Quadriceps-hamstring EMG activity during functional, closed kinetic chain exercise to fatigue

It has been hypothesized that the ability of the neuromuscular system to co-contract muscles for joint stabilization may be impaired during the development of fatigue. The purpose of this study was to examine muscle activation of the quadriceps and hamstring muscles during a prolonged closed kinetic chain exercise, the forward lunge. Eight males and two females [mean (SD) age 26.0 (2.3) years, height 177.2 (13.6) cm, body mass 82.8 (17.1) kg] with no prior knee pathology volunteered for this study. Subjects performed repeated forward lunges onto their dominant leg at the cadence of one full lunge cycle every 2 s, until the point of volitional failure. Digital switches were positioned to record foot-strike and knee-strike of the lunge leg at the midpoint of the lunge, as well as heel-strike upon return to stance. During the lunge performance, surface electromyographic (EMG) signals of the vastus lateralis (VL), vastus medialis (VM), biceps femoris (BF), and semitendinosus (ST) muscles of the supporting leg were measured. Heart rate was also monitored every 30 s during the performance. All EMG data were full-wave rectified, partitioned into up and down phases, and integrated over the entire exercise period. The results demonstrated a significant increase in activation of the VL, VM, and BF during performance of the forward lunge to volitional failure (P < 0.05). No significant increase was shown for the ST. Heart rate increased significantly over the course of the lunge. These findings suggest that activation of the VL, VM, and BF muscles occurs as a unit during performance of the forward lunge during both concentric and eccentric lunge phases. Accepted: 25 October 1999     

Semitendinosus tendon regeneration after anterior cruciate ligament reconstruction: can we use it twice?

Purpose

It has been demonstrated that the semitendinosus tendon can regenerate after being harvested in its whole length and thickness for anterior cruciate ligament (ACL) reconstruction. Ultrasound studies and guided biopsies of the regenerated tendon have shown compatibility and resembling features of the normal tendon. The question is if this neo-tendon is biologically and functionally adequate for re-use?

Methods

Two randomised groups of 150 volunteers were followed up for two years after harvesting the semitendinosus only (25) or the semitendinosus and gracilis tendons (25) in ACL reconstruction. The patients were followed up with clinical and ultrasound examinations, biopsies and histological tests. Surgical exploration was done in three patients for macroscopic verification. The injected arteries of four lower limbs were dissected and the tendon’s arterial supplies were examined.

Results

Seventy-two percent of the cases showed regeneration of the semitendinosus tendons. The neotendons were inserted mostly below the knee joint (83.3 %) where they had fused with the gracilis tendon, and above the joint (60 %) when the gracilis was harvested as well. The isokinetic strength of the hamstrings and quadriceps was not significantly diminished on the operated side. A macroscopic and histological analysis of the regenerated tendons demonstrates close resemblance to normal anatomy, with focal areas of fibrosis. In one patient the regenerated tendon was used for medial patellofemoral ligament reconstruction.

Conclusion

The semitendinosus muscle can recover and the tendon has great potential to regenerate after harvesting for ACL reconstruction. Our data suggest that the regenerated tendons could be used for iterative ligament reconstruction.     

半腱肌腱与同种异体肌腱解剖重建踝关节外侧副韧带治疗慢性踝关节不稳的疗效比较

目的比较自体半腱肌腱与同种异体肌腱重建踝关节外侧副韧带治疗慢性踝关节不稳的临床疗效。方法回顾性分析自2012-06—2014-12在踝关节镜联合小切口下分别应用同种异体肌腱与自体半腱肌腱解剖重建踝关节外侧副韧带治疗慢性踝关节不稳68例。半腱肌腱组35例,异体肌腱组33例。比较2组手术时间、住院时间、手术费用,以及末次随访时VAS评分、AOFAS评分、IKDC评分、距骨倾斜角和距骨前移距离。结果 68例均获得13~38(22.7±5.2)个月随访。半腱肌腱组手术时间明显长于异体肌腱组,但在住院时间和手术费用方面优于异体肌腱组,差异有统计学意义(P0.05)。2组末次随访时VAS评分、AOFAS评分、IKDC评分、距骨倾斜角和距骨前移距离比较差异无统计学意义(P0.05)。结论同种异体肌腱与自体半腱肌腱重建踝关节外侧副韧带治疗慢性踝关节不稳均能获得良好临床疗效,临床中可根据患肢膝关节健康状况、运动期望值及经济承受能力综合分析,个体化选择移植物。     

关节镜下半腱肌腱单束重建前交叉韧带前内侧束损伤

目的观察关节镜下半腱肌腱单束重建前交叉韧带（ACL）前内侧束损伤的临床疗效。方法采用关节镜下半腱肌腱单束重建ACL前内侧束损伤患者18例,对比术前及术后末次随访时Lysholm、IKDC评分及KT-1000双侧膝关节胫骨结节前移差。结果 18例患者术后伸膝无受限,4周膝关节屈曲均达到110°,术后3个月膝关节屈曲120°-140°,平均124°。术后18例患者均获得随访,随访时间为6-18（12.5±5.3）个月;末次随访时患者IKDC、Lysholm评分均明显高于术前（P〈0.05）,屈膝30°位KT-1000双侧膝关节胫骨结节前移差明显小于术前（P〈0.05）。结论关节镜下自体半腱肌腱单束解剖重建ACL前内侧束损伤可以恢复膝关节的稳定性,临床疗效较好。     

四股腘绳肌腱重建膝前交叉韧带后骨隧道增宽与术后康复程序的关系

目的　探讨膝关节前交叉韧带 (ACL)重建术后骨道增宽与不同康复程序的关系。方法　将 6 5例用四股半腱、股薄肌腱重建ACL的患者分为 2组 ,A组 33例 (男 19例 ,女 14例 ,平均年龄 31 2± 12 4岁 ) ,所有患者均使用德国Paessler教授的技术进行单纯ACL重建 ,术后用激进的康复程序进行功能康复。B组 32例 (男 2 0例 ,女 12例 ,平均年龄 30 3± 10 3岁 ) ,所有患者除了ACL重建外 ,还同时接受了半月板缝合修补手术或用Microfracture方法修复软骨损伤的手术 ,这组患者术后均用保守的康复程序进行康复治疗。术后 6个月用CorelDRAW 8 0软件对数字化的标准后前位和侧位X线片上胫骨骨道的的上、中、下部的宽度进行测量 ,去除测量结果中X线片的放大值后进行t检验。结果　采用保守康复程序的B组患者术后 6个月膝关节正、侧位X线片上 ,胫骨骨道的前后径和横径的上、中、下部的增宽程度均比采用激进康复程序的A组要明显减小。结论　手术后康复程序是ACL重建手术后骨道增宽的原因之一 ,它可能通过影响骨道增宽来间接影响功能恢复和远期疗效     

Differences in the rehabilitation period following two methods of anterior cruciate ligament replacement: semitendinosus/gracilis tendon vs. ligamentum patellae

This study compared patient outcome during the early rehabilitation phase following two different methods of anterior cruciate ligament (ACL) reconstruction: ligamentum patellae (LP) and semitendinosus/gracilis tendon (SG) based reconstruction. The study included 50 consecutive patients treated by each method, examined 6 weeks and 3, 6 and 12 months after surgery. Patients in the SG group showed significantly better Lysholm scores at 6 and 12 months, Tegner Activity Scale scores at 3 months, and pain profile assessments at 6 weeks and 3 months than those in the LP group. Significant advantages were observed in LP group in the Overall Knee Score at 6 weeks and in range-of-motion at 6 weeks and 3 and 6 months post-surgery. Stability tests revealed no significant differences between patients in the two groups. SG-based reconstruction of the ACL thus demonstrates advantages over LP-based reconstruction regarding pain and function, while LP-based reconstruction was associated with an earlier return of motion.     

Revision ACL reconstruction using doubled semitendinosus and gracilis tendons: a follow-up study

Abstract Few papers report the results of revision ACL reconstruction with hamstrings tendons. We report our results with revision anterior cruciate ligament (ACL) surgery using a doubled gracilis and semitendinosus tendons (DGST) graft, in association with an exta-articular procedure. Twelve patients underwent ACL revision surgery using autogenous homolateral DGST graft in association with an extra-articular procedure and were evaluated at a mean follow-up of 35 months. At follow-up evaluation, all patients scored negatively on the Lachman test and normally or near normally on the jerk test. The KT 1000 evaluation showed a average side-to-side difference at 30 lb and MM of 1.4±1.7 mm and 1.6±1.6 mm, respectively. The Lysholm score was 98±2 (range, 94–100); excellent results (score 95–100) were obtained in 83% of cases, good results (score 84–94) in 17%, and no fair or poor results. At the IKDC evaluation, the result was excellent (normal) in one-thirds of cases and good (nearly normal) in twothirds. Therefore, the use of hamstring tendons in association with lateral tenodesis seems to be a good alternative to the use of allografts or contralateral bone-patellar tendon-bone graft in revision ACL reconstructions.     

关节镜下半腱肌加股薄肌肌腱自体移植重建膝关节前交叉韧带(附24例报告)

24例膝关节前交叉韧带 (ACL)患者在关节镜下行半腱肌加股薄肌肌腱自体移植重建术。术后平均随访 12个月。按照 L ysholm膝关节功能评分 :术前 (5 2 .4± 15 .9)分 ,术后 6、12、2 4个月的评分分别为 (85 .0±12 .2 )分、(89.3± 11.7)分、(90 .8± 10 .5 )分 ,与术前比较均有明显统计学差异 (P<0 .0 1)。认为关节镜下半腱肌加股薄肌肌腱自体移植重建 ACL 具有生物力学性质好、取材处并发症少、手术创伤小、固定方法可靠、临床效果优良等特点 ,值得临床推荐使用     

半腱肌重建膝关节内侧副韧带和前交叉韧带的疗效分析

我们应用关节镜下重建前交叉韧带的同时辅助切口，采用半腱肌移位动力性重建内侧副韧带14例，随访显示效果良好。