Research progress of tibial-graft fixation methods on anterior cruciate ligament reconstruction / 中国修复重建外科杂志

OBJECTIVE@#To review the studies about the tibial-graft fixation methods on anterior cruciate ligament (ACL) reconstruction, in order to provide clinical reference.@*METHODS@#The literature about the tibial-graft fixation methods on ACL reconstruction at home and abroad was extensively reviewed, and the factors that affect the selection of fixation methods were summarized.@*RESULTS@#The knee flexion angle, graft tension, and graft fixation device are mainly considered when the tibial-graft was fixed on ACL reconstruction. At present, the graft is mainly fixed at 0°/30° of knee flexion. The study shows that the knee joint is more stable after fixed at 30°, while the incidence of knee extension limitation decrease after fixed at 0°. In terms of graft tension, a good effectiveness can be obtained when the tension level is close to 90 N or the knee flexion is 30° to recover the affected knee over-restrained 2 mm relative to the healthy knee. In terms of the graft device, the interference screw is still the most commonly used method of tibial-graft fixation, with the development of all-inside ACL reconstruction in recent years, the cortical button fixation may become the mainstream.@*CONCLUSION@#Arthroscopic reconstruction is the main treatment of ACL rupture at present. However, there is no optimal fixation method for the tibial-graft, the advantages and disadvantages of each fixation methods need to be further studied.

Effect of simple knee trainer on knee active flexion for hemiplegics after stroke / 中国康复理论与实践

@#Objective To observe the clinical efficacy of simple knee trainer on active knee flexion in patients with hemiplegia after stroke.Methods From March, 2020 to May, 2021, 46 hemiplegics after stroke in Beijing Bo'ai Hospital were randomly divided into control group (n = 23) and experimental group (n = 23). Both groups accepted routine rehabilitation training, and the experimental group accepted knee flexion exercise training in sitting position through the simple knee trainer, for eight weeks. They were measured active knee flexion angle in sitting position and maximum flexion angle in walking before and after training, as well as Holden Functional Ambulation Category (FAC).Results Both active knee flexion angle in sitting position and maximum flexion angle in walking significantly increased in both groups after training (|t| > 6.991, P < 0.001), and increased more in the experimental group than in the control group (t > 2.185, P < 0.05). The grade of FAC also improved in both groups (|Z| > 2.828, P < 0.01), and no significant difference was found between groups (Z = -0.821, P = 0.412).Conclusion The application of simple knee trainer can effectively improve the active range of motion of knee, which may be used in clinic- and community-based rehabilitation.

Knee Joint Moment Estimation During Walking via Wearable Inertial Sensor Network / 医用生物力学

Objective To estimate knee adduction moment (KAM) and knee flexion moment (KFM) under different gait test conditions via an inertial sensor network (ISN). Methods Twelve healthy young male subjects wore eight inertial sensors (located in the trunk, pelvis, both thighs, both shanks, both feet) and walked under different test conditions (changing foot progression angle, trunk sway angle, step width and walking speed). An ISN was used to extract biomechanical features as the input of recurrent neural network (RNN), so as to estimate the KAM and KFM. Results The overall KAM estimation accuracy: relative root mean square error (rRMSE) was 8.54% and r=0.84. The overall KFM estimation accuracy was rRMSE=6.40% and r=0.94. Conclusions The model can be used as the basis for load estimation of knee joints out of the lab and its potential application includes gait training and rehabilitation assessment after knee surgery.

Construction and simulation mechanical analysis of dynamic knee joint finite element model based on CT image / 中国骨伤

OBJECTIVE@#To construct a dynamic knee joint finite element model based on CT image data and verify the validity of the model. To provide a simulation model and basic data for biomechanical research of the knee joint by further finite element analysis.@*METHODS@#The CT data of a healthy male knee joint was selected. With the help of Mimics 19.0 and Hypermesh 12.0 software, a high simulation finite element model of knee joint was established following steps, including geometric reconstruction, reverse engineering, meshing and material characterization. The dynamic knee flexion model was generated by determining the boundary conditions and torque loading, and the validity of themodel was confirmed. The biomechanical changes of the tibiofemoral and patellofemoral joints under different knee flexion angles were analyzed by applying the loads (500 N) to the finite element model during knee flexion.@*RESULTS@#A finite element model of knee joint was established based on CT images and anatomical characteristics. The model included three-dimensional elements such as bone, ligament, cartilage, meniscus and patellar retinaculum. The different finite element models of knee flexion states were produced by applying different torques after establishing boundary conditions. According to equivalent conditions (knee flexion 30 degrees, quadriceps tendon under 200 N stretch), the peak stress value of patella was 2.209 MPa and the average Mises stress was 1.132 MPa; the peak stress value of femoral trochlear was 1.405 MPa and the average Mises stress was 0.936 MPa. The validity of the model was proved by the difference between the model and previous studies of 1% to 13.5%. Dynamic model loading showed that the Mises stressof tibiofemoral joint decreased with the increase of knee flexion angle, while the Mises stress of patellofemoral joint was positively correlated with knee flexion angle. The Mises stress of cartilage stress planes at different knee flexion angles was significantly different(<0.05).@*CONCLUSION@#The finite element model established in this study is more comprehensive and can effectively simulate the biomechanical characteristics of dynamic knee joint, which provides support for further simulation mechanics researches of the knee joint.

Application of internal and external lysis combined with Ilizarov external fixation technology for severe knee pathological flexion contracture deformity in children / 中国修复重建外科杂志

Objective: To investigate the effectiveness of internal and external lysis combined with Ilizarov external fixation technology for severe knee pathological flexion contracture deformity in children. Methods: A retrospective analysis was made on 12 children (12 knees) with severe knee pathological flexion contracture deformity who were treated with internal and external lysis and Ilizarov external fixation between August 2012 and January 2017. There were 9 boys and 3 girls with an age of 3-12 years (mean, 8.4 years). There were 8 cases of tuberculosis, 3 cases of haemophilia A, and 1 case of residual deformity after extensive hemangioma drug injection. The disease duration ranged from 5 months to 4 years, with an average of 20.3 months. The degree of knee contracture was (67.42±23.30)°, and the range of motion of knee was (38.33±14.98)°. The preoperative Western Ontario and McMaster University Osteoarthritis Index (WOMAC) score was 78.42±15.57. The complication was observed after operation, and the degree of knee contracture, range of motion, and WOMAC score at 3 months and 1 year after operation were recorded and compared with those before operation. Results: The operations completed successfully in all children. All the 12 cases were followed up 9-24 months (mean, 14.5 months). All incisions healed by first intention after operation. The knee function of all children improved significantly and the weight-bearing walking function of the lower limbs restored. The degree of knee contracture, range of motion, and WOMAC score were significantly improved at 3 months and 1 year after operation (P0.05). Conclusion: For severe knee pathological flexion contracture deformity in children, application of internal and external lysis combined with Ilizarov external fixation has advantages, such as small trauma, rapid recovery, and early postoperative knee function training, and good effectiveness.

Changes in patellar tendon length during passive knee flexion in the menstrual cycle / 体力科学

The purpose of this study was to investigate the changes in patellar tendon length during passive knee flexion in the menstrual cycle. The right knee joints of 10 adult women with stable menstrual cycles were evaluated. Measurement of patellar tendon length was performed when the knee joint was bent flexibly at six angles (0°, 30°, 60°, 90°, 110°, and 130°), and the long-axis image of the patellar tendon was transversely superimposed at each angle. A photograph was taken with an ultrasonic device. Measurements were performed once during each of the four phases of the menstrual cycle (menstrual, follicular, ovulatory, and luteal phases) classified by the basal body temperature method. There were no significant differences in patellar tendon length at each knee flexion angle in each phase of the menstrual cycle. In the luteal phase, the patellar tendon was stretched significantly at 90° and 130° compared to knee flexion of 0°.

Effect of knee flexion angles during maximum isometric hip extension / 体力科学

The purpose of this study was to examine the effects of knee flexion angles during maximum isometric hip extension. Ten healthy men performed maximum isometric hip extension in prone position at 15° and 90° knee flexion. Then, the hip extension torque was measured, and electromyographic (EMG) data were obtained from the biceps femoris long head, semitendinosus, semimembranosus, adductor magnus, and gluteus maximus muscles. The EMG data were full-wave rectified and integrated (IEMG). The IEMG values obtained during the measurement of isometric hip extension were normalized with the values collected at 90° knee flexion (normalized IEMG [NIEMG]). The hip extension torque at 15° knee flexion was significantly greater than that at 90° knee flexion. The NIEMG values from the hamstrings at 15° knee flexion significantly increased compared with those at 90° knee flexion. Meanwhile, the NIEMG values from the gluteus maximus at 90° knee flexion were significantly greater than those at 15° knee flexion. However, the NIEMG values from the adductor magnus did not significantly differ between 15° and 90° knee flexion. These results indicate that the hamstrings effectively generate contracting force during isometric hip extension and at knee extended position because its fiber length was close to the optimal length.

Nocturnal Cramps in Patients with Lumbar Spinal Canal Stenosis Treated Conservatively: A Prospective Study

STUDY DESIGN: Prospective cohort study with questionnaire. PURPOSE: To compare the treatment outcome of nocturnal leg cramps in lumbar spinal canal stenosis (LSCS) patients on conservative treatment with historical surgical cohorts and to determine the sensitivity and specificity as well as positive predictive value and negative predictive value of knee flexion test suggested for LSCS patient. OVERVIEW OF LITERATURE: True prevalence of nocturnal leg cramps in LSCS patients as well as the clinical outcome of its surgical treatment have been reported. METHODS: A questionnaire suggested from previous study with minor modifications was used in this study. Clinical data was collected. Knee flexion test was performed in two groups. RESULTS: The prevalence of nocturnal leg cramp was higher in the LSCS group compared to the control group (second group). In LSCS patients, 38 (88%) had improved leg cramps after the conservative treatment, 3 (6.97%) remained unchanged, and 2 (4.6%) had worsened leg cramps. Of the 43 patients, 21 (48.8%) had no disturbance to their activities of daily living. In the LSCS group, the sensitivity and specificity of the knee flexion test was 53.5% and 33.3%, respectively. The knee flexion test in the LSCS group had a positive predictive value and a negative predictive value of 65.71% and 23.1%, respectively. CONCLUSIONS: Our study demonstrated that nocturnal leg cramps were significantly more frequent in LSCS patients than in the control group.

What is the most effective protocol to induce fatiguein knee joint muscles? a systematic review

The aim of this study was to review the literature to see how the protocols are designed to induce kneejoint muscles fatigue using an isokinetic dynamometer. Materials and Methods: This study consisted of asystematic review and the search for the theoretical composition was performed in the PubMed databaseusing as descriptors the words muscle fatigue, knee, and isokinetic, and as filters the words Abstract available,Humans, Randomized Controlled Trial, and English language. It was not set limits for year of publications.Results: twenty nine studies were found, from which, seventeen were excluded due to exclusion criteria.Conclusion: It became evident in the present review that the greatest reduction in the peak torque occurs inprotocols that use series of trials without determining the number of repetitions, requiring that the movementbe executed until attaining exhaustion. However, if there is a need to determine a number of repetitionsto decrease the the knee joint torque to the levels close to the one attained in the exhaustion protocol, theprotocol that most reduced the knee joint flexor and extensor torque was the one that used five series of 30repetitions with interval of one minute between series, independent of the angular speed and the type ofcontraction, concentric or excentric.

The effect of knee flexion with the patient in the supine position and under general anesthesia for reducing postoperative low back pain

BACKGROUND: Postoperative low back pain is common. Some studies have indicated that the use of a lumbosacral wedge is effective in reducing the incidence of postoperative low back pain. This study aimed to evaluate the effect of knee flexion with the patient in the supine position and under general anesthesia for reducing postoperative low back pain. METHODS: 261 patients who were undergoing surgery under general anesthesia were randomized to the supine position (Group I) or the supine position with both knees in flexion (Group II). The incidence of low back pain and the pain score (VAS) were measured at the following time points: postoperatively 6 hours, 1 day, 2 days, 3 days and 4 days. RESULTS: The incidence of low back pain in group II was significantly lower than that in Group I at postoperative 6 hours, 1 day and, 2 days (P < 0.05). But, no significant differences of their pain scores were observed between the groups. CONCLUSIONS: We conclude that the intraoperative supine position with both knees in flexion can reduced the incidence of postoperative low back pain in a fashion like using a lumbosacral wedge to support the lumbosacral area.

The effect of knee flexion with the patient in the supine position and under general anesthesia for reducing postoperative low back pain

BACKGROUND: Postoperative low back pain is common. Some studies have indicated that the use of a lumbosacral wedge is effective in reducing the incidence of postoperative low back pain. This study aimed to evaluate the effect of knee flexion with the patient in the supine position and under general anesthesia for reducing postoperative low back pain. METHODS: 261 patients who were undergoing surgery under general anesthesia were randomized to the supine position (Group I) or the supine position with both knees in flexion (Group II). The incidence of low back pain and the pain score (VAS) were measured at the following time points: postoperatively 6 hours, 1 day, 2 days, 3 days and 4 days. RESULTS: The incidence of low back pain in group II was significantly lower than that in Group I at postoperative 6 hours, 1 day and, 2 days (P < 0.05). But, no significant differences of their pain scores were observed between the groups. CONCLUSIONS: We conclude that the intraoperative supine position with both knees in flexion can reduced the incidence of postoperative low back pain in a fashion like using a lumbosacral wedge to support the lumbosacral area.

fMRI study of brain of stroke patients during knee extension-flexion of the affected side / 中华物理医学与康复杂志

Objective To investigate the underlying mechanism of motor recovery of the hemiplegic lower extremity in stroke patients. Methods The brain activation pattern during sequential extension-flexion of the affect-ed knee of 7 stroke patients and 8 healthy subjects was observed by blood-oxygen- level-dependent fMRI (BOLD-fM-RI) and analyzed by microsoft SPM5. Results When executing unilateral knee flexion-extension, contralateral paracentral lobe and contralateral supplementary motor area and right temporal gyms and inferior parietal lobes of both sides were significantly activated in all the healthy subjects, while the ipsilateral parietal lobe BA7 and BA5 were sig-nificantly activated in 6 of the 7 stroke patients. Conclusions Sequential extension-flexion of the affected knee of stroke patients was probably dependent on the activation of BA7 and BA5 in the intact side. Compensatory activation of the intact hemisphere might be one of the main mechanisms for the paretic lower extremity motor recovery in stroke patients.

Effects of the Balance Control of the Affected Lower Extremityon Balance and Gait in Hemiparetic Patients

OBJECTIVE: To investigate the effects of balance control of affected lower extremity on berg balance scale and gait in hemiparetic patients, using the newly developed balance control trainer of lower extremity. METHOD: Thirty five hemiparetic patients who could stand and ambulate more than 10 meters without assist on even surface were included in this study. The balance control trainer of lower extremity was designed to measure weight shift and knee flexion angle of hemiparetic side and to play a game named "Board cleaner" which use these data, so considering the vertical movement of the center of gravity. We measured above three parameters, and also evaluated with clinical tests including berg balance scale (BBS). We evaluated correlations between parameters on the balance control trainer of lower extremity and clinical parameters. RESULTS: Weight shifting to affected side statistically significantly correlated only with BBS. Affected knee flexion had statistically significant correlations with all clinical tests examined, especially 10 meters walking time (10mWT), timed up and go test (TUG), and BBS. Scores earned from board cleaner game also had statistically significant correlations with all clinical tests examined, especially 10mWT, TUG, and BBS. CONCLUSION: Correlation exists between the ability to control the affected knee measured by balance control trainer of lower extremity and clinical parameters including 10mWT, TUG, and BBS, so we think the balance control trainer can be a useful tool for the evaluation in hemiparetic patients.

Effect of Alternative Splinting at Extension and 90degrees Flexion on Range of Motion after Open Reduction and Internal Fixation of Distal Femur Fracture

PURPOSE: To evaluate the usefulness of early range of motion exercise by using 90degrees knee flexion splint after open reduction and internal fixation in fracture of distal femur. MATERIALS AND METHODS: We reviewed twenty-six cases of distal femur fractures which were treated with open reduction and internal fixation from February 2002 to November 2003. One group (group A) were treated by using 30degrees knee flexion splint, the other group (group B) were treated by using 90degrees flexion and full extension splint alternativley by post-operative 1 week. The follow up period was minimally 12 months. The range of motion and Schatzker and Lambert criteria were evaluated. RESULTS: The mean period to gain 90degrees knee flexion was 11.4 (7~14) weeks in group A, and 6.6 (3~8) weeks in group B. Mean range of motion was 94.7degrees (average flexion contracture 9.5degrees ) in A group and 108.7degrees (average flexion contracture 6.3degrees ) in B group at 12 weeks follow-up. According to Schatzker and Lambert criteria, excellent result was achieved in 10 cases (38%), good result in 13 cases (50%), fair result in 3 cases (12%). CONCLUSION: This study demonstrates that alternative splinting at extension and 90degrees flexion contribute to early recovery of range of motion in distal femur fractures treated with internal fixation.

Emg-angle relationship during maximum voluntary movement / 体力科学

The purpose of this study is to investigate the relationship between joint angle and EMG activity concerning the human knee joint and hamstring muscles. Ten healthy males participated in this study. They performed maximum voluntary isokinetic knee flexion in the flexion angle range of 0° to 120° in a prone position on a table. The EMG activities of the semitendinosus, semimembranosus, long and short heads of the biceps femoris muscles were detected by bipolar fine wire electrode, and were integrated at knee flexion range intervals of 15° from 0° to 120°. After three months, the same examination was performed with the same subjects to confirm the reliability of this study. Results showed the mean peak isokinetic torque was attained from a 15° to 45° knee flexion angle. The EMG activities of the hamstring muscles varied with changes in the knee flexion angle. The integrated EMG of the semitendinosus, semimembranosus and short head of the biceps femoris muscles in-creased gradually as the knee flexion angle was increased from 0° to 105°. The peak integrated EMG of these three muscles was attained between 90° and 105° knee flexion in both trials. On the other hand, the peak integrated EMG of the long head of the biceps femoris muscle was largest at a knee angle ranging from 15° to 30°. Peak integrated EMG decreased when the knee flexion angle increased in both trials. These results show that the electromyographic activity of agonist muscles during maximum voluntary movement varied with the change of muscle length or joint angle. Therefore, it was considered that the relationship between joint torque and joint angle is influenced not only by the sarcomere length and the moment arm but also muscle activities of agonist muscles, even if the movement is performed with maximum effort.

Divergence of Femoral interference screw versus Knee Flexion Angle during Endoscopic ACL Reconstruction

The endoscopic single-incision technique using interference fit screws to secure patellar tendon-bone plugs in the femoral and tibial tunnels has been very popular method for ACL reconstruction. However, several potential complications has been reported such as violation of the posterior wall of the femoal tunnel, laceration of graft during femoral screw insertion, protrusion of the tibial bone block distally due to a lengthy graft and more frequently divergence of the femoral interference screw. We performed 56 consecutive endoscopic ACL reconstruction. In Groi.p I, femoral tunnel drilling were performed at 70-80 degrees of knee flexion. In Group 11, they were done at $5 degrees of knee flexion. Postoperative radiographic analysis of bone-interference screw divergence angle shows 5.9 degrees in AP view, 6.21 degrees in Lateral view in Group I and 3.14 degrees, 3.35 degre.s in Group II respectevely. In conclusion, Bone-interference screw divergence can be decreased with less knee flexion about 45 degree during preparing femoral tunnel.

Arthrocopic Reconstruction of the Posterior Cruciate Ligment: The Effects of femoral attachment points and knee flexion angles at the time of graft fixation on posterior stability / 대한정형외과학회잡지

The purpose of this study is to compare the effects of the femoral attachment points of the graft and knee flexion angles at the time of graft fixation on stability of posterior cruciate ligament reconstruction. We analyzed the posterior stability of the knee on 23 patients(24 knees) with posterior cruciate ligament injury whose posterior cruciate ligament had been reconstructed arthroscopically and followed for minimum 1 year period at Asan Medical Center from May 1992 to June 1994. The patients were divided into the two groups according to femoral attachment points of the graft and knee flexion angles at the time of graft fixation. The distance from the junction of the intercondylar notch with trochlear groove of the femoral attachment points and knee flexion angles were 11mm and 0°-30° in group A and 7mm and 70°-90° in group B, respectively. 11 knees were included in group A and 13 knees in group B. Posterior stability was determined by difference in posterior tibial translation between the injured and the opposite knee with Telos device. In group A, 5 cases were at the range of 0-2mm, 3 cases 3-5 mm, 3 cases 6-10mm. In group B, 10 cases were at the range of 0-2mm and 3 cases 3-5mm, respectively. Differences in posterior tibial translation on average were 3.6mm and 1.7mm in group A and B, respectively. Conclusively, arthroscopic postrior cruciate ligament reconstruction with femoral attachment point at 7mm from the junction of interconlylar notch with trochlear groove and 70°

Early results of supracondylar femoral osteotomy in severe knee flexion contractures in polio patients

Twenty one polio patients with severe knee flexion contractures admitted at the Santo Tomas University Hospital, Clinical Division from 1984 to 1990 were studied. There were 11 males and 10 females with age ranging from 12 to 18 years with a mean of 14.3 years. The degree of knee flexion ranged from 45 to 120 degrees with an average of 62.5 degrees. Clinical data included the ranges of motion, the stability of the hip, knee and ankle. Manual muscle testing as well as limb length and girth were recorded. the technique as described by Huckstep was conducted either as a one or two staged procedure with or without preliminary skeletal tractions. One patient required an internal fixation on the osteotomized fragments for stability. Two patients had residual flexion contracture of 5 ad 10 degrees after removal of cast. Only one patient abandoned her braces and opted to use her wheel chair despite healed osteotomy. (Author)

Surgical Treatment for the Knee Flexion Deformity in Spastic Cerebral Palsy / 대한정형외과학회잡지

Equinus deformity of ankle, adduction and flexion deformity of hip and flexion contracture of knee are most common deformities in spastic cerebral palsy. There were many surgical treatment methods according to its causes. Authors has analysed 115 patients(224 operation) who had been operated with three procedure (Modified Egger's op, Proximal hamstring elongation, Distal hamstring elongation) and compared the results of these procedure at Sam Yook Rehabilitation Center from Jan. 1980 to Dec. 1987. The following results are obtained: 1. The results of Modified Egger's operation were unsatisfied because of complicaLion and little angle correction ability of flexion contracture of knee joint. 2. Even though there was no differences in angle correction ability of flexion contracture of knee joint between two procedures, the results of proximal hamstring elongation were superior to them of distal elongtion because early walking ability is more easily improved.

The Treatment Selection of Knee Flexion Deformity after Poliomyelitis / 昆明医科大学学报

The 98 cases of knee flexion deformity after poliomyelitis were treated in our department. The treatment selection for diffrent degrees of the flexion deformity are discussed. The flexion less that 20? need plaster cast only. The flexion from 20? to 30? can fully correct with su pracondylar femoral osteotomy. In the flexion more that 30?, the skele(?)al traction into inferior tibia should be done previously, then supracondylar femoral osteotomy carried out to correct the flexion less that 30? siter traction. It is pointed out that the muscle balance operation must be done as soon as the flexion was corrected. The muscle balance operation can prevent from recurrence of the deformity and (?)limilate the factor recurrent.