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

Three-dimensional lower limb kinematics and kinetics in femoroacetabular impingement syndrome (FAIS) patients with and without borderline developmental dysplasia of the hip (BDDH) during level walking

PURPOSE

The impact of femoroacetabular impingement syndrome (FAIS) on gait has been reported; however, no studies have documented the effects of Borderline Developmental Dysplasia of the Hip (BDDH) combined with FAIS on gait. This study aimed to evaluate the kinematic and kinetic abnormalities of the lower extremities in patients with combined FAIS and BDDH during level walking.

METHODS

A total of 42 participants were included, consisting of 14 patients with FAIS + BDDH, 14 with isolated FAIS and 14 healthy controls. Full-cycle kinematic and kinetic data were collected via motion capture and force plates. Gait analysis was performed in three planes (sagittal, coronal and transverse) for the hip, knee, ankle and pelvis joints. The range of motion (ROM), kinematics and kinetics were compared across the three groups.

RESULTS

Compared with isolated FAIS patients, FAIS + BDDH patients presented a significantly greater hip flexion angle during terminal stance (P < 0.05). Moreover, the hip abduction moment was significantly reduced in the loading response and midstance phases in FAIS + BDDH patients (P < 0.05). The knee extension moment was significantly reduced during terminal stance in both FAIS groups (P < 0.05). The ankle dorsiflexion angle was significantly greater during midstance in FAIS + BDDH patients than in healthy controls, with concomitant reductions in the ankle dorsiflexion moment (P < 0.05). No significant differences were found in the range of motion (ROM) of the pelvis or hip joints and hip moment arm among the three groups (P > 0.05).

CONCLUSION

Compared with patients with isolated FAIS, patients with FAIS combined with BDDH exhibit a gait pattern characterized by biomechanical defects of the hip joint similar to developmental dysplasia of the hip (DDH), increased knee stiffness, and compensatory alterations in the ankle joint.

LEVEL OF EVIDENCE

V.

Walking gait biomechanics in individuals with quadriceps tendon autograft anterior cruciate ligament reconstruction

Introduction

Walking is a vital movement, corresponding to physical activity, health, and independent living. Persistent abnormal lower extremity kinetics and kinematics during walking may influence long-term joint health. Anterior cruciate ligament (ACL) injuries are common sport-related knee joint injuries resulting in short- and long-term dysfunctional movement patterns. Re-establishing normal gait biomechanical patterns following ACL reconstruction (ACLR) is a universal long-term rehabilitative goal and indicator of restored function. The use of the quadriceps tendon (QT) graft technique by orthopedic surgeons is increasing and growing evidence suggests it's viable for ACLR. However, no information is available examining walking gait biomechanics in QT-ACLR patients. Our study evaluated three-dimensional hip and knee joint biomechanics during the stance phase of walking gait in patients with QT-ACLR by comparing the ACLR and nonsurgical limbs. We hypothesized hip and knee joint biomechanics will differ between the QT-ACLR and nonsurgical limbs during the stance phase of gait.

Methods

We recruited a convenience sample of 14 patients with unilateral QT-ACLR ∼11 months post-surgery from an orthopedic surgery clinic. Three-dimensional hip and knee kinematics and kinetics and vertical ground reaction force were assessed while participants walked at self-selected speeds. Data were time-normalized from 0%-100% (% stance phase), and ACLR and nonsurgical limbs were compared using curve analyses with 95% confidence intervals. Cohen's d effect sizes identified clinical differences between limbs.

Results

The ACLR limb was significantly different from the nonsurgical limb for knee flexion angle (1%-8% and 58%-85%), knee flexion moment (14%-23%), hip flexion moment (60%-67%), knee adduction angle (9%-32%, 92%-100%), knee adduction moment (53%-81%), hip frontal plane angle (0%-100%), hip abduction moment (31%-35% and 71%-76%), knee external rotation angle (0%-100%), knee internal rotation moment (55%-84%), hip transverse plane angle (20%-39% and 88%-100%), and hip internal rotation moment (56%-88%). All significant findings had large effect sizes (d > 0.8).

Discussion

Three-dimensional biomechanical gait alterations are present at the knee and hip following QT-ACLR when comparing between limbs. This pattern is consistent with other ACLR graft types. Participants demonstrated gait patterns associated with quadriceps avoidance and reduced proximal forces during the loading response and terminal stance phases. Rehabilitation and functional movement programs should target these deficits.

Assessment of hip joint mechanics during walking in people with Marfan syndrome

BACKGROUND

Marfan syndrome (MFS) is an autosomal dominant connective tissue disorder and is associated with muscle dysfunction. Individuals with MFS exhibit quadriceps weakness, hip joint pain, and an increased incidence of hip osteoarthritis (OA) compared to the general population, yet the underlying biomechanical factors associated with these poor hip-related outcomes are not well understood.

RESEARCH QUESTION

The purpose of this study was to assess the effects of MFS on gait mechanics and to determine the relationship of gait mechanics with hip-related outcomes within the MFS group.

METHODS

Eighteen people with MFS and 18 healthy, asymptomatic controls underwent 3D gait analysis. All study participants completed the Hip disability and Osteoarthritis Outcome Survey (HOOS) to obtain patient reported outcomes. (PROs). Between group differences in demographics, HOOS scores, and gait mechanics were analyzed via independent t-tests, a Kruskal-Wallis test, and a multi variate analysis of covariance while adjusting for age, respectively. A Spearman's rank-order correlation was used to assess the relationship between HOOS sub-scores and kinetic and kinematic parameters.

RESULTS

The MFS cohort was significantly older than the control cohort and ambulated with altered sagittal plane pelvis, knee and ankle kinematics as well as ankle kinetics. The MFS cohort ambulated with a higher hip transverse plane range of motion, hip extensor moment impulse (HEMI), peak hip abduction moments and hip abduction moment impulse. The MFS group also exhibited a higher hip internal rotation moment (HIRM) compared to the control group. The MFS cohort also self-reported worse hip-related PRO. Higher HIRM and HEMI were associated with worse hip-related pain and QOL within the MFS group.

SIGNIFICANCE

These results suggest that people with MFS walk with altered pelvic and lower extremity joint mechanics which may be associated with the higher incidence rates of hip OA and poor hip-related PRO observed in the MFS population.

Exploratory analysis of gait mechanics in farmers

Farmers may be at a higher risk of developing hip osteoarthritis (OA) due to the high demands of their occupation. To the authors' knowledge, the gait patterns of farmers that may be associated with hip joint degeneration have yet to be analyzed. Therefore, this study compares gait mechanics between farmers and non-farmers (controls). It is hypothesized that farmers would exhibit altered lower extremity joint mechanics during walking when compared to matched controls. This exploratory study included five farmers and five sex-, age-, and body mass index (BMI)-matched controls. A 3D gait analysis was performed while study participants walked at a self-selected speed on an instrumented treadmill. Sagittal plane hip, knee, and ankle kinetics and kinematics were assessed. Effect sizes and between-group differences in demographics and gait mechanics were assessed. There were no group differences in walking speed, total stance time as well as hip and knee joint kinematics (p > 0.05). Farmers exhibited statistical trends (p = 0.07-0.08) of lower peak ankle plantarflexion angles, higher plantarflexor moments, higher knee flexion moment impulse, and higher peak vertical ground reaction force during the first and second halves of stance. Additionally, farmers ambulated with a significantly higher knee extensor moment (p = 0.04) and moment impulse (p = 0.05) during the first half of stance and a higher ankle plantarflexion moment impulse (p = 0.04). The results demonstrate a multi-joint gait alteration in farmers compared to non-farmers and may suggest a compensatory gait pattern to optimize hip joint mechanics and mitigate hip joint degeneration. These results provide a preliminary understanding of the impact that agricultural occupations have on joint mechanics that may be associated with the increased prevalence of hip OA in the farming population.

The relationship of peak ankle dorsiflexion angle with lower extremity biomechanics during walking

PURPOSE

Abnormal lower limb movement patterns have been observed during walking in individuals with limited ankle dorsiflexion. The purpose of this study was to investigate the relationships of peak ankle dorsiflexion angle during the stance phase of walking with the lower extremity biomechanics at the corresponding moment and to determine a cutoff value of functional limited ankle dorsiflexion during walking.

METHODS

Kinematic and kinetic data of 70 healthy participants were measured during walking. Spearman's correlation coefficients were calculated to establish the association between peak ankle dorsiflexion and angle and moment of ankle, knee, and hip, ground reaction force, and pelvic movement at peak ankle dorsiflexion. All variables significantly related to peak ankle dorsiflexion were extracted as a common factor by factor analysis. Maximally selected Wilcoxon statistic was used to perform a cutoff value analysis.

RESULTS

Peak ankle dorsiflexion positively correlated with ankle plantar flexion moment (r = 0.432; p = 0.001), ankle external rotation moment (r = 0.251; p = 0.036), hip extension angle (r = 0.281; p = 0.018), hip flexion moment (r = 0.341; p = 0.004), pelvic ipsilateral rotation angle (r = 0.284; p = 0.017), and medial, anterior, and vertical ground reaction force (r = 0.324; p = 0.006, r = 0.543; p = 0.001, r = 0.322; p = 0.007), negatively correlated with knee external rotation angle (r = -0.394; p = 0.001) and hip adduction angle (r = -0.256; p = 0.032). The cutoff baseline value for all 70 participants was 9.03°.

CONCLUSIONS

There is a correlation between the peak ankle dorsiflexion angle and the lower extremity biomechanics during walking. If the peak ankle dorsiflexion angle is less than 9.03°, the lower limb movement pattern will change significantly.

The impact of pediatric obesity on biomechanical differences across the gait cycle at three walking speeds

BACKGROUND

Obesity impacts a child's ability to walk with resulting biomechanical adaptations; however, existing research has not comprehensively compared differences across the gait cycle. We examined differences in lower extremity biomechanics across the gait cycle between children with and without obesity at three walking speeds.

METHODS

Full gait cycles of age-matched children with obesity (N = 10; BMI: 25.7 ± 4.2 kg/m2) and without obesity (N = 10; BMI: 17.0 ± 1.9 kg/m2) were analyzed at slow, normal, and fast walking speeds. Main and interaction effects of group and speed across hip, knee, and ankle joint angles and moments in sagittal, frontal, and transverse planes were analyzed using one-dimensional statistical parametric mapping.

FINDINGS

Compared to children without obesity, children with obesity had greater hip adduction during mid-stance, while also producing greater hip extensor moments during early stance phase, abductor moments throughout most of stance, and hip external rotator moments during late stance. Children with obesity recorded greater knee flexor, knee extensor and knee internal rotator moments during early stance, and knee external rotator moments in late stance than children without obesity; children with obesity also demonstrated greater ankle plantarflexor moments throughout mid and late stance. Interaction effects existed within joint kinetics data; children with obesity produced greater hip extensor moments at initial contact and toe-off when walking at fast compared to normal walking speed.

INTERPRETATION

While few kinematic differences existed between the two groups, children with obesity exhibited greater moments at the hip, knee, and ankle during critical periods of controlling and stabilizing mass.

Persistent underloading of patellofemoral joint following hamstring autograft ACL reconstruction is associated with cartilage health

OBJECTIVE

To determine the longitudinal changes of patellofemoral joint (PFJ) contact pressure following anterior cruciate ligament reconstruction (ACLR). To identify the associations between PFJ contact pressure and cartilage health.

DESIGN

Forty-nine subjects with hamstring autograft ACLR (27 males; age 28.8 [standard deviation, 8.3] years) and 19 controls (12 males; 30.7 [4.6] years) participated. A sagittal plane musculoskeletal model was used to estimate PFJ contact pressure. A combined T1ρ/T2 magnetic resonance sequence was obtained. Assessments were performed preoperatively, at 6 months, 1, 2, and 3 years postoperatively in ACLR subjects and once for controls. Repeated Analysis of Variance (ANOVA) was used to compare peak PFJ contact pressure between ACLR and contralateral knees, and t-tests to compare with control knees. Statistical parametric mapping was used to evaluate the associations between PFJ contact pressure and cartilage relaxation concurrently and longitudinally.

RESULTS

No changes in peak PFJ contact pressure were found within ACLR knees over 3 years (preoperative to 3 years, 0.36 [CI, -0.08, 0.81] MPa), but decreased over time in the contralateral knees (0.75 [0.32, 1.18] MPa). When compared to the controls, ACLR knees exhibited lower PFJ contact pressure at all time points (at baseline, -0.64 [-1.25, -0.03] MPa). Within ACLR knees, lower PFJ contact pressure at 6 months was associated with elevated T2 times (r = -0.47 to -0.49, p = 0.021-0.025).

CONCLUSIONS

Underloading of the PFJ following ACLR persists for up to 3 years and has concurrent and future consequences in cartilage health. The non-surgical knees exhibited normal contact pressure initially but decreased over time achieving limb symmetry.

Hip loading asymmetry in Lenke type 1 idiopathic scoliosis: Effect of spinal fusion and sex

BACKGROUND

Thoracic curvatures are most common in patients with idiopathic scoliosis. The literature highlights an imbalance of hip joint moments in the frontal plane quantified with a symmetry index. Spinal arthrodesis can reduce this symmetry index which then tends towards 0. Furthermore, asymptomatic women present lower hip moment in the frontal plane than asymptomatic men. This difference could influence the symmetry index in the case of patients with idiopathic scoliosis. Therefore, the main objective of this study was to show a significant positive effect of spinal arthrodesis on the symmetry index. The secondary objective was to compare the symmetry index between sexes before spinal fusion.

METHOD

The retrospective study included 20 patients with Type-1 Lenke curve idiopathic scoliosis, who performed a gait analysis before and one year after spinal fusion. The gait analysis consisted of walking back and forth at spontaneous speed.

FINDINGS

While significantly lower curvatures were depicted, the symmetry index showed a significantly lower value after spinal fusion (p < 0.03). The symmetry index showed no significant difference between sexes (p > 0.05).

INTERPRETATION

The study shows the effect of surgical fusion on the symmetry index, although the latter remains significant compared to the norm. Literature reveals that spinal fusion tends to the symmetrisation of the body's center of mass and increases ranges of motion on the trunk and pelvis. This could favour symmetry of hip moment in the frontal plane. Future research should investigate other Type Lenke curves before and after surgery, and the effect of braces on this symmetry index.

The surgical destabilization of the abductor muscle leads to development of instability-associated hip osteoarthritis in mice

Osteoarthritis (OA) of the hip is a common and debilitating painful joint disease. However, there is paucity of surgically induced hip OA models in small animals that allow scientists to study the onset and progression of the disease. A growing body of evidence indicates a positive association between periarticular myotendinous pathology and the development of hip OA. Thus, in the current study, we aimed to establish a novel mouse instability-associated hip OA model via selective injury of the abductor complex around the hip joint. C57BL6/J mice were randomized to sham surgery or abductor injury, in which the myotendinous insertion at the third trochanter and greater trochanter were surgically detached. Mice were allowed free active movement until they were sacrificed at either 3 weeks or 20 weeks post-injury. Histologic analyses and immunohistochemical staining of the femoral head articular cartilage were performed, along with microCT (µCT) analysis to assess subchondral bone remodeling. We observed that mice receiving abductor injury exhibited significantly increased instability-associated OA severity with loss of proteoglycan and type II collagen staining compared to sham control mice at 20 weeks post-surgery, while comparable matrix metalloproteinase 13 expression was observed between injury and sham groups. No significant differences in subchondral bone remodeling were found after 3 or 20 weeks following injury. Our study further supports the link between abductor dysfunction and the development of instability-associated hip OA. Importantly, this novel surgically induced hip OA mouse model may provide a valuable tool for future investigations into the pathogenesis and treatment of hip OA.

Hip adduction angle during wider step-width gait affects hip adduction moment impulse

BACKGROUND

Decreasing an external hip adduction moment (HAM) impulse during stance is important to prevent the progression of hip osteoarthritis. A hip adduction angle (HAA) during walking influences the HAM impulse. Although a wider step-width (WS) gait is a gait modification to decrease a peak HAM, no study has reported the HAM impulse and HAA.

RESEARCH QUESTION

We investigated whether the HAA influences the peak HAM and HAM impulse during WS gait.

METHODS

Twenty-six healthy young adults walked with normal step-width (NS) and WS comfortably. They were not instructed about hip adduction motion during gait, and the peak HAM, HAM impulse, HAA, and other gait parameters were evaluated using a 3D motion capture system. The participants were divided into two groups according to the HAA size during WS gait. The percentage reduction of HAM variables (the WS condition relative to the NS condition) and other gait parameters were compared between the groups.

RESULTS

No difference in gait parameters was found between the groups. The percentage reduction of the HAM impulse in participants with smaller HAA was significantly higher than that in participants with larger HAA (14.5 % vs. 1.6 %, p < 0.01). Also, during normal step-width gait, the large HAA group showed a significantly larger HAA compared to the small HAA group (about 3°).

SIGNIFICANCE

Participants with smaller HAA could decrease the HAM impulse more effectively during WS gait compared with those with larger HAA. Thus, the HAA would influence the HAM impulse reduction effect on the WS gait. We recommend paying attention to the HAA to decrease the HAM with the WS gait.

Evaluation of gait recovery after total knee arthroplasty using wearable inertial sensors: A systematic review

PURPOSE

This study aimed to conduct a systematic review of the recent research output to present more evidence of the current clinical applications of wearable sensors to determine the change and the recovery in gait function pre- and post-total knee arthroplasty (TKA).

METHODS

A systematic search of the PubMed, ScienceDirect, and Scopus databases was conducted in October 2022. Inclusion criteria consisted of applying acceleration wearable sensors for pre- and post-arthroplasty assessment of the gait cycle. Studies reporting gait analysis using wearable sensors in patients with knee osteoarthritis at any time after total or partial knee arthroplasty (KA) were also included. Each included study was assessed using the Joanna Briggs Institute Critical Appraisal Tool for Quasi-Experimental studies.

RESULTS

Twelve articles were finally considered. The extracted data included essential characteristics of participants, KA studies and their characteristics, sensor technology characteristics and the clinical protocols, gait parameter changes, and various clinical outcome scores at different follow up times after KA. Postoperative examinations were performed from 5 days to 1 year after KA. Clinical outcome scores and gait variables for all patient groups, with or without postoperative rehabilitation, showed various recovery profiles. A variety of wireless sensor devices for gait analysis were recorded. Also, different types of KA were found in the studies.

CONCLUSIONS

The study's findings showed that acceleration-based gait analysis has notable clinical use in monitoring patients after KA. This application provides objective information on the functional outcome beyond the use of clinical outcome scores. More extensive prospective studies are required to investigate gait function further with the help of wearable sensors in patients with knee osteoarthritis.

Correlating Biomechanical Gait Analysis With Patient-Reported Outcomes After Hip Arthroscopy for Femoroacetabular Impingement Syndrome

Background

Postoperative biomechanics after hip arthroscopy for femoroacetabular impingement syndrome (FAIS) are an outcome of interest, but correlation with patient-reported outcomes (PROs) remains unclear.

Purpose/Hypothesis

The purpose of this study was to assess the correlation between changes in hip biomechanics in FAIS patients after hip arthroscopy and changes in PRO scores. We hypothesized that gait analysis would demonstrate significant correlations between pre- and postoperative changes in biomechanics and changes in PRO scores.

Study Design

Descriptive laboratory study.

Methods

FAIS patients without dysplasia or arthritis who underwent primary hip arthroscopy for labral repair and femoroplasty underwent preoperative and 1-year postoperative 3-dimensional motion tracking and biomechanical testing during normal gait. Joint kinematics calculated included flexion/extension (sagittal plane), abduction/adduction (frontal plane), and internal/external rotation (transverse plane). Peak hip angles and moments were compared between baseline and 1-year postoperative measures. At baseline, 1-year, and 2-year postoperatively, patients completed the following PRO surveys: 12-Item Short Form Health Survey (SF-12), modified Harris Hip Score (mHHS), and Hip disability and Osteoarthritis Outcome Score (HOOS). Joint kinematics that significantly improved 1 year after surgery were assessed for correlations with PRO scores.

Results

A total of 10 patients (12 hips) were enrolled prospectively. PROs significantly improved at 1 and 2 years postoperatively compared with baseline values for HOOS, mHHS, and SF-12 Physical Component Score, with all patients achieving the minimal clinically important difference (MCID) on the HOOS Sport/Recreation and Quality of Life subscales. From preoperatively to 1-year postoperatively, significant improvements were seen in peak hip abduction angle (from -2.3° ± 1.8° to -4.6° ± 1.8°; P = .0058) and peak hip extension moment (from -1.03 ± 0.19 to -0.85 ± 0.20 N·m/kg; P = .014); however, there were no significant correlations between these changes and the pre- to postoperative changes on any PRO scores.

Conclusion

Gait analysis of FAIS patients after hip arthroscopy demonstrated small, albeit significant, changes in postoperative hip kinetics and kinematics; however, these changes did not correlate with the large, clinically significant improvements in PROs at 1 year after surgery.

Clinical Relevance

The results of this study suggest that the degree of improvement in short-term PROs after hip arthroscopy for FAIS may not be related to small changes in biomechanics postoperatively.

The relationship of hip loading asymmetry and radiological parameters of the spine in Lenke type 1 idiopathic scoliosis

BACKGROUND

Idiopathic scoliosis does not only cause structural changes in the spine, but also functional changes of the musculoskeletal system.

RESEARCH QUESTION

Does idiopathic scoliosis lead to asymmetric hip loading in severe Lenke type 1 deformity?

METHODS

23 patients (18 girls, 5 boys) aged 15 ± 2.8 years with an adolescent idiopathic main thoracic curve (Cobb angle 48.8°+/- 9.2°) were included. Measured X-ray parameters were: Cobb angle of primary thoracic and secondary lumbar curve, translation of the C7- plumb line, apical thoracic vertebra and apical lumbar vertebra from the central sacral vertical line. Subjects were examined by means of kinematic and kinetic gait analysis. The symmetry index (SI) was calculated as a ratio of hip frontal moments during a single stance for both sides when the symmetrical load was considered SI = 0 + /- 29.36 (0 +/- 1 SD of the mean SI of the healthy population). The Pearson correlation coefficient was used to show the relation between hip loading and radiologic measures of spinal deformity.

RESULTS

Only 34.8% of subjects with Lenke type 1 deformity showed symmetrical hip loading. Significant negative correlation was proved between SI and apical thoracic vertebra translation (R = - 0541; p < 0,05) as well as between SI and coronal imbalance (R = -0,5197; p < 0,05). There was no correlation between SI and the magnitude of the primary thoracic curve (R = -0.19; p = 0.385). Coronal imbalance correlates positively with translation of apical thoracic vertebra (R = 0,7255; p < 0,05).

SIGNIFICANCE

Two-thirds of subjects with Lenke type 1 deformity showed asymmetrical hip loading. This asymmetry is related to the translation of the apical thoracic vertebra and coronal imbalance and is not related to the magnitude of the main thoracic curve. On the contrary, the secondary lumbar curve plays role in the compensatory mechanism of the trunk.

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.

A Systematic Review of the Associations Between Inverse Dynamics and Musculoskeletal Modeling to Investigate Joint Loading in a Clinical Environment

The assessment of knee or hip joint loading by external joint moments is mainly used to draw conclusions on clinical decision making. However, the correlation between internal and external loads has not been systematically analyzed. This systematic review aims, therefore, to clarify the relationship between external and internal joint loading measures during gait. A systematic database search was performed to identify appropriate studies for inclusion. In total, 4,554 articles were identified, while 17 articles were finally included in data extraction. External joint loading parameters were calculated using the inverse dynamics approach and internal joint loading parameters by musculoskeletal modeling or instrumented prosthesis. It was found that the medial and total knee joint contact forces as well as hip joint contact forces in the first half of stance can be well predicted using external joint moments in the frontal plane, which is further improved by including the sagittal joint moment. Worse correlations were found for the peak in the second half of stance as well as for internal lateral knee joint contact forces. The estimation of external joint moments is useful for a general statement about the peak in the first half of stance or for the maximal loading. Nevertheless, when investigating diseases as valgus malalignment, the estimation of lateral knee joint contact forces is necessary for clinical decision making because external joint moments could not predict the lateral knee joint loading sufficient enough. Dependent on the clinical question, either estimating the external joint moments by inverse dynamics or internal joint contact forces by musculoskeletal modeling should be used.

Prevalence of Gluteus Medius Pathology on Magnetic Resonance Imaging in Patients Undergoing Hip Arthroscopy for Femoroacetabular Impingement: Asymptomatic Tears Are Rare, Whereas Tendinosis Is Common

BACKGROUND

There is a paucity of literature on asymptomatic gluteus medius pathology. Moreover, no studies have examined the prevalence of asymptomatic gluteus medius pathology.

PURPOSE

To describe the prevalence of asymptomatic gluteus medius pathology in patients undergoing hip arthroscopy for femoroacetabular impingement.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A database search of our institution was performed for patients undergoing hip arthroscopy for labral treatment between February 2008 and January 2019. Patients were included if they had gluteus medius pathology identified through magnetic resonance imaging (MRI). Patients were deemed to be asymptomatic if they lacked greater trochanteric hip tenderness, abductor weakness, a positive Trendelenburg sign, or a positive Trendelenburg gait on physical examination. Patients were excluded if they were unwilling to participate or did not have a documented physical examination or MRI read in the database.

RESULTS

A total of 2851 hips (2452 patients) met the inclusion/exclusion criteria. Gluteus medius pathology was found in 871 hips (30.6%) on MRI. Symptomatic gluteus medius pathology was observed in 414 (14.5%) hips, of which 305 (10.7%) had tendinosis, 99 (3.5%) had partial-thickness tears, and 10 (0.4%) had full-thickness tears. Asymptomatic gluteus medius pathology was observed in 457 (16.0%) hips, of which 408 (14.3%) had tendinosis and 49 (1.7%) had partial-thickness tears. No hips with full-thickness tears on MRI were asymptomatic. Patients with asymptomatic partial-thickness tears were significantly older than those with only tendinosis (45.3 vs 39.4 years, respectively; P = .001). Patients aged 40 years or older had a 2.11 (1.80-2.50) (P < .001) relative risk of asymptomatic pathology compared with patients younger than 40 years.

CONCLUSION

Although there is a meaningful prevalence of asymptomatic gluteus medius tendinosis, the prevalence of asymptomatic gluteus medius tears is low. Treatment of gluteus medius tendinosis should therefore be based not solely on MRI findings but rather on a complete clinical evaluation. In contrast, MRI findings of partial or full-thickness gluteus medius tears may be more likely to have clinical significance.

Patients with Symptomatic Hip Osteoarthritis Have Altered Kinematics during Stair Ambulation

BACKGROUND

Osteoarthritis (OA) is a degenerative joint disease. Understanding contributing factors to slowing or stopping disease progression is crucial. There has been no research describing lower extremity kinematics of the hip, knee, and ankle during stair ambulation in individuals with hip OA.

OBJECTIVE

To explore the differences in lower extremity kinematics between participants with clinical and morphological findings of hip OA and controls.

DESIGN

A cross-sectional study.

SETTING

Clinical research laboratory.

PARTICIPANTS

Participants with radiographic and symptomatic signs of hip OA (n = 42) and healthy controls (n = 30) were enrolled.

INTERVENTIONS

Participants underwent hip magnetic resonance imaging (MRI). The Scoring Hip Osteoarthritis with MRI (SHOMRI) method was used to assess cartilage abnormalities. Self-reported measures of hip pain and function were obtained using the Hip Disability and Osteoarthritis Outcome Score (HOOS). Participants were assigned into a symptomatic hip osteoarthritis group (HOA) with SHOMRI>0 and HOOS≤80, and a control group (CG) with SHOMRI = 0 and HOOS>90. Patients underwent 3D motion analysis during stair ascent/descent at self-selected speed.

MAIN OUTCOME MEASURES

The primary outcome measurements were peak hip, knee, and ankle kinematics. General Estimation Equations were used to compare kinematics between groups (P ≤ .05).

RESULTS

The HOA group ascended stairs with a more internally rotated hip (CG = 1.77 ± 6.3; HOA = 4.97 ± 4.2; P = .02), more abducted hip (CG = -5 ± 2.7, HOA = -3.5 ± 3; P = .02), and a more externally rotated knee (CG = -8.02 ± 3; HOA = -10.63 ± 6.3; P = .02) and ankle (CG = -11.8 ± 6.1; HOA = -16.3 ± 5.6; P = .01). Similarly, HOA participants descended stairs with a more extended knee (CG = -15.5 ± 4.9; HOA = -12 ± 4.9; P = .01), and more externally rotated knee (CG = -10.1 ± 4.4; HOA = -13.1 ± 6.6; P = .04) and ankle (CG = -13.5 ± 5.3; HOA = -17.9 ± 5.5; P = .002).

CONCLUSION

Participants with hip OA-related morphology and symptoms ambulate stairs utilizing abnormal lower extremity mechanics.