Isokinetic evaluation of quadriceps and hamstrings symmetry following anterior cruciate ligament reconstruction

After anterior cruciate ligament (ACL) reconstruction, isokinetic muscle parameters are commonly measured to assess the dynamic status of the knee and to monitor progress in rehabilitation. This study evaluated the symmetry of the quadriceps and hamstrings musculature in postsurgical and contralateral normal limbs of subjects who had undergone one of two types of ACL reconstruction. Subjects were also evaluated for differences on selected isokinetic parameters between types of surgery and lengths of postoperative periods. Postsurgical and normal contralateral limbs of 46 subjects aged 18 to 49 years (mean, 23.7 years) were divided into groups according to type of autogenous intraarticular ACL substitute and length of postoperative period. Results of paired t-tests and analyses of variance indicated significant asymmetries between limbs for all measures of quadriceps and hamstrings musculature strength and endurance (p less than .001) irrespective of the type of reconstruction technique. Average surgical knee deficits in hamstrings endurance were significantly less for the long-term (41 to 101 months) follow-up group (1.9%) than for the intermediate (24 to 40 months) group (12.1%). The results suggest that extended periods of time are required to approximate hamstrings endurance symmetry after ACL reconstruction. Asymmetries between postsurgical and contralateral normal limbs in these subjects may reflect either incomplete rehabilitation or an inability to regain full isokinetic strength and endurance after ACL reconstruction.     

髌韧带替代前交叉韧带重建术后股四头肌及guo绳肌等速测试结果

目的评价前交叉韧带(ACL)损伤经骨-髌韧带-骨(BPB)重建术后患侧及健侧膝关节股四头肌及腘绳肌的向心性收缩及离心性收缩功能的变化,重点观测作为协同保护前交叉韧带的腘绳肌拮抗性离心性收缩在不同运动速度及不同的关节位置下的功能变化.方法用Cybex-770型等速测试系统对30例陈旧性前交叉韧带损伤经关节镜行BPB替代ACL重建术后的患者进行患肢及健肢的股四头肌及腘绳肌的向心性和离心性收缩的肌肉功能进行测试.结果 显示在30°/s、60°/s、90°/s、120°/s的4组测试运动速度下患膝的股四头肌及在30°/s、60°/s、90°/s三组测试运动速度下患膝腘绳肌的向心性及离心性收缩的峰力矩都较健侧有明显下降,具显著性差异(P<0.05),而在120°/s运动速度下两下肢腘绳肌的向心性及离心性收缩峰力矩已无显著性差异.患肢腘绳肌离心性收缩与股四头肌向心性收缩的峰力矩之比(H/Q的E/C)及两者的向心性收缩峰力矩之比(H/Q的C/C)在4组运动速度下均大于健侧,具极显著性差异(P<0.01).随着运动速度的加大及膝关节的伸直两个比值逐步加大,H/Q的E/C比值在膝关节近伸直位时达到最高峰.结论前交叉韧带损伤BPB替代ACL重建术后患肢的股四头肌及腘绳肌都发生了废用性萎缩,但后者比前者恢复要快,术后2年在较快速运动下两侧腘绳肌的收缩功能已无明显差异,患侧肢体适应性地加强了作为保护前交叉韧带的动力装置腘绳肌的收缩功能,尤其是离心性收缩,随着运动速度的加快及膝关节的逐渐伸直至ACL最易损伤处这种保护反应达到最高峰.     

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.     

Effects of knee bracing on the functional performance of patients with anterior cruciate ligament reconstruction

OBJECTIVE: To compare the functional performance of subjects with unilateral anterior cruciate ligament (ACL) reconstruction. DESIGN: Cross-sectional comparative clinical trial. SETTING: A physical therapy outpatient department. SUBJECTS: Thirty-one subjects with unilateral ACL reconstruction for more than 5 months. INTERVENTION: Patients under 3 bracing conditions: (1) DonJoy Brace, (2) mechanical placebo brace, or (3) no brace. Running and turning 10 times on a 22-meter figure-8 runway, and running and jumping (and landing) on a semicircular path. MAIN OUTCOME MEASURES: Speed of running and turning, speed of running and jumping, and accuracy of landing after the jump. RESULTS: Subjects performed similarly in conditions 1 and 2 in all the tests, but the speeds of running and turning were significantly slower in conditions 1 and 2 than condition 3 (p =.008--.000). Results of the run and jump tests were not different among all conditions. CONCLUSION: Knee bracing may not improve functional performance of subjects 5 months after ACL reconstruction. The use of such a brace could actually slow down running and turning, irrespective of the mechanical constraints of the brace. These functional outcomes need to be noted when such a brace is used on this group of subjects.     

The effect of insufficient quadriceps strength on gait after anterior cruciate ligament reconstruction.

OBJECTIVE: To determine the effect of quadriceps strength and joint stability on gait patterns after anterior cruciate ligament injury and reconstruction. DESIGN: Cross-sectional comparative study in which four groups underwent motion analysis with surface electromyography. BACKGROUND: Individuals following anterior cruciate ligament rupture often demonstrate reduced knee angles and moments during the early stance phase of gait. Alterations in gait can neither be ascribed to instability nor to quadriceps weakness alone when both are present. METHODS: Twenty-eight individuals with complete anterior cruciate ligament rupture (10 patients with acute rupture, 8 patients following reconstruction with quadriceps strength >90% of the uninvolved side [strong-anterior cruciate ligament reconstructed group], and 10 patients after reconstruction with quadriceps strength <80% of the uninvolved side [weak-anterior cruciate ligament reconstructed group]), and 10 uninjured subjects underwent an examination of their lower extremity to collect kinematics, kinetics, and electromyography during walking and jogging. Anterior cruciate ligament reconstruction was arthroscopically assisted and a double loop semitendinosis-gracilis autograft or allograft was used as a graft source. All reconstructed subjects had stable knees, full range of motion, and no effusion or pain at the time of testing (more than three months after surgery). RESULTS: Knee angles and moments of the strong group were indistinguishable from the uninjured group during early stance of both walking and jogging. The weak subjects had reduced knee angles and moments during walking, and jogged similarly to the deficient subjects. Regression analysis revealed a significant effect between early stance phase knee angles and moments and quadriceps strength during both walking and jogging. CONCLUSION: Inadequate quadriceps strength contributes to altered gait patterns following anterior cruciate ligament reconstruction. RELEVANCE: Rapid strengthening following anterior cruciate ligament injury or reconstruction may contribute to a safe return to high-level activities.     

Comparison of two electrical stimulation protocols on quadriceps muscle after anterior cruciate ligament surgery. Feasability study]

OBJECTIVES: To evaluate the feasibility of a study comparing the effects of two protocols of electrical stimulation of the quadriceps femoris after anterior cruciate ligament surgery. MATERIAL: Seven sportsmen with a mean age of 26 yrs were randomly grouped in two: a 20 Hz stimulated group (4 patients) and a 80 Hz stimulated group (3 patients). After surgery all patients received electrical stimulation of the quadriceps femoris, five days a week, for 12 weeks, and had a standard program of voluntary contractions. The main outcome assessed before and three months after surgery were: quadriceps and hamstring peak torque at 90, 180 and 240 degrees /second, maximal isometric quadriceps at 75 degrees of flexion and muscle and subcutaneous fat volumes of the thigh using MRI. RESULTS: After 12 weeks of rehabilitation, the thigh muscle volume deficit of the operated limb was between 3 and 9% in the 20 Hz stimulated group and between 1 and 2% in the 80 Hz stimulated group. Quadriceps peak torque deficit was less than 30% except for two patients in the 20 Hz stimulated group. Maximal isometric quadriceps deficit of the operated limb was higher than 30% except for two patients in the 20 Hz stimulated group. CONCLUSION: The study showed that comparison of two protocols of electrical stimulation of the quadriceps femoris after anterior cruciate ligament surgery is possible if stimulation period is not more than four weeks.     

Effect of a functional knee brace on knee flexion and extension strength after anterior cruciate ligament reconstruction

OBJECTIVES: To investigate the effect of a knee brace on knee flexion and extension muscular strength of patients after anterior cruciate ligament (ACL) reconstruction and to evaluate whether the effect of the brace depends on patient symptoms and muscular strength. DESIGN: Repeated measures. SETTING: A university-based outpatient orthopedic clinic and musculoskeletal assessment laboratory. PARTICIPANTS: Twenty-seven patients (14 women, 13 men; mean age, 28+/-11 y) having undergone arthroscopically assisted ACL reconstruction by using a semitendinosus and gracilis autograft. INTERVENTION: A custom-fit ACL functional knee brace. MAIN OUTCOME MEASURES: The brace effect was calculated as the change in peak torque observed with the brace, expressed as a percentage of peak torque observed without the brace, during isokinetic concentric knee flexion and extension movements performed at 90 degrees /s. Patient symptoms were quantified by using a disease-specific health-related quality of life questionnaire. RESULTS: Knee flexion strength decreased significantly with the brace (mean brace effect=-7.3%, P<.05). The brace effect during knee flexion varied considerably (-52% to 47%) and was significantly related to peak torque observed without the brace (r=-.50, P<.01). All other comparisons and correlations were not significant. CONCLUSIONS: These findings suggest that brace effects depend on patient strength. A brace may inhibit knee flexion strength of stronger patients, yet result in no change or even improvements in strength of weaker patients. Future research is required to further elucidate which patients may derive most benefit or detriment from bracing.     

Electromyographic biofeedback and recovery of quadriceps femoris muscle function following anterior cruciate ligament reconstruction

The purpose of this study was to compare the effects of biofeedback-facilitated exercise with exercise alone on the recovery rate of quadriceps femoris muscle function following anterior cruciate ligament (ACL) reconstruction. Functional measures included 1) a dynamometric test of quadriceps femoris muscle isometric peak torque during the 12th postoperative week and 2) the number of days post-operatively that a patient achieved full active extension of the knee. Twenty-two patients with acute ACL injury were randomly assigned to a Treatment (biofeedback) Group (n = 11) or a Control (nonfeedback) Group (n = 11) during the first therapy session one week after reconstructive surgery. After the patients had completed the 12-week exercise program, the quadriceps femoris muscle isometric peak torque in the operative limb was compared with that in the nonoperative limb at three angles (90 degrees, 60 degrees, and 45 degrees) of extension. An analysis of variance revealed significant differences between the Treatment and Control Groups at all three angles. Mean recovery time was calculated for each group, and a t test for independent samples indicated a significant difference between the groups. These results demonstrate that the addition of biofeedback to muscle strengthening exercises facilitates the rate of recovery of quadriceps femoris muscle function following ACL reconstruction.     

重建前交叉韧带移植物生长的MR信号改变初步研究

目的探讨术后生长良好的重建前交叉韧带(ACL)移植物MR信号改变过程。方法选取48例ACL重建患者,Lysholm平均积分由术前54分升至术后83.5分,总结其术后4～22个月重建ACL移植物的MR信号改变。扫描序列包括SE T_1WI、GE T_2WI和STIR序列。结果 4～9个月内大部分重建ACL信号增高,术后12～22个月大部分重建ACL信号降低,与正常韧带相仿。结论生长良好的重建ACL移植物,术后MR信号呈现由高到低的变化过程,1年后信号与正常韧带相仿。     

Effect of an anterior-sloped brace joint on anterior tibial translation and axial tibial rotation: A motion analysis study

Background

Anterior tibial translation and axial tibial rotation are major biomechanical factors involved in anterior cruciate ligament injuries. This study sought to evaluate a brace prototype designed with an anterior-sloped joint, in terms of its efficacy in attenuating anterior tibial translation and axial tibial rotation during landing, using a motion analysis approach.

Methods

Ten healthy male subjects performed single-leg landing tasks from a 0.6-m height with and without the brace prototype. Ground reaction force and kinematics data were obtained using a motion-capture system and force-plates. Anterior tibial translation and axial tibial rotation were determined based on tibial and femoral marker reference frames. Vertical and anterior–posterior ground reaction forces, hip, knee and ankle joint range-of-motions and angular velocities, anterior tibial translation and axial tibial rotation were compared between unbraced and braced conditions using Wilcoxon signed-rank test.

Findings

We found no significant difference in peak vertical and anterior–posterior ground reaction forces (p = 0.770 and p = 0.332 respectively) between unbraced and braced conditions. Knee joint range-of-motion and angular velocity were lower (p = 0.037 and p = 0.038 respectively) for braced condition than unbraced condition. Anterior tibial translation and axial tibial rotation were reduced (p = 0.027 and p = 0.006 respectively) in braced condition, compared to unbraced condition.

Interpretation

The anterior-sloped brace joint helps to attenuate anterior tibial translation and axial tibial rotation present in the knee joint during landing. It is necessary to test the brace prototype in a sporting population with realistic sports landing situations in order to assess its effectiveness in lowering anterior cruciate ligament injury risk.     

Rehabilitation outcome in patients recovering from reconstruction of the anterior cruciate ligament: a preliminary report

Background. Injuries of the knee joint with ACL tears cause instability of the knee. Surgical reconstruction is indicated for young, active people with functional instability of the knee, and not merely a tear in the ACL. The term "young people" is relative: even 50-year old men with no degenerative changes in the knee joint can be qualified for surgery. After surgical reconstruction intensive rehabilitation is required to restore static and dynamic proprioception of the knee. Material and methods. We examined 15 patients (a preliminary group) who underwent ACL reconstruction using the Bone-Patellar Tendon-Bone (BPTB) technique. One uear after surgery the patients were evaluated using the International Knee Documentation Committee (IKDC) knee rating scale and the Quality of Life scale of the American Academy of Orthopedic Surgeons, Council of Musculoskeletal Specialty Societies. Gait analysis was performed using an Ultraflex system (ground reaction forces and goniometry). A modified Romberg's test was added in order to examine proprioception. Results. The results from the IKDC scale gave 12 poor results and 3 good. The Quality of Life scale shows disappointment in 9 patients, satisfaction in 4 and indifference in 2. The modified Romberg's test revealed significantly decreased control of the operated joint. Gait analysis revealed a decreased range of motion in the operation joint on the sagittal plane. Conclusions. Surgical treatment cannot give satisfactory results without intensive and comprehensive rehabilitation. Physiotherapeutic goals should be not only recovery of a full range of motion and muscle strength, but also neuromuscular and proprioceptional reeducation.     

Muscle training in chronic anterior cruciate ligament insufficiency--a comparative study.

The aim of the investigation was to study and compare the effect of two basically different training methods on muscle strength and knee function on a consecutive and prospective series of 26 conservatively treated patients with chronic anterior cruciate ligament injury. The two training models were: model Q directed towards specific training of knee extensor muscle strength and model F aiming at training of the lower extremity and trunk muscles in functional weightbearing patterns. The parameters evaluated were: isometric and isokinetic muscle strength, a performance test (one-leg hop test), and a functional score. The results after a three-month training period showed in both groups a significant increase of muscle strength in both knee extensors and knee flexors. No significant difference of isokinetic strength values between the two groups was observed. The isometric gain of knee extension was significantly higher in the Q group. The one-leg hop test value and the functional score were also significantly increased in both groups. However, the hop test indicated a more favourable result in the group who were trained functionally.     

双头空心加压螺钉固定前交叉韧带胫骨止点撕脱骨折的生物力学研究*

目的探究双头空心加压螺钉固定前交叉韧带(ACL)胫骨止点撕脱骨折的生物力学效果及减少髁间窝撞击风险的可能性。方法以猪膝关节(30例)作为实验样本。参照Meyers分型,将其制成Ⅲ型骨折。按随机数字表法分为A组(双头空心加压螺钉)、B组(空心拉力螺钉)及C组(缝线),每组10例。通过检测初始位移和失效负载(峰值负载及屈服负载),观察螺帽埋入骨块情况及失效类型,以探究双头空心加压螺钉固定该骨折的生物力学特性。结果 A组的峰值负载(443.10±8.54)N与C组(457.00±26.53)N差异无统计学意义(P0.05),但明显大于B组的峰值负载(361.70±18.76)N,差异有统计学意义(P0.05)。A组的屈服负载明显大于B组的屈服负载(P0.05),但明显小于C组的屈服负载(P0.05)。A组样本的初始位移(1.38±0.14)mm均明显短于B、C两组(1.94±0.12)和(3.98±0.19)mm,差异有统计学意义(P0.05)。A组样本的螺帽均埋入骨块内,B组样本的螺帽均明显突出于ACL实质。结论双头空心加压螺钉固定ACL胫骨止点撕脱骨折的早期生物力学强度明显优于空心拉力螺钉及缝线固定,且与空心拉力螺钉相比不易造成髁间窝撞击。     

关节镜下微创治疗18例胫骨平台骨折合并前交叉韧带胫骨止点撕脱骨折的疗效观察

目的 探讨关节镜下微创治疗胫骨平台骨折合并前交叉韧带(ACL)胫骨止点撕脱骨折的手术效果.方法 选择2016年7月-2019年7月上海市宝山区罗店医院骨科和锦州医科大学附属第三医院骨二科收治的18例胫骨平台骨折合并ACL胫骨止点撕脱骨折的患者.利用关节镜进行关节腔检查、处理合并症、复位骨折及微创内固定,采用膝关节功能H...     

基于3D-CT的前交叉韧带解剖重建及功能性预后的临床研究

目的观察基于3D-CT辅助的前交叉韧带(ACL)重建术股骨止点的解剖性和功能性预后。方法2011年1月-2012年1月,完成采用3D-CT辅助下ACL自体肌腱移植重建术16例,平均(32±11)岁,平均病程(41.4±46.1)个月,平均随访时间(16.7±3.5)个月。术后用3D-CT观察患者股骨隧道位置,手术前、后采用Lysholm评分对膝关节功能进行评定。结果术后3D-CT观察到股骨隧道位置良好,按照四格表测量方法,隧道中心与生理性AM和PL束连线中点接近。术前Lysholm评分总分为(66.9±6.4)分,手术后Lysholm评分总分提高至(83.5±5.3)分,手术前后Lysholm评分差异有显著性(t=8.25,P0.001)。结论 3D-CT辅助可准确判定ACL重建手术的解剖性,指导医生实施解剖重建,有助于患者获得良好的功能性预后。