Knee Joint Stability Research Articles

The Indirect Role of Gluteus Medius Muscle in Knee Joint Stability during Unilateral Vertical Jump and Landing on Unstable Surface in Young Trained Males

(1) In the present investigation, we tested the hypothesis that unilateral countermovement jump performance is associated with knee joint stabilization ability during unilateral landing on unstable surface. (2) Twenty-five male sport students were tested for dynamometric knee extension and flexion, and hip abduction isometric strength. Myolectric activity of vastus lateralis and medialis, gluteus medius, and biceps femoris muscles were measured during unilateral countermovement vertical jump performed on a force plate, and during unilateral landing on unstable surface. (3) Vertical jump impulse negatively correlated with biceps femoris activation at landing. Participants with greater hip abduction force performed greater vertical jump impulse, and activated the biceps femoris less when landing on unstable surface. Furthermore, participants with smaller knee flexion/extension torque ratio increased biceps femoris/vastus medialis activation ratio at landing. (4) We conclude that hip abduction strength is an important contributor to unilateral vertical jump performance. Because biceps femoris is considered the synergist of the anterior cruciate ligament, we also propose that hip abductors are primary frontal plane protectors of the knee joint by reducing knee valgus and stress, allowing for smaller biceps femoris co-activation (secondary protection) at landing on unstable surface.

English

Knee injuries are common in sports and depending on the mechanism of fall, injury of different ligaments can occur. Knee injury mostly involves the anterior cruciate ligament (ACL), and is the most common injury reported on MRI. It can be associated with posterolateral corner (PLC) injury and other osseous injuries, these injuries are rarely reported as they are very complex in structure. A detail knowledge about this complex helps to evaluate the associated ligaments as well. In association with anterior cruciate ligament injuries presence of a Segond fracture indicates occurrence of a concomitant or isolated injury to the posterolateral corner injury. The evaluation of these associated injuries along with anterior cruciate ligament aids in their repair and hence improving the postoperative outcome. Three main components of posterolateral corner are divided into three layers – superficial, middle, and deep. Clinically few tests have been advised to evaluate injury of different structures of knee joint. For example - McMurray's test and Ege's test are used to evaluate meniscus, Lachman test, Anterior drawer test and Pivot Shift Test are performed to evaluate anterior cruciate ligament tear while posterior drawer test is done to evaluate posterior cruciate ligament tear. Availability of special closely coupled extremity coils, high field systems, open system & extremity units have made MRI supplemental to clinical examination and plain radiographs for virtually all suspected disorders of knee. Here, we are presenting a case of MRI of knee injury involving posterolateral corner injury with anterior cruciate ligament tear and Segond fracture. Along with anterior cruciate ligament, medial meniscus, other ligaments and osseous injury are associated as well. The other structures responsible for stabilizing the knee joints are posterolateral corner and meniscus, which when involved may need to be treated simultaneously with anterior cruciate ligament tear, for full re stabilization of knee joint. If any associated fracture is present, it has to be treated simultaneously as well.

RESEARCH ON STABILITY OF ATHLETE KNEE QULUS LIGTE RECONSTRUCTION

ABSTRACT Introduction: ACL injury of the knee joint is common in sports. Due to the special characteristics of strong physical confrontation and high speed, basketball has a high risk of ACL injury. Objective: To investigate the stability of anterior cruciate ligament (ACL) reconstruction on knee injury in athletes. Methods: In the south, medical research selected 3 cases of unilateral injuries in men's basketball athletes with arthroscopic anterior cruciate ligament autogenous tendon revascularization. We started collecting and recording data of three players three days after rehabilitation training, at various stages in the process Results: At the end of rehabilitation training, 10 weeks after operation, the pain disappeared, the range of motion of the knee joint increased significantly, muscle atrophy of bilateral lower limbs diminished, knee joint stability improved, knee joint muscle strength of the affected leg strengthened, and the rehabilitation goal was basically accomplished. Conclusions: Early rehabilitation training can effectively restore the movement function of the patient's knee joint, improve the efficiency of rehabilitation and shorten the rehabilitation period, thus helping the injured individual recover from the injury and return to the game rapidly. Level of evidence II; Therapeutic studies - investigation of treatment results.

Feasibility study of early prediction of postoperative MRI findings for knee stability after anterior cruciate ligament reconstruction

BackgroundAt present, the most effective and mature treatment after ACL injury and tear is ACL reconstruction, but the rehabilitation process after ACL reconstruction that is very long, so it is very important to find early MRI positive findings of knee instability.MethodsWe retrospectively collected the clinical and imaging data of 70 patients who underwent ACL reconstruction from January 2016 to December 2019; Based on clinical criteria, the patients were divided into a stable group (n = 57) and an unstable group (n = 13); We measured the MRI imaging evaluation indexes, including the position of the bone tunnel, graft status, and the anatomical factors; Statistical methods were used to compare the differences of imaging evaluation indexes between the two groups; The prediction equation was constructed and ROC curve was used to compare the prediction efficiency of independent prediction factors and prediction equation.ResultsThere were significant differences in the abnormal position of tibial tunnel entrance, percentage of the position of tibial tunnel entrance, position of tibial tunnel exit, lateral tibial posterior slope (LTPS), width of intercondylar notch between stable knee joint group and unstable knee joint group after ACL reconstruction (P < 0.05); The position of tibial tunnel exits and the lateral tibial posterior slope (LTPS) and the sagittal obliquity of the graft were independent predictors among surgical factors and self-anatomical factors (P < 0.05); The prediction equation of postoperative knee stability was established: Logit(P) = -1.067–0.231*position of tibial tunnel exit + 0.509*lateral tibial posterior slope (LTPS)-2.105*sagittal obliquity of the graft; The prediction equation predicted that the AUC of knee instability was 0.915, the sensitivity was 84.6%, and the specificity was 91.2%.ConclusionsWe found that abnormalities of the position of the exit of the bone tunnel, lateral tibial posterior slope (LTPS) and sagittal obliquity of the graft were the early MRI positive findings of knee instability after ACL reconstruction. It is helpful for clinicians to predict the stability of knee joint after ACL reconstruction.

Operative management of closed tibial plateau fracture treated with posteriomedial plate with inclusion or exclusion of anteriolateral plate

The proximal tibia is involved in body weight transmission though the knee joint and leg, it plays a vital role in the knee joint function and stability. Fractures of proximal tibia have historically been difficult to treat because of its subcutaneous location of the anteromedial surface of the tibia. Severe bone and soft tissue injuries are not infrequent and there is high incidence of open fractures compared to other long bones. This study was a prospective study done on 20 consenting cases of closed tibial plateau fractures who were admitted with posteriomedial plate with inclusion or exclusion of anteriolateral and have come for follow up during the study period chosen based on the inclusion and exclusion criteria. In our study Average time for union of fracture was 18 weeks (range from 16-24 weeks). In our study two patients developed knee stiffness One patient with knee joint stiffness is due to lack of postoperative mobilization .Second patient developed knee stiffness due to patella fracture treated with TBW and physiotherapy and regain 900 of flexion.

EARLY DIAGNOSIS AND PRIMARY REPAIR OF A RARE INJURY OF SUPERFICIAL MEDIAL COLLATERAL LIGAMENT OF KNEE: STENER-TYPE LESION

Introduction: Medial Collateral ligament (MCL) is the primary stabilizer of knee joint against valgus stress force. Sprains of MCL are fairly common due to any injury and are treated conservatively most of the time. These have been classified by Hughston in grades I, II and III based on the severity. While grades I and II mostly have only sprain of the ligament, grade III is complete tears and may warrant surgical correction. Stener-type lesion is a rare finding seen with grade III MCL injuries. Here, superficial MCL (sMCL) tears at its distal insertion and is retracted upwards leading to pes anserinus tendon to lie in between the bed and its distal end. This does not allow the MCL tendon to regain its attachment to bed and needs surgical correction. Material/Methods: We report five patients who presented to us with stener-like lesion. They were then operated with repair of MCL tendon and its reattachment to the Tibial bed using similar techniques. Pre-procedure outcome values (Lysholm score and KOOS score) were evaluated and the patients were followed up for 1 year. At the final follow up, final outcome values were calculated along with complete clinical examination was done. Results: All five patients were fully satisfied and reported no problems in resuming work and daily activities. Clinical evaluation was done and there was reported no joint laxity or opening of joint line with varus/valgus stress conditions. There was a complete range of motion reported in all patients. There was no limping/misalignment or gait disturbances reported at the end of follow up in any of the patients. Conclusion: Stener-type lesion of knee is rare and is needed to be explored further. Our study emphasizes the early diagnosis and surgery with excellent results of cases reported in due course of time. Very limited literature is currently available for this severe sMCL injury. Thus, longer studies involving a larger number of cases and extended follow up are needed in future to explore the ways of early diagnosis and various treatment options further.

All-inside reconstruction of anterior cruciate ligament with single-bundle autogenous peroneal longus tendon

Objectives:To evaluate the curative effect of all-inside reconstruction of anterior cruciate ligament with single-bundle autogenous peroneal longus tendon.Methods:A total of 21 people who met the including criteria were enrolled into this study. The autogenous peroneal longus tendon were got to all-inside anterior cruciate ligament reconstruction. The complications were documented, while the clinical consequences was evaluated by Lachman test, KOOS, SF - 36 and AOFAS.Results:There were no serious complications after operation. Lachman test showed that the stability of knee joint after operation was significantly improved (P < 0.05). The KOOS score significantly improved at 12 months postoperatively, including pain, symptoms, activity of daily living, sport and recreation function and knee related quality of life, compared with those before operation (P<0.05). In addition, the SF-36 score also significantly improved at 12 months postoperatively compared with those preoperatively, with statistically significant differences in physical functioning, physical role functioning, bodily pain, general health perceptions, emotional role functioning and social role functioning (P<0.05), whereas no statistically significant differences in vitality and mental health (P>0.05).Conclusion:The all-inside reconstruction of anterior cruciate ligament with single-bundle peroneal longus tendon can effectively restore the stability of knee joint, reduce postoperative pain, improve the function of knee joint, and provide high satisfaction.

Early knee status affects self-reported knee function 1 year after non-surgically treated anterior cruciate ligament injury

ObjectivesThe primary aim was to assess impact of early knee status on self-reported knee function at 3 and 12 months and on quadriceps strength at 12 months after non-surgically treated ACL injury. The secondary aim was to describe the recovery of muscle strength during the first year after the injury. DesignProspective cohort study. Participants70 patients (42 males; mean age 27 ± 7 years) with acute ACL injury. Main outcomeKnee symptoms, knee function and sporting activities were assessed with the International Knee Documentation Committee Subjective Knee Form (IKDC-SKF). Muscle strength was assessed with an isokinetic dynamometer. Clinical assessment performed at baseline was used to evaluate early knee status. ResultsGlobal knee function, knee joint stability during ADL, gait pattern and one-legged squat assessed in mean 2 weeks after injury hadimpact on self-reported knee function at 3 and 12 months (r2 0.105–0.267). Mean limb symmetry index (LSI) of muscle strength and jump performance were 91–98% at 12 months. ConclusionEarly knee symptoms affect self-reported knee function at 3 and 12 months, while other factors are important for gaining muscle strength. Muscle strength recovered during the first year after ACL injury and reached mean LSI above 90%. Level of evidenceProspective cohort study, level II.

DETERMINATION OF THE STRESS OF ANTERIOR CRUCIATE LIGAMENT IN VARIOUS DEGREES OF KNEE FLEXION, COMPARISON OF NORMAL AND RECONSTRUCTED LIGAMENT

Background: Knee joint stability is enhanced by ligamentus structures such as anterior cruciate (ACL), posterior cruciate (PCL), medial collateral (MCL) and lateral collateral ligaments (LCL). Rupture of ACL is the most common knee injuries, especially in sport related activities. The aim of this study is to evaluate the stress developed in knee joint structures in various degrees of knee flexion in ACL ruptured compared to normal condition. Method: CT scan images of knee joint were used to create 3d model of knee joint by use of Mimics software. Abaqus software was used to evaluate the stress developed in knee joint in normal and in ACL reconstructed conditions in various degrees of knee flexion. Results: The stress developed in ACL and other knee joint structures increased significantly by increase in knee joint flexion. The stress of knee joint structures (especially in ACL) in ACL reconstructed condition was more than that of normal condition. Conclusion: It is recommended to immobilize the knee joint in extension up to [Formula: see text] of knee flexion in those with ACL injuries. The stress of ACL increased due to an increase in tibia translation associated with knee flexion.

Comparative Analysis of the Results of Lateral Extra-Articular Tenodesis in Anatomical Anterograde Plasty of the Anterior Cruciate Ligament

AIM OF STUDY To analyze the results of lateral extra-articular tenodesis (LET) of the semitendinosus muscle tendon (STMT) and iliotibial tract (ITT) in patients with severe anterior rotational instability of the knee joint during anatomical anterograde reconstruction of the anterior cruciate ligament (rACL) with a BTB graft. MATERIAL AND METHODS We studied 138 patients with the Pivot shift test – 3+ and the Lachman test 2+ or 3+ degree after arthroscopic rACL with a BTB autograft. In 65 cases (47.1%) rACL was supplemented with LET of STMT (group 1), the remaining 73 patients (52.9%) – LET of ITT (group 2). RESULTS According to IKDC-2000, KOSS and Lysholm-Tegner scores, the groups did not differ statistically. However, pain in the LET zone, LET failure with the appearance of the Pivot shift test – 1+, revision reconstructions – were more often observed in group 2 (p&lt;0.05). Popliteal hematomas (p&lt;0.001), longer operations (p&lt;0.01) were more often observed in group 1. CONCLUSION Lateral extra-articular tenodesis is a clinically effective addition to anatomical anterograde reconstruction of the anterior cruciate ligament with BTB autograft in patients with Pivot shift test 3+ and Lachman test 2+ or 3+. However, a more reliable option is lateral extra-articular tenodesis of the semitendinosus muscle tendon. At the same time, lateral extra-articular tenodesis of the iliotibial tract is a simpler, faster and more cost-effective technique, still demonstrating good indicators of knee joint stability.

The effect of gender, age, and body mass index on the\xa0medial and lateral posterior tibial slopes: a magnetic resonance imaging study

BackgroundThe posterior tibial slope (PTS) is crucial in knee joint stability and in maintaining the natural movement of the knee. An increase in the PTS is associated with various knee pathologic conditions, such as anterior cruciate ligament (ACL) injury and anterior tibial translation (ATT). In the present study, we aimed to establish native medial and lateral PTS values for adult Saudis and to identify any association between PTS and gender, age, and body mass index (BMI).Materials and methodsA total of 285 consecutive, normal, magnetic resonance imaging (MRI) studies of the knee were included in the study. The PTS was measured using the proximal anatomical axis of the tibia. The Kruskal-Wallis test was used to compare the medial and lateral PTS angles between age groups. The difference between the medial and lateral posterior tibial slopes was assessed using the Wilcoxon signed-rank test. The Mann-Whitney U test was performed to compare the medial and lateral PTS angles between men and women. Age, gender, and BMI were analyzed by multivariate linear regression to determine whether they positively predict the medial and lateral PTS angles.ResultsThe mean physiological medial PTS was 5.86 ± 3.0° and 6.61 ± 3.32°, and the lateral PTS was 4.41 ± 3.35° and 4.63 ± 2.85° in men and women, respectively. This difference showed no statistically significant gender dimorphism (p > 0.05). The medial PTS was significantly larger than the lateral PTS (p < 0.0001). There was no statistically significant difference in the medial and lateral PTS angles between age groups (p > 0.05). Higher BMI was significantly associated with a steeper medial PTS (p = 0.001).ConclusionsThis study provided native values for medial and lateral PTS angles in Saudis, which can assist surgeons in maintaining normal knee PTS during surgery. The PTS was not influenced by age. The medial PTS was significantly larger than the lateral PTS in men and women. The PTS showed no significant gender dimorphism. BMI was significantly associated with the medial PTS.

Study of outcome of knee joint in patients with fracture distal femur versus fracture ipsilateral femur and tibia

The posture on the two wheeler at the speed we travel, makes knee the vulnerable joint of all in any of the mishaps. We as orthopedic surgeons see the fractures around the knee joint as one of the most studied concept in the subject. This is a prospective study conducted, over 2 years, in Krishna Institute of Medical Sciences, Deemed to be University, Karad. In this study, 20 cases of fracture distal femur and 20 cases of ipsilateral fracture femur and tibia were studied to evaluate outcome of knee joint and post surgical stabilization of fractures. The fractured limb was stabilized with splinting the limb in Thomas splint or plaster slab. The type of fracture, type of fracture fixation, duration of hospital stay, time of union and time to start weight bearing are evaluated. According to Neer’s score, Good outcome was found in both Fracture Distal femur and Ipsilateral Fracture Femur and tibia. The functional outcome was found to be better in diaphyseal fractures femur and tibia treated with intramedullary interlock nailing which allowed early mobilization and weight bearing than in intra-articular fractures treated with plating. Bony union occurred early in closed, diaphyseal and simple transverse or oblique fractures and delayed in open, intraarticular and comminuted fractures.

A prospective study of surgical management of Schatzker Type V (Bicondylar) &amp; Type Vi tibial plateau fracture by dual plating

AIM: To assess the clinical and functional outcome of surgically treated proximal tibial fractures with dual plating at AIMS, B.G. Nagara during August 2018 to December 2020.Objectives1.To assess the articular surface anatomical reduction of PROXIMAL tibia perfectly by operative treatment with internal fixation.2.To assess the union of fractures radiologically after internal fixation with dual plates3.To assess the clinical outcome associated with this treatment modalitya.Range of movements of knee jointb.Relief of pain for the patientc.Return to routine daily activities and workMaterials and Methods: Total number of cases studied were 20.•Inclusion criteria: All patients who are skeletally mature with proximal tibia fracture Schatzker type V and VI (>18 years), AO Muller type 41-C1, 41-C2, 41-C3, Gustilo-Anderson type I and II compound proximal tibial fracture.•Exclusion Criteria: Patients with Gustilo-Anderson Type 3 compound tibial plateau fractures, Children with proximal tibial fractures with intact growth plate, patients with pathological proximal tibial fractures apart from osteoporosis.Observation and Results: Our study used Honkonen Jarvinen Criteria for radiological, functional, clinical outcome which showed excellent to good result. Our study reported Honkonen Jarvinen Clinical outcome to be 85% excellent, 12% good and 2% fair. The functional outcome was 80% excellent, 14% good, 4% fair and 2% poor. The Radiological outcome showed 79% excellent, 15% good, 0.70% fair results.Conclusion: From this study we conclude that, proximal tibial fractures (Schatzker type V and type VI) managed surgically with dual plating gives excellent anatomic reduction, accurate axial and articular alignment with rigid internal fixation by dual locking plate, achieving a stable and better functional knee joint.

Star Excursion Balance Test as an Exercise to Improve Static and Dynamic Balance in Community-Dwelling Persons with Unilateral Osteoarthritis of Knee

Knee joint stability is important for postural stability.Abnormal weight distribution is common in individualswith unilateral osteoarthritis of knee (OA knee) as compensatory mechanism for pain and joint malalignments.Various forms of conventional physiotherapy interventions have been used to prevent further degenerativeprocess. Star excursion balance test (SEBT) has been invented to assess dynamic postural stability. Thispresent study was aimed to investigate effects of SEBT as a postural control exercise training tool(SEBTx)in persons with unilateral OA knee. Fourteen participants were randomly assigned to control group (n = 7)and SEBTx group (n = 7). The control group received weekly routine physiotherapy interventions (jointmobilization, ultrasound therapy, transcutaneous electrical nerve stimulation, and taping). In addition tothe routine interventions, the SEBTxgroup was instructed to perform SEBTxfor 30 min/session, 3 sessions/week, for 4 weeks. Primary outcome (weight distributionon posturography in 8 directions – anterior, Rt.anterolateral, Rt.lateral, Rt. posterolateral, posterior, Lt. posterolateral, Lt. lateral, Lt. anterolateral)wasmeasured at baseline and4 weeks post-intervention. Secondary outcomes numeric pain rating scale (NPRS)and Timed Up and Go test (TUG) were used to assess pain and dynamic balance, respectively. Resultsshowed thatweight distribution inSEBTx group significantly improved in the Lt. posterolateral and posteriordirections post-intervention. Moreover, NPRS in SEBTx group significantly reduced from 47.9±7.4 to33.3±6.0. Lastly, TUG significantly reduced from 13.5±0.9 to 11.5±0.7 s in SEBTx group. In conclusion,the SEBTx should be applied to improve postural balance in individuals with unilateral (OA knee).

Tibialis anterior allograft versus hamstring tendon autograft for anterior cruciate ligament reconstruction:long-term clinical outcomes

To compare the clinical outcomes of arthroscopic anterior cruciate ligament (ACL) reconstruction (ACLR) with a tibialis anterior allograft (TAA)versus hamstring tendon autograft (HTA) after 10 years follow-up. A clinical data of 107 patients who underwent arthroscopic ACLR with a single bundle tendon between March 2007 and March 2010 was retrospectively analyzed. Among the patients, 48 patients were reconstructed with a tibialis anterior allograft (TAA group), including 26 males and 22 females, ranging in age from 16 to 38 years, with a mean of 27.2±6.2 years;59 patients were reconstructed with a hamstring tendon autograft (HTA group), including 31 males and 28 females, ranging in age from 16 to 40 years, with a mean of 28.0±7.6 years. The preoperative tibial anterior displacement and knee joint function, as well as knee joint stability, tibial anterior displacement and knee joint function at 10 years after operation were observed. Lachman test was used to evaluate the forward joint stability and pivot shift test to evaluate the rotational stability of the knee;KT-2000 side-to-side difference (SSD) was used to measure tibial anterior displacement;International Knee Documentation Committee(IKDC) score and Lysholm score were used to evaluate knee function. The incisions of both groups were healed by first intention, and no early complications occurred after operation. All patients were followed-up 10 to 13 years, the mean time was 11.7 years. There was no graft failure were found during the follow up period. The KT-2000 SSD of the TAA group and the HTA group at ten years after operation were 1.9±0.7 and 1.8±0.6 respectively, which were significantly improved than 8.8±0.9 and 8.6±1.0 preoperatively(P<0.05), but there were no significant difference between the two groups(P>0.05). The total Lysholm score of the TAA group and the HTA group at ten years after operation were 90.4±4.4 and 90.7±3.4 respectively, which were significantly improved than 51.4±13.3 and 51.2±14.6 preoperatively(P<0.05), but there were no significant difference between the two groups(P>0.05). The total IKDC score of the TAA group and the HTA group at ten years after operation were 91.5±4.1 and 90.9±3.2 respectively, which were significantly improved than 45.8±12.2 and 47.0±14.5 preoperatively(P<0.05), but there were no significant difference between the two groups(P>0.05). No significant difference were found between the two groups in Lachman test and pivot shift test at 10 years after operation (P>0.05). The TAA and HTA have equal long term effect in ACL reconstruction, doctors and patients can choose the graft according to the actual situation.

Effects of neuromuscular exercise therapy on the joint stability of patients with knee osteoarthritis

Objective: To evaluate the effects of neuromuscular exercise therapy on joint stability of knee osteoarthritis (OA) patients. Methods: One hundred and ten patients with knee OA were enrolled in this ongoing prospective cohort study at Arthritis Clinic and Research Center, Peking University People's Hospital from September 2017 to October 2018. The treatment consisted of six-week neuromuscular exercise therapy. The participants were followed up at 6 weeks and 3 months after the therapy. The stability of the joint was evaluated by the index of knee joint stability (IKJS), which was extracted by a novel knee-aiming task combined with the multiscale entropy (MSE) analysis of the complexity of the light spot trajectories. The secondary outcomes were pain on the visual analogue scale (VAS, 0-100), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), quality of life on the Euro-quality of life-5 Dimensional (EQ-5D) VAS form, 30-second chair stand test and 40-meter walk test. One-way repeated measures ANOVA analysis was applied to compare the outcomes at baseline and 6 weeks and 3 months. Pearson partial analysis was used to investigate the correlation between the IKJS and the Kellgren-Lawrence (K/L) rate, pain and knee function. Results: Ninety-six participants ((65±8) years, 21 males, 75 females) completed 3-month follow-up. There was a significant improvement in IKJS at the 6-week visit compared with that at baseline (0.369, 95% confidence interval (CI) 0.241-0.496, P<0.001). The IKJS dropped at 3-month visit compared with 6-week visit, but was still better than that at baseline (0.178, 95%CI: 0.042-0.314, P=0.008). The correlation between IKJS and K/L rate, severity of pain, WOMAC or knee function was not significant (r=-0.131, -0.059, -0.231, 0.124, all P>0.05). There was improvement in pain VAS, WOMAC, EQ-5D-VAS, 30-second chair stand test and 40-meter walk test at 6 weeks and 3 months (all P<0.05). Conclusion: The neuromuscular exercise therapy is effective in improving the joint stability of the knee OA patients. However, the effect gradually diminished over time. In addition, neuromuscular exercise can help relieve pain, improve the function and quality of life in patients with knee OA.

Potential Instability and Malfunction of Knee Joints with Vastus Medialis Impairment after Total Knee Arthroplasty

Four pairs of fresh-frozen cadaver knees (eight knees, four male knees) with a mean age of 72 ± 7 years were used for tests involving a customized simulator capable of controlling quadriceps loading conditions. The muscle force distribution of the quadriceps for the normal loading condition was applied on the basis of muscle cross-sectional area data, as previously reported (VM: 31 N; RF/VI: 49 N; VL: 45 N). To simulate vastus medialis (VM) impairment, we set the muscle force for VM in the muscle force distribution of the quadriceps at zero (VM: 0 N; RF/VI: 49 N; VL: 45 N). The joint reaction forces and moments on knee joints that underwent total knee arthroplasty (TKA) did not differ significantly according to VM impairment status for all flexion angles (p &gt; 0.05). Nevertheless, the vectors of internal–external moments mostly showed a tendency for alteration from external to internal due to VM impairment. This tendency was evident in 9 cases in 12 total test pairs (with and without VM impairment). Furthermore, the vectors of the anterior–posterior reaction forces mostly showed a tendency to increase anteriorly due to VM impairment. This tendency was also evident in 9 cases in 12 total test pairs (with and without VM impairment). These results indicate that posterior dislocation of the tibia may be induced if VM impairment occurs after TKA. In conclusion, VM impairment in knee joints undergoing TKA may contribute to posterior dislocation of the tibia by a paradoxical roll-back with enhancements of the anterior joint reaction force and external moment during knee-joint flexion. Our findings may be valuable for understanding the mechanism of potential instability and malfunction due to VM impairment in knee joints after TKA, and may help to optimize clinical/rehabilitation training plans to improve the prognosis (stability and function) of knee joints undergoing TKA.

Effectiveness of partial anterior cruciate ligament suture repair with wide awake local anesthesia no tourniquet technique

To investigate the effectiveness of partial anterior cruciate ligament (ACL) suture repair with wide awake local anesthesia no tourniquet (WALANT) technique. Between July 2017 and July 2019, 18 patients with partial ACL injury were admitted. There were 10 males and 8 females, with an average age of 40.5 years (range, 22-57 years). There were 5 cases on the left knee and 13 cases on the right knee. Forteen cases had a clear history of trauma or sports injury, and 4 cases had no obvious cause. The time from injury to operation was 1-6 months (median, 3 months). Partial ligament was sutured using WALANT technique under arthroscopy. The operation time, total hospital stay, and postoperative hospital stay were recorded. Lachman test and anterior drawer test were performed to evaluate the knee joint stability after treatment, and Lysholm and International Knee Documentation Committee (IKDC) scores were used to evaluate the knee function. Five-point Likert scaling were used to evaluate postoperative patient satisfaction. The operation time was 30-100 minutes (mean, 64.2 minutes). The total hospital stay was 2-12 days (mean, 4.5 days). Postoperative hospital stay was 1-4 days (mean, 1.8 days). All incisions healed by first intention after operation, and no surgery-related complications occurred. All patients were followed up 12-36 months (mean, 19.1 months). Lachman test and anterior drawer test were negative after operation. Lysholm score and IKDC score at 6 and 12 months after operation were significantly higher than those before operation, and at 12 months after operation were higher than those at 6 months after operation, the differences were significant ( P<0.05). At last follow-up, according to five-point Likert scaling of patient satisfaction, 7 cases were very satisfied, 10 cases were relatively satisfied, and 1 case was general. The total patient satisfaction rate was 94.4% (17/18). MRI scan showed the good ligament tension. Using WALANT technique to repair partial ACL injuries under arthroscopy can retain the patient's own ligament tissue to the maximum extent and achieve satisfactory short-term effectiveness.

Electromechanical delay of the hamstrings following semitendinosus tendon autografts in return to competition athletes.

Knee flexor electromechanical delay (EMD) has been proposed as a contributing factor to non-contact anterior cruciate ligament (ACL) injury risk and the semitendinosus (ST) autograft technique has been shown to impair knee flexor torque at large angles of knee flexion. The purpose of this study was to analyse the effects of ACL reconstruction (ACLR) using the ST tendon autograft technique on knee flexor EMD across the knee flexion range of motion, in athletes who had returned to competition. Athletes with ACLR (n = 8 females, n = 3 males, 1.7 ± 0.5years post-surgery) and non-injured control athletes (n = 6 females, n = 4 males) performed rapid maximal voluntary contractions of isometric knee flexion and extension at 30°, 50°, 70°, 90°,and 105° of knee flexion. Electrical activity of the ST, biceps femoris (BF), vastus lateralis, and vastus medialis was recorded using surface electromyography. No change in EMD for the knee flexors or extensors was observed across joint angles. Greater EMD was found only for the BF in the ACLR limb of injured athletes compared to the contralateral limb (P < 0.05). In post-hoc analysis, evidence of ST tendon regrowth was noted for only 2/11 athletes. While the EMD-joint angle relationship appeared to be unaffected by ST tendon harvest for ACLR, the absence of ST tendon regrowth should be considered. Despite return to competition, greater BF EMD was found, which may impair knee joint stabilization capacity by delaying the transfer time of muscle tension to the tibia after ST autograft.

Changes in gastrocnemii activation at mid-to-late stance markedly affects the intact and anterior cruciate ligament deficient knee biomechanics and stability in gait

IntroductionWe aimed to quantify the sensitivity in biomechanical response and stability of the intact and anterior cruciate ligament deficient (ACL-D) joints at mid-to-late stance periods of gait to the alterations in activation of gastrocnemii (Gas) muscles. MethodsA validated kinematics-driven musculoskeletal finite-element model of the lower extremity is used to compute knee joint response and stability under reported kinetics–kinematics of healthy subjects. Activation in Gas is altered under prescribed gait data at the mid-to-late stance of gait and associated changes in remaining muscle forces/contact forces/areas/ACL force and joint stability are computed in both intact and ACL-D joints. ResultsIn the intact joint, the anterior-tibial-translation (ATT) as well as ACL and joint contact forces follow variations in Gas forces. Both the stability and ATT of an ACL-D joint are restored to the near-intact levels when the activity in Gas is reduced. Knee joint instability, excessive ATT as well as larger peak articular contact stresses with a posterior shift in contact areas are estimated under greater Gas forces. ConclusionsACL-D joint is unstable with ATT > 10 mm under larger activities in Gas. Gas is an ACL-antagonist while hamstrings and soleus are ACL-agonists. The near-intact joint stability and ATT of an ACL-D joint can be restored at a lower activation in Gas; or in other words, when activation in ACL-antagonist muscles drops compared with that in ACL-agonist muscles. Results could help analyze the gait of ACL-D copers and non-copers and provide better understanding towards improved preventive, diagnostic, and treatment approaches.