Comparison of Electro-Myo Stimulation to lsokinetic Training in Increasing -Power of the Knee Extensor Mechanism *

A clinical study of six individuals was set up to compare an Electro-Myo stimulation protocol to an isokinetic protocol. The objective of the study was to see which was more effective in increasing power in the knee extensor mechanism. Results of the study showed that isokinetics were superior to Electro-Myo stimulation in increasing power. One question that remained unanswered in the testing was whether a higher faradic current, if tolerated, would be more efficient in increasing the power of a muscle group than would isokinetics. J Orthop Sports Phys Ther 1980;2(1):20-24.     

Case Study: Rehabilitation of a Surgically Repaired Medial Collateral Knee Ligament Using a Limited Motion Cast and lsokinetic Exercise*

Recent studies indicate that early mobilization of surgically repaired collateral ligaments leads to a more rapid gain in tensile strength compared to immobilized ligaments. Other advantages of early mobilization include prevention of muscle atrophy, joint stiffness, and articular cartilage fibrillation. Because of these observations, a professional Australian Rules footballer with a complete rupture of the right medial collateral ligament of his knee joint, was commenced, after surgical repair, on an early controlled mobilization program using a limited motion cast (LMC) and isokinetic exercise. Rehabilitation was commenced after 2 weeks of immobilization in a LMC, and progressed through four stages, all coupled with isokinetic exercise. Weeks 2-6, exercise in LMC through 20-60 degrees ; weeks 7-8, exercise out of LMC through 15- 1 OOO; weeks 8-9, exercise through a full range of movement, 0-130'; weeks 10- 12, exercise through a full range plus inner range 0-30' repetitions. The footballer returned to full competition approximately 12 weeks postsurgery with no medial collateral laxity and almost normal Cybex IP parameters. J Orthop Sports Phys Ther 1986;7(4):154-158.     

膝关节韧带外科——匹兹堡观点

膝关节前交叉韧带重建手术已广泛在全球开展.现在其有20种以上的手术方法和至少5种移植物被经常应用.最常用的髌腱(B-P-B)和绳肌腱均不能达到重建止点结构、恢复生物力学特性以及神经反射功能的目的.尤其是绳肌腱由于固定点和内固定物的影响更难达到上述完美要求.     

Angular Specificity and Test Mode Specificity of Isometric and lsokinetic Strength Training *

This study examined the angular specificity and test mode specificity of strength training. Six males and six females (X = 22.6 years) were assigned to groups which trained either isometrically (90 degrees ) or isokinetically (30 degrees /second). They trained their left elbow extensors at 80% of their maximum voluntary contraction on a modified Cybex(R) apparatus for 10 weeks, three sessions per week, with 50 contractions per session. Before and after training, both groups were tested isometrically (70, 90, 110 degrees ) and isokinetically (30 degrees /second). When tested isometrically, both groups improved equally, and strength was increased at all three test angles to about the same extent. When tested isokinetically, both groups improved, but the isokinetic group improved to a greater extent. In conclusion, no angular specificity of training was demonstrated within 20 degrees of the training angle, and no test mode specificity was seen for isometric testing. However, isometric training showed less transfer to an isokinetic test. J Orthop Sports Phys Ther 1983;5(2):58-65.     

Editorial Commentary: Knee Arthroscopy: How Fast Is Too Fast? How Slow Is Too Slow?

Although the quality of knee arthroscopy is not determined with a stopwatch, in general, an operation should not take significantly longer than average for a routine and uncomplicated procedure. On the other hand, rushing through an operation is never acceptable. Hurrying to complete an operation to meet a given time standard is not only undesirable, but also unsafe for the patient.     

Editorial Commentary: Autograft Beats Allograft for Most Knee Ligament Surgery

Knee ligament reconstruction can be performed with autograft or allograft. The use of an autograft has been shown to improve outcomes in primary anterior cruciate ligament reconstruction for young, active patients, and also in revision anterior cruciate ligament reconstruction surgery. A systematic review of posterior cruciate ligament reconstruction showed no difference in outcomes between autograft and allograft tissue. There is a paucity of data comparing autograft versus allograft for fibular collateral ligament and posterolateral corner reconstructions, alone or combined with other ligament surgery. Allograft advantages include no donor site morbidity and reduced operative time. Disadvantages include increased cost and higher failure rates in younger patients. Autograft tissue should be considered in younger, active patients whenever possible.     

lsokinetic Characteristics of Ballet Dancers and the Response to a Season of Ballet Training*

Clinical isokinetic characteristics for professional ballet artists were determined preseason and at "peak" season. Twenty-eight dancers (equal N/sex) were studied at 45, 90, and 180 per second. The data indicated that, while male relative torques were similar to other athletes previously reported, the females were lower than most other female athletes. With training, males showed virtually no change at the slow and intermediate speeds, but improved at 180 per second, while females improved at all three speeds but, significantly, only at 180 per second. Males generated significantly more torque than females and the torque-velocity characteristics between sexes were parallel. Clinical characteristics showed the dancers to have quadricep balance between legs and proportional (hamstrings/quadriceps) within legs (no effects of training on either). The data indicates that male dancers have characteristics similar to other athletes, that females are lower in relative torque than other female athletes, and that dance training affects only torque at functional velocities.J Orthop Sports Phys Ther 1984;5(4):207-211.     

Relationship Between Ligament Forces and Contact Forces in Balancing at Total Knee Surgery

BackgroundSpacer blocks, tensors, or instrumented tibial trials are current methods of balancing the knee during surgery but there are no current techniques for measuring ligament forces. Our goal was to study the relationship between the collateral ligament forces and the condylar contact forces to determine whether there was equivalence.MethodsA test rig was constructed modeling an artificial knee joint with collateral ligaments. The ligament forces as well as the lateral and medial tibial contact forces were measured during flexion for different positions of the femoral component on the femur, producing a set of forces for the simulated conditions. A regression analysis was used to study the correlation between the ligament and contact forces.ResultsThe combined medial and lateral ligament and contact forces showed a linear relation with a correlation coefficient of 0.98. For the medial and lateral sides separately, the correlations were 0.85 and 0.88, respectively, with more than 80% of points within a ±25% deviation from the linear relations. This deviation from the linear correlation is linked to differences in medial-lateral femoral-tibial contact point locations at different flexion angles.ConclusionWithin balancing accuracies generally achieved at surgery, the collateral ligament forces were linearly correlated to the condylar contact forces. These forces can also be equally correlated to the distraction forces as well as the moments at which condylar liftoff would occur from varus-valgus moments. This indicated a unification of the different balancing parameters, and hence such quantitative methods can be used interchangeably.     

膝腱反射检查对前交叉韧带断裂和重建后本体感觉功能的评价

目的探讨膝腱反射检查对前交叉韧带断裂和重建后本体感觉功能的评价和意义。方法对20例单纯前交叉韧带断裂,采用关节镜下自体四股半腱肌-股薄肌肌腱重建。常规方法检查膝腱反射,双极表面电极电刺激髌韧带并记录股内侧肌肌电图。观察前交叉韧带断裂和重建后膝腱反射和肌电图的客观改变,结合临床"打软腿"的主观症状,研究主、客观相互关系。结果3项指标手术前后两样本率比较,差异有统计学意义(PKJ=0.004,PEMG=0.022,PS=0.000);3项指标手术前后改变率之间两两比较,差异无统计学意义(PKJ-EMG=0.495,PKJ-S=0.476,PEMG-S=0.163)。结论提出"前交叉韧带-膝腱反射弧"的观点,将膝腱反射检查作为前交叉韧带断裂和重建后的常规查体,借此评价膝关节本体感觉功能,以指导本体感觉的康复锻炼。     

Knee Kinematics in Anterior Cruciate Ligament-Substituting Arthroplasty With or Without the Posterior Cruciate Ligament

Few studies have compared functional kinematics in knees using identical prostheses with or without the posterior cruciate ligament (PCL). This study contrasted in vivo knee kinematics with an anterior cruciate ligament-substituting arthroplasty with and without PCL retention. We hypothesized that knees without PCLs would exhibit less femoral posterior translation, and consequently less maximum knee flexion. Fifty-six knees were studied using dynamic radiography at least one year post-surgery, with twenty-seven knees retaining the PCL and twenty-nine knees having the PCL sacrificed. Consistent with our hypothesis, PCL-sacrificing knees showed more anterior femoral condylar positions. Contrary to our hypothesis, PCL-sacrificing knees demonstrated greater knee flexion during kneeling (122° versus 115°). Contracted PCLs in severely deformed knees likely were the cause of limited flexion in some retaining knees.     

膝关节置换术后的关节摩擦音或弹响

膝关节置换术后的关节摩擦音或弹响的发生并不罕见,发病率0%~18%不等。其主要机制是髌骨周围纤维组织的增生,在髌骨上极与股四头肌肌腱连接部形成或者不形成明确的纤维结节。导致膝关节置换术后关节摩擦音或弹响的因素有很多,比如假体类型、关节线的改变、髌骨高度、髌骨厚度、髌骨轨迹异常、手术创伤等等。术后关节摩擦音或弹响,特别是伴有疼痛时,对患者术后膝关节功能的恢复和生活质量的提高有着明显影响。治疗方法包括保守治疗、关节直接切开术和关节镜手术。但膝关节置换术后的关节摩擦音或弹响的影响因素及治疗方式仍存在很多争议。     

Knee arthroscopy after yttrium or osmic acid injection

This study presents the macroscopic and histologic results of 35 knee arthroscopies performed on patients with rheumatoid arthritis, some months after an yttrium or osmic acid intraarticular injection. The procedure was most often performed after a failure of the injection or a relapse of synovitis. Arthroscopy provides an understanding of the cause of synoviorthesis failure--insufficient action of the product on the synovitis or its poor diffusion, fibri-nonecrotic deposits, or cartilaginous lesions--and may be used both diagnostically and therapeutically.     

Revision Surgery after Vertebroplasty or Kyphoplasty

Background

We wanted to investigate the leading cause of failed vertebroplasty or kyphoplasty.

Methods

Twelve patients (10 females and 2 males) who underwent revision surgery after vertebroplasty or kyphoplasty were included. In 4 cases, vertebroplasty was done for two or more levels. Six cases with kyphoplasty were included. Through the retrospective review of the radiographic studies and medical record, we analyzed the etiology of the revision surgery.

Results

Uncontrolled back pain was the main clinical presentation. In 4 cases, neurological symptoms were noted, including one case with conus medullaris syndrome. The average time to the revision surgery after vertebroplasty or kyphoplasty was 15 months. Infection (4 cases) and progressive kyphosis with collapse (8 cases) were the causes for the revision. A solid pattern of inserted bone cement and bone resorption around the cement were noted in the all cases with progressive collapse and kyphosis.

Conclusions

Infection, misdiagnosis and progressive kyphosis were causes of the revision surgery after vertebroplasty and kyphoplasty. A solid pattern of accumulation of bone cement and peri-cement bone resorption might be related with the progressive collapse.     

Posterior Cruciate Ligament Retention or Substitution During Total Knee Arthroplasty Does Not Affect Long-Term Bone Mineral Density or Quality

Background

Physical activity is recognized as one of the factors that influence bone mineral density (BMD) and bone quality after total knee arthroplasty (TKA). According to biomechanical analyses after posterior cruciate ligament (PCL) retaining (PCLR) and substituting (PCLS) TKA, each implant design has different kinematics and kinetics. The purposes of this study were: (1) to perform within-patient comparisons of the midterm and long-term effects of PCL retention in mobile-bearing TKA on proximal femur and tibia BMD and calcaneus bone quality measured using ultrasound and (2) to identify correlations between them.