RESUMEN
The purpose of this study was (1) to determine the utility of shear wave elastography as a predictor for the mechanical failure of superficial knee ligaments and (2) to determine the viability of shear wave elastography to assess injury risk potential. Our hypothesis was that shear wave elastography measurements of the anterolateral ligament and medial collateral ligament would directly correlate with the material properties and the mechanical failure of the ligament, serving as a prognostic measurement for injury risk. 8 cadaveric specimens were acquired, and tissue stiffness for the anterolateral ligament and medial collateral ligament were evaluated with shear wave elastography. The anterolateral ligament and medial collateral ligament were dissected and isolated for unilateral mechanical failure testing. Ultimate failure testing was performed at 100 % strain per second after 50 cycles of 3 % strain viscoelastic conditioning. Each specimen was assessed for load, displacement, and surface strain throughout failure testing. Rate of force, rate of strain development, and Young's modulus were calculated from these variables. Shear wave elastography stiffness for the anterolateral ligament correlated with mean longitudinal anterolateral ligament strain at failure (R2 = 0.853; P<0.05). Medial collateral ligament shear wave elastography calculated modulus was significantly greater than the anterolateral ligament shear wave elastography calculated modulus. Shear wave elastography currently offers limited reliability in the prediction of mechanical performance of superficial knee ligaments. The utility of shear wave elastography assessment for injury risk potential remains undetermined.
Asunto(s)
Diagnóstico por Imagen de Elasticidad , Humanos , Diagnóstico por Imagen de Elasticidad/métodos , Anciano , Masculino , Femenino , Ligamento Colateral Medial de la Rodilla/diagnóstico por imagen , Ligamento Colateral Medial de la Rodilla/fisiopatología , Ligamento Colateral Medial de la Rodilla/lesiones , Persona de Mediana Edad , Articulación de la Rodilla/diagnóstico por imagen , Articulación de la Rodilla/fisiología , Estrés Mecánico , Ligamentos Colaterales/diagnóstico por imagen , Ligamentos Colaterales/fisiopatología , Ligamentos Colaterales/fisiología , Fenómenos Biomecánicos , Cadáver , Anciano de 80 o más AñosRESUMEN
BACKGROUND: Knee instability in midflexion may contribute to patient dissatisfaction following total knee arthroplasty (TKA). Midflexion instability involves abnormal motions and tissue loading in multiple planes. Therefore, we quantified and compared the tensions carried by the medial and lateral collateral ligaments (MCL and LCL) following posterior-stabilized (PS) TKA through knee flexion, and then compared these tensions with those carried by the native knee. Finally, we examined the relationships between collateral ligament tensions and anterior tibial translation (ATT). METHODS: Eight cadaveric knees (from 5 male and 3 female donors with a mean age of 62.6 years and standard deviation of 10.9 years) underwent PS TKA. Each specimen was mounted to a robotic manipulator and flexed to 90°. ATT was quantified by applying 30 N of anterior force to the tibia. Tensions carried by the collateral ligaments were determined via serial sectioning. Robotic testing was also conducted on a cohort of 15 healthy native cadaveric knees (from 9 male and 6 female donors with a mean age of 36 years and standard deviation of 11 years). Relationships between collateral ligament tensions during passive flexion and ATT were assessed via linear and nonlinear regressions. RESULTS: MCL tensions were greater following PS TKA than in the native knee at 15° and 30° of passive flexion, by a median of ≥27 N (p = 0.002), while the LCL tensions did not differ. Median tensions following PS TKA were greater in the MCL than in the LCL at 15°, 30°, and 90° of flexion, by ≥4 N (p ≤ 0.02). Median tensions in the MCL of the native knee were small (≤11 N) and did not exceed those in the LCL (p ≥ 0.25). A logarithmic relationship was identified between MCL tension and ATT following TKA. CONCLUSIONS: MCL tensions were greater following PS TKA with this typical nonconforming PS implant than in the native knee. Anterior laxity at 30° of flexion was highly sensitive to MCL tension during passive flexion following PS TKA but not in the native knee. CLINICAL RELEVANCE: Surgeons face competing objectives when performing PS TKA: they can either impart supraphysiological MCL tension to reduce anterior-posterior laxity or maintain native MCL tensions that lead to heightened anterior-posterior laxity, as shown in this study.
Asunto(s)
Artroplastia de Reemplazo de Rodilla , Cadáver , Inestabilidad de la Articulación , Articulación de la Rodilla , Rango del Movimiento Articular , Humanos , Femenino , Masculino , Persona de Mediana Edad , Artroplastia de Reemplazo de Rodilla/métodos , Inestabilidad de la Articulación/fisiopatología , Inestabilidad de la Articulación/etiología , Fenómenos Biomecánicos , Anciano , Rango del Movimiento Articular/fisiología , Articulación de la Rodilla/fisiopatología , Articulación de la Rodilla/cirugía , Ligamento Colateral Medial de la Rodilla/cirugía , Ligamento Colateral Medial de la Rodilla/fisiopatología , Adulto , Ligamentos Colaterales/cirugía , Ligamentos Colaterales/fisiologíaRESUMEN
BACKGROUND: The metacarpophalangeal (MCP) joint's collateral ligaments have been extensively debated, with no clear consensus on their mechanics. Understanding their function is crucial for comprehending joint movement and stability. METHODS: A thorough search was conducted across databases, including PubMed, Scopus, Cochrane library and grey literature. A total of 59 articles were identified, and after rigorous evaluation, six articles were included in the review. RESULTS: The analysis underscores two principal findings. Firstly, the principal and accessory collateral ligaments exhibit consistent tension influenced by the MCP joint's position. This tension varies across different sections of the ligaments. Secondly, the ligaments' interaction with the joint structure plays a pivotal role in defining the range of motion of the joint. CONCLUSION: Preliminary findings from this review indicate that MCP joint collateral ligament tension varies with joint position. Increased tension in the principal collateral ligament during flexion and isometric behavior of its volar portion in extension are observed. The accessory ligament may tighten during extension. The shape of the metacarpal head appears to influence this tension. These insights, while informative, call for further detailed research to deepen our understanding of MCP joint mechanics.
Asunto(s)
Ligamentos Colaterales , Articulación Metacarpofalángica , Rango del Movimiento Articular , Articulación Metacarpofalángica/fisiología , Articulación Metacarpofalángica/anatomía & histología , Humanos , Ligamentos Colaterales/anatomía & histología , Ligamentos Colaterales/fisiología , Rango del Movimiento Articular/fisiología , Fenómenos BiomecánicosRESUMEN
The superficial medial collateral ligament (sMCL) of the human knee joint has functionally separate anterior and posterior fiber bundles. The two bundles are alternatively loaded as the knee flexion angle changes during walking. To date, the two bundles are usually not distinguished in knee ligament simulations because there has been little information about their material properties. In this study, we conducted quasi-static tensile tests on the sMCL of matured porcine stifle joints and obtained the material properties of the anterior bundle (AB), posterior bundle (PB), and whole ligament (WL). AB and PB have similar failure stress but different threshold strain, modulus, and failure strain. As a result, we recommend assigning different material properties (i.e., modulus and failure strain) to the two fiber bundles to realize biofidelic ligament responses in human body models. However, it is often inconvenient to perform tensile tests on AB and PB. Hence, we proposed a microstructural model-based approach to predict the material properties of AB and PB from the test results of WL. Such obtained modulus values of AB and PB had an error of 2% and 0.3%, respectively, compared with those measured from the tests. This approach can reduce the experimental cost for acquiring the needed mechanical property data for simulations.
Asunto(s)
Ligamentos Colaterales , Ligamento Colateral Medial de la Rodilla , Humanos , Animales , Porcinos , Articulación de la Rodilla/fisiología , Caminata , Ligamentos Colaterales/fisiología , Ligamento Colateral Medial de la Rodilla/fisiología , Fenómenos Biomecánicos , Cadáver , Rango del Movimiento Articular/fisiologíaRESUMEN
The response of soft tissue to loading can be obtained by strain assessment. Typically, strain can be measured using electrical resistance with strain gauges (SG), or optical sensors based on the digital image correlation (DIC), among others. These sensor systems are already established in other areas of technology. However, sensors have a limited range of applications in medical technology due to various challenges in handling human soft materials. The aim of this study was to compare directly attached foil-type SG and 3D-DIC to determine the strain of axially loaded human ligament structures. Therefore, the medial (MCL) and lateral (LCL) collateral ligaments of 18 human knee joints underwent cyclic displacement-controlled loading at a rate of 20 mm/min in two test trials. In the first trial, strain was recorded with the 3D-DIC system and the reference strain of the testing machine. In the second trial, strain was additionally measured with a directly attached SG. The results of the strain measurement with the 3D-DIC system did not differ significantly from the reference strain in the first trial. The strains assessed in the second trial between reference and SG, as well as between reference and 3D-DIC showed significant differences. This suggests that using an optical system based on the DIC with a given unrestricted view is an effective method to measure the superficial strain of human ligaments. In contrast, directly attached SGs provide only qualitative comparable results. Therefore, their scope on human ligaments is limited to the evaluation of changes under different conditions.
Asunto(s)
Ligamentos Colaterales , Humanos , Fenómenos Biomecánicos , Ligamentos Colaterales/fisiología , Articulación de la Rodilla/fisiología , Imagenología Tridimensional , Estrés MecánicoRESUMEN
Skeletal muscle works as a dynamic joint stabilizer, assisting the underlying ligaments in restricting joint angulation by actively resisting external loads. Despite its clinical importance, little is known about the muscle strength required to produce torque to help ligaments restrict joint angulation within the physiological range permitted by the joint structure. In this study, we introduce a method for measuring the strength of the elbow musculature in restraining valgus angulation and present the values obtained in 20 healthy young men. Each participant was fastened to a Biodex dynamometer, with the elbow joint flexed to 90° and the varus-valgus axis aligned to the dynamometer's rotation axis. Maximal voluntary isometric ramp contraction of shoulder internal rotators was performed while the humeroulnar joint gap was monitored with an ultrasound apparatus. The largest torque recorded while the humeroulnar joint gap did not exceed a predetermined individualized threshold was considered to be the elbow varus strength of the participant. The elbow varus strength of the dynamic stabilizer was found to be 41 ± 12 Nm, which agreed with the value estimated by our musculoskeletal model. The inter-operator reliability test indicated excellent reliability (ICC (2,1) = 0.91). These findings suggest that the present method is valid for measuring the strength of the elbow musculature in restraining the valgus angulation. Measurements of this aspect of strength are expected to provide insights for understanding and preventing elbow injuries.
Asunto(s)
Ligamentos Colaterales , Articulación del Codo , Inestabilidad de la Articulación , Masculino , Humanos , Codo , Articulación del Codo/fisiología , Reproducibilidad de los Resultados , Cadáver , Ligamentos Colaterales/fisiología , Fuerza Muscular , Fenómenos BiomecánicosRESUMEN
OBJECTIVE: The injury of the annular ligament can change the stress distribution and affect the stability of the elbow joint, but its biomechanical mechanism is unclear. The present study investigated the biomechanical effects of different flexion angles of the annular ligament on elbow joint stability. METHODS: A cartilage and ligament model was constructed using SolidWorks software according to the magnetic resonance imaging results to simulate the annular ligament during normal, loosened, and ruptured conditions at different buckling angles (0°, 30°, 60°, 90°, and 120°). The fixed muscle strengths were 40 N (F1), 20 N (F2), 20 N (F3), 20 N (F4), and 20 N (F5) for the triceps, biceps, and brachial tendons and the base of the medial collateral ligament and lateral collateral ligament. The different elbow three-dimensional (3D) finite element models were imported into ABAQUS software to calculate and analyze the load, contact area, contact stress, and stress of the medial collateral ligament of the olecranon cartilage. RESULTS: The results showed that the stress value of olecranon cartilage increased under different conditions (normal, loosened, and ruptured annular ligament) with elbow extension, and the maximum stress value of olecranon cartilage was 2.91 ± 0.24 MPa when the annular ligament was ruptured. The maximum contact area of olecranon cartilage was 254 mm2 with normal annular ligament when the elbow joint was flexed to 30°, while the maximum contact area of loosened and ruptured annular ligament was 283 and 312 mm2 at 60° of elbow flexion, and then decreased gradually. The maximum stress of the medial collateral ligament was 6.52 ± 0.23, 11.51 ± 0.78, and 18.74 ± 0.94 MPa under the different conditions, respectively. CONCLUSION: When the annular ligament ruptures, it should be reconstructed as much as possible to avoid the elevation of stress on the surface of the medial collateral ligament of the elbow and the annular cartilage, which may cause clinical symptoms.
Asunto(s)
Ligamentos Colaterales , Articulación del Codo , Humanos , Ligamentos Colaterales/lesiones , Ligamentos Colaterales/fisiología , Articulación del Codo/fisiología , Análisis de Elementos Finitos , Rango del Movimiento Articular/fisiología , Rotura/fisiopatologíaRESUMEN
BACKGROUND: Improved knowledge of in vivo function of the collateral ligaments is essential for enhancing rehabilitation and guiding surgical reconstruction as well as soft-tissue balancing in total knee arthroplasty. The aim of this study was to quantify in vivo elongation patterns of the collateral ligaments throughout complete cycles of functional activities. METHODS: Knee kinematics were measured using radiographic images captured with a mobile fluoroscope while healthy subjects performed level walking, downhill walking, and stair descent. The registered in vivo tibiofemoral kinematics were then used to drive subject-specific multibody knee models to track collateral ligament elongation. RESULTS: The elongation patterns of the medial collateral ligament varied distinctly among its bundles, ranging from lengthening of the anterior fibers to shortening of the posterior bundle with increases in the knee flexion angle. The elongation patterns of the lateral collateral ligament varied considerably among subjects. It showed an average 4% shortening with increasing flexion until 60% to 70% of the gait cycle, and then recovered during the terminal-swing phase until reaching its reference length (defined at heel strike). CONCLUSIONS: The observed nonuniform elongation of the medial collateral ligament bundles suggests that single-bundle reconstruction techniques may not fully restore healthy ligament function. Moreover, the observed ligament elongation patterns indicate greater varus than valgus laxity in the loaded knee. CLINICAL RELEVANCE: Through providing key knowledge about the in vivo elongation patterns of the collateral ligaments throughout complete cycles of functional activities, this study offers in vivo evidence for benchmarking ligament reconstruction and soft-tissue balancing in total knee arthroplasty.
Asunto(s)
Artroplastia de Reemplazo de Rodilla/rehabilitación , Ligamentos Colaterales/fisiología , Articulación de la Rodilla/fisiología , Benchmarking , Fenómenos Biomecánicos , Femenino , Humanos , Masculino , Adulto JovenRESUMEN
BACKGROUND: It remains unclear how the head and stem diameters for the radial head prosthesis could affect mechanical properties of the lateral collateral ligament measured by strain changes during elbow and forearm motions. METHODS: Eight cadaveric specimens were secured to the device, which allows elbow flexion-extension and forearm pro-supination. Using six different implant combinations comprising 2 sizes for the head (long- and short-axis of the native head) and 3 sizes for the stem (press-fit, -1 mm, and -2 mm downsizing), prostheses were attached via the posterior approach. A differential variable reluctance transducer placed on the central portion of the radial collateral ligament were used for strain measurement with elbow flexion at 0°, 30°, 60°, and 90°. At each position, the strain patterns with the forearm in the neutral and 45° pro-supination positions were also assessed. FINDINGS: Specimens implanted with long-axis head component showed greater increases in the ligament strain during elbow flexion than intact specimens or those implanted with short-axis head. Compared to press-fit stem, implants with downsizing to -1 mm approximated strain patterns during pro-supination with elbow extension to intact condition. INTERPRETATION: Morphologic variation of the head and stem components in radial head prostheses led to altered strain patterns in the lateral collateral ligament during elbow and forearm motions. A short-axis head component can be used to prevent excessive strain changes after the prosthesis application. Downsizing of the stem component might be an option for approximating the biomechanics at the radiocapitellar joint during forearm rotation to the intact elbow.
Asunto(s)
Ligamentos Colaterales , Prótesis de Codo , Anciano , Fenómenos Biomecánicos , Cadáver , Ligamentos Colaterales/fisiología , Humanos , Masculino , Presión , Rango del Movimiento Articular , Rotación , SupinaciónRESUMEN
The proximal interphalangeal joint (PIPJ) is a complex anatomical structure. In managing fracture dislocations about the PIPJ, the aim is to restore a congruent joint that allows for smooth gliding motion. Detailed knowledge of the anatomy and biomechanics of the PIPJ is necessary in managing these injuries with predictable success. The breadth of techniques previously described in the treatment of such injuries is testament to the difficulties faced in achieving optimal clinical and radiological outcomes. In this article we detail the anatomy and biomechanics of the PIPJ and summarize current literature and principles for the treatment of dorsal fracture dislocations.
Asunto(s)
Traumatismos de los Dedos/cirugía , Articulaciones de los Dedos/anatomía & histología , Articulaciones de los Dedos/fisiología , Fractura-Luxación/cirugía , Fenómenos Biomecánicos/fisiología , Ligamentos Colaterales/anatomía & histología , Ligamentos Colaterales/fisiología , Fijadores Externos , Traumatismos de los Dedos/fisiopatología , Fractura-Luxación/fisiopatología , Fijación de Fractura , Humanos , Placa Palmar/anatomía & histología , Placa Palmar/fisiologíaRESUMEN
PURPOSE: This study investigated the length changes of the anterior bundle of the medial collateral ligament (AMCL) and the lateral ulnar collateral ligament (LUCL) in forearm pronation and supination under axial load in vivo. METHODS: Six healthy volunteers (2 males and 4 females, the average age of 44.6 years) were included in the study. CT scan of elbow joints was obtained at positions of forearm pronation and supination before and after load with the elbow extension. Mimics, Geomagic Studio, 3-matic Medical and Geometry Sketchpad were used to reconstruct three-dimensional models and analyze length changes of AMCL and LUCL. The AMCL and LUCL were divided, respectively, to three parts: the medial part, the middle part and the lateral part. RESULTS: Our results showed the length of the medial and middle parts of the AMCL significantly decreased from pronation to supination without load (0.46 mm, P < 0.05 and 0.43 mm, P < 0.05). With load, the length of the medial part and the middle of the AMCL significantly decreased from pronation to supination (0.62 mm, P < 0.05 and 0.44 mm P < 0.05). However, the length of the LUCL almost remained static for the forearm pronation and supination regardless of the axial load. CONCLUSION: The results showed that tension of the AMCL increases in forearm pronation, and increased tension on the ligament during impact may pave the way to injury. The AMCL of elbow may be easier to be injured in forearm pronation.
Asunto(s)
Ligamentos Colaterales/anatomía & histología , Articulación del Codo/anatomía & histología , Antebrazo/fisiología , Rango del Movimiento Articular/fisiología , Adulto , Fenómenos Biomecánicos , Ligamentos Colaterales/diagnóstico por imagen , Ligamentos Colaterales/fisiología , Articulación del Codo/diagnóstico por imagen , Articulación del Codo/fisiología , Femenino , Antebrazo/anatomía & histología , Voluntarios Sanos , Humanos , Imagenología Tridimensional , Masculino , Pronación/fisiología , Supinación/fisiología , Tomografía Computarizada por Rayos X , Lesiones de CodoRESUMEN
This study aimed to quantify the elongation patterns of the collateral ligaments following TKA during functional activities of daily living. Using mobile video-fluoroscopy to capture radiographic images of the knee in a group of six patients, each with an ultra-congruent knee implant, tibiofemoral kinematics were reconstructed throughout complete cycles of level gait, downhill walking, stair descent, and squat activities. Kinematic data were then used to drive subject-specific multibody knee models to estimate length-change patterns of the LCL as well as three bundles of the MCL. In addition, a sensitivity analysis examined the role of the attachment site in the elongation patterns. Our data indicate a slackening of the LCL but non-uniform length-change patterns across the MCL bundles (ranging from lengthening of the anterior fibers to shortening of the posterior fibers) with increasing knee flexion angle. Near-isometric behavior of the intermediate fibers was observed throughout the entire cycle of the studied activities. These length-change patterns were found to be largely consistent across different activities. Importantly, length-change patterns were critically sensitive to the location of the femoral attachment points relative to the femoral component. Thus, in TKA with ultra-congruent implants, implantation of the femoral component may critically govern post-operative ligament function.
Asunto(s)
Actividades Cotidianas , Artroplastia de Reemplazo de Rodilla , Ligamentos Colaterales/fisiología , Anciano , Fenómenos Biomecánicos , Fémur/fisiología , Humanos , Rodilla/diagnóstico por imagen , Rodilla/fisiología , Prótesis de la Rodilla , Persona de Mediana Edad , Movimiento/fisiología , Tibia/fisiologíaRESUMEN
OBJECTIVE: To evaluate the elastic modulus of various ligaments of the forelimbs of cadaveric horses. SAMPLE: 408 ligaments from 37 forelimbs of 10 Thoroughbred cadavers and cadavers of 9 other horse breeds. PROCEDURES: Collateral ligaments and straight and oblique sesamoid ligaments were harvested from the proximal interphalangeal, metacarpophalangeal, carpal, and elbow joints of both forelimbs of all 19 horses. Ligament dimensions were measured, and the elastic modulus was determined by tensile testing the ligaments with a strain rate of 1 mmâ¢s-1. RESULTS: Elastic modulus of the ligaments differed significantly among joints. Highest mean ± SE elastic modulus was for the medial collateral ligament of the metacarpophalangeal joints of Thoroughbreds (68.3 ± 11.0 MPa), and the lowest was for the lateral collateral ligament of the elbow joints of other breeds (2.8 ± 0.3 MPa). Thoroughbreds had a significantly higher elastic modulus for the collateral ligaments of the proximal interphalangeal and metacarpophalangeal joints, compared with values for the other breeds. There was large variation in elastic modulus. Elastic modulus was negatively affected by age. In the ligaments in the distal aspect of the forelimbs, elastic modulus was negatively affected by height at the highest point of the shoulders (ie, withers). CONCLUSIONS AND CLINICAL RELEVANCE: Cross-sectional area and elastic modulus of collateral ligaments in the forelimbs of equine cadavers differed between breeds and among joints, which may have been reflective of their relative physiologic function under loading during exercise.
Asunto(s)
Ligamentos Colaterales/fisiología , Caballos/fisiología , Ligamentos Articulares/fisiología , Animales , Cadáver , Huesos del Carpo , Elasticidad , Femenino , Miembro Anterior/fisiología , Masculino , Articulación Metacarpofalángica , Huesos SesamoideosRESUMEN
BACKGROUND: Athletes have traditionally been subdivided into risk classifications for ACL injury relative to the biomechanical traits they display during landing. This investigation aimed to discern whether these separate risk classifications elicit strain differences on the ACL and MCL during landing. It was hypothesized that the higher risk simulation profiles would exhibit greater ACL strain and that the ACL would exhibit greater strain than the MCL under all conditions. METHOD: The mechanical impact simulator was used to simulate landing on a cohort of 46 cadaveric specimens. The simulator applied external joint loads to the knee prior to impulse delivery. These loads were organized into a series of profiles derived from in vivo motion capture previously performed on a cohort of 44 athletes and represented various risk classifications. Strain gauges were implanted on the ACL and MCL and simulations performed until a structural failure was elicited. Differences were assessed with Kruskal-Wallis tests. FINDINGS: The highest-risk profiles tended to exhibit greater peak ACL strain and change in ACL strain than the baseline- and moderate-risk profiles. Specimens that failed during lower-risk simulations expressed greater strain at these loads than specimens that completed higher-risk simulations. The ACL recorded greater strain than the MCL throughout all simulation profiles. INTERPRETATION: This behavior justifies why neuromuscular interventions have greater impact on higher-risk athletes and supports the continued screening and targeted training of those athletes that express greater injury risk. The loading disparity between ACL and MCL justifies their limited concomitant injury rate.
Asunto(s)
Lesiones del Ligamento Cruzado Anterior/fisiopatología , Ligamento Cruzado Anterior/fisiología , Ligamentos Colaterales/fisiología , Traumatismos de la Rodilla/fisiopatología , Adulto , Traumatismos en Atletas/fisiopatología , Fenómenos Biomecánicos , Cadáver , Femenino , Humanos , Articulación de la Rodilla/fisiología , Masculino , Adulto JovenRESUMEN
Three-dimensional finite element model of elbow was established to study the effect of medial collateral ligament (MCL) in maintaining the stability of elbow joint. In the present study a three-dimensional geometric model of elbow joint was established by reverse engineering method based on the computed tomography (CT) image of healthy human elbow. In the finite element pre-processing software, the ligament and articular cartilage were constructed according to the anatomical structure, and the materials and contacts properties were given to the model. In the neutral forearm rotation position and 0° flexion angle, by comparing the simulation data of the elbow joint with the experimental data, the validity of the model is verified. The stress value and stress distribution of medial collateral ligaments were calculated at the flexion angles of elbow position in 15°, 30°, 45°, 60°, 75°, 90°, 105°, 120°, 135°, respectively. The result shows that when the elbow joint loaded at different flexion angles, the anterior bundle has the largest stress, followed by the posterior bundle, transverse bundle has the least, and the stress value of transverse bundle is trending to 0. Therefore, the anterior bundle plays leading role in maintaining the stability of the elbow, the posterior bundle plays supplementary role, and the transverse bundle does little. Furthermore, the present study will provide theoretical basis for clinical recognizing and therapy of elbow instability caused by medial collateral ligament injury.
Asunto(s)
Ligamentos Colaterales/fisiología , Articulación del Codo/fisiología , Análisis de Elementos Finitos , Rango del Movimiento Articular , Fenómenos Biomecánicos , Cadáver , Humanos , Tomografía Computarizada por Rayos XRESUMEN
The anterior bundle of the medial collateral ligament (AMCL) resists the loads that arise at the elbow during overhand throwing and has commonly been divided into posterior and anterior bands. While these anterior and posterior bands have been thought to bear the load at different flexion angles, any transition of the load distribution between the two bands is poorly understood and has not considered laxity (slack). This study considers the AMCL as three bands and quantifies the mechanical response to vertical distraction, simulating valgus-load joint opening, through the sequential superposition of the band responses after the elimination of inherent laxity. Eight cadaveric elbow specimens were used for the study. The intact AMCL of each specimen was tested under vertical distraction in a specialized load frame at four elbow flexion angles and then subsequently retested after two longitudinal transections. The greatest laxity at full extension and full flexion belonged to the posterior (1.9 mm) and anterior (2.4 mm) band, respectively. At the lesser and higher flexion angles, the greatest structural stiffness belonged to the anterior and middle band. The overall AMCL was the most structurally stiff at 60°, with approximately 150 N of force required for 2% elongation. This study shows that the different bands of the AMCL may have different load bearing properties at different flexion angles, causing each band to support different proportions of an imposed load. The presence of the laxity may impose a load-bearing delay, causing load-bearing in each band to begin asynchronously. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:2027-2034, 2019.
Asunto(s)
Ligamentos Colaterales/fisiología , Articulación del Codo/fisiología , Adulto , Fenómenos Biomecánicos , Humanos , Masculino , Persona de Mediana Edad , Soporte de PesoRESUMEN
There are limited radiographic-guided injection techniques of the insertion of the distal interphalangeal joint (DIPJ) collateral ligaments. The objective of this study was to develop and evaluate a palmar/plantar radiographic-guided injection of the collateral ligament insertion in cadavers. Fifty limbs were used to develop the technique and 24 additional limbs were used to evaluate accuracy. An 18 G, 9 cm spinal needle was placed in the depression between the palmar digital neurovascular bundle and arch of the ungular cartilage with dorsodistal advancement towards the distal phalanx collateral fossa. Radiographs verified ideal needle location on the proximal border of the distal phalanx at the collateral fossa. Dye was injected. Hoof walls were partially removed and collateral ligaments were dissected with needles in place to determine needle and dye location. Accuracy of needle placement into the insertion of the DIPJ collateral ligament was 41/48 (85 per cent), with lower accuracy of dye within the ligament (34/48; 71 per cent). Dye entered the DIPJ in 2/48 injections, but dye entered periligamentous structures in 22/48 (46 per cent) injections. A palmar/plantar radiographic-guided injection of the insertion of the DIPJ collateral ligament had high accuracy rate with low injection rate of the DIPJ in cadavers.
Asunto(s)
Ligamentos Colaterales/fisiología , Miembro Anterior/fisiología , Caballos , Inyecciones Intraarticulares/veterinaria , Radiografía/veterinaria , Articulación del Dedo del Pie/fisiopatología , Animales , Cadáver , Inyecciones Intraarticulares/métodosRESUMEN
BACKGROUND: The conservation of the joint anatomy is an important factor in total knee arthroplasty (TKA). The restoration of the femoral posterior condylar offset (PCO) has been well known to influence the clinical outcome after TKA. OBJECTIVE: The purpose of this study was to determine the mechanism of PCO in finite element models with conservation of subject anatomy and different PCO of ±1, ±2, ±3 mm in posterior direction using posterior cruciate ligament-retaining TKA. METHODS: Using a computational simulation, we investigated the influence of the changes in PCO on the contact stress in the polyethylene (PE) insert and patellar button, on the forces on the collateral and posterior cruciate ligament, and on the quadriceps muscle and patellar tendon forces. The computational simulation loading condition was deep knee bend. RESULTS: The contact stresses on the PE insert increased, whereas those on the patellar button decreased as posterior condylar offset translated to the posterior direction. The forces exerted on the posterior cruciate ligament and collateral ligaments increased as PCO translated to the posterior direction. The translation of PCO in the anterior direction, in an equivalent flexion angle, required a greater quadriceps muscle force. CONCLUSIONS: Translations of the PCO in the posterior and anterior directions resulted in negative effects in the PE insert and ligament, and the quadriceps muscle force, respectively. Our findings suggest that orthopaedic surgeons should be careful with regard to the intraoperative conservation of PCO, because an excessive change in PCO may lead to quadriceps weakness and an increase in posterior cruciate ligament tension.
Asunto(s)
Artroplastia de Reemplazo de Rodilla , Ligamentos Colaterales/anatomía & histología , Análisis de Elementos Finitos , Articulación de la Rodilla/anatomía & histología , Modelos Anatómicos , Fenómenos Biomecánicos , Ligamentos Colaterales/fisiología , Simulación por Computador , Humanos , Articulación de la Rodilla/fisiología , Prótesis de la Rodilla , Modelos Biológicos , Rango del Movimiento ArticularRESUMEN
BACKGROUND: The modified Jobe technique of ulnar collateral ligament (UCL) reconstruction has previously been biomechanically compared with primary repair augmented with internal bracing. However, the docking technique has not been compared with repair with internal bracing. HYPOTHESIS: Load to failure, gapping, and valgus opening angle are similar under valgus loading at 90° of flexion between repair with internal bracing and the docking technique for the UCL. STUDY DESIGN: Controlled laboratory study. METHODS: Nine matched pairs of fresh-frozen cadaveric elbows were potted with the forearm in neutral rotation. The palmaris longus tendon graft was harvested, and the bone was sectioned 14 cm proximal and distal to the elbow joint. First, native UCL testing was performed at 90° of flexion with 0.5 N·m preload, followed by a 5 N·m valgus moment to the elbow in cycles of 1, 10, 100, and 1000 at 1 Hz. The specimens were then loaded to failure at a rate of 0.2 mm/s. Next, the elbows were randomly divided into matched pairs to undergo either UCL reconstruction with docking technique or UCL repair augmented with internal bracing. Last, these specimens underwent testing as aforementioned. RESULTS: Load to failure, gapping, and valgus opening angle did not differ significantly between native ligaments that underwent reconstruction or repair with internal bracing, paired native ligaments and reconstructions, paired native ligaments and repairs augmented with internal bracing, or reconstructions and repairs augmented with internal bracing. CONCLUSION: UCL reconstruction with docking technique and repair augmented with internal bracing provides valgus stability to the medial elbow comparable to the native ligament at 90°. No significant differences were noted between docking reconstruction and repair techniques for load to failure, gapping, or valgus opening angle during cyclic loading at time zero. CLINICAL RELEVANCE: Our results suggest that UCL repair with internal bracing has a similar biomechanical profile at the time of initial fixation compared with the docking technique of UCL reconstruction.