Neuromuscular function in anterior cruciate ligament reconstructed patients at long-term follow-up

BackgroundThe permanence of neuromuscular adaptations following anterior cruciate ligament reconstruction is not known. The aim of this study was to compare bilateral muscle co-contraction indices, time to peak ground reaction force, and timing of muscle onset between anterior cruciate ligament reconstruction subjects 10–15 years post reconstruction with those of matched uninjured controls during a one-leg hop landing.MethodsNine healthy controls and 9 reconstruction subjects were recruited. Clinical and functional knee exams were administered. Lower limb co-contraction indices, time to peak ground reaction force, and muscle onset times were measured bilaterally. Differences in clinical and functional outcomes were assessed with unpaired t-tests, and mixed model repeated measures were used to examine effects of group, limb and interaction terms in electromyography measures.Findings89% of control knees were clinically “normal”, whereas only 33% of reconstructed knees were “normal”. Anterior cruciate ligament-reconstructed subjects tended to achieve shorter functional hop distances but demonstrated symmetrical lower limb electromyography measures that were no different from those of controls' with the exception that biceps femoris activation was delayed bilaterally prior to ground contact but was greater during the injury risk phase of landing.InterpretationWith the exception of hamstring activation, lower limb electromyography measures were largely similar between ligament-reconstructed and matched control subjects, which was in contrast to the clinical findings. This result brings into question the significance of neuromuscular function at this long-term follow-up but raises new questions regarding the role of symmetry and pre-injury risk.     

Gait perturbation response in chronic anterior cruciate ligament deficiency and repair

OBJECTIVE: To determine how chronic anterior cruciate ligament deficient and surgically repaired subjects react to unexpected forward perturbations during gait as compared to healthy controls. DESIGN: Gait testing of 10 chronic anterior cruciate ligament deficient subjects prior to and three months following reconstructive surgery, and 10 uninjured controls. BACKGROUND: The ability of an anterior cruciate ligament injured individual to react and maintain equilibrium during gait perturbations is critical for the prevention of reinjury. No studies have investigated how these individuals respond to unexpected perturbations during normal gait. METHODS: An unexpected forward perturbation was induced upon heel strike using a force plate capable of translational movement. RESULTS: Prior to surgery, the anterior cruciate ligament subjects exhibited a greater knee extensor moment in response to the perturbation compared to healthy controls. Following surgery, the anterior cruciate ligament injured subjects exhibited a static knee position and a sustained knee extensor moment throughout stance in response to the perturbation as compared to controls. CONCLUSIONS: These data suggest that chronic anterior cruciate ligament deficient subjects rely heavily on knee extensor musculature to prevent collapse in response to an unexpected perturbation. This same reactive response was more pronounced 3 months following surgery. RELEVANCE: The results suggest that, prior to and following surgery, chronic anterior cruciate ligament injured subjects respond differently than healthy controls to an unexpected perturbation during gait. Anterior cruciate ligament injured or repaired subjects do not reduce or avoid vigorous contraction of the quadriceps muscles when responding to gait perturbations.     

Pediatric anterior cruciate ligament reconstruction

An increasing number of anterior cruciate ligament (ACL) injuries are seen in children now than in the past due to increased sports participation. The natural history of ACL deficient knees in active individuals, particularly in children is poor. Surgical management of ACL deficiency in children is complex due to the potential risk of injury to the physis and growth disturbance. Delaying ACL reconstruction until maturity is possible but risks instability episodes and intra-articular damage. Surgical options include physeal-sparing, partial transphyseal and complete transphyseal procedures. This article reviews the management of ACL injured skeletally immature patients including the functional outcome and complications of contemporary surgical techniques.     

Measurement of brake response time after right anterior cruciate ligament reconstruction

OBJECTIVE: Recommendations on safe driving after anterior cruciate ligament (ACL) reconstruction have been largely intuitive. We studied brake response time in patients who participated in outpatient rehabilitation after right ACL reconstruction. DESIGN: Prospective, repeated measures design comparing 14 patients post-ACL reconstruction with 21 subjects with normal knees. INTERVENTIONS AND MAIN OUTCOME MEASURES: The following measures were assessed every 2 weeks for 10 weeks: brake response time, 6-meter walk time, knee range of motion, pain, and joint effusion. Statistical testing used analysis of covariance with repeated measures. Significant variables were analyzed separately and post hoc tests conducted using the least squares differences method. Both groups were compared with published norms from the American Automobile Association. RESULTS: No significant gender differences across main effects were detected. Brake response times for men improved significantly after week 6 (p < .05) and week 10 (p < .01). Brake response times for women in the ACL treatment group matched controls at 6 weeks. Six-meter walk times for control subjects were faster than those for the ACL group preoperatively (2.6 sec vs 5.5 sec), but equalized by week 6. CONCLUSIONS: After right ACL reconstruction, brake reaction times of rehabilitated men and women matched those of established controls after 4 to 6 weeks. Measuring brake response times during rehabilitation may ensure that individual patients return to driving in a safe and timely manner.     

Graft healing in anterior cruciate ligament reconstruction

Objective

To determine the relationship between lower extremity alignment and MTSS amongst non-professional athletes

Design

In a prospective Study, sixty six subjects were evaluated. Bilateral navicular drop test, Q angle, Achilles angle, tibial angle, intermalleolar and intercondylar distance were measured. In addition, runner's height, body mass, history of previous running injury, running experience was recorded. Runners were followed for 17 weeks to determine occurrence of MTSS.

Results

The overall injury rate for MTSS was 19.7%. The MTSS injury rate in girls (22%) was not significantly different from the rate in boys (14.3%). Most MTSS injuries were induced after 60 hours of exercise, which did not differ between boys and girls. There was a significant difference in right and left navicular drop (ND) in athletes with MTSS. MTSS had no significant correlation with other variables including Quadriceps, Tibia and Achilles angles, intercondylar and intermaleolar lengths and lower extremity lengths.

Limitation

All measurements performed in this study were uniplanar and static. The small sample size deemed our main limitation. The accurate assessment of participants with previous history of anterior leg pain for MTSS was another limitation.

Conclusion

Although a significant relationship between navicular drop and MTSS was found in this study; there was not any significant relationship between lower extremity alignment and MTSS in our sample study.     

Pathogenesis of anterior cruciate ligament injury

Pathology, part of the basic science of medicine and nursing, is an understanding of how cellular mechanisms and organ systems function conjointly in the physical body. An awareness of the biomechanics and pathophysiology related to a particular mechanism of injury (MOI) provides a more appreciative sense of how tissues become damaged. Cognizance of the variables and risk factors involved in MOI specific to anatomic structures not only helps the Health Care Provider (HCP) decide which treatment options are necessary, but knowing risk factors helps in preventive tactics, counseling an athlete for optimal training, and rehabilitation of the injured athlete. This article discusses the pathophysiology related to anterior cruciate ligament (ACL) injury, one of the most common and costly ligamentous knee injuries. The differentiation between contact versus noncontact mechanisms and risk factors plaguing women athletes will be listed.     

Pediatric anterior cruciate ligament reconstruction outcomes

Treatment of pediatric anterior cruciate injuries have become an area of controversy sparking much debate about best management strategies. Delaying surgery until skeletal maturity has often been shown to result in unfavorable outcomes due to concomitant meniscal and chondral injuries in this population. There have been numerous techniques used to reconstruct the ACL in the skeletally immature patient; however, most studies are limited by small patient numbers and other methodological concerns. With recent publications reporting failure rates as high as 15–25 % and growth disturbances being uncommon but now reported within almost every technical category, patient and caregiver education become of paramount importance. Key principles will be outlined that may help to avoid some of the pitfalls that occur when dealing with this unique population.     

Approaching the ruptured anterior cruciate ligament

Anterior cruciate ligament (ACL) disruptions are common injuries that currently hold a fearsome reputation among athletes of all abilities and disciplines. Indeed, if the diagnosis is missed at first presentation, it is difficult to attribute ongoing instability and recurrent injury to an ACL tear. Classically, patients then often improve shortly before repeatedly reinjuring their knee. At some point, the knee may lock, necessitating an arthroscopic meniscectomy. Tragically, this then hastens the progression of joint arthrosis and the decline of the joint function. While the burden of responsibility does not lie solely with the junior doctor or the general practitioner, it is often at the first consultation that the natural history of this devastating injury is decided. The ability to recognise, institute early management and reassure patients with ACL tears about the future is an invaluable asset to the non-specialist junior doctor. Once diagnosed, the responsibility of advising and further counselling of patients with ACL injuries is best left to the orthopaedic knee specialist. Family practitioners and emergency room doctors should not feel pressured to offer advice on specialist areas such as return to sports without reconstruction or indeed the need for reconstruction. Indeed, decisions to return to sports with ACL-deficient knees have all too often led to disastrous reinjury events to the articular cartilage and/or the menisci.     

前交叉韧带重建后的感染

背景：前交叉韧带重建后感染的发生率比较低,但这种感染会导致灾难性的结果,目前对这种感染的诊断和治疗还没有取得一致的意见。目的：探讨导致前交叉韧带重建术后感染的原因、如何早期诊断,并探讨合适的治疗方案,以尽量保护膝关节的功能。方法：以＂anterior cruciate ligament,reconstruction,infection＂为检索词,检索Pubmed数据库（2007至2012年）;以＂前交叉韧带,重建,感染＂为检索词,检索万方数据库（2007至2012年）。以与前交叉韧带重建后感染的相关文献为评价指标,纳入与前交叉韧带重建后感染相关的内容,排除重复研究。结果与结论：细菌污染手术工具或者韧带移植物是导致前交叉韧带重建后感染的最常见原因,移植物固定的方式和重建后感染之间可能有一定的关系。典型的前交叉韧带重建术后感染的症状和普通的化脓性关节炎的症状类似,但有的前交叉韧带重建后感染的病例并没有感染的典型表现。前交叉韧带重建后感染的诊断需要依靠临床症状、实验室检查（C-反应蛋白和血沉）、膝关节穿刺等方法。大多数外科医师选择静脉使用敏感的抗生素、膝关节灌洗并保留移植物作为自体移植物重建前交叉韧带后感染的首选治疗方法。当感染难以控制或者移植物看起来确实有感染迹象时应该考虑取出移植物。     

Bilateral accommodations to anterior cruciate ligament deficiency and surgery

OBJECTIVE To determine bilateral lower extremity joint accommodations during gait in anterior cruciate ligament deficient subjects and uninjured controls. DESIGN: Gait testing of 10 chronic anterior cruciate ligament deficient subjects prior to and 3 months following reconstructive surgery, and 10 uninjured controls. BACKGROUND: It is possible that bilateral joint accommodations could occur as a result of anterior cruciate ligament injury and in response to surgical repair. Few studies have investigated bilateral joint accommodations to anterior cruciate ligament injury and there is little consistency in the reported results. METHODS: Bilateral lower extremity kinematic and kinetic data were collected from 12 walking trials and inverse dynamics calculations were made to estimate bilateral knee and hip joint angle, moment, and power patterns during the stance phase of gait. RESULTS: Control subjects exhibited asymmetrical hip but symmetrical knee joint moment and power patterns. In contrast, the anterior cruciate ligament deficient subjects exhibited symmetrical hip and asymmetrical knee joint moment and power patterns prior to and following reconstructive surgery. CONCLUSIONS: Gait asymmetry in healthy subjects should not be considered pathological. In addition, chronic anterior cruciate ligament injury results in joint specific, bilateral lower extremity accommodations in gait mechanics. These accommodations persist 3 months following surgical repair.     

关节镜下前交叉韧带重建材料及其重建的理论研究与临床应用

背景:前交叉韧带是膝关节内的核心结构,近年来前交叉韧带损伤的发生率逐渐增高.目的:就前交叉韧带的损伤机制、手术方法、移植物选择、等长重建、重建韧带翻修等问题进行综述,为临床治疗前交叉韧带损伤提供一定的参考.方法:应用计算机检索Medline数据库(1996-01/2009-03),以Anterior cruciate ligament.implant、reconstruction、repair为检索词;应用计算机检索重庆维普数据库(1996-01/2009-03)、清华同方数据库(1996-01/2009-03),以前交叉韧带、移植物、重建、修补为检索词.结果与结论:共收集200篇关于关节镜下前交叉韧带重建的文献,排除发表时间较早、重复及类似研究,纳入18篇符合标准的文献.前交叉韧带是稳定膝关节的重要结构,运动及日常生活中多种因素可导致其损伤,治疗不当将严重影响运动能力或丧失运动能力.为恢复膝关节结构和功能,对损伤的前交叉韧带需要进行重建已成为共识.随着技术的不断进步和手术器械的研制创新,关节镜下重建术已成为当今治疗前交叉韧带损伤的主流方法.尽管治疗前交叉韧带损伤的手术方法很多,但还没有哪一种能完全复制前交叉韧带的解剖关系,手术是否能减少前交叉韧带伤后的继发损害目前还没有定论.对手术方式、移植物的选择、术后康复以及其他辅助治疗等方面仍有大量工作需要完善.     

Loading response following anterior cruciate ligament reconstruction during the parallel squat exercise

OBJECTIVE: To determine if individuals 1.5-15 months post-anterior cruciate ligament reconstruction demonstrated an equal loading response on their involved and uninvolved lower extremity during a parallel squat exercise versus a control group. DESIGN: Four-group repeated measures design with one between-subject factor (time post-anterior cruciate ligament reconstruction) and two within-subject factors (knee angle and added weight). BACKGROUND: It has been a clinical observation that post-anterior cruciate ligament reconstruction, individuals do not place equal amounts of weight upon each lower extremity during double-leg exercises. METHODS: Twenty-four subjects were in each of the experimental groups, 1.5-4 months, 6-7 months, and 12-15 months post-anterior cruciate ligament reconstruction, while 24 subjects without history of lower extremity pathology/injury served as the control group. Pedar in-shoe sensors were placed inside the subjects' shoes to record loading response patterns during the exercises. All performed 3 sets of 9 randomized squats to each of the three knee flexion angles (30 degrees, 60 degrees, and 90 degrees ) with the three different weights (20.45 kg bar only, 35%, and 50% body mass) using a Smith squat rack. A three-way repeated measures ANOVA (P < 0.050) was used to compare the differences between groups in loading response statically between the uninvolved and involved lower extremity for each of the different weights at each knee flexion angle during the squat exercise. RESULTS: The three-way repeated measures ANOVA revealed that there was a significant group effect (P < 0.001). Thus, the amount of time post-anterior cruciate ligament reconstruction affected the difference in the subjects' loading response for the uninvolved and involved lower extremities. There was also a three-way interaction, indicating that the difference in loading response was dependent on the group, amount of knee flexion, and amount of added weight (P = 0.010). CONCLUSION: These data suggest that subjects significantly load their uninvolved lower extremity until 12-15 months post-anterior cruciate ligament reconstruction. RELEVANCE: Based on the results of this study, caution may be warranted when adding resistance during the parallel squat for an individual's first year post-anterior cruciate ligament reconstruction, particularly with less knee flexion to avoid compensation and injury.     

Biomechanical comparison of anterior cruciate ligament repair with internal brace augmentation versus anterior cruciate ligament repair without augmentation

BackgroundNewer repair techniques of anterior cruciate ligament tears, including augmentation with internal brace, have shown promising clinical results. Few biomechanical studies exist comparing anterior cruciate ligament repair only versus repair with internal brace. The purpose of this study was to compare the load to failure and stiffness of anterior cruciate ligament repair with internal brace augmentation versus repair-only.MethodsProximal femoral avulsion type anterior cruciate ligament injuries were created in 20 cadaver knees. Anterior cruciate ligament repair-only or repair with internal brace was performed using arthroscopic tools. Load to failure and failure modes were collected, with calculations of stiffness and energy to failure performed.FindingsThe average load to failure for the internal brace group was higher than the repair-only group: 693 N (SD 248) versus 279 N (SD 91), P = .002. The stiffness and energy to failure values were higher for the internal brace group than the repair-only group: 83 N/mm versus 58 N/mm, P = .02 and 16.88 J (SD 12.44) versus 6.91 J (SD 2.49), P = .04, respectively. Failure modes differed between groups (P = .00097) with 80% failure in the repair-only due to suture pull through the anterior cruciate ligament and 90% failure in the internal brace group due to suture button pull through the femur.InterpretationThere was higher load to failure, stiffness, and energy to failure for the internal brace group compared to the repair-only group, and a high positive correlation between bone density and load to failure for the internal brace group.Clinical significanceAnterior cruciate ligament repair with internal brace augmentation demonstrates significantly higher load to failure. It may be a useful adjunct to protect the anterior cruciate ligament repair from failure during the early stages of healing.     

组织工程化韧带在前交叉韧带运动损伤修复中的作用

背景:交叉韧带是膝关节内的核心性稳定结构,具有制导膝关节生理活动并限制非生理性活动的功能,其中前交叉韧带的作用更为重要,其损伤的治疗已成为目前运动医学研究的热点.目的:探讨前交叉韧带生理功能、损伤机制,综述其修复过程中组织工程化材料的研究成果.方法:应用计算机检索1990-01/2011-02 PubMed数据库及维普数据库有关前交叉韧带组织工程研究进展、肌腱支架材料生物力学分析、生物材料在肌腱组织工程中应用及组织工程技术在修复肌腱缺损临床应用方面的相关文献,英文检索词"anterior cruciate ligament,biological materials,damage,treatment",中文检索词"前交叉韧带,生物材料,损伤,治疗",检索文献量总计102篇.结果与结论:前交叉韧带损伤后组织工程化康复措施得到了较快发展,从材料的选择来看,单一移植材料难免会存在诸多不足,不利于韧带的康复,复合材料可以结合不同材料的特性对韧带组织工程化材料进行配置,可以弥补单一材料的生物相容性、降解速度、生物力学性能、材料的韧性等不足,另外,对组织工程化材料进行功能结构加工也是尤为重要,这样可以更大程度的为细胞提供吸附、成长和分化的良好环境.同时,基因技术的进步以及各种新型材料的研制,必将在更大程度上满足前交叉韧带康复的需要.     

组织工程化韧带在前交叉韧带运动损伤修复中的作用

背景：交叉韧带是膝关节内的核心性稳定结构,具有制导膝关节生理活动并限制非生理性活动的功能,其中前交叉韧带的作用更为重要,其损伤的治疗已成为目前运动医学研究的热点。目的：探讨前交叉韧带生理功能、损伤机制,综述其修复过程中组织工程化材料的研究成果。方法：应用计算机检索1990-01/2011-02PubMed数据库及维普数据库有关前交叉韧带组织工程研究进展、肌腱支架材料生物力学分析、生物材料在肌腱组织工程中应用及组织工程技术在修复肌腱缺损临床应用方面的相关文献,英文检索词＂anterior cruciate ligament,biological materials,damage,treatment＂,中文检索词＂前交叉韧带,生物材料,损伤,治疗＂,检索文献量总计102篇。结果与结论：前交叉韧带损伤后组织工程化康复措施得到了较快发展,从材料的选择来看,单一移植材料难免会存在诸多不足,不利于韧带的康复,复合材料可以结合不同材料的特性对韧带组织工程化材料进行配置,可以弥补单一材料的生物相容性、降解速度、生物力学性能、材料的韧性等不足,另外,对组织工程化材料进行功能结构加工也是尤为重要,这样可以更大程度的为细胞提供吸附、成长和分化的良好环境。同时,基因技术的进步以及各种新型材料的研制,必将在更大程度上满足前交叉韧带康复的需要。     

Quantitative analysis of anterior cruciate ligament instability

The purpose of this study was to quantify end-feel by evaluating instantaneous stiffness and change in stiffness of the tibiofemoral joint. Normal (n = 26), anterior cruciate ligament (ACL) deficient (n = 6), and posterior cruciate ligament (PCL) deficient (n = 2) subjects were tested using the KT 2000 knee ligament arthrometer. Analogue force and displacement data were digitized, filtered, and calibrated. Force-displacement curves in the region of anterior tibial displacement were approximated using 5th degree polynomial functions. Stiffness and change in stiffness were determined analytically by the first and second derivatives of these functions. Subjects with confirmed ACL deficiency had lower values for stiffness and change in stiffness in the region of the curves believed to be indicative of ACL function, compared to contralateral knees and control subjects. RELEVANCE: First and second derivatives of tibiofemoral force-displacement curves give the stiffness and the change in stiffness respectively for anterior displacement of the tibia relative to the femur. This information concerning knee stability in vivo may be useful for diagnosis and follow-up.     

本体感觉训练在膝前交叉韧带重建术后康复中的应用

目的探讨本体感觉训练在前交叉韧带重建术后康复中的作用。方法将前交叉韧带重建术后患者42例按病区分为本体感觉促进组(26例)和对照组(16例),对照组应用一般康复训练方法,本体感觉促进组应用一般康复训练方法和本体感觉强化训练。术后6个月进行患者位置觉测定、膝关节功能评分及关节稳定性检查。结果在被动角度重现测试中,本体感觉促进组患侧膝的总平均偏差为(4.10±1.38)°,健侧膝的总平均偏差为(3.76±1.93)°,两侧膝比较,差异无统计学意义(P>0.05)。对照组患侧膝的总平均偏差为(4.85±1.55)°,健侧膝的总平均偏差为(3.56±1.72)°,患侧膝的总平均偏差显著大于健侧(P<0.01)。本体感觉促进组的Lysholm评分显著高于对照组(P<0.05)。2组患侧膝Lanchman和Pivotshift检查均为阴性。结论前交叉韧带重建术后应用强化本体感觉训练能促进下肢功能的恢复。     

Anatomical single bundle anterior cruciate ligament reconstruction

We present a review of the literature looking at the anatomy of the Anterior Cruciate Ligament, the biomechanical aspects of ACL reconstruction, review the outcomes of single and double bundle ACL reconstruction and present the current techniques for anatomic single bundle reconstruction.     

膝关节前交叉韧带的MRI三维成像研究

目的 探讨MRI三维成像技术(M3D/cube T2WI)在膝关节前交叉韧带(anterior cruciate ligament,ACL)正常显示和损伤诊断的价值.方法 选取30例正常自愿者(对照组)及11例ACL损伤病例(损伤组),在GE 1.5 T磁共振分别行MRI常规膝关节矢状面T1WI、FSE压脂T2WI(f...