Giving way event during a combined stepping and crossover cutting task in an individual with anterior cruciate ligament deficiency

Tibiofemoral Kinematics During Compressive Loading of the ACL-Intact and ACL-Sectioned Knee: Roles of Tibial Slope, Medial Eminence Volume, and Anterior Laxity

BACKGROUND

Tibial geometry and knee laxity have been identified as risk factors for both noncontact anterior cruciate ligament (ACL) rupture and instability in the setting of ACL insufficiency via clinical studies; yet, their biomechanical relationships with tibiofemoral kinematics during compressive loading are less well understood. The purpose of this study was to identify the relative contributions of sagittal tibial slope, medial tibial eminence volume, and anterior knee laxity to tibiofemoral kinematics with axial compression in both ACL-intact and ACL-sectioned cadaveric knees.

METHODS

Computed tomography (CT) data were collected from 13 human cadaveric knees (mean donor age, 45 ± 11 years; 8 male). Validated algorithms were used to calculate the sagittal slope of the medial and of the lateral tibial plateau as well as volume of the medial tibial eminence. Specimens were then mounted to a robotic manipulator. For both intact and ACL-sectioned conditions, the robot compressed the knee from 10 to 300 N at 15° of flexion; the net anterior tibial translation of the medial and lateral compartments and internal tibial rotation were recorded. Simple and multiple linear regressions were performed to identify correlations between kinematic outcomes and (1) osseous geometric parameters and (2) anterior laxity during a simulated Lachman test.

RESULTS

In ACL-intact knees, anterior tibial translation of each compartment was positively correlated with the corresponding sagittal slope, and internal tibial rotation was positively correlated with the lateral sagittal slope and the sagittal slope differential (p ≤ 0.044). In ACL-sectioned knees, anterior tibial translation of the medial compartment was positively associated with medial sagittal slope as well as a combination of medial tibial eminence volume and anterior laxity; internal tibial rotation was inversely correlated with anterior knee laxity (p < 0.05).

CONCLUSIONS

Under compressive loading, sagittal slope of the medial and of the lateral tibial plateau was predictive of kinematics with the ACL intact, while medial tibial eminence volume and anterior laxity were predictive of kinematics with the ACL sectioned.

CLINICAL RELEVANCE

The relationships between tibial osseous morphology, anterior laxity, and knee kinematics under compression may help explain heightened risk of ACL injury and might predict knee instability after ACL rupture.

Differences in EMG-moment relationships between ACL-injured and uninjured adults during a weight-bearing multidirectional force control task

Anterior cruciate ligament injury (ACLi) reduces mechanical knee joint stability. Differences in muscle activation patterns are commonly identified between ACLi individuals and uninjured controls (CON); however, how and which of these differences are adaptations to protect the knee or adversely increase risk of joint instability remain unclear. Since the neuromuscular system integrates activity of all muscles crossing the knee to create a moment-of-force that opposes an external load, this study sought to quantify differences in individual muscle electromyography (EMG)-moment relationships between ACLi and CON. Participants isometrically modulated ground reaction forces during a standing force matching protocol to elicit combinations of sagittal, frontal and transverse plane moments. Partial least squares regressions determined which internal joint moment(s) predicted activation of 10 leg muscles for each group. Compared to CON, ACLi demonstrated greater contribution of rectus femoris to knee extension, semitendinosus and gastrocnemii to knee flexion, and lateral gastrocnemii to knee external rotation moments. ACLi also showed lower contributions of biceps femoris to knee flexion, medial gastrocnemius to internal rotation, and varied hip muscle contributions to frontal plane hip moments. Between group differences in EMG-moment relationships during static conditions suggest neuromuscular contributions to sagittal plane stability increases after ACL injury, while knee stability during knee abduction and external rotation is reduced. Clinical Significance: Clinical assessments of ACLi should account for deficits in frontal and rotational plane stability by including tasks that elicit such loads. Improving hamstring muscle balance, hip abductor and gastrocnemius function may benefit ACLi rehabilitation interventions and should be studied further. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Influence of the Anterolateral Ligament on Knee Laxity: A Biomechanical Cadaveric Study Measuring Knee Kinematics in 6 Degrees of Freedom Using Dynamic Radiostereometric Analysis

Background:

An anterior cruciate ligament (ACL) rupture often occurs during rotational trauma to the knee and may be associated with damage to extracapsular knee rotation–stabilizing structures such as the anterolateral ligament (ALL).

Purpose:

To investigate ex vivo knee laxity in 6 degrees of freedom with and without ALL reconstruction as a supplement to ACL reconstruction.

Study Design:

Controlled laboratory study.

Methods:

Cadaveric knees (N = 8) were analyzed using dynamic radiostereometry during a controlled pivotlike dynamic movement simulated by motorized knee flexion (0° to 60°) with 4-N·m internal rotation torque. We tested the cadaveric specimens in 5 successive ligament situations: intact, ACL lesion, ACL + ALL lesion, ACL reconstruction, and ACL + ALL reconstruction. Anatomic single-bundle reconstruction methods were used for both the ACL and the ALL, with a bone-tendon quadriceps autograft and gracilis tendon autograft, respectively. Three-dimensional kinematics and articular surface interactions were used to determine knee laxity.

Results:

For the entire knee flexion motion, an ACL + ALL lesion increased the mean knee laxity (P < .005) for internal rotation (2.54°), anterior translation (1.68 mm), and varus rotation (0.53°). Augmented ALL reconstruction reduced knee laxity for anterior translation (P = .003) and varus rotation (P = .047) compared with ACL + ALL–deficient knees. Knees with ACL + ALL lesions had more internal rotation (P < .001) and anterior translation (P < .045) at knee flexion angles below 40° and 30°, respectively, compared with healthy knees. Combined ACL + ALL reconstruction did not completely restore native kinematics/laxity at flexion angles below 10° for anterior translation and below 20° for internal rotation (P < .035). ACL + ALL reconstruction was not found to overconstrain the knee joint.

Conclusion:

Augmented ALL reconstruction with ACL reconstruction in a cadaveric setting reduces internal rotation, varus rotation, and anterior translation knee laxity similar to knee kinematics with intact ligaments, except at knee flexion angles between 0° and 20°.

Clinical Relevance:

Patients with ACL injuries can potentially achieve better results with augmented ALL reconstruction along with ACL reconstruction than with stand-alone ACL reconstruction. Furthermore, dynamic radiostereometry provides the opportunity to examine clinical patients and compare the recontructed knee with the contralateral knee in 6 degrees of freedom.

Anterior laxity, lateral tibial slope, and in situ ACL force differentiate knees exhibiting distinct patterns of motion during a pivoting event: A human cadaveric study

Knee instability following anterior cruciate ligament (ACL) rupture compromises function and increases risk of injury to the cartilage and menisci. To understand the biomechanical function of the ACL, previous studies have primarily reported the net change in tibial position in response to multiplanar torques, which generate knee instability. In contrast, we retrospectively analyzed a cohort of 13 consecutively tested cadaveric knees and found distinct motion patterns, defined as the motion of the tibia as it translates and rotates from its unloaded, initial position to its loaded, final position. Specifically, ACL-sectioned knees either subluxated anteriorly under valgus torque (VL-subluxating) (5 knees) or under a combination of valgus and internal rotational torques (VL/IR-subluxating) (8 knees), which were applied at 15 and 30° flexion using a robotic manipulator. The purpose of this study was to identify differences between these knees that could be driving the two distinct motion patterns. Therefore, we asked whether parameters of bony geometry and tibiofemoral laxity (known risk factors of non-contact ACL injury) as well as in situ ACL force, when it was intact, differentiate knees in these two groups. VL-subluxating knees exhibited greater sagittal slope of the lateral tibia by 3.6 ± 2.4° (p = 0.003); less change in anterior laxity after ACL-sectioning during a simulated Lachman test by 3.2 ± 3.2 mm (p = 0.006); and, at the peak applied valgus torque (no internal rotation torque), higher posteriorly directed, in situ ACL force by 13.4 ± 11.3 N and 12.0 ± 11.6 N at 15° and 30° of flexion, respectively (both p ≤ 0.03). These results may suggest that subgroups of knees depend more on their ACL to control lateral tibial subluxation in response to uniplanar valgus and multiplanar valgus and internal rotation torques as mediated by anterior laxity and bony morphology.

ACL Deficiency Increases Forces on the Medial Femoral Condyle and the Lateral Meniscus with Applied Rotatory Loads

BACKGROUND

The articular surfaces and menisci act with the anterior cruciate ligament (ACL) to stabilize the knee joint. Their role in resisting applied rotatory loads characteristic of instability events is unclear despite commonly observed damage to these intra-articular structures in the acute and chronic ACL injury settings.

METHODS

Ten fresh-frozen human cadaveric knees were mounted to a robotic manipulator. Combined valgus and internal rotation torques were applied in the presence and absence of a 300-N compressive load. Forces carried by the individual menisci and via cartilage-to-cartilage contact on each femoral condyle in ACL-intact and ACL-sectioned states were measured using the principle of superposition.

RESULTS

In response to applied valgus and internal rotation torques in the absence of compression, sectioning of the ACL increased the net force carried by the lateral meniscus by at most 65.8 N (p < 0.001). Moreover, the anterior shear force carried by the lateral meniscus increased by 25.7 N (p < 0.001) and 36.5 N (p = 0.042) in the absence and presence of compression, respectively. In response to applied valgus and internal rotation torques, sectioning of the ACL increased the net force carried by cartilage-to-cartilage contact on the medial femoral condyle by at most 38.9 N (p = 0.006) and 46.7 N (p = 0.040) in the absence and presence of compression, respectively. Additionally, the lateral shear force carried by cartilage-to-cartilage contact on the medial femoral condyle increased by at most 21.0 N (p = 0.005) and by 28.0 N (p = 0.025) in the absence and presence of compression, respectively. Forces carried by the medial meniscus and by cartilage-to-cartilage contact on the lateral femoral condyle changed by <5 N as a result of ACL sectioning.

CONCLUSIONS

ACL sectioning increased the net forces carried by the lateral meniscus and medial femoral condyle-and the anterior shear and lateral shear forces, respectively-in response to multiplanar valgus and internal rotation torque.

CLINICAL RELEVANCE

These loading patterns provide a biomechanical rationale for clinical patterns of intra-articular derangement such as lateral meniscal injury and osseous remodeling of the medial compartment seen with ACL insufficiency.

Biomechanical and neuromuscular adaptations during the landing phase of a stepping-down task in patients with early or established knee osteoarthritis

BACKGROUND

To compare the knee joint kinematics, kinetics and EMG activity patterns during a stepping-down task in patients with knee osteoarthritis (OA) with control subjects.

METHODS

33 women with knee OA (early OA, n=14; established OA n=19) and 14 female control subjects performed a stepping-down task from a 20cm step. Knee joint kinematics, kinetics and EMG activity were recorded on the stepping-down leg during the loading phase.

RESULTS

During the stepping-down task patients with established knee OA showed greater normalized medial hamstrings activity (p=0.034) and greater vastus lateralis-medial hamstrings co-contraction (p=0.012) than controls. Greater vastus medialis-medial hamstrings co-contraction was found in patients with established OA compared to control subjects (p=0.040) and to patients with early OA (p=0.023). Self-reported knee instability was reported in 7% and 32% of the patients with early and established OA, respectively.

CONCLUSIONS

The greater EMG co-activity found in established OA might suggest a less efficient use of knee muscles or an attempt to compensate for greater knee laxity usually present in patients with established OA. In the early stage of the disease, the biomechanical and neuromuscular control of stepping-down is not altered compared to healthy controls.

Biomechanical techniques to evaluate tibial rotation. A systematic review

PURPOSE

This article systematically reviewed the biomechanical techniques to quantify tibial rotation, for an overview of how to choose a suitable technique for specific clinical application.

METHODS

A systematic search was conducted and finally 110 articles were included in this study. The articles were categorized by the conditions of how the knee was examined: external load application, physical examination and dynamic task.

RESULTS

The results showed that two-thirds of the included studies measured tibial rotation under external load application, of which over 80% of the experiments employed a cadaveric model. The common techniques used included direct displacement measurement, motion sensor, optical tracking system and universal force moment sensor. Intra-operative navigation system was used to document tibial rotation when the knee was examined by clinical tests. For dynamic assessment of knee rotational stability, motion analysis with skin reflective markers was frequently used although this technique is less accurate due to the skin movement when compared with radiographic measurement.

CONCLUSION

This study reports various biomechanical measurement techniques to quantify tibial rotation in the literatures. To choose a suitable measurement technique for a specific clinical application, it is suggested to quantify the effectiveness of a new designed surgical technique by using a cadaveric model before applying to living human subjects for intra-operative evaluation or long-time functional stability assessment. Attention should also be paid on the study's purpose, whether to employ a cadaveric model and the way of stress applied to the knee.

LEVEL OF EVIDENCE

IV.

Influence of anticipation on movement patterns in subjects with ACL deficiency classified as noncopers

STUDY DESIGN

Two-factor, mixed experimental design.

OBJECTIVES

To compare movement patterns of subjects who are anterior cruciate ligament (ACL) deficient and classified as noncopers to controls during early stance of anticipated and unanticipated straight and cutting tasks.

BACKGROUND

Altered neuromuscular control of subjects that are ACL deficient and noncoper theoretically influences movement patterns during unanticipated tasks.

METHODS AND MEASURES

The study included 16 subjects who are ACL deficient, classified as noncopers, and 20 healthy controls. Data were collected using an Optotrak Motion Analysis System and force plate integrated with Motion Monitor Software to generate knee joint angles, moments, and power. Each testing session included anticipated tasks, straight walking task (ST), and 45 degrees side-step cutting tasks (SSC), followed by a set of unexpected straight walking (STU) and unexpected sidestep cutting (SSCU) tasks in a random order. For all tasks speed was maintained at 2 m/s. Peak knee angle, moment, and power variables during early stance were compared using 2-way mixed-effects ANOVA models.

RESULTS

For both the straight and sidestep tasks, the noncoper group did not show a dependence on whether the task was anticipated or unanticipated (group-by-condition interaction) for the knee angle (straight, P = .067; side-step cutting, P = .103), moment (straight, P = .079; side-step cutting, P = .996), and powers (straight, P = .181; side-step cutting, P = .183) during the loading response phase. However, during both straight and side-step cutting tasks, the subjects in the noncoper group used significantly lower knee flexion angles (straight, P = .002; side-step cutting, P = .019), knee moments (straight, P = .005; side-step cutting, P < .001), and knee powers (straight, P = .013; side-step cutting, P <.001).

CONCLUSIONS

This study suggests subjects that are ACL deficient and classified as noncopers use a common abnormal movement pattern of lower knee extensor loading even during unanticipated tasks.

Measurement of functional recovery in individuals with acute anterior cruciate ligament rupture

OBJECTIVES

To measure functional recovery following acute anterior cruciate ligament (ACL) rupture using a simple and reliable clinical movement analysis system. Clinic based methods that simultaneously quantify different aspects of movement over a range of activities and model functional recovery will help guide rehabilitation.

METHODS

A longitudinal study was used to measure gait variables at initial physiotherapy attendance and then at monthly intervals using a digital camcorder and computer for quantitative analysis. Jogging and distance hopping were added during recovery. A sample of 63 ACL deficient subjects entered the study and 48 subjects were measured at least three times. To determine the pattern of recovery, repeated measurements were analysed using a least square fit of the data.

RESULTS

Gait variables took between 95 and 130 days post injury to reach the control mean and stabilise shortly after this. Hopping distance for the injured leg took 62 days to recover to within normal limits and 5 months post injury to reach the control mean. Jogging was already within the control limits at 30 days post injury and demonstrated little change with recovery.

CONCLUSIONS

Functional recovery of multiple variables has been modelled. In the early phase of post injury, gait velocity seems to be the most useful variable to measure improvement. Recovery of more challenging activities appears to take an average of 5 months. Therefore, patients may need to be monitored in physiotherapy until this time and advised not to return to sport until sufficient recovery is demonstrated on activities such as distance hopping.

Knee and hip angle and moment adaptations during cutting tasks in subjects with anterior cruciate ligament deficiency classified as noncopers

STUDY DESIGN

Two-factor mixed-design study, with factors including group (control and noncoper) and task (sidestep, crossover, and straight).

OBJECTIVES

To compare the knee and hip joint angles and moments of control subjects and subjects with an anterior cruciate ligament (ACL) deficient knee classified as noncopers, during a sidestep, crossover, and straight-ahead task.

BACKGROUND

Subjects with ACL deficiency primarily note difficulty with cutting tasks as opposed to straight-ahead tasks. Yet, previous studies have primarily focused on straight-ahead tasks.

METHODS AND MEASURES

Fifteen subjects with ACL deficiency classified as noncopers, based on the number of giving-way episodes (>1) and global question of knee function (<60%), were included in this study. These subjects (10 male, 5 female; age range, 18-49 years) were compared to a healthy control group (7 male, 7 female; age range, 19-47 years). Position data collected at 60 Hz were combined with anthropometric and ground reaction force data collected at 420 Hz to estimate 3-dimensional knee and hip joint angles and moments. All subjects performed 3 tasks including a step and 45 degrees sidestep cut, step and 45 degrees crossover cut, and step and proceed straight. Two-way mixed-model ANOVAs were used to compare peak angle and moment variables between 10% to 30% of stance.

RESULTS

The ACL-deficient noncoper group had 1.8 degrees to 5.7 degrees less knee flexion angle compared to the control group across tasks (P<.043). The ACL-deficient noncoper group used 22% to 27% lower knee extensor moment during weight acceptance compared to the control group (P<.001). The sagittal plane hip extensor moments were 34% to 39% higher in the ACL-deficient noncoper group compared to the control group (P<.025). Hip frontal (P<.037) and transverse plane (P<.04) moments also distinguished the ACL-deficient noncoper from the control group.

CONCLUSIONS

This study suggests that individuals who do not cope well after ACL injury rely on a hip control strategy during cutting tasks.

Kinematic analysis of functional lower body perturbations

BACKGROUND

Sudden changes in direction on a single weight-bearing-limb are commonly associated with injury to the lower extremity. The purposes of this study were to assess the between day reliability of hip, knee, and ankle kinematic displacements achieved with internal and external femur-on-weight-bearing-tibia rotation perturbations and to determine the effect of these perturbations on three dimensional hip, knee and ankle kinematics.

METHODS

Twenty recreationally active, healthy college students with no history of significant orthopedic injury (10 male, 10 female) were subjected to a forward and either internal or external rotary perturbation of the trunk and thigh on the weight-bearing-tibia while three dimensional kinematics were simultaneously collected. The protocol was repeated 24-48 h later to assess reliability.

FINDINGS

External perturbations resulted in significant internal rotation (IR) of the tibia on the femur (mean 7.3 (SD 3.9 degrees)) and IR of the femur on the pelvis (mean 6.8 (SD 5.4 degrees)) (P<0.05). Internal perturbations resulted in significant external rotation (ER) of the tibia on the femur (mean 6.8 (5.9 degrees)) and ER of the femur on the pelvis (mean 10.7 (SD 96.1 degrees)) (P<0.05). Additionally the external perturbation results in a significantly greater knee valgus (mean 3.6 (SD 2.2 degrees)) position while the internal perturbation results in a significantly greater knee varus position (mean 2.3 (SD 3.5 degrees)) (P<0.05). External perturbation hip and knee total joint displacements revealed moderate to strong reliability (Intraclass Correlation Coefficient(2,k)=0.67-0.94) while internal perturbations revealed slightly higher Intraclass Correlation Coefficients(2,k)(0.80-0.96).

INTERPRETATION

The lower extremity perturbation device provides a consistent external and internal perturbation of the femur on the weight-bearing-tibia. The observed transverse and frontal plane kinematics are similar to motions observed during cross-over and side-stepping tasks.

Muscle activation patterns of selected lower extremity muscles during stepping and cutting tasks

Lower extremity muscle activations during crossover and side step cut tasks are hypothesized to play an important role in controlling knee motion, and therefore, impact the design of knee injury prevention and rehabilitation programs. However, the contribution of lower extremity muscles to frontal and transverse plane moments during cutting tasks is unclear. The purpose of this study was to compare the muscle activation patterns of selected lower extremity muscles (vastus lateralis, medial/lateral hamstrings and medial/lateral gastrocnemius) of subjects performing a stepping down and side step cut, a stepping down and crossover cut and an equivalent straight ahead task. Ground reaction force was used to determine the cut angle, stance time and compare the lower limb loading during each task. Electromyography data during all tasks were normalized to the average activation during the straight ahead tasks to determine relative changes in muscle activation between the straight ahead and different cut styles (crossover and side step). There were no differences in the pattern of muscle activation of the vastus lateralis, or lateral hamstring muscles when comparing the cutting tasks to the equivalent straight ahead task. However, the crossover cut task resulted in significantly higher muscle activation of the medial hamstrings and lateral gastrocnemius muscles relative to both the side step cut and straight ahead tasks. These results suggest the medial/lateral hamstrings and medial/lateral gastrocnemius play a role in transverse and frontal plane control during cut tasks.

Associations of knee angles, moments and function among subjects that are healthy and anterior cruciate ligament deficient (ACLD) during straight ahead and crossover cutting activities

The objective of this study was to compare knee angles and moments of healthy subjects (n=20) and subjects that were anterior cruciate ligament deficient (ACLD) (n=16) during stepping and crossover cutting activities. Subjects that were ACLD were separated into high (n=7) and low (n=9) functioning groups based on knee functional ratings. Knee angles and moments were estimated using three dimensional motion tracking and force plate data. The results suggest that knee angle and moment data were associated with level of functioning of ACLD subjects. Primarily knee frontal and transverse plane moments distinguished the stepping and crossover cut activities. Only some of the findings for the ACLD group were attributed to increasing knee stability.

Self-reported giving-way episode during a stepping-down task: case report of a subject with an ACL-deficient knee

STUDY DESIGN

Case report.

OBJECTIVE

To describe the knee kinematics and moments of a giving-way trial of a subject with an anterior-cruciate-ligament- (ACL) deficient knee relative to his non-giving-way trials and to healthy subjects during a step-down task.

BACKGROUND

Episodes of giving way are believed to damage joint structures, therefore treatments aim to prevent giving-way episodes, yet few studies document giving-way events.

METHODS

The giving-way trial experienced by a 32-year-old male subject with ACL deficiency during a step-down task was compared to his non-giving-way trials (n = 5) and data from healthy subjects (n = 20). Position data collected at 60 Hz were combined with anthropometric data and ground reaction force data collected at 300 Hz to estimate knee displacement and 3-dimensional angles and net joint moments.

RESULTS

The knee joint displacement was higher during the giving-way trial: from 4% to 32% of stance, reaching 9.0 mm at 18% of stance as compared to 1.6 +/- 0.7 mm for the non-giving-way trials. After 4% of stance, the knee flexion angle of the giving-way trial was 6.6 degrees higher than the non-giving-way trials and was associated with a higher knee extension moment. The knee frontal plane moment was near neutral during early stance of the giving-way trial in contrast to the non-giving way and healthy subjects which demonstrated a knee abduction moment.

CONCLUSIONS

The response of this subject to the giving-way event suggests that higher knee flexion angles may enhance knee stability and, in reaction to the giving-way event, that knee extension moment may increase.

Kinematics, kinetics, and finite element analysis of commonplace maneuvers at risk for total hip dislocation

Dislocation remains a disturbingly frequent complication of total hip arthroplasty (THA). Over the past several years, increasingly rigorous biomechanical approaches have been developed for studying dislocation, both experimentally and computationally. Realism of the input motion challenge data has lagged behind most other aspects of this body of work, and anterior dislocation maneuvers remain unstudied. To enhance realism of biomechanical studies of dislocation, motion data are here reported for ten THA-aged subjects, each repeatedly performing seven maneuvers known to be dislocation-prone. An optoelectronic motion tracking system and a recessed force plate captured the kinematics and ground reaction forces of these maneuvers. Using an established inverse dynamics model to estimate hip joint loading, 354 motion trials were evaluated using an existing finite element model of THA dislocation. Worst-case-scenario THA constructs were simulated (22 mm femoral head, acetabular cup orientations at the limit of the accepted safe zone), in order to deliberately induce impingement and dislocation. The results showed a high incidence of computationally predicted dislocation for all movements studied, but also that risk was very maneuver-dependent, with patients being six times more likely to dislocate from a low-sit-to-stand maneuver than from stooping. These new motion data hopefully will help facilitate systematic efforts to reduce the incidence of dislocation.