to 4.5 (postoperatively). The average Lysholm and subjective IKDC scores were 83 and 77.4, respectively. Two patients were graded as B (nearly normal) and six as C (abnormal), according to the IKDC knee evaluation form. KT-2000 arthrometry demonstrated that sagittal knee laxity was more than 5 mm in all knees (side to side difference). MRI demonstrated grade three signal alterations at the repair site of meniscus in three patients and signs of cartilage damage in two patients. All patients were asymptomatic during daily activities but seven out of eight reported pain or effusion after sports. Medial meniscus repair in the ACL-deficient knee is not contraindicated. The need of reducing the level of physical activity is essential.     

膝关节半月板损伤的MRI诊断及分类

半月板损伤是膝关节紊乱最常见的原因之一。磁共振检查是目前最敏感最准确的检查方法，面且对半月板撕裂的类型能做出较准确的判断。     

膝关节损伤核磁共振成像诊断分析

目的探讨G-SCAN检查对膝关节损伤的诊断价值。方法 120例膝关节损伤,采用G-SCAN（0.25T可旋转式核磁共振成像仪）膝关节表面线圈检查,分别采用自旋回波序列、梯度回波序列、脂肪抑制序列,做矢状位、冠状位及横断位扫描。结果 G-SCAN可以清楚显示膝关节半月板、韧带及骨挫伤。本组120例病例中,半月板损伤95例,其中单纯外侧半月板损伤63例,单纯内侧半月板损伤8例,内、外侧半月板同时损伤24例;韧带损伤85例,其中前交叉韧带损伤68例,后交叉韧带损伤19例,胫侧副韧带损伤65例,腓侧副韧带损伤5例;骨挫伤35例,其中单纯胫骨挫伤22例,单纯股骨挫伤5例,胫骨及股骨同时挫伤8例。结论 G-SCAN是诊断膝关节结构损伤的最佳检查方法之一,可为临床医生选择合适的治疗方法提供依据,具有重要的临床价值。     

膝关节半月板囊肿22例MRI分析

目的：分析膝关节半月板囊肿的MRI特点，提高对该病的认识。方法：回顾性分析22例膝关节半月板囊肿的MRI表现并与关节镜或手术结果对照。探讨半月板囊肿发生的部位、形态、信号特征及与半月板的毗邻关系。结果：22例半月板囊肿中，内侧半月板囊肿4例(18．1％)，外侧半月板囊肿18例(81．8％)。22例半月板囊肿中显示半月板水平撕裂15例(68．2％)，纵行撕裂3例(18．1％)。结论：半月板囊肿好发于外侧半月板，并与半月板的撕裂相关，表明MRI对诊断半月板囊肿有较高的临床价值。     

内侧副韧带股骨止点深埋术治疗膝关节内侧松弛

目的　探讨膝关节内侧副韧带止点深埋术治疗膝关节内侧松弛的手术适应证和手术操作方法。　方法　 1999年 11月～ 2 0 0 1年 12月 ,共收治 2 9例膝关节内侧松弛的患者 ,行内侧副韧带股骨止点深埋术 :游离内侧副韧带的股骨止点 ,连同止点骨块 (1.5cm× 1.5cm)在原位深埋0 .5cm ,并用螺钉固定。　结果　所有患者随访 3～ 2 7个月 ,平均 9个月。除 1例合并前交叉韧带下止点撕脱骨折外 ,其余患者膝关节内侧松弛均消失 ,膝关节功能正常。　结论　股骨止点深埋术对于治疗单纯膝关节内侧松弛、内侧分离在 0 .5cm以内患者疗效满意 ,手术操作简单。     

Imaging of the knee joint with emphasis on magnetic resonance imaging

The knee joint is frequently affected by trauma as well as degenerative and inflammatory disorders, involving the internal structures (i.e. ligaments, menisci, cartilage, synovial membrane) and the adjacent bones. Plain radiographs represent an indispensable basis for diagnosis. For further analysis magnetic resonance imaging (MRI) has become the method of choice, and has widely replaced computed tomography, arthrography and stress examinations. Extensive experience has been accumulated in MRI of the knee joint in recent years. In addition, advances in MRI technology have had a major impact on diagnostic accuracy. In this paper, diagnosis of various lesions of the knee joint, such as meniscal and ligamental injuries, aseptic necrosis, lesions of the hyaline cartilage, occult fractures and inflammatory lesions will be discussed. Offprint requests to: M. F. Reiser     

Measurement and comparison of the difference in normal medial and lateral knee joint opening

This paper reports the amount of medial and lateral knee joint opening in the general population. Knee joint lateral and medial opening at 20° knee flexion was quantified on manual varus and valgus stress test, respectively, with custom made device. One hundred men and women between the ages of 20–60 years were evaluated for their joint openings. Patients with previous knee surgeries or chronic knee pains were excluded from the study. Measurements were done twice by two different orthopedic surgeons who were blinded from each other. The mean age of the study group was 39 years (range 20–60 years) and 43 years for women (range 20–60 years) and 34 years for men (range 20–60). The mean lateral and medial knee joint space opening was 7.0° (range 3–9°) and 4.1° (range 2–7°), respectively, in the overall population; in the male population, it was 6.7° (range 3–9°) and 3.9° (range 2–7°), respectively, and in the female population, it was 7.2° (range 3–9°) and 4.3° (range 3–7°), respectively. Conversion to displacement in millimetres, the overall mean lateral and medial joint displacement was 9.3 mm (range 5.1–13.6 mm) and 4.8 mm (range 3.5–10.7 mm), respectively; for males, it was 9.1 (range 5.1–11.9 mm) and 4.6 mm (range 3.5–7.9 mm), respectively, for females, it was 9.8 mm (range 7.2–13.6 mm) and 4.9 mm (range 3.7–10.7 mm), respectively. The prevalence of the overall population that exceeds 6 mm or more lateral joint space opening was 91% (male 90% and female 92%) and medial joint space was 8% (male 4% and female 12%). Statistically, significant differences were seen between medial and lateral opening in male, female and the overall population (p<0.001). The female population exhibited wider opening in both medial and lateral joint opening than the male population (p<0.05). The interexaminer reliability showed no significant difference (p>0.05). More than 91% of the Korean population showed wide lateral joint space opening in the bilateral knee. However, none complained of functional instability or symptoms except for non-pathologic laxity detected by the physician. We strongly recommend bilateral comparison of the knee that has wide lateral joint opening.     

Loading of the knee during 3.0T MRI is associated with significantly increased medial meniscus extrusion in mild and moderate osteoarthritis

Purpose

Standard knee MRI is performed under unloading (ULC) conditions and not much is known about changes of the meniscus, ligaments or cartilage under loading conditions (LC). The aim is to study the influence of loading of different knee structures at 3 Tesla (T) in subjects with osteoarthritis (OA) and normal controls.

Materials and methods

30 subjects, 10 healthy and 20 with radiographic evidence of OA (10 mild and 10 moderate) underwent 3 T MRI under ULC and LC at 50% body weight. All images were analyzed by two musculoskeletal radiologists identifying and grading cartilage, meniscal, ligamentous abnormalities. The changes between ULC and LC were assessed. For meniscus, cartilage and ligaments the changes of lesions, signal and shape were evaluated. In addition, for the meniscus changes in extrusion were examined. A multivariate regression model was used for correlations to correct the data for the impact of age, gender, BMI. A paired T-Test was performed to calculate the differences in meniscus extrusion.

Results

Subjects with degenerative knee abnormalities demonstrated significantly increased meniscus extrusion under LC when compared to normal subjects (p = 0.0008–0.0027). Subjects with knee abnormalities and higher KL scores showed significantly more changes in lesion, signal and shape of the meniscus (80% (16/20) vs. 20% (2/10); p = 0.0025), ligaments and cartilage during LC.

Conclusion

The study demonstrates that axial loading has an effect on articular cartilage, ligament, and meniscus morphology, which is more significant in subjects with degenerative disease and may serve as an additional diagnostic tool for disease diagnosis and assessing progression in subjects with knee OA.     

Anatomic variations of the shape of the menisci: a neonatal cadaver study

Meniscal injuries in children and adolescents are being seen with increased frequency. The menisci are two crescentic lamellae whose functions are to deepen the articular surfaces of the tibial plateu for reception of the condyles of the femur. In our study, our aim is to determine the variations of the shapes and attachments of the menisci in newborns. This study was performed on 11 neonatal cadavers, 22 knee joints that were obtained from the anatomy laboratory. The variations of the shape of the menisci were noted. We found that 77% of the lateral menisci were discoid. This percent is higher than the previously reported percents of the lateral discoid menisci. The different shapes of the menisci were determined as horse shoe, sickle, sided U, sided V and C shaped. We did not determine any discoid medial menisci. We believe that our study will provide support to the neonatal anatomy of the knee, concerning with the surgical procedures and arthroscopy of the knee joint.This study was presented at the 6th international symposium of clinical anatomy, Varna, Bulgaria, 8–10 October 2004     

应用膝关节旋转半月板解剖型和固定半月板解剖型假体手术治疗膝退行性骨关节炎的临床分析

目的探讨应用膝关节旋转半月板解剖型和固定半月板解剖型假体治疗膝退行性骨关节炎的临床疗效。方法2009年2月—2013年1月选择在我院进行住院治疗的膝退行性骨关节炎患者132例,根据随机原则分为观察组与对照组各66例,行人工膝关节置换手术治疗,分别将旋转膝关节假体和固定膝关节假体进行人工植入固定,采用美国膝关节外科学会的评分系统(KSS)对患膝在术后当日与术后3个月进行膝关节评分和功能评分。结果所有患者都顺利完成手术,术中无严重并发症发生。随访3个月,观察组与对照组的总显效率分别为93.9%和80.3%,组间比较差异有统计学意义(P<0.05)。观察组的髌骨不稳、感染和下肢深静脉血栓形成等并发症发生率明显低于对照组,差异有统计学意义(P<0.05)。两组术后当天的膝关节评分和功能评分比较无统计学差异,术后3个月时评分都明显上升,同时评分在组内与组间比较有统计学差异(P<0.05)。结论人工膝关节置换手术治疗膝退行性骨关节炎有较好的预后,而旋转假体的应用能更加有效改善患膝屈伸活动和功能,疗效满意。     

In vitro load transmission in the canine knee: The effect of medial meniscectomy and varus rotation

The purpose of this study was to determine the in vitro load-transmission characteristics of the canine knee, paying particular attention to the positioning effect of the meniscus in the coronal plane. The intact joint was first loaded and then tested under two different loading conditions after a complete medial meniscectomy. The first set of test conditions attempted to simulate those used by previous investigators, by ignoring the spacer effect of the meniscus. The second set of tests were carried ouf following varus rotation of the joint (to account for the loss of the meniscal spacer) to assure initial contact in both tibiofemoral compartments at the start of test cycle. It is presumed that this varus realignment occurs during weight bearing following meniscectomy in vivo. As in previous studies, the joints experienced slightly larger displacements (although not statistically significant) and had lower stiffness values following medial meniscectomy than when intact. However, following varus realignment of the joint after meniscectomy, the displacement was markedly smaller (–35% to –40%;P<0.01) and the structural stiffness was much greater (47–123%;P<0.05) over the range of forces analyzed, compared with the intact joint. The ratio of dissipated to input energy was 42% for the intact joint, and increased following meniscectomy to 54% (P<0.05) with realignment and 55% (P<0.05) without realignment. Measured contact area decreased by 17% (P<0.05) following meniscectomy alone, and by 12% (P<0.05) following meniscectomy with realignment. Scince varus rotation of the joint following meniscectomy resulted in an increase in structural stiffness, it was concluded that the medial meniscus reduces the structural stiffness of the intact joint. In addition, the meniscus has a role in elastic energy storage and increasing contact area. A model is presented to explain both the decrease in stiffness after meniscectomy without varus rotation and the increase in stiffness after meniscectomy with varus rotation, employing linear springs of unequal length and different stiffnesses. After removal of the softer meniscal element and allowing joint approximation to occur, loading of the stiffer articular element results in an initially stiffer preparation.     

膝关节半月板周缘性移位 MRI 诊断与分析

目的：应用 MRI 观察半月板周缘性移位现象,确定半月板周缘性移位严重程度与膝关节周围结构的关系,探讨其临床意义。方法回顾分析148例患者膝关节 MRI 检查图像,将患者按年龄大小分为中青年组、中老年组、老年组,以半月板关节囊缘超出胫骨平台边缘定义为半月板周缘性移位,以膝关节内侧半月板与膝关节内侧副韧带、外侧半月板与髂胫束之间的位置关系来确定半月板移位的严重程度。结果148例患者半月板移位总发生率为48.6%(72/148),中青年组发生率为34.8%(8/23)、中老年组发生率为46.1%(35/76)、老年组发生率为59.2%(29/49),各年龄组间比较差异有统计学意义(χ2=4.15,P <0.05),半月板移位发生率随年龄增加而增加,移位程度随年龄增加而严重。结论半月板移位及严重程度与患者年龄密切相关;以膝关节内、外侧半月板与内侧副韧带、外侧髂胫束之间的位置关系来确定半月板移位严重程度有重要的临床意义。     

Possible reflex pathway between medial meniscus and semimembranosus muscle: an experimental study in rabbits

Meniscus is a well innervated tissue with four types of receptors. These receptors are mainly concentrated at the anterior and posterior horns. Although they are intended to be a part in reflex arc, this function has not been thoroughly evaluated. We hypothesized that electrical stimulation of the normal meniscus would elicit electromyographic activity of the hamstring muscle via the reflex arc. Five adult domestic male rabbits were used in this study. Under general anesthesia, knee arthrotomy and thigh dissection were done to expose medial meniscus and semimembranosus muscle. Menisci were stimulated by Teflon-coated bipolar needle electrodes. Needles were placed in the posterior horn of the medial menisci. Two Teflon-coated monopolar needle electrodes were placed in semimembranosus muscle. A four-channel electromyograph was used for recording. Two different potentials were recorded from the target muscle. The first response had a very short distal latency and its amplitude was changing in accordance with the strength of the stimulus, suggesting that this response was being elicited by direct muscle stimulation. The second delayed response with less amplitude also appeared in some traces. The latency and the amplitude of this second response were fairly stable stating that this delayed response was being generated by a reflex pathway and seen in all subjects.     

膝关节半月板脱位的MRI诊断

目的 探讨膝关节半月板脱位的MRI表现及诊断价值。方法 回顾性分析20例经临床手术证实的膝关节半月板脱位均经MRI检查。主要临床表现为膝关节疼痛。结果 膝关节半月板脱位并半月板撕裂15例；同时膝关节半月板脱位并骨关节炎14例。MRI征象：半月板脱离膝关节面。伴有撕裂可见T2WI稍高信号。T1WI为等信号。结论 膝关节半月板脱位MRI可提供准确的诊断。     

Presumptive subarticular stress reactions of the knee: MRI detection and association with meniscal tear patterns

Objective MRI detects subchondral marrow findings in painful knees which bear resemblance to spontaneous osteonecrosis of the knee (SONK). Gathering evidence suggests that the primary or predominant pathogenesis of these lesions is physical stress. This study analyzes the patient characteristics and meniscal pathology associated with these lesions—herein referred to as presumptive subarticular stress related (PSSR) lesions.Design and patients All patients were scanned using a standardized imaging protocol. The criterion for a PSSR lesion was a subchondral marrow edema pattern encompassing a more focal, low-signal zone adjacent to or contiguous with the subchondral cortex. Patients were identified using an electronic database search of cases reported by one experienced musculoskeletal radiologist.Results Twenty-five PSSR lesions were identified among 1,948 MRI evaluations of the knee. Twenty-one PSSR lesions occurred in the medial compartment, and four occurred in the lateral compartment. There was no sex predilection. Patients with PSSR lesions were older than other patients undergoing MRI evaluation (mean 66 years versus 52 years, P<0.001). Meniscal tears occurred more commonly in cases with PSSR lesions than in the group as a whole (76% versus 45%, P<0.001). Radial and posterior root tears were more common in knees with PSSR lesions than in other knees with meniscal tears (53% versus 26%, P<0.01).Conclusions PSSR lesions are associated with meniscal tears and, more specifically, with meniscal tear patterns that dramatically increase contact forces across the knee joint. This observation supports the hypothesis that mechanical stress is important in the pathogenesis of these subarticular lesions that are detected by MRI.     

MRI在膝关节软骨病变中的应用及研究进展

膝关节是人体最大最复杂的关节,关节软骨在维持关节正常活动中起到重要作用。关节软骨病变是影响膝关节稳定性的重要因素。磁共振成像（magnetic resonance imaging,MRI）对诊断膝关节软骨病变具有良好的空间分辨率和组织对比度,是目前评价关节软骨病变最有效的无创技术,其在膝关节疾病诊断中的应用日益广泛并显示出独特的优势。