Complete rupture of the distal semimembranosus tendon with secondary hamstring muscles atrophy: MR findings in two cases

Complete rupture of the hamstring muscles is a rare injury. The proximal musculo-tendinous junction is the most frequent site of rupture. We present two cases of complete rupture of the distal semimenbranosus tendon, which clinically presented as soft-tissue masses. MR imaging permitted the correct diagnosis. There has been only one other such case reported. Received: 15 October 1999 Revision requested: 6 February 2000 Revision received: 8 March 2000 Accepted: 13 March 2000     

The influence of meniscal lesions on reflex activity in the hamstring muscles

Meniscal lesions are among the most common knee injuries and substantially affect the mechanical function of the knee joint. In addition, the presence of mechanoreceptors in the meniscus suggests that the menisci are also involved in the sensorimotor control of the knee. The objective of this study was to investigate the influence of an isolated meniscal lesion on the reflex behaviour of the hamstring muscles, which are involved in the sensorimotor control of the knee joint. For this purpose, we mechanically induced tibial translation in 19 patients in a standing position and analysed the biphasic response of the hamstrings consisting of a short-latency response (SLR) and a medium-latency response (MLR). Moreover, we determined anterior tibial translation. A comparison of electromyographic data for the healthy legs versus the injured legs showed no significant differences in either SLRs or MLRs. Although there was a tendency to an increase in tibial translation, no significant difference between the legs in anterior tibial translation was found. In conclusion, our experimental work did not reveal any substantial effects of a meniscal lesion on the reflex behaviour of the hamstrings. Our data suggest that the menisci appear to play only a minor role for the sensorimotor induced anterior posterior knee stability.     

Anterior cruciate ligament reconstruction in females: a comparison of hamstring tendon and patellar tendon autografts

This study compared hamstring (HS) and patellar tendon (PT) anterior cruciate ligament (ACL) reconstruction in females. Sixty-five patients (43 HS, 22 PT) were evaluated at a mean 3.8-year postoperatively. Evaluation included IKDC 2000, SF-36, Cincinnati sports activity scores, anterior knee pain (AKP), kneeling pain, range of motion and anterior knee laxity. One PT patient sustained a traumatic graft rupture. There were no differences between the two grafts in terms of anterior knee laxity or IKDC scores. The HS group had higher sports activity scores and higher scores on the Physical Functioning and General Health subscales of the SF-36. Despite no difference in AKP, there was greater kneeling pain in the PT patients, who also had greater extension deficits. Both HS and PT are satisfactory ACL grafts in females, but HS grafts were associated with less morbidity, greater return to preinjury level of activity and higher quality of life scores.     

兔四股半腱肌腱重建前交叉韧带的生物力学研究

目的应用动物模型研究四股半腱肌腱重建兔前交叉韧带（ACL）后的生物力学转归以及是否可以通过将四股半腱肌腱编织改善等张性的方法促进束间融合,改善生物力学性能。方法采用成年健康新西兰大白兔32只,分为两组,每组16只,一组行常规自体四股半腱肌腱重建ACL（常规重建组）,另一组行编织的四股半腱肌腱重建ACL手术（编织组）。每组于术后26周和52周各处死8只进行ACL观察,并每组取6只行生物力学测试对比研究。结果常规重建组26及52周共16例韧带中,5例融合为一束,11例存在分束。编织组16例标本中,13例合为一束,3例呈不同程度的分束状态。生物力学测试显示：常规重建的韧带26和52周的最大载荷分别达到正常韧带的22．63％和35．87％,编织组26和52周的最大载荷达到正常韧带的33．17％和67．20％;编织组26、52周标本的最大载荷和硬度均显著高于常规重建组。结论四股半腱肌腱作为前交叉韧带的移植物,各束之间可以发生融合、部分融合以及分束的状态,原因可能与它们之间的相对运动有关,通过编织减少这种相对运动,可以促进各束融合,提高生物学及生物力学性能。     

关节镜下自体腘绳肌腱重建交叉韧带

目的:关节镜下以半腱肌、股薄肌腱重建膝交叉韧带,分析影响疗效的因素。方法:关节镜下可吸收挤压螺钉固定四股绳肌腱修复膝交叉韧带损伤8例8膝,术后即行功能锻炼。结果:8例患者得到随访,随访时间6~30个月,平均14.8个月。术前8例抽屉试验、Lachman征均为阳性,术后检查均为阴性。根据Lysholm评分标准,术前评分平均53.75分,术后平均90.71分,手术前后评分有显著性差异(t=2.21,P<0.05)。结论:半腱肌、股薄肌腱具有良好的抗拉强度和刚度,生物可吸收挤压螺钉固定强度满意,在关节镜下用四股绳肌腱重建膝前交叉韧带是一种疗效可靠的治疗方式。     

The proximal hamstring muscle-tendon-bone unit: A review of the normal anatomy, biomechanics, and pathophysiology

Proximal hamstring injuries occur during eccentric contraction with the hip and the knee on extension; hence they are relatively frequent lesions in specific sports such as water skiing and hurdle jumping. Additionally, the trend toward increasing activity and fitness training in the general population has resulted in similar injuries. Myotendinous strains are more frequent than avulsion injuries. Discrimination between the two types of lesions is relevant for patient management, since the former is treated conservatively and the latter surgically. MRI and Ultrasonography are both well suited techniques for the diagnosis and evaluation of hamstring tendon injuries. Each one has its advantages and disadvantages. The purpose of this article is to provide a comprehensive review of the anatomy and biomechanics of the proximal hamstring muscle-tendon-bone unit and the varied imaging appearances of hamstring injury, which is vital for optimizing patient care. This will enable the musculoskeletal radiologist to contribute accurate and useful information in the treatment of athletes at all levels of participation.     

关节镜下腘绳肌腱结"瓶颈"式固定重建后交叉韧带的早期疗效

目的探讨关节镜下采用腘绳肌腱结“瓶颈”式固定方法重建后交叉韧带的临床疗效。方法自2002年4月～2005年6月对13例后交叉韧带损伤患者在关节镜下采用多股腘绳肌腱结“瓶颈”式固定方法进行重建,术后随访7个月以上,并通过关节屈伸活动度、后抽屉试验、Lachman试验、Lysholm评分、国际膝关节文献委员会(IKDC)评分进行疗效评定。结果全部病例均获随访,时间7～26个月,平均13．4个月。术后＞6个月时随访,无一例膝关节伸直受限,屈膝＞140°11例,屈膝120°1例,屈膝100°1例。后抽屉试验：Ⅰ度11例,Ⅱ度2例;Lachman,征≤Ⅰ度阳性11例,Ⅱ度2例。Lysholm评分为(90．47±4．13)分,较术前(78．82±2．46)分有明显改善(t=2．416,P=0．029)。IKDC评级：A级6例,B级5例,C级1例。结论采用腘绳肌腱结“瓶颈”式固定方法关节镜下重建后交叉韧带,组织相容性好,损伤小,降低了手术费用,有一定临床应用前景。     

Initial fixation strength of a hybrid technique for femoral ACL graft fixation

Aperture fixation with interference screws matching the diameter of the tunnel is associated with the risk of graft laceration and graft rotation. A hybrid fixation technique (extracortical and aperture fixation) with undersized interference screws provides a higher fixation strength when compared to an aperture fixation using only a screw matching the size of the tunnel and also reduces the risk of graft laceration. This research is an experimental laboratory study. We evaluated the initial fixation strength at time-zero of an extracortical-, a hybrid- and an aperture fixation in ACL reconstruction using extracortical buttons and different sized interference screws in porcine knees. The tests were performed using a single cycle and cyclic loading protocol. Analysis of yield load, maximum load and stiffness in the single cycle loading test showed no statistically significant differences for hybrid fixation with a 1 mm undersized screw and aperture fixation with a screw matching the size of the tunnel. Cyclic loading tests showed a statistically significant difference between hybrid and aperture fixation. The use of an undersized screw alone in aperture fixation resulted in insufficient fixation strength. The initial fixation strength of the hybrid technique with undersized screws is higher compared to an interference screw fixation alone. The hybrid fixation technique is an alternative for ACL graft fixation.