Unilateral hip osteoarthritis: The effect of compensation strategies and anatomic measurements on frontal plane joint loading

Relevance of instrumented gait analysis in the prediction of the rebound phenomenon after guided growth intervention

Predictors of rebound after correction of coronal plane deformities using temporary hemiepiphysiodesis (TH) are not well defined. The following research questions were tested: (1) Is the dynamic knee joint load useful to improve rebound prediction accuracy? (2) Does a large initial deformity play a critical role in rebound development? (3) Are BMI and a young age risk factors for rebound? Fifty children and adolescents with idiopathic knee valgus malalignment were included. A deviation of the mechanical femorotibial angle (MFA) of ≥ 3° into valgus between explantation and the one-year follow-up period was chosen to classify a rebound. A rebound was detected in 22 of the 50 patients (44%). Two predictors of rebound were identified: 1. reduced peak lateral knee joint contact force in the first half of the stance phase at the time of explantation (72.7% prediction); 2. minor initial deformity according to the MFA (70.5% prediction). The best prediction (75%) was obtained by including both parameters in the binary logistic regression method. A TH should not be advised in patients with a minor initial deformity of the leg axis. Dynamic knee joint loading using gait analysis and musculoskeletal modeling can be used to determine the optimum time to remove the plates.

Effects of hip osteoarthritis on lower body joint kinematics during locomotion tasks: a systematic review and meta-analysis

Introduction

Motion analysis can be used to gain information needed for disease diagnosis as well as for the design and evaluation of intervention strategies in patients with hip osteoarthritis (HOA). Thereby, joint kinematics might be of great interest due to their discriminative capacity and accessibility, especially with regard to the growing usage of wearable sensors for motion analysis. So far, no comprehensive literature review on lower limb joint kinematics of patients with HOA exists. Thus, the aim of this systematic review and meta-analysis was to synthesise existing literature on lower body joint kinematics of persons with HOA compared to those of healthy controls during locomotion tasks.

Methods

Three databases were searched for studies on pelvis, hip, knee and ankle kinematics in subjects with HOA compared to healthy controls during locomotion tasks. Standardised mean differences were calculated and pooled using a random-effects model. Where possible, subgroup analyses were conducted. Risk of bias was assessed with the Downs and Black checklist.

Results and Discussion

A total of 47 reports from 35 individual studies were included in this review. Most studies analysed walking and only a few studies analysed stair walking or turning while walking. Most group differences were found in ipsi- and contralateral three-dimensional hip and sagittal knee angles with reduced ranges of motion in HOA subjects. Differences between subjects with mild to moderate and severe HOA were found, with larger effects in severe HOA subjects. Additionally, stair walking and turning while walking might be promising extensions in clinical gait analysis due to their elevated requirements for joint mobility. Large between-study heterogeneity was observed, and future studies have to clarify the effects of OA severity, laterality, age, gender, study design and movement execution on lower limb joint kinematics.

Systematic Review Registration

PROSPERO (CRD42021238237).

Lower limb joint loading in patients with unilateral hip osteoarthritis during bipedal stance and the effect of total hip replacement

Osteoarthritis of the hip is a common condition that affects older adults. Total hip replacement is the end-stage treatment to relief pain and improve joint function. Little is known about the mechanical load distribution during the activity of bipedal stance, which is an important daily activity for older adults who need to rest more frequently. This study investigated the distribution of the hip and knee joint moments during bipedal stance in patients with unilateral hip osteoarthritis and how the distribution changed 1 year after total hip replacement. Kinematic and kinetic data from bipedal stance were recorded. External hip and knee adduction moments were calculated and load distribution over both limbs was calculated using the symmetry angle. Preoperatively, the non-affected limb carried 10% more body weight than the affected limb when standing on two legs. Moreover, the mean external hip and knee adduction moments of the non-affected limb were increased compared to the affected limb. At follow-up no significant differences were observed between the patients' limbs. Preoperative and postoperative changes in hip adduction moment were mainly explained by the combination of the vertical ground reaction force and the hip adduction angle. Stance width also explained changes in the hip and knee adduction moments of the affected leg. Furthermore, as with walking, bipedal standing also showed an asymmetric mechanical load distribution in patients with unilateral hip osteoarthritis. Overall, the findings suggest the need for preventive therapy concepts that focus not only on walking but also on optimizing stance towards a balanced load distribution of both legs.

Do individuals with knee osteoarthritis walk with distinct knee biomechanics and muscle activation characteristics? An investigation of knee osteoarthritis, hip osteoarthritis, and asymptomatic groups

BACKGROUND

Biomechanical markers including reductions in sagittal plane kinematics and moments, increases in knee adduction moments (KAM), and altered muscle activations have been identified as hallmark indicators of knee osteoarthritis (OA). However, it remains unknown whether these features of knee OA gait are exclusive to the diseased joint.

RESEARCH QUESTION

To determine whether specific gait outcomes previously linked to symptomatic medial compartment knee OA are unique to knee OA by concurrently investigating a group of asymptomatic individuals and those with hip OA.

METHODS

16 individuals with moderate medial compartment knee OA, 16 individuals with moderate hip OA, and 16 asymptomatic controls were recruited. Participants walked on a treadmill while segment kinematics and ground reaction forces were recorded. Sagittal plane kinematics and sagittal and frontal plane moments were calculated. Surface electromyograms were recorded from lateral and medial hamstrings and gastrocnemius and vastus lateralis and medialis. Discrete variable analysis was used to investigate knee joint mechanics and muscle activation ratios. Analysis of Variance models using Bonferroni corrections determined between group differences (α = 0.0167).

RESULTS

Sagittal plane knee kinematics and moments were statistically similar among all groups (p > 0.0167). No differences were found for peak KAM and impulse between knee OA and asymptomatic groups (p > 0.0167) but peak KAM (p = 0.006 and impulse (p = 0.001) were greater in the knee OA group compared to hip OA. The hip OA group had a lower KAM impulse (p < 0.0167) compared to the knee OA and asymptomatic groups. A greater LH:MH activation ratio (p < 0.0167) was found in the knee OA group compared to hip OA and asymptomatic groups. No other activation ratio differences were found (p > 0.0167).

SIGNIFICANCE

Medial and lateral hamstring muscle activation levels may provide utility as a knee OA gait biomarker compared to biomechanical outcomes, quadriceps and gastrocnemius activation, when differentiating knee OA from asymptomatic and hip OA cohorts.

Effects of Walking With a Cane on Frontal Plane Hip Joint Loading in Patients With Late-Stage Unilateral Hip Osteoarthritis

Objective

To investigate the effects of walking with a cane on frontal plain bilateral hip joint loading in patients with late-stage unilateral hip osteoarthritis (OA).

Design

Nonrandomized experimental design.

Setting

Urban inpatient hospital.

Participants

Adults (men, n=10; women, n=17) with osteoarthritis who were scheduled for total hip arthroplasty (N=27).

Intervention

Gait with and without a T-cane was assessed using a 3-dimensional motion analysis system.

Main Outcome Measures

Peak hip adduction moment and hip adduction moment impulse, vertical ground reaction force, and ground reaction force impulse were assessed under 4 different conditions: OA side vs non-OA side with non-cane gait, OA side vs non-OA side with cane gait, non-cane vs cane gait on OA side, and non-cane vs cane gait on non-OA side. The lateral trunk lean angle in the stance phase on both sides was compared between with and without a cane. Pain during walking with and without a cane was also determined using a visual analog scale (0=no pain; 100=most painful).

Results

Walking with a cane reduced the peak hip adduction moment from an average of 0.76 to 0.57 Nm/kg (reduction approximately 25%) and the mean hip adduction moment impulse from 50.58 to 42.78 Nm/kg (reduction approximately 15%) on the affected side. Walking with a cane reduced the peak ground reaction force from an average of 10.15 to 9.20 N/kg but did not markedly affect the mean ground reaction force impulse on the affected side. The mean impulse of vertical ground force and hip adduction moment on the nonaffected side with a T-cane was larger than that without a cane (940.4 vs 899.2, 73.7 vs 68.8, respectively), albeit without statistical significance. The mean lateral trunk lean angle on the affected side was 5.85±3.95 degrees with a non-cane gait and 4.46±2.66 degrees with a T-cane gait, showing a significant difference. Furthermore, walking with a cane was associated with a significant decrease in the visual analog scale of pain from 42.1 to 26.4.

Conclusion

These findings indicate that walking with a cane reduces the load and pain on the affected hip joint. The effect of the cane on the trunk lean was small, but it is worth noting that walking with a cane may increase the load on the healthy side.

Gait asymmetry of lower extremities reduced immediately after minimally invasive surgery among patients with lumbar disc herniation

BACKGROUND

Lumbar disc herniation patients with increased pain exhibit greater gait asymmetry in stance time, swing time and single support time. Percutaneous endoscopic lumbar discectomy, as a minimally invasive surgical procedure has been used to treat patients with lumbar disc herniation. The objective of this study was to evaluate the immediate impact of the percutaneous endoscopic lumbar discectomy on gait asymmetry in spatiotemporal and kinetic parameters among lumbar disc herniation patients.

METHODS

Marker trajectories and ground reaction forces were measured during walking among 67 lumbar disc herniation patients and 15 healthy controls. Spatiotemporal gait parameters were analyzed via Visual3D. Muscle force and joint contact force were calculated with OpenSim. Gait asymmetry of those parameters were assessed with asymmetry index.

FINDINGS

After surgery, gait asymmetry in gait cycle time, step length, peak biceps femoris long head, tensor fasciae latae and rectus femoris muscle forces, and peak hip and knee joint contact forces reduced immediately. Postoperatively, increased gait cycle time and decreased step length were found in the affected side. Moreover, decreased peak biceps femoris long head, tensor fasciae latae and rectus femoris muscle forces, and peak hip joint contact force were observed in the contralateral side.

INTERPRETATION

These results suggested compensation strategy that biceps femoris long head, tensor fasciae latae and rectus femoris in the contralateral side were mainly used to compensate the affected side preoperatively in lumbar disc herniation patients, with less compensation between lower limbs after surgery, which may provide an insight into postoperative rehabilitation.

Comparison of Gait Symmetry and Joint Moments in Unilateral and Bilateral Hip Osteoarthritis Patients and Healthy Controls

Patients with unilateral hip osteoarthritis show a characteristic gait pattern in which they unload the affected leg and overload the unaffected leg. Information on the gait characteristics of patients with bilateral hip osteoarthritis is very limited. The main purposes of this study were to investigate whether the gait pattern of both legs of patients with bilateral hip osteoarthritis deviates from healthy controls and whether bilateral hip osteoarthritis patients show a more symmetrical joint load compared to unilateral hip osteoarthritis patients. In this prospective study, 26 patients with bilateral hip osteoarthritis, 26 patients with unilateral hip osteoarthritis and 26 healthy controls were included. The three groups were matched for gender, age and walking speed. Patients were scheduled for a unilateral total hip arthroplasty on the more affected/more painful side. All participants underwent a three-dimensional gait analysis. Gait kinematics and gait kinetics of patients and controls were compared using Statistical Parametric Mapping. Corrected for speed, the gait kinematics and kinetics of both legs of patients with bilateral hip osteoarthritis differed from healthy controls. Bilateral patients had symmetrical knee joint loading, in contrast to the asymmetrical knee joint loading in unilateral hip osteoarthritis patients. The ipsilateral leg of the bilateral patients could be included in studies in addition to unilateral hip osteoarthritis patients as no differences were found. Although patients with bilateral hip osteoarthritis show more symmetrical frontal plane knee joint moments, a pathological external knee adduction moment in the second half of stance was present in the ipsilateral leg in patients with unilateral and bilateral hip osteoarthritis. The lateral adjustment of the knee adduction moment may initiate or accelerate progression of degenerative changes in the lateral compartment of the knee.

Basic Body Awareness Therapy versus standard care in hip osteoarthritis. A randomized controlled trial

BACKGROUND

Compensational movement patterns in hip osteoarthritis (HOA) are associated with hip dysfunction. Basic Body Awareness Therapy (BBAT) promotes functional movement quality and might, accordingly, be beneficial in HOA.

OBJECTIVE

To examine the outcomes of BBAT compared to standard care in people with HOA after first receiving patient education (PE).

STUDY DESIGN

A prospective, assessor-blinded, and block-randomized controlled trial.

METHODS

Community-living adults with HOA participating in PE were randomly allocated to an intervention group receiving BBAT in groups (12 sessions offered once a week), or a comparison group. Data at baseline (pretest) and at 6 months (posttest) were analyzed. Primary outcomes were pain during walking assessed by the Numeric Rating Scale (NRS) and function by the Hip Osteoarthritis Outcome Score, subscale ADL (HOOS A). Secondary outcomes addressed physical capacity, movement quality, and self-reported aspects of function and health.

RESULTS

At pretest, there were no significant differences in demographic and test data between the intervention (n = 51) and the comparison (n = 50) group. Forty-one intervention and 45 comparison participants completed the posttest. At posttest, no significant differences in change between groups were found on NRS (p = 0.694, effect size (ES) = 0.02) or HOOS A (p = 0.783, ES = 0.07). Among secondary outcomes, movement quality improved significantly more (p < 0.001, ES = 0.84) in the intervention group. Compliance with BBAT varied substantially. Per-protocol analysis showed changes in favor of the intervention group for self-efficacy (p = 0.049, ES = 0.36), health (p = 0.037, ES = 0.44), and function (p = 0.029, ES = 0.53) when only intervention participants who completed at least 10 sessions of BBAT were included.

CONCLUSIONS

BBAT was not found to be a more effective treatment modality than self-initiated standard care to reduce pain during walking and improve daily functioning in people with HOA. Movement quality was significantly more improved in participants receiving BBAT, and improvement in other health aspects was associated with sufficient therapy compliance.

Impact of subject-specific step width modification on the knee and hip adduction moments during gait

BACKGROUND

Patients with hip osteoarthritis (OA) exhibit an increased step width (SW) during walking before and up to 2 years after total hip arthroplasty. Wider SW is associated with a reduction in the external knee adduction moment (KAM), but there is a lack of research regarding the effect of SW on the hip adduction moment (HAM).

RESEARCH QUESTION

Is a wider SW an effective compensatory mechanism to reduce the hip joint loading? We hypothesized that (1) an increased SW reduces, (2) a decreased SW increases the KAM/HAM, and (3) secondary kinematic gait changes have an effect on the KAM/HAM.

METHODS

Twenty healthy individuals (24.0 ± 2.5 years of age) underwent instrumented gait analyses with 4 different subject-specific SW modifications (habitual, halved, double, and triple SW). The resulting external KAMs and HAMs were compared using statistical parametric mapping (SPM).

RESULTS

Post hoc testing demonstrated significantly lower HAM for both the double (p < 0.001, 15-31 % and 61-98 % of the stance phase) and the triple SW (p < 0.001, 1-36 % and 58-98 %) compared to the habitual SW. The extent of the reduction at the first and second peak was comparable for HAM (15-25 % reduction) and less pronounced at the first peak of KAM (9-11 % reduction) compared to the second peak of KAM (19-28 % reduction). In contrast, halving the SW did not lead to a significant change in KAM or HAM compared to the habitual SW (p > 0.009).

SIGNIFICANCE

An increase in SW is an effective and simple gait mechanism to reduce the frontal plane knee and hip joint moments. However, hypothesis 2 could not be confirmed, as halving the SW did not cause a significant change in KAM or HAM. Given the results of the present study, gait retraining with regard to an increased SW may be an adequate, noninvasive option for the treatment of patients with hip OA.

Trunk movement compensation identified by inertial measurement units is associated with deficits in physical performance, muscle strength and functional capacity in people with hip osteoarthritis

BACKGROUND

Trunk movement compensation characterized as ipsilateral trunk lean and posterior rotation with respect to pelvis during stance phase of walking is common in people with hip osteoarthritis and a biomarker of deficits in physical function in older adults. However, the relationship between trunk movement compensation on deficits in physical performance, muscle strength and functional capacity is unknown.

METHODS

A cross-sectional study design was used. Two inertial measurement units were used to assess trunk movement compensation during the six-minute-walk-test. Knee extension, knee flexion and hip abduction strength were measured using hand-held dynamometer. Multivariate regression models, controlling for self-reported hip pain, were used to regress trunk movement compensation onto six-minute-walk-test and muscle strength measures. Pairwise t-tests were used to evaluate the difference trunk movement compensation has on functional capacity by comparing the first and last minute of the six-minute-walk-test.

FINDINGS

Thirty-five participants (63.3 ± 7.4 years, 57% male, 28.6 ± 4.5 kg/m²) were enrolled. Greater trunk movement compensation was related to poorer six-minute-walk-test (p = 0.03; r = -0.46). Greater hip abduction weakness was related to increased trunk movement compensation in both the sagittal (p = 0.05; r = -0.44) and frontal (p = 0.04; r = -0.38) planes. Participants demonstrated greater frontal plane trunk movement compensation during the last minute compared to the first minute of the six-minute-walk-test (p < 0.01).

INTERPRETATION

Trunk movement compensation, identified by inertial measure units, is a clinically relevant measure and has a moderate-to-strong relationship on deficits in physical performance, muscle strength and functional capacity. Inertial measurement units can be used as a practical means of measuring movement quality in the clinical setting.

Effects of step length and cadence on hip moment impulse in the frontal plane during the stance phase

Background

An excessive daily cumulative hip moment in the frontal plane (determined as the product of hip moment impulse in the frontal plane during the stance phase and mean number of steps per day) is a risk factor for the progression of hip osteoarthritis. Moreover, walking speed and step length decrease, whereas cadence increases in patients with hip osteoarthritis. However, the effects of step length and cadence on hip moment impulse in the frontal plane during the stance phase are not known. Therefore, this study aimed to examine the effects of step length and cadence on hip moment impulse in the frontal plane during the stance phase.

Methods

We used a public dataset (kinetic and kinematic data) of over-ground walking and selected 31 participants randomly from the full dataset of 57 participants. The selected participants walked at a self-selected speed and repeated the exercise 15 times. We analyzed the data for all 15 trials for each participant. Multiple regression analysis was performed with the hip moment impulse in the frontal plane during the stance phase as the dependent variable and step length and cadence as independent variables.

Results

The adjusted R² in this model was 0.71 (p < 0.001). The standardized partial regression coefficients of step length and cadence were 0.63 (t = 5.24; p < 0.001) and −0.60 (t =  − 4.58; p < 0.001), respectively.

Conclusions

Our results suggest that low cadence, not short step length, increases the hip moment impulse in the frontal plane. Our findings help understand the gait pattern with low hip moment impulse in the frontal plane.

Identification of Patients with Similar Gait Compensating Strategies Due to Unilateral Hip Osteoarthritis and the Effect of Total Hip Replacement: A Secondary Analysis

Despite good clinical functional outcome, deficits in gait biomechanics exist 2 years after total hip replacement surgery. The aims of this research were (1) to group patients showing similar gait adaptations to hip osteoarthritis and (2) to investigate the effect of the surgical treatment on gait kinematics and external joint moments. In a secondary analysis, gait data of 51 patients with unilateral hip osteoarthritis were analyzed. A k-means cluster analysis was performed on scores derived via a principal component analysis of the gait kinematics. Preoperative and postoperative datasets were statistically tested between clusters and 46 healthy controls. The first three principal components incorporated hip flexion/extension, pelvic tilt, foot progression angle and thorax tilt. Two clusters were discriminated best by the peak hip extension during terminal stance. Both clusters deviated from healthy controls in spatio-temporal, kinematic and kinetic parameters. The cluster with less hip extension deviated significantly more. The clusters improved postoperatively but differences to healthy controls were still present one year after surgery. A poor preoperative gait pattern in patients with unilateral hip osteoarthritis is associated with worse gait kinematics after total hip replacement. Further research should focus on the identification of patients who can benefit from an adapted or individualized rehabilitation program.

Knee Load Distribution in Hip Osteoarthritis Patients After Total Hip Replacement

Reduced external knee adduction moments in the second half of stance after total hip replacement have been reported in hip osteoarthritis patients. This reduction is thought to shift the load from the medial to the lateral knee compartment and as such increase the risk for knee osteoarthritis. The knee adduction moment is a surrogate for the load distribution between the medial and lateral compartments of the knee and not a valid measure for the tibiofemoral contact forces which are the result of externally applied forces and muscle forces. The purpose of this study was to investigate whether the distribution of the tibiofemoral contact forces over the knee compartments in unilateral hip osteoarthritis patients 1 year after receiving a primary total hip replacement differs from healthy controls. Musculoskeletal modeling on gait was performed in OpenSim using the detailed knee model of Lerner et al. (2015) for 19 patients as well as for 15 healthy controls of similar age. Knee adduction moments were calculated by the inverse dynamics analysis, medial and lateral tibiofemoral contact forces with the joint reaction force analysis. Moments and contact forces of patients and controls were compared using Statistical Parametric Mapping two-sample t-tests. Knee adduction moments and medial tibiofemoral contact forces of both the ipsi- and contralateral leg were not significantly different compared to healthy controls. The contralateral leg showed 14% higher medial tibiofemoral contact forces compared to the ipsilateral (operated) leg during the second half of stance. During the first half of stance, the lateral tibiofemoral contact force of the contralateral leg was 39% lower and the ratio 32% lower compared to healthy controls. In contrast, during the second half of stance the forces were significantly higher (39 and 26%, respectively) compared to healthy controls. The higher ratio indicates a changed distribution whereas the increased lateral tibiofemoral contact forces indicate a higher lateral knee joint loading in the contralateral leg in OA patients after total hip replacement (THR). Musculoskeletal modeling using a detailed knee model can be useful to detect differences in the load distribution between the medial and lateral knee compartment which cannot be verified with the knee adduction moment.

Gait kinematics of the hip, pelvis, and trunk associated with external hip adduction moment in patients with secondary hip osteoarthritis: toward determination of the key point in gait modification

Background

A larger daily cumulative hip loading, which is the product of the external hip adduction moment (HAM) impulse during gait and the number of steps per day has been identified as a factor associated with the progression of secondary hip osteoarthritis (OA). The cause of the increased HAM impulse in patients with hip OA has not been identified. The purpose of this study was to identify the gait parameters associated with HAM impulse during gait in patients with secondary hip OA.

Methods

Fifty-five patients (age 22–65 years) with mild-to-moderate secondary hip OA participated in this cross-sectional study. The HAM impulse during gait was measured using a three-dimensional gait analysis system. To identify the gait parameters associated with HAM impulse, hierarchical multiple regression analysis was performed. The first model (basic model) included body weight and stance phase duration. The second models included gait parameters (gait speed; ground reaction force [GRF] in frontal plane; and hip, pelvic, and trunk angle in frontal plane) and hip pain in addition to the basic model.

Results

Body weight and stance phase duration explained 61% of the variance in HAM impulse. In the second model, which took into account body weight and stance phase duration, hip adduction angle (9.4%), pelvic tilt (6.5%), and trunk lean (3.2%) in addition to GRF explained the variance in the HAM impulse. Whereas larger hip adduction angle and pelvic tilt toward the swing limb were associated with a larger HAM impulse, larger trunk lean toward the stance limb was associated with smaller HAM impulse.

Conclusion

In patients with excessive hip adduction and pelvic tilt toward the swing limb during gait, gait modification may contribute to the reduction of hip joint loading.

Abnormal Joint Loading During Gait in Persons With Hip Osteoarthritis Is Associated With Symptoms and Cartilage Lesions

BACKGROUND

Hip joint loading in persons with hip osteoarthritis (OA) is not well studied, and its associations with symptoms and lesions are unknown.

OBJECTIVES

To determine whether hip joint loading differs between people with and without radiographic hip OA, and to identify its associations with patients' symptoms and cartilage morphology.

METHODS

Forty-eight patients (28 male; mean ± SD age, 56.0 ± 12.2 years) with hip OA and 95 controls (40 male; age, 43.2 ± 13.6 years) participated in this cross-sectional analysis. Pelvic radiographs, questionnaires, magnetic resonance imaging (MRI), and gait analysis were conducted. The Hip disability and Osteoarthritis Outcome Score (HOOS) was used to assess symptoms. Cartilage morphology was graded on MRI scans using the Scoring Hip Osteoarthritis with Magnetic Resonance Imaging (SHOMRI) system. Biomechanical variables included peak external hip joint moment (Newton meters per kilogram) and moment impulses (Newton meters times milliseconds per kilogram) in all planes. Generalized estimating equations were used to compare the biomechanical characteristics between groups. In the patients with OA, associations of moment impulses with HOOS and SHOMRI scores were assessed with partial correlations.

RESULTS

The OA group exhibited higher peak external hip flexion and adduction moments (P<.001) and higher hip flexion, adduction, and external rotation moment impulses (P = .001-.039). Increased hip flexion moment impulses were correlated with worse HOOS subscale scores (r = -0.361 to -0.424, P<.05) and worse femoral SHOMRI grades (ρ = 0.256-0.315, P<.05). Increased hip external rotation moment impulses were correlated with worse femoral SHOMRI grades (ρ = 0.283-0.372, P<.05).

CONCLUSION

Persons with hip OA exhibited abnormally high hip joint loads during walking, and high loads were associated with worse self-reported symptoms and cartilage morphology. J Orthop Sports Phys Ther 2019;49(12):917-924. Epub 14 Oct 2019. doi:10.2519/jospt.2019.8945.

Are changes in radiological leg alignment and femoral parameters after total hip replacement responsible for joint loading during gait?

Background

Gait kinematics after total hip replacement only partly explain the differences in the joint moments in the frontal plane between hip osteoarthritis patients after hip replacement and healthy controls. The goal of this study was to determine if total hip replacement surgery affects radiological leg alignment (Hip-Knee-Shaft-Angle, femoral offset, Neck-Shaft-Angle and varus/valgus alignment) and which of these parameters can explain the joint moments, additionally to the gait kinematics.

Methods

22 unilateral hip osteoarthritis patients who were scheduled for total hip replacement were included in the study. Preoperatively and 1 year postoperatively all patients had biplanar radiographic examinations and 3D gait analysis.

Results

The operated leg showed significantly (P < 0.05) more varus (1.1°) as well as a larger femoral offset (+ 8 mm) and a larger Hip-Knee-Shaft-Angle (+ 1.3°) after total hip replacement; however no significant differences in the joint moments in the frontal plane compared to healthy controls were found. The hip moment (first half of stance) and the knee moments (first and second half of stance) were mostly determined by the varus/valgus alignment (29% and respectively 36% and 35%). The combination with a kinematic parameter (knee range of motion, foot progression angle) increased the predictive value for the knee moments.

Conclusion

In our patient group the joint moments after total hip replacement did not differ from healthy controls, whereas radiological leg alignment parameters changed significantly after the total hip replacement. A combination of these radiological leg parameters, especially the varus alignment, and the deviating kinematics explain the joint moments in the frontal plane during gait after total hip replacement surgery. For surgeons it is important not to create too much of a structural varus alignment by implanting the new hip joint as varus alignment can increase the knee adduction moment and the risk for osteoarthritis of the medial knee compartment.

Trial registration

This study was retrospectively registered with DRKS (German Clinical Trials Register) under the number DRKS00015053. Registered 1st of August 2018.

Hip joint moments during walking in people with hip osteoarthritis: a systematic review and meta-analysis

OBJECTIVE

This systematic review and meta-analysis investigated surrogate measures of hip joint loading during walking in people with hip osteoarthritis (OA).

METHODS

Five databases were searched up to January 14^th, 2018. Studies that measured hip joint moments in the frontal or sagittal plane during walking in people with hip OA and used either a healthy control group or the unaffected leg to compare hip joint moments were included. Standardised mean differences (SMD) in sagittal and frontal plane moments were pooled as appropriate, using a random effect approach. Methodological quality was assessed using the Downs and Black checklist.

RESULTS

Thirteen studies with 1,141 participants were eligible and suitable for meta-analyses. Overall, people with hip OA had lower sagittal (SMD -0.55 (95% confidence interval (CI) -1.00 to -0.10) and frontal plane moments (SMD -0.63 (95% CI -0.92, -0.34) compared to controls. However, substantial heterogeneity was observed (I² ≤ 89%). Results by disease stage suggest that people with end-stage hip OA have lower sagittal (SMD -0.96; -1.30, -0.61; I² = 69%) and frontal (SMD -1.17; 95% CI -1.71, -0.64; I² = 85%) plane moments compared to controls. People with less severe hip OA than end-stage disease have comparable sagittal (SMD 0.37; 95% CI -0.17, 0.90; I² = 69%) and frontal (SMD -0.24; 95% CI -0.76, 0.27; I² = 51%) plane moments compared to controls.

CONCLUSION

Hip joint loading may be dependent on disease stage. People with end-stage hip OA under-loaded compared to controls, while those who were not awaiting hip joint replacement had comparable hip joint loads to controls.

Knee motion and muscle activation patterns are altered in hip osteoarthritis: The effect of severity on walking mechanics

BACKGROUND

Knee function is impaired in individuals with moderate hip osteoarthritis. How this extends to those undergoing total hip arthroplasty is unknown despite the common requirement for knee arthroplasty in this population. The study purpose was to determine whether sagittal plane knee joint movements and quadriceps and hamstring activation patterns differ between individuals with either moderate or severe unilateral hip osteoarthritis, and between ipsilateral and contralateral knees.

METHODS

20 individuals with moderate osteoarthritis and 20 with severe osteoarthritis were recruited. Sagittal knee motion and surface electromyograms from the hamstrings and quadriceps were collected during treadmill walking at a self-selected speed. Principal component analysis captured amplitude and temporal sagittal plane motion and EMG waveform features. Student's t-tests and Analysis of Variance determined between group differences and within/between group leg differences.

FINDINGS

The severe groups' contralateral knee was in greater flexion at initial contact and demonstrated a movement profile of a longer stance phase (p < 0.001). The severe group had reduced sagittal plane knee motion (p < 0.0001); more so in the ipsilateral knee (p < 0.0001). The severe group had greater hamstring (p = 0.009) and quadriceps activation (p < 0.001) overall, specifically mid-stance quadriceps bilaterally (p = 0.002). Ipsilateral sagittal plane knee motion was reduced in both groups. Compared with those with moderate osteoarthritis, individuals with severe osteoarthritis walk with reduced sagittal plane knee motion bilaterally, suggesting prolonged contralateral stance, and elevated mid-stance hamstring and quadriceps activation.

INTERPRETATION

Altered kinematics and muscle activity could contribute to a greater mechanical demand on the contralateral knee in those with more severe hip osteoarthritis.

Altered erector spinae activity and trunk motion occurs with moderate and severe unilateral hip OA

People with hip osteoarthritis (OA) demonstrate altered movement patterns in the hip joint, as well as the pelvis and spine. While kinematic changes have been described in the literature, little is known about the associated erector spinae (ES) activity. Increased or prolonged ES activity may contribute to the low back pain often associated with hip OA. Using a cross-sectional cohort study, 3D trunk motions and ES surface electromyography were recorded on 19 individuals with severe OA (SOA), 20 with moderate hip OA (MOA), and 19 asymptomatic (ASYM) individuals during treadmill walking, using standardized collection and processing procedures. Principal component analysis was used to derive electromyographic amplitude and temporal waveform features. Three-dimensional thoracic motion in a global system, and thoraco-lumbar motion was calculated. Various statistical analyses determined between group differences (α = 0.05). In the sagittal plane, thoracic motion was greater in the SOA group (p < 0.001), whereas the ASYM group used less thoraco-lumbar motion than either OA group (p ≤ 0.002). Greater frontal plane angular excursion during early stance was found in the thoracic region in the SOA group (p ≤ 0.001) . With increasing OA severity, bilateral ES activity increased during the swing phase of gait (p < 0.001), whereas during stance, the SOA ipsilateral ES activity was higher than other groups (p < 0.001). Statement of clinical significance: with moderate and severe OA, sagittal, and frontal trunk motion increases during gait. ES activity during the entire gait cycle is more sustained with increased disease severity, which may aide our understanding of low back pain associated with hip OA. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1826-1832, 2018.

Abnormal loading of the hip and knee joints in unilateral hip osteoarthritis persists two years after total hip replacement

A total hip replacement (THR) is a common and routine procedure to reduce pain and restore normal activity. Gait analysis can provide insights into functional characteristics and dynamic joint loading situation not identifiable by clinical examination or static radiographic measures. The present prospective longitudinal study tested whether 2 years after surgery a THR would restore dynamic loading of the knee and hip joints in the frontal plane to normal. Instrumented gait analysis was performed shortly before surgery and approximately 2 years after THR on 15 unilateral hip osteoarthritis (OA) patients. 15 asymptomatic matched individuals were recruited as healthy controls. Results showed that abnormal joint loading persisted 2 years after THR. The 2nd external knee adduction moment in terminal stance in the affected (-34%, p = 0.002, d = 1.22) and non-affected limb (-25%, p = 0.035, d = 0.81) was lower compared to controls and thus indicated a shift in the knee joint load distribution from medial to lateral. A correlation analysis revealed that a smaller hip range of motion explained 46% of 2nd knee adduction moment alterations. In contrast, the 2nd external hip adduction moment in terminal stance was postoperatively higher in the affected (+22%, p = 0.007, d = 1.04) and non-affected limb (+22%, p = 0.005, d = 1.05). Here, 51% of 2nd hip adduction moment alterations can be explained with a greater hip adduction angle. Patients with a THR may therefore be at higher risk for abnormal joint loading and thus for the development of OA in other joints of the lower extremities. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.