Knee Braces - an evaluation of treatment effectiveness after reconstruction of anterior crucial ligament

Background Despite extensive research providing significant progress in rehabilitation treatment of the anterior crucial ligament injuries, the problem concerning the choice of the most advantageous protection after reconstruction operation is still to be solved. Material and method Seventy one patients after reconstruction of anterior crucial ligament of the knee were examined objectively and subjectively to evaluate the effectiveness of three types of Rehabilitation Knee Braces in protecting of knee instability. All patients were examined by using Elgon Electrogoniometr to control dislocation of the knee and by using score test. Results Objective goniometric and subjective score tests gives better stability results of knee braces with strong construction. Conclusions In conclusion I affirmed Knee Braces sufficiently secure the knee against displacement in the joint and effectively protect the anterior crucial ligament against traumatic activity, which justifies their application rehabilitation after surgical reconstruction of anterior crucial ligament.     

Electromyographic and biomechanic analysis of anterior cruciate ligament deficiency and functional knee bracing

OBJECTIVE: Examine the neuromuscular response to functional knee bracing relative to anterior tibial translations in vivo. DESIGN: During randomised brace conditions, electromyographic data with simultaneous skeletal tibiofemoral kinematics were recorded from four anterior cruciate ligament deficient subjects to investigate the effect of the DonJoy Legend functional brace during activity. BACKGROUND: Knee braces do not increase knee stability but may influence afferent inputs from proprioception and therefore one might expect changes in muscle firing patterns, amplitude and timing. METHODS: Hoffman bone pins affixed with markers were implanted into the tibia and femur for kinematic measurement. The EMG data from the rectus femoris, semitendinosus, biceps femoris, and lateral head of the gastrocnemius were integrated for each subject in three separate time periods: 250 ms preceding footstrike and two consecutive 125 ms time intervals following footstrike. RESULTS: With brace, semitendinosus activity significantly decreased 17% prior to footstrike whereas bicep femoris significantly decreased 44% during A2, (P<0.05). Rectus femoris activity significantly increased 21% in A2 (P<0.05). No consistent reductions in anterior translations were evident. CONCLUSION: Our preliminary findings, based on a limited number of subjects, indicate joint stability may result from proprioceptive feedback rather than the mechanical stabilising effect of the brace. Despite a significant increase in rectus femoris activity upon landing, only one subject demonstrated an increase in anterior tibial drawer. RELEVANCE: Studies have shown functional braces do not mechanically stabilise the anterior cruciate ligament deficient knee. Perhaps bracing alters proprioceptive feedback. It has been shown that bracing the anterior cruciate ligament deficient knee may affect hamstring and quadriceps activity. Our findings stresses the importance of functional knee bracing combined with proprioceptive and muscular coordination training in order to increase joint stability.     

双骨道与三骨道前交叉韧带双束重建的生物力学比较

背景:关节镜下前交叉韧带重建可以有效地解决前交叉韧带损伤引起的膝关节不稳症状,而双骨道(胫骨单骨道-股骨单骨道)与三骨道(胫骨单骨道-股骨双骨道)前交叉韧带重建是目前较为常用的重建方式。目的:探讨双骨道与三骨道前交叉韧带双束重建对膝关节稳定性的影响。方法:选用8具新鲜正常成人尸体膝关节标本,分别进行双骨道与三骨道前交叉韧带双束重建,然后在MTS-809生物力学测试系统上测试膝关节在胫前加载(134N)以及胫骨旋转加载(5Nm内旋)下屈曲0°,15°,30°,60°,90°时的膝关节稳定性。结果与结论:①胫前加载:在所测的5个角度下,两重建组的胫前位移较前交叉韧带完整组均增大,但差异无显著性意义(P>0.05);双骨道重建组较三骨道重建组胫前位移增大,但差异无显著性意义(P>0.05)。②旋转加载:在所测的5个角度下,前交叉韧带完整组的胫前位移最小,双骨道重建组与三骨道重建组比较,在膝关节屈曲0°,15°和90°时,差异无显著性意义(P>0.05),在膝关节屈曲30°和60°时,三骨道重建组胫前位移小于双骨道重建组,差异有显著性意义(P<0.05);三骨道重建组与前交叉韧带完整组比较,差异无显著性意义(P>0.05)。提示双骨道与三骨道前交叉韧带双束重建均可促进膝关节前后及旋转稳定性的恢复,三骨道前交叉韧带双束重建与双骨道前交叉韧带双束重建相比,显示了更好恢复膝关节旋转稳定性的作用。     

护理康复路径管理对促进膝前交叉韧带本体感觉功能恢复的影响

目的探讨护理康复路径管理对促进膝前交叉韧带本体感功能恢复的影响。方法选取膝关节前交叉韧带损伤患者204例,分为观察组和对照组,各102例。观察组采用护理康复路径管理方法,对照组运用传统康复训练方法。结果手术后4周、12周、24周两组患者伤膝各角度位置觉偏差差异具有统计学意义(P0.05)。结论护理康复路径管理对膝关节前交叉韧带损伤患者的本体感觉恢复具有显著的提高作用。     

康复训练对前交叉韧带体部部分损伤作用临床观察

目的:介绍前交叉韧带体部部分损伤的康复训练方法,总结其近期临床疗效。方法:对32例前交叉韧带体部部分损伤的患者进行1年以上系统的康复指导,按照Lysholm膝关节功能评分标准,康复前膝关节功能评分为51±18．09分。康复内容包括肌力、活动度、本体感受器训练和肌肉牵张训练等方面。通过膝关节功能评分总结这种训练方法的可行性和效果。结果:康复后6个月膝关节功能评分为74．5±14．49分,康复后12个月膝关节功能评分为75．56±14．75分。统计学分析显示,康复训练前后评分比较有显著差异。结论:对于不合并有严重后内、后外侧韧带复合结构损伤的前交叉韧带体部部分损伤,采用该方法进行康复训练是切实可行且有效的。     

The effect of graft stiffness on knee joint biomechanics after ACL reconstruction--a 3D computational simulation

OBJECTIVE: The objective was to determine the effect of varying graft stiffness and initial graft tension on knee kinematics and graft tension after anterior cruciate ligament reconstruction. DESIGN: A 3D computational knee model was used. BACKGROUND: Many factors influencing the biomechanical outcome of anterior cruciate ligament reconstruction have been investigated. However, there are no reports on the effect of variations in graft stiffness on knee behavior. METHODS: A 3D computational knee model was used to simulate anterior cruciate ligament reconstruction using three different grafts with stiffnesses similar to the anterior cruciate ligament (graft 1), a 10mm bone-patellar tendon-bone graft (graft 2), and a 14 mm bone-patellar tendon-bone graft (graft 3). The initial graft tension was set to 0 or 40 N with the knee at 30 degrees of flexion. A 134 N anterior tibial drawer load and a 400 N quadriceps load were applied to the knee, and kinematics and graft tension were calculated. RESULTS: When fixed with no initial tension, graft 1 was found to under-constrain the knee, while graft 2 slightly over-constrained the knee, and graft 3 over-constrained the knee when compared to the intact knee. When an initial graft tension of 40 N was used, all of the reconstructed knees were more constrained than when an initial tension of 0 N was used. CONCLUSIONS: This study suggests that graft stiffness has a direct impact on knee biomechanics after anterior cruciate ligament reconstruction. An optimal anterior cruciate ligament reconstruction can be achieved if the anterior cruciate ligament is replaced by a graft with similar structural stiffness. RELEVANCE: This study showed that if the graft material and fixation sites are selected such that the anterior cruciate ligament structural stiffness is retained, normal knee kinematics can be restored.     

前交叉韧带与膝关节本体感觉关系的研究进展

前交叉韧带是膝关节的重要稳定结构,与膝关节的本体感觉密切相关。本文将对前交叉韧带的神经功能、膝关节本体感觉以及两者之间的关系进行综述。     

适应膝关节肌力变化：是重建前交叉韧带后康复治疗的基本原则

背景：前交叉韧带重建后早期如何干预以减少肌力下降和切取腘绳肌腱后对屈膝肌电-机械延迟的影响是一个值得研究的方向。目的：采用文献分析法重点对前交叉韧带重建后膝关节肌力的变化及康复的进展进行了综述分析。方法：以＂Anterior Cruciate Ligament;hamstring;Muscle Strength＂和＂前交叉韧带;肌力;腘绳肌;电-机械延迟＂为中英文检索词,计算机检索2000年1月至2014年1月PubMed数据库及万方医学网相关文献。选择与前交叉韧带重建后肌力的改变、评价方法及重建后肌力康复相关的文献。最终纳入34篇文献进行探讨。结果与结论：研究表明：切取腘绳肌腱会导致术后的屈膝肌力和胫骨内旋肌力的降低,从而影响膝关节的稳定性和功能活动水平。综合临床和等速肌力测试的结果,可以对前交叉韧带重建后的疗效进行综合评定,H/Q比率（屈/伸比）的改变能够用于指导前交叉韧带损伤后的康复。前交叉韧带重建后移植物塑形过程比其他动物实验研究更长,肌腱松弛度是影响电机械延迟的重要因素之一。在基本康复训练原则的基础上根据个体功能水平及时做出相应的调整,充分体现个性化训练。国内外研究均表明前交叉韧带重建肌力康复始于重建手术之前,以尽早开始肌肉收缩的再训练从而最大程度地防止肌肉萎缩。存在的问题主要集中在康复手段的更细化和科学化以及早期康复训练的＂度＂的把握上。     

Neuromuscular training improves knee proprioception in athletes with a history of anterior cruciate ligament reconstruction: A randomized controlled trial

BackgroundAthletes exhibit deficits in knee proprioception following anterior cruciate ligament reconstruction. Neuromuscular training programs improve knee proprioception in uninjured athletes; however, the effects on knee proprioception in athletes who have undergone anterior cruciate ligament reconstruction is not well understood. The purpose of this study was to examine the effects of a neuromuscular training program on knee proprioception in athletes who have returned to sport following anterior cruciate ligament reconstruction.MethodsTwenty-four male athletes, who had undergone anterior cruciate ligament reconstruction within the previous 6–12 months and returned to sport, participated in this randomized controlled trial. Athletes were randomly allocated to an experimental group (n = 12) that took part in an 8-week neuromuscular training program or a control group (n = 12) that simply continued their typical training routine. Knee position sense was assessed at baseline and after the 8-week period (post-testing). One-way analysis of covariance, with baseline performance included as a covariate, was used to compare knee position sense errors for the reconstructed limbs of the experimental and control groups at the post-testing time point.FindingsKnee position sense errors decreased by 51.7% for the experimental group and only 4.4% for the control group over the 8-week period. As a result, the experimental group demonstrated lower knee position sense errors, compared to the control group, at the post-testing time point (P < .001).InterpretationAthletes with a history of anterior cruciate ligament reconstruction may benefit from participation in a neuromuscular training program, even after completing post-operative rehabilitation.     

Effects of neuromuscular training on knee joint stability after anterior cruciate ligament reconstruction

[Purpose] This study examined the effects of neuromuscular training on knee joint stability after anterior cruciate ligament reconstruction. [Subjects and Methods] The subjects were 16 adults who underwent arthroscopic anterior cruciate reconstruction and neuromuscular training. The Lysholm scale was used to assess functional disorders on the affected knee joint. A KT-2000 arthrometer was used to measure anterior displacement of the tibia against the femur. Surface electromyography was used to detect the muscle activation of the vastus medialis oblique, vastus lateralis, biceps femoris, and semitendinosus before and after neuromuscular training. [Results] There was significant relaxation in tibial anterior displacement of the affected and sound sides in the supine position before neuromuscular training. Furthermore, the difference in the tibial anterior displacement of the affected knee joints in the standing position was reduced after neuromuscular training. Moreover, the variation of the muscle activation evoked higher muscle activation of the vastus medialis oblique, vastus lateralis, biceps femoris, and semitendinosus. [Conclusion] Neuromuscular training may improve functional joint stability in patients with orthopedic musculoskeletal injuries in the postoperative period.Key words: Arthrometer, Anterior cruciate ligament reconstruction, Neuromuscular training     

Assessment of functional knee bracing: an in vivo three-dimensional kinematic analysis of the anterior cruciate deficient knee

OBJECTIVE: To describe three-dimensional tibial and femoral movements in vivo and examine the effect of a brace on knee kinematics during moderate to intense activity. DESIGN: Skeletal kinematics of anterior cruciate ligament deficient knees was measured with and without braces during moderate to intense activity. BACKGROUND: Invasive markers implanted into the tibia and femur are the most accurate means to directly measure skeletal motion and may provide a more sensitive measure of the differences between brace conditions. METHODS: Steinmann traction pins were implanted into the femur and tibia of four subjects having a partial or complete anterior cruciate ligament rupture. Non-braced and braced conditions were randomly assigned and subjects jumped for maximal horizontal distance to sufficiently stress the anterior cruciate ligament. RESULTS: Intra-subject peak vertical force and posterior shear force were generally consistent between conditions. Intra-subject kinematics was repeatable but linear displacements between brace conditions were small. Differences in angular and linear skeletal motion were observed across subjects. Bracing the anterior cruciate ligament deficient knee resulted in only minor kinematic changes in tibiofemoral joint motion. CONCLUSION: In this study, no consistent reductions in anterior tibial translations were observed as a function of the knee brace tested. Relevance. Investigations have reported that knee braces fail when high loads are encountered or when load is applied in an unpredictable manner. Questions remain regarding tibiofemoral joint motion, in particular linear displacements. The pin technique is a means for direct skeletal measurement and may provide a more sensitive measure of the differences between brace conditions.     

Biomechanical evaluation of intra-articular and extra-articular procedures in anterior cruciate ligament reconstruction: a finite element analysis

BACKGROUND: Intra-articular techniques (single and double bundles) are the most widely used procedures for the anterior cruciate ligament reconstruction. Lemaire introduced in 1967 the extra-articular techniques, and combined intra-articular and extra-articular reconstruction, to better restore the stability of the knee. However, the effectiveness of these procedures (intra-articular, extra-articular combined or not with intra-articular) seems to be controversial. METHODS: In the present study, we developed numerical models of a knee joint to evaluate the effects of these different procedures on the kinematics and biomechanics of the knee during an internal rotation test. Six cases were simulated: intact anterior cruciate ligament, intra-articular reconstructed anterior cruciate ligament (single and double bundles), extra-articular reconstructed anterior cruciate ligament alone, and combination of extra- and intra-articular reconstructions. The loading condition was an internal tibial torque of 2 N m at 0 degrees, 15 degrees, 30 degrees and 45 degrees of knee flexion. Internal rotation of the tibia and forces within the grafts and the ligaments were calculated. FINDINGS: This study showed that both single and double bundles intra-articular reconstructions restore similar internal rotation control and biomechanics of the soft structures as the intact anterior cruciate ligament situation. On the other hand, our results indicate that extra-articular reconstruction reduces appreciably the internal rotation and modifies the charges distribution in the soft structures when compared to the intact anterior cruciate ligament. INTERPRETATION: The extra-articular procedure alters the kinematics of the knee, which might overconstraint the ligaments and the femorotibial joints, leading to the failure of the anterior cruciate ligament reconstruction.     

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.     

A finite element simulation of the effect of graft stiffness and graft tensioning in ACL reconstruction

BACKGROUND: The anterior cruciate is the most frequent knee ligament to be totally disrupted. Surgical reconstruction of the anterior cruciate ligament is a common practice to treat the disability or chronical instability of knees due to anterior cruciate ligament insufficiency. Some of the factors that influence the success or failure of the anterior cruciate ligament reconstruction are the integrity of secondary restraints, the preoperative laxity of the knee, the status of the articular and meniscal cartilages, the selection of the graft material, the surgical technique, the graft tension and the postoperative rehabilitation. METHODS: In this paper we present and discuss the results obtained with a three-dimensional finite element model of the human knee joint corresponding to different aspects of human anterior cruciate ligament reconstruction. In particular, this model was used to investigate the effect of graft stiffness and graft tensioning on the knee joint biomechanics. The initial graft tension was set to 0, 20, 40 or 60 N with the knee at 0 degrees , 30 degrees and 60 degrees of flexion. Three different stiffnesses corresponding to those of patellar tendon, gracilis and quadrupled semitendinosus grafts were analyzed. FINDINGS: The resulting kinematics in each of these cases under an anterior load of 134 N was compared to that of the intact knee. The obtained results showed that, after reconstruction, the closest anterior tibial translation to that of the intact knee is obtained with a bone-patellar tendon-bone graft with a pretension of 60 N. INTERPRETATION: However, this initial tension produces an important additional stress in the graft during the knee movement. This may cause problems in revascularization and remodelling during the postoperative healing process. A lower pretension of about 40 N should therefore be recommended in the present conditions.     

前交叉韧带重建后本体感觉训练前后步行参数变化的计算机辅助三维步态分析系统比较

背景:目前关于前交叉韧带重建后训练对患者静态本体感觉或平衡的影响研究较多,对动态步行稳定性的研究较少。目的:利用三维步态分析系统对前交叉韧带重建后患者本体感觉训练后步行的稳定性进行分析。方法:单侧前交叉韧带重建患者32例,重建后3～6个月,可独立步行,膝关节无明显肿胀疼痛。所有患者本体感觉训练前及训练2个月后进行步态分析。结果与结论:本体感觉训练后患者步频(P<0.01)、步长(P<0.01)、步速(P<0.05)、患足廓清地面最大距离(P<0.001)均较训练前明显改善。行走时,骨盆摆动、上身摆动三维扑捉图像与训练前相比更对称,更协调。提示利用三维步态分析系统比较本体感觉训练的效果,对评估步行过程中不自觉的关节稳定和姿势、平衡的调整和维持具有重要意义。     

前交叉韧带重建后本体感觉训练前后步行参数变化的计算机辅助三维步态分析系统比较

背景：目前关于前交叉韧带重建后训练对患者静态本体感觉或平衡的影响研究较多,对动态步行稳定性的研究较少。目的：利用三维步态分析系统对前交叉韧带重建后患者本体感觉训练后步行的稳定性进行分析。方法：单侧前交叉韧带重建患者32例,重建后3～6个月,可独立步行,膝关节无明显肿胀疼痛。所有患者本体感觉训练前及训练2个月后进行步态分析。结果与结论：本体感觉训练后患者步频（P〈0.01）、步长（P〈0.01）、步速（P〈0.05）、患足廓清地面最大距离（P〈0.001）均较训练前明显改善。行走时,骨盆摆动、上身摆动三维扑捉图像与训练前相比更对称,更协调。提示利用三维步态分析系统比较本体感觉训练的效果,对评估步行过程中不自觉的关节稳定和姿势、平衡的调整和维持具有重要意义。     

Nachbehandlung der vorderen Kreuzbandplastik

Most surgeons agree that postoperative rehabilitation is an important part of the final outcome after anterior cruciate ligament (ACL) reconstruction. With the aim of a full return of knee function in terms of stability, strength, range of motion and neuromuscular control different methods of rehabilitation are performed in different phases of graft healing. A review of the literature of prospective and randomized studies revealed the following information for the rehabilitation after ACL reconstruction with a bone-patellar tendon-bone (BPTB) autograft: a brace is not required. Full weight bearing reduces anterior knee pain and has no negative effect. Neuromuscular electrical stimulation increases muscle strength and improves kinematics. Cold therapy has no positive effect. Early joint motion can avoid the negative effect of immobilization. The literature on rehabilitation after ACL reconstruction with hamstrings is not sufficient for a consensus opinion.     

Effect of muscle loads and torque applied to the tibia on the strain behavior of the anterior cruciate ligament: an in vitro investigation

Background

Very little is known about the effects of applied torque about the long axis of the tibia in combination with muscle loads on anterior cruciate ligament biomechanics. The purpose of this study was to determine the effect of muscle contraction and tibial torques applied about the long axis of the tibia on anterior cruciate ligament strain behavior.

Methods

Six cadaver knee specimens were used to measure the strain behavior of the anterior cruciate ligament. Internal and external axial torques were applied to the tibia when the knee was between 30° and 120° of flexion in combination with the conditions of no muscle load, isolated quadriceps load, and simultaneous quadriceps and hamstring loading.

Findings

The highest anterior cruciate ligament strain values were measured when the muscles were not loaded, when the knee was at 120° of flexion, and when internal tibial torques were applied to the knee. During muscle loading the highest anterior cruciate ligament strain values were measured at 30° of flexion and then the strain values gradually decreased with increase in knee flexion. During co-contraction of the quadriceps and hamstring muscles the anterior cruciate ligament was unstrained or minimally strained at 60°, 90° and 120° of knee flexion.

Interpretation

This study suggests that quadriceps and hamstring muscle co-contraction has a potential role in reducing the anterior cruciate ligament strain values when the knee is in deep flexion. These results can be used to gain insight into anterior cruciate ligament injury mechanisms and to design rehabilitation regimens.     

Proprioception as one of the factors deciding on the model of rehabilitation after reconstruction of ACL

Injuries of the knee joint with ACL tears are causing frontal instability of the knee. In cases of second and third degree instability it is advised to operate - reconstruction of anterior crucial ligament. The operation is the beginning of a rehabilitation program. It is very importand to rebuild static and dynamic proprioception of the knee. In the paper we present most recent opinions on that problem. We explain the role of proprioception on the knee function, also we present a hypothetical model of rehabilitation programme in different activity.     

前交叉韧带损伤膝关节6个自由度静态加载体的稳定性

背景:由于膝关节的体外标本无法模拟膝关节的真实运动,而体内的运动测试又无法获得骨结构的运动信息,因而不能得到准确的膝关节稳定性数据,也就无法对膝关节损伤的早期诊断及防治措施进行深入的研究.目的:应用计算机三维重建技术、2D/3D图像配准技术及图像处理技术对前交叉韧带损伤膝关节6个自由度变化进行静态加载体内稳定性测试.方法:8例患者单侧膝关节前交叉韧带断裂而对侧正常,膝关节在屈曲0°,30°,60°和90°时分别进行134 N前加载.采集各角度相互垂直的2D图像,与3D CT图像在虚拟X射线投射系统进行2D/3D图像配准,还原膝关节不同角度时的股骨和胫骨相对3D位置关系,获得膝关节6个自由度数据.结果与结论:前交叉韧带断裂后胫骨前移均明显增加,在完全伸直(0°)时胫骨前移最小,胫骨前移在30°时达到最大;胫骨前移在60°和90°时逐渐减小,各角度间比较差异均有显著性意义(P=0.000).前交叉韧带断裂后,膝关节胫骨内旋、内移均较健侧增加(P=0.000).提示通过2D/3D图像配准技术可以实现对膝关节静态加载的体内稳定性分析;前交叉韧带损伤后膝关节前移、内旋和内移均明显增加.