Bilateral Medial Tibiofemoral Joint Stiffness in Full Extension and 20° of Knee Flexion (original) (raw)
2021
This study aimed to evaluate the influence of measuring the length of the medial collateral ligament (MCL) to compare the MCL burden when the knee joint is placed under valgus stress in the open and closed and closed kinetic chain. Two examiners conducted the examination. The MCL length was measured using ultrasonography. Two subjects were measured in unload bearing and load-bearing positions, with and without valgus stress test at the knee joint extension and 30° flexion, under eight different measurement conditions. The MCL of the subject was delineated in the longitudinal direction using an ultrasound system. The attachment points of the medial femoral and tibial condyle of the MCL were identified, and the ligament length was measured. The MCL rate before and after the valgus stress test in the loading and unloading positions was calculated. The MCL length increased by an average of 8.9% when the external stress test was performed in the non-weight bearing and knee extension posi...
Tibiofemoral Joint Positioning for the Valgus Stress Test
Journal of Athletic Training, 2010
Context: Recommendations on the positioning of the tibiofemoral joint during a valgus stress test to optimize isolation of the medial collateral ligament (MCL) from other medial joint structures vary in the literature. If a specific amount of flexion could be identified as optimally isolating the MCL, teaching and using the technique would be more consistent in clinical application.
The Effects of Tibiofemoral Angle and Body Weight on the Stress Field in the Knee Joint
Volume 2: Biomedical and Biotechnology Engineering, 2007
Osteoarthritis (OA) is a degenerative disease of articular cartilage that may lead to pain, limited mobility and joint deformation. It has been reported that abnormal stresses and irregular stress distribution may lead to the initiation and progression of OA. Body weight and the frontal plane tibiofemoral angle are two biomechanical factors which could lead to abnormal stresses and irregular stress distribution at the knee. The tibiofemoral angle is defined as the angle made by the intersection of the mechanical axis of the tibia with the mechanical axis of the femur in the frontal plane. In this study, reflective markers were placed on the subjects' lower extremity bony landmarks and tracked using motion analysis. Motion analysis data and force platform data were collected together during single-leg stance, double-leg stance and walking gait from three healthy subjects with no history of osteoarthritis (OA), one with normal tibiofemoral angle (7.67º), one with varus (bow-legged) angle (0.20º) and one with valgus (knocked-knee) angle (10.34º). The resultant moment and forces in the knee were derived from the data of the motion analysis and force platform experiments using inverse dynamics. The results showed that Subject 1 (0.20º valgus) had a varus moment of 0.38 N-m/kg, during single-leg stance, a varus moment of 0.036 N-m/kg during static double-leg stance and a maximum varus moment of 0.49 N-m/kg during the stance phase of the gait cycle. Subject 2 (7.67º valgus tibiofemoral angle) had a varus moment of 0.31 N-m/kg, during single-leg stance, a valgus moment of 0.046 N-m/kg during static double-leg stance and a maximum varus moment of 0.37 N-m/kg during the stance phase of the gait cycle. Subject 3 (10.34º valgus tibiofemoral angle) had a varus moment of 0.30 N-m/kg, during single-leg stance, a valgus moment of 0.040 N-m/kg during static double-leg stance and a maximum varus moment of 0.34 N-m/kg during the stance phase of the gait cycle. In general, the results show that the varus moment at the knee joint increased with varus knee alignment in static single-leg stance and gait.
Collateral ligament strains during knee joint laxity evaluation before and after TKA
Clinical Biomechanics, 2013
Background: Passive knee stability is provided by the soft tissue envelope. There is consensus among orthopedic surgeons that good outcome in Total Knee Arthroplasty requires equal tension in the medial/lateral compartment of the knee joint, as well as equal tension in the flexion/extension gap. The purpose of this study was to quantify the ligament laxity in the normal non-arthritic knee before and after Posterior-Stabilized Total Knee Arthroplasty. We hypothesized that the Medial/Lateral Collateral Ligament shows minimal changes in length when measured directly by extensometers in the native human knee during varus/valgus laxity testing. We also hypothesized that due to differences in material properties and surface geometry, native laxity is difficult to reconstruct using a Posterior-Stabilized Total Knee. Methods: Six specimens were used to perform this in vitro cadaver test using extensometers to provide numerical values for laxity and varus-valgus tilting in the frontal plane. Findings: This study enabled a precise measurement of varus-valgus laxity as compared with the clinical assessment. The strains in both ligaments in the replaced knee were different from those in the native knee. Both ligaments were stretched in extension, in flexion the Medial Collateral Ligament tends to relax and the Lateral Collateral Ligament remains tight. Interpretation: As material properties and surface geometry of the replaced knee add stiffness to the joint, we recommend to avoid overstuffing the joint, when using this type of Posterior-Stabilized Total Knee Arthroplasty, in order to obtain varus/valgus laxity close to the native joint.
The relationships between active extensibility, and passive and active stiffness of the knee flexors
Journal of Electromyography and Kinesiology, 2004
Insufficient active knee flexor stiffness may predispose the anterior cruciate ligament to injury. Insufficient passive stiffness may result in insufficient active stiffness. Similarly, higher levels of musculotendinous extensibility may inhibit active and passive muscle stiffness, potentially contributing to an increased risk of injury. The literature is both limited and inconsistent concerning relationships between extensibility, passive stiffness, and active stiffness. Extensibility was measured as the maximal active knee extension angle from a supine position with the hip flexed to 90 v . Passive stiffness was calculated as the slope of the momentangle curve resulting from passive knee extension. Active stiffness was assessed via acceleration associated with damped oscillatory motion about the knee. Stepwise multiple regression indicated that passive stiffness accounted for 25% of active muscle stiffness variance. The linear combination of extensibility and passive stiffness explained only 2% more variance compared to passive stiffness alone. Musculotendinous extensibility was moderately related to passive muscle stiffness, and weakly related to active muscle stiffness. The moderate relationship observed between active and passive stiffness emphasizes the dependence of active muscle stiffness on cross-bridge formation, and the relatively smaller contribution from parallel elastic tissues. Additionally, heightened extensibility does not appear to be a predisposing factor for reduced muscle stiffness. #
Journal of Orthopaedic Research, 2005
Past studies of the healing of the medial collateral ligament (MCL) in animal models have been conducted over a variety of healing intervals, some as early as 1 week. One concern with testing at early healing intervals is the difficulty in identifying and isolating the tissues that carry load. The purpose of this study was to determine if isolation of the MCL and healing time are critical factors in the assessment of structural strength in this model. Furthermore, the effect of immobilization on these critical factors was investigated. Our approach was to calculate the load-sharing ratio between the MCL and the MCL plus capsule. A 4 mm gap was created in the midsubstance of both hindlimb MCLs of 52 female New Zealand White rabbits (n = 104). Of these, 29 rabbits had their right hindlimb pin immobilized (immobilized group), leaving the left hindlimb non-immobilized. Testing was performed at 3 (n = 12), 6 (n = 22), and 14 (n = 24) weeks. The remaining 23 rabbits, which had both limbs non-immobilized (non-immobilized group), were tested at 3 (n = lo), 6 (n = 12), 14 (n = 12), and 40 (n = 12) weeks. For both groups, half of the specimens at each healing interval were used to test the MCL alone and half to test the MCL plus capsule, except for 3 week immobilized joints where only the MCL plus capsule was tested. Additionally, MCL (n = 12), MCL plus capsule (n = 6), and capsule alone (n = 5) were tested from normal animals. The load-sharing ratio at MCL failure for the normal joint was 89%, suggesting an MCL-dominated response. For the nonimmobilized group, the load-sharing ratio was 24% at 3 weeks of healing, suggesting a capsule-dominated response. At and after 6 weeks of healing, an MCL-dominated response was observed, with the ratio being 68% or greater. Thus, at less than 6 weeks of healing, the structural strength capabilities of the joint may be better represented by the medial structures rather than the isolated MCL. Immobilization delayed the transition from a capsule-dominated response to an MCL-dominated response in this model.
The importance of the valgus stress test in the diagnosis of posterolateral instability of the knee
Injury, 2006
Background: The diagnosis of posterolateral instability of the knee is often based on a typical indirect mechanism of injury, a history of ''giving way'' and a positive dial test. Our search of the English literature revealed no mention of including the valgus stress test in the diagnostic protocol for posterolateral instability. Hypothesis: Based on our experience, we hypothesised that a medial collateral ligament (MCL) tear will also produce a positive dial test and that a valgus stress test would provide differential diagnostic information. Methods: The MCL's of 14 fresh cadaveric knees (7 cadavers) were cut to simulate a grade 3 tear, taking care not to damage the medial retinaculum or the posteromedial stabilisersrs of the knee. The amount of tibial external rotation (the dial test) was measured for each knee before and after transection of the MCL. Results: The results of the dial test after transection of the MCL were similar to those stemming from a solitary injury to the posterolateral corner. There was a significant increase in external rotation of the knee in 308 and 908 of flexion. More over, external rotation in 308 was significantly greater than external rotation in 908 of knee flexion. Conclusions: Whenever suspecting a posterolateral complex injury, one has to carefully perform a valgus stress test in 08 and 308. Although the support of a clinical study is needed in order to make a definite conclusion, the dial test is probably not reliable in the presence of medial instability, and alternative diagnostic measures should be used.
Journal of ISAKOS: Joint Disorders & Orthopaedic Sports Medicine
ObjectiveInvestigate the patellar force-displacement profile (ligament stiffness) of patellofemoral disorders.MethodsFifty-two knees from 34 consecutive patients (mean 31.6 years and 53% male) were analysed including 24 knees with patellofemoral pain (PFP), 19 with potential patellofemoral instability (PPI) and 9 with objective patellofemoral instability (OPI). Physical examination, patient-reported outcome measures (Kujala and Lysholm Scores), standard radiography and MRI or CT were performed in all patients. Instrumented stress testing (Porto Patella testing device) concomitantly with imaging (MRI or CT) was performed to calculate ligament stiffness.ResultsThe force-displacement curves in patients with PPI and OPI displayed a similar pattern, which was different from that of the PFP group. Patients with PPI showed higher ligament stiffness (a higher force was required to displace the patella) than the patients in the OPI group. Patients with OPI had a statistically significant sha...
2015
Background: There is continued controversy related to flexibility gains from different stretching protocols and within single protocols. Stretching methods include static, ballistic, dynamic, and proprioceptive neuromuscular facilitation (PNF). A combination of stretching methods may be an improved way to increase active knee range of motion (ROM). This study evaluated a single program formulated with static and ballistic components. Objective: To compare active knee ROM following stretching programs which either included combined static and ballistic stretching (CSBS) or static stretching (SS) alone. It was hypothesized that CSBS would show a greater increase in active knee ROM than SS. Setting: The pre-and post-measurements were performed in a laboratory. Subjects were randomly assigned to either treatment group or a non-stretching control group and given written instructions on how to perform their designated protocol at home. Subjects: Forty-three (33M, 10F) healthy collegiate aged participants (24.0 + 3.69 yrs, 176.21 + 10.0 cm, 78.15 + 12.93 kg) with no history of injury to the lower extremity or low back for the previous 6 months were eligible to participate in the study. Interventions: Two treatment groups either performed SS or CSBS for 30 seconds on each leg, twice a day for 2 weeks. All subjects but 3 provided both legs, and each leg was evaluated separately, providing 83 total measurements. Main Outcome Measures: A Johnson Digital Inclinometer was used to measure active knee extension. A mixed ANOVA with a Tukey post hoc test was used for statistical analysis. Results: There was no statistically significant difference in active knee ROM between groups at the pre-test, F(2,80)=1.062, p=.351, partial ƞ2=.026 (SS: 52.56 + 7.50º, CSBS: 49.84 + 8.91⁰, control: 49.39 + 10.09⁰). There was a statistically significant difference in active knee ROM between groups at the posttest, F(2,80)=29.034, p .05). There was homogeneity of covariance's, as assessed by Box's test of equality of covariance matrices (p = .076). There was homogeneity of variances, as assessed by Levene's test of homogeneity of variance (p>.05). Conclusions: SS and CSBS are equally effective for improving active knee ROM. A trend indicating CSBS showing only slightly greater differences may be due to limited time allowed to master the CSBS method, with no supervision during stretching sessions. • Nathan Blackhurst, MS, LAT, ATC, is the Head Athletic Trainer at San Luis High School, a 5A school in the Yuma, AZ area. His full-time employment includes teaching the Career and Technical Education Sports Medicine and Rehabilitation Services program.