Functional improvements desired by patients before and in the first year after total hip arthroplasty

Hip resurfacing arthroplasty in women: A novel ceramic device enables near normal gait function

BACKGROUND

Gait function improves after Total Hip Arthroplasty (THA) but is not restored to normal levels. Metal-on-metal Resurfacing Arthroplasty (MoM-HRA) is an alternative to THA and has shown to restore normal levels gait function and physical activity but has been restricted to men owing to problems of metal-ion release. Ceramic HRA (cHRA) removes the cobalt-chrome bearing surfaces, thereby eliminating these specific metal-ion concerns and aiming to be safe for females.

RESEARCH QUESTION

Is there a difference in gait function of female cHRA patients compared to female THA using subjective and objective measures?

METHODS

Fifteen unilateral cHRA and 15 unilateral THA, age and BMI matched, completed patient reported outcome measures (PROMs) (Oxford Hip Score, EQ5d and MET score) and underwent gait analysis using an instrumented treadmill pre- (2-10 weeks) and post-operatively (52-74 weeks). Maximum walking speed (MWS), Vertical GRF of the stance phase, GRF symmetry index (SI) and spatiotemporal gait measures were recorded. Patients were compared to age, gender and BMI healthy controls (CON).

RESULTS

There were no differences in PROMs or gait function between groups pre-operatively. Post- operatively, cHRA had a higher MET score (11.2 vs 7.1, p = 0.02) and a higher MWS (6.2 vs 6.8 km/hr, p = 0.003) compared to THA. cHRA had a similar GRF profile to CON, whereas THA had a reduced push-off force at 70-77 % of the stance phase compared to CON. At faster walking speeds of 6 km/hr walking speed, THA displayed an asymmetric GRF profile (SI<4.4 %) whereas the cHRA patients continued to display a symmetrical gait profile. cHRA was able to increase step length from pre-op levels (63 vs 66 cm, p = 0.02) and produced a larger step length compared to THA (73 vs 79 cm, p = 0.02).

SIGNIFICANCE

Female cHRA returned to levels of gait function and activity similar to healthy controls unlike female THA.

Development of a clinical prediction rule to identify physical activity after total hip arthroplasty

OBJECTIVE

To develop clinical prediction rule (CPR) of physical activity at 1-year after total hip arthroplasty (THA).

DESIGN

Retrospective cohort study.

SETTING

University hospital with orthopedic surgery.

PARTICIPANTS

The study group included 321 patients (56 men) who underwent primary THA.

INTERVENTION

Not applicable.

MAIN OUTCOMES MEASURES

The data collected included age, body mass index, clinical score from the questionnaires, hip pain, range of motion, muscle strength, and Physical functions (10-Meter Walk Test, Timed Up and Go test and Sit-to-stand). Patients were classified into sufficient and insufficient activity groups based on their University of California, Los Angeles (UCLA) activity score 1 year after THA. Variables measured preoperatively and at 3 weeks postoperatively were analyzed using univariate and multivariate methods to derive CPR for physical activity.

RESULTS

A CPR was developed using the following five factors and cut-offs: age, ≤70.5 years; preoperative UCLA activity score, ≥3.5; preoperative hip abduction strength, ≥0.54 Nm/kg; preoperative knee extension strength, ≥1.04 Nm/kg; and 10-Meter Walk Test, ≤8.49 s at 3 weeks after surgery. The presence of four of the five factors predicted a sufficient physical activity level at 1-year, with a positive likelihood ratio of 5.94 and probability of 85.4%. The presence of five predictor variables increased the probability of sufficient physical activity after THA to 94.7%.

CONCLUSION

This study developed a CPR for physical activity at 1-year after THA. Having four or more of the five measurements were useful indicators for predicting of physical activity at 1 year postoperatively.

Dual Mobility Cup: Does It Improve Patient's Satisfaction After Total Hip Arthroplasty? A Prospective Comparative Randomized Study

INTRODUCTION

Despite the great success of total hip arthroplasty (THA), many patients were fairly dissatisfied after surgery. Therefore, patient-reported outcome measures have become of an utmost importance in assessing the results after joint replacement. This study was conducted to compare the postoperative patient-reported satisfactions after implantation of two commonly used THA designs.

METHODS

Of 180 patients, who initially fulfilled the study selection criteria and received cementless THA, 165 patients were finally eligible and enrolled in this prospective comparative randomized study. All surgeries were carried out between 2010 and 2018. Two groups of homogenous demographic and clinical data were present. Group A patients (n = 80) were treated by large head THA, whereas group B (n = 85) received dual mobility cup designs. The Western Ontario McMaster Universities Osteoarthritis Index and visual analog scale were used for clinical evaluation. The degree of improvement that the patient expected and hoped before undergoing their surgeries was estimated using the score of the new knee society. The self-administered patient satisfaction scale was used to record the levels of patient satisfaction after surgery, and their values were statistically analyzed in relation to preoperative expectation scores (ie, score of the new knee society) and different clinical and sociodemographic variables.

RESULTS

After a mean follow-up of 79 ± 4.13 months (range 24 to 96 months), both groups recorded a significant improvement (P < 0.05) in Western Ontario McMaster Universities Osteoarthritis Index and visual analogue scale scores. Patients of group B were significantly more satisfied (P < 0.05) than those of group A up to the first postoperative year. Certain studied variables were linked to superior satisfaction results among group B at the last follow-up.

CONCLUSIONS

Dual mobility THA provides better patient satisfaction than their standard large head alternatives specifically among elderly patients, socially unsupported individuals, farmers, heavy manual workers, and those with high levels of expectations.

CLINICAL TRIAL REGISTRATION

Clinical Trials.gov identifier: NCT04333316.

Effects of types and degrees of ankylosing spondylitis hip structural damages on post-total hip arthroplasty outcome measurements

To determine the effects of ankylosing spondylitis (AS)-associated hip damages on the outcome measurements after total hip arthroplasty (THA).The medical records of 122 patients with AS (181 hips) who underwent THA were retrospectively reviewed. The mean follow-up was 43.9 (32-129) months. The types and degrees of hip damages were evaluated by preoperative hip X-rays. The patients were grouped according to the satisfaction degree after the operation. Univariable and multivariable statistical analyses were conducted.The intraclass correlation coefficients for the assessment between the 2 reviewers in the study were 0.86 to 0.97. Cox regression showed that femoral head erosion severity had an effect on the recovery time of independent walking without crutches postoperatively (odds ratio = 1.467, 95% confidence interval: 1.050-2.409, P = .025). The mean time to recover independent walking in the severe femoral head erosion group was 7.3 ± 0.9 weeks, which was 4.6 ± 0.4 weeks longer than in the non-severe femoral head erosion group, as confirmed by the log-rank (Mantel-Cox) test (Chi-squared = 11.684, P = .001). The multivariable analysis showed that higher acetabular sclerosis scores correlated with lower postoperative dissatisfaction risk (odds ratio = 0.322, 95% confidence interval: 0.136-0.764). The multiple linear regression analysis showed that postoperative range of motion (ROM) improvement was affected by preoperative ROM of the hip, space narrowing degree, and ceramic-ceramic material for the weight-bearing surface (F = 179.81, P < .001), with preoperative ROM of the hip having the greatest impact.Severe femoral head erosion prolongs the recovery time of independent walking after THA. Acetabular sclerosis is not associated with poor outcomes in patients with AS-associated hip damage undergoing THA.

Pragmatic Home-Based Exercise after Total Hip Arthroplasty - Silkeborg: Protocol for a prospective cohort study (PHETHAS-1)

Introduction: Rehabilitation exercises are offered to patients after total hip arthroplasty (THA); however, the effectiveness and optimal type and dose of exercise remains unknown. The primary objective of this trial is to indicate the preliminary efficacy of home-based rehabilitation using elastic band exercise on performance-based function after THA, based on the relationship between the performed exercise dose and the change in performance-based function (gait speed) from 3 (start of intervention) to 10 weeks (end of intervention) after surgery. The secondary objective is to investigate if a dose-response relationship exists between the performed exercise dose and changes in: hip-related disability, lower-extremity functional performance, and hip muscle strength Methods: In this prospective cohort study, patients scheduled for THA will be consecutively included until 88 have completed the intervention period from 3 to 10 weeks postoperatively. Participants perform the standard rehabilitation program with elastic band exercises. Exercise dose (exposure) will be objectively quantified using a sensor attached to the elastic band. The primary outcome is gait speed measured by the 40-m fast-paced walk test. Secondary outcomes include: patient reported hip disability (Hip disability and Osteoarthritis Outcome Score (HOOS)), hip muscle strength (hand-held dynamometry) and lower extremity function (30-s chair stand test). Discussion: This trial will add knowledge concerning the relationship between performed exercise dose and post-operative outcomes after THA. The protocol paper describes the study design and methods in detail, including the statistical analysis plan. Trial registration: Pre-registered on March 27, 2017 at ClinicalTrails.gov (ID: NCT03109821).

Gait analysis in patients after bilateral versus unilateral total hip arthroplasty

BACKGROUND

Gait abnormalities were reported in patients after total hip arthroplasty (THA). One-stage bilateral THA was introduced for bilateral hip pathologies, showing similar clinical and surgical outcome to unilateral procedure. However, no studies analyze the gait features after bilateral THA surgery compared to unilateral THA.

RESEARCH QUESTION

Are there differences in gait characteristics between bilateral and unilateral THA patients and are there differences between these cases and asymptomatic age-matched healthy subjects?

METHODS

In this prospective observational study, thirty-five patients with bilateral (n = 18) or unilateral THA (n = 17) and twenty asymptomatic age-matched volunteers were studied. Participants underwent three-dimensional gait analysisin order to detect gait spatial-temporal and kinematic (Gait Variable Score - GVS) parameters. Mobility (Timed Up and Go - TUG), fear of movement (Tampa Scale of Kinesiophobia - TSK) and pain during walking (Numeric Rating Scale - NRS) were also assessed. Patients were evaluated the day before surgery and at seven days, whereas healthy subjects underwent a single evaluation. ANOVA was used to assess differences between the three groups at each time-point and within-group differences in bilateral and unilateral groups.

RESULTS

At baseline, no differences between the two groups of patients were found. As expected, their gait spatial-temporal and kinematic parameters and functional variables were impaired with respect to healthy subjects, both before and after surgery. After surgery, GVS Pelvic-TILT closer to normative values, longer stance and shorter swing phases were found in bilateral cases compared to unilateral patients. Moreover, a higher NRS score was found in bilateral patients, whereas TUG and TSK revealed no differences between the two groups of patients.

SIGNIFICANCE

The current findings, focusing on short-term effectiveness of bilateral THA, could assist physiotherapists in selecting the best ambulation training and an appropriate rehabilitation approach immediately after surgery.

PROGRESSIVE REHABILITATION AFTER TOTAL HIP ARTHROPLASTY: A PILOT AND FEASIBILITY STUDY

BACKGROUND

The incidence of total hip arthroplasty (THA) has increased, due in part to younger individuals undergoing the procedure. Surgical techniques and biomaterials have improved, but rehabilitation has not kept pace with the needs of a changing demographic.

HYPOTHESIS/PURPOSE

The purpose of this study was to evaluate the feasibility and preliminary effectiveness of a progressive strengthening and functional retraining intervention after THA.

STUDY DESIGN

Intervention study.

METHODS

Twenty patients participated in the control group (n=10) or experimental group (n=10). The experimental intervention had few supervised sessions in the early phase after THA (weeks 0-12), followed by supervised, progressive, and high-level activity retraining in the later phase (weeks 12-16). Training in the experimental group was tailored to individual patient goals, which included a variety of vocational and recreational activities. The control group participated in usual rehabilitation care as prescribed by their surgeon. Therefore, the duration and content of rehabilitation of the control group therapy was not constrained. Testing included three-dimensional motion analysis of gait and a clinical evaluation prior to surgery and 16 weeks post-surgery. Change scores were calculated for pain, the Timed Up and Go (TUG), the Stair Climb Test (SCT), the Six-minute Walk Test (6MWT), the Thirty Second Chair Rise Test (30-CRT), strength, the Hip Outcome Scale (HOS), the Hip Dysfunction and Osteoarthritis Outcome Score for Joint Replacement (HOOS Jr), ground reaction force during stance, hip abduction moment, sit to stand ground reaction force, and symmetry between limbs during stance and sit to stand and compared between groups. Patient satisfaction and number of rehabilitation visits were also compared. Safety and feasibility were assessed using descriptive analysis of the number adverse events.

RESULTS

One patient dropped from the control group prior to rehabilitation. The intervention group had a significantly greater improvement for the 6MWT than the control group (p=0.011), functional questionnaires (p=0.034), hip abduction strength on the non-surgical side (p=0.01) and greater satisfaction (96 vs 84 out of 100; p=0.03) at the conclusion of the intervention. The intervention group demonstrated a significantly greater improvement in force symmetry during sit-to-stand (p=0.041) as compared to the control group. There were no other significant differences in change scores for functional measures or discrete biomechanical metrics.

CONCLUSION

This physical therapy protocol, which focused on reducing supervised visits early after THA and retraining higher level activities later in the course of recovery, had a positive effect on biomechanics and functional outcomes without compromising safety. The effect of the experimental intervention was most appreciable for the 6MWT, non-surgical hip strength, satisfaction, and movement symmetry.

LEVEL OF EVIDENCE

2B.

Pragmatic Home-Based Exercise after Total Hip Arthroplasty - Silkeborg: Protocol for a prospective cohort study (PHETHAS-1)

Introduction: Rehabilitation exercises are offered to patients after total hip arthroplasty (THA); however, the effectiveness and optimal type and dose of exercise remains unknown. The primary objective of this trial is to indicate the preliminary efficacy of home-based rehabilitation using elastic band exercise on performance-based function after THA, based on the relationship between the performed exercise dose and the change in performance-based function (gait speed) from 3 (start of intervention) to 10 weeks (end of intervention) after surgery. The secondary objective is to investigate if a dose-response relationship exists between the performed exercise dose and changes in: hip-related disability, lower-extremity functional performance, and hip muscle strength Methods: In this prospective cohort study, patients scheduled for THA will be consecutively included until 88 have completed the intervention period from 3 to 10 weeks postoperatively. Participants perform the standard rehabilitation program with elastic band exercises. Exercise dose (exposure) will be objectively quantified using a sensor attached to the elastic band. The primary outcome is gait speed measured by the 40-m fast-paced walk test. Secondary outcomes include: patient reported hip disability (Hip disability and Osteoarthritis Outcome Score (HOOS)), hip muscle strength (hand-held dynamometry) and lower extremity function (30-s chair stand test). Discussion: This trial will add knowledge concerning the relationship between performed exercise dose and post-operative outcomes after THA. The protocol paper describes the study design and methods in detail, including the statistical analysis plan. Trial registration: Pre-registered on March 27, 2017 at ClinicalTrails.gov (ID: NCT03109821).

Changes of and interrelationships between performance-based function and gait and patient-reported function 1 year after total hip arthroplasty

Background

The aim of this prospective study is to evaluate the degree of improvement in, and interrelationships between, performance-based function, gait, and patient-reported function 1 year after total hip arthroplasty (THA) in patients with primary hip osteoarthritis (OA).

Materials and methods

Thirty-four patients with hip OA, with a mean age of 67 years (standard deviation, SD 9 years), and 25 age- and gender-matched healthy controls performed three performance-based functional tests, instrumented three-dimensional gait analysis, and completed the Hip disability and Osteoarthritis Outcome Score prior to and 1 year after THA. Effect sizes with 95 % confidence intervals were calculated as measures of the magnitude of improvement in performance after surgery.

Results

Performance-based function displayed large improvements 1 year after THA. Overall gait patterns, quantified using a kinematic and a kinetic gait index, respectively, revealed moderate improvements in kinematics of the operated limb and kinetics of the contralateral limb. Patient-reported function displayed the largest improvement after surgery.

Conclusions

The findings of this study suggest that objectively measured improvements in performance-based function and gait are not in line with patient-reported functional improvements, highlighting the importance of using both subjective and objective methods for evaluating function following THA.

Level of evidence

III.

Hip abductor strength and fatigue are associated with activity levels more than 1 year after total hip replacement

Despite improvements in pain and function, people who undergo total hip arthroplasty (THR) may not always return to desired levels of physical activity (PA). The factors associated with low activity levels are not fully understood. Abductor weakness and fatigue have both been proposed as factors that limit activity in older adults or people with hip osteoarthritis, but have not been investigated after THR. We hypothesized that abductor weakness and fatigue are associated with lower activity levels in people who have undergone a THR and that fatigue mediates the association between abductor strength and activity. We evaluated 16 subjects (24 ± 10 months post-THR; age 56.8 ± 8.4 yrs; BMI 31 ± 7 kg/m² ). Fatigue was assessed using the PROMIS fatigue short-form 7a. Peak isometric hip abductor torque was assessed using a dynamometer with subjects in a sidelying position. We assessed activity level using the UCLA activity score. We used Pearson correlations to explore the associations among the variables. Next we used a three-step linear regression procedure to test whether or not fatigue acted as a mediator between abductor torque and UCLA activity scores. Higher abductor torque was associated with less fatigue (R²  = 0.275; p = 0.037) and with higher UCLA scores (R²  = 0.488, p = 0.003). Higher fatigue was associated with lower UCLA scores (R²  = 0. 307, p = 0.017), however there was no evidence of mediation. This suggests that addressing both abductor strength and fatigue may increase physical activity. Statement of Clinical Significance: Fatigue and abductor weakness should be evaluated in sedentary THR patients presenting for long-term follow-up. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1519-1525, 2018.

Rehabilitation needs approached by health professionals at a rheumatism hospital

OBJECTIVE

The aim of the present study was to examine the characteristics of patients referred to occupational therapists (OTs), physiotherapists (PTs) and social workers (SWs) at a rehabilitation unit in a hospital specializing in rheumatology, and the rehabilitation needs that clinicians and patients agreed should be addressed in the encounters with the particular health professional groups.

METHODS

Consecutive hospitalized patients at a rheumatism hospital were recruited by the health professionals. Questions about patient characteristics and rehabilitation needs were posed. Free-text responses to questions about rehabilitation needs were coded by the International Classification of Functioning, Disability, and Health (ICF).

RESULTS

The patients varied considerably in age distribution, disease duration, disability level and diagnoses, and several patients had comorbidities. The rehabilitation needs classified under the component Body Function fell into the chapters: Sensory Functions and Pain (PTs), Functions of Cardiovascular System (PTs), Neuromusculoskeletal and Movement-Related Functions (OTs, PTs); under the Activity and Participation component, these were: General Tasks and Demands (OTs), Mobility (OTs), Self-Care (PTs), Interpersonal Interactions and Relationships (SWs) and Major Life Stress (SWs); and under the Environmental Factors component these were: Products and Technology (OTs) and Services, Systems and Politics (SWs).

CONCLUSIONS

The patients were fairly heterogeneous. The needs identified in the encounters with the different professional groups fell into all three components of the ICF, and there was only a minor overlap between the health professionals at the chapter level of the ICF.

Physical Functioning and Prediction of Physical Activity After Total Hip Arthroplasty: Five-Year Followup of a Randomized Controlled Trial

OBJECTIVE

To examine whether the 1-year effects from a previous walking skill training program on walking and stair climbing still persist 5 years following total hip arthroplasty (THA), to examine recovery of physical functioning from before to 5 years after surgery, and to identify predictors of physical activity 5 years after THA from preoperative measures.

METHODS

We performed a 5-year followup of a randomized controlled trial and a longitudinal study. Sixty participants with a mean age of 70 years (range 50-87 years; 95% confidence interval 68, 72 years) were assessed. Outcome measures were the 6-minute walk test, the stair climbing test (SCT), active hip range of motion (ROM), self-efficacy, Hip Dysfunction and Osteoarthritis Outcome Score (HOOS), and University of California, Los Angeles (UCLA) activity scale. Data were analyzed by Student's t-tests, generalized linear model, and multivariate regression analyses.

RESULTS

The training and control groups were approximately equal on outcome measures of physical functioning, pain, and self-efficacy at 5 years (P > 0.05). In the total group, the recovery course was unchanged from 1 to 5 years (P > 0.05), except for 9% improvement in ROM (P < 0.001) and an increase in time on SCT of 18% (P = 0.004). Preoperative HOOS pain (P = 0.022) and HOOS sport (P = 0.019) predicted UCLA activity scale 5 years after THA.

CONCLUSION

At 5 years after THA, the control group had caught up with the training group on physical functioning, and the participants led an active lifestyle. Those with worse preoperative scores on pain and physical functioning in sport were at risk of being less physically active in the long term following THA.

Identifying clinically meaningful benchmarks for gait improvement after total hip arthroplasty

There are no established benchmarks for gait mechanics after total hip arthroplasty (THA). This study sought to identify minimum clinically important postoperative (MCIP) or minimum clinically important improvement (MCII) values for self-selected walking speed, sagittal plane dynamic hip range of motion (HROM) (peak flexion-peak extension) and peak hip adduction moments measured during quantitative gait analysis. Preoperative and 1-year postoperative data collected during quantitative gait analysis, along with Harris Hip Scores (HHS), for 145 subjects were collected from a motion analysis data repository. The MCIP (or MCII) was defined as the 75th percentile mark on a plot of the cumulative percent of subjects with HHS ≥ 80 versus the postoperative value (or change) in the respective variable. 95% confidence intervals (CI) were calculated. Logistic regression was used to test the association of age, sex, BMI, and preoperative HHS with benchmarks. The MCIP of speed was 1.34 m/s (95%CI 1.30, 1.37); MCII was 0.32 (0.30, 0.35) m/s. The HROM MCIP was 30.0° (29.4°, 30.7°); MCII was 13.3° (12.1°, 14.8°). The adduction moment MCIP was 4.2% Body Weight × Height (4.0, 4.4); MCII was 0.87 (0.57, 1.17) % Body Weight × Height. Women were more likely to achieve MCII for HROM and MCIP for adduction moment (ORs 2.4-11.6, p ≤ 0.031). Lower BMI predicted HROM and adduction moment MCIPs (ORs 0.85-0.88, p ≤ 0.015). Lower preoperative HHS predicted speed, HROM and adduction moment MCIIs (ORs 0.95-0.97, p ≤ 0.012). With further validation, clinically-relevant gait benchmarks can enhance efforts to improve THA outcomes.

Preoperative factors associated with postoperative gait kinematics and kinetics after total hip arthroplasty

OBJECTIVE

To determine how patient factors: age, sex, body mass index (BMI), clinical scores and physical exam findings, are associated with gait recovery after total hip arthroplasty (THA).

METHOD

145 subjects, who were evaluated with standard gait analysis, the Harris Hip Score (HHS), and a physical exam including passive range of motion (ROM), hip abductor strength assessment, before and after primary unilateral THA, were identified from an IRB-approved repository. Sagittal plane dynamic ROM and 3D peak external moments were averaged from operated-side normal-speed trials at each visit. We used linear regression analysis to evaluate the association among preoperative clinical factors and postoperative gait, with and without controlling for the influence of preoperative gait variables.

RESULTS

Sagittal and transverse plane moments, and the peak abduction moment seen in early stance, significantly improved after THA (p < 0.001, effect size d = 0.22-1.04). The peak adduction moment did not change significantly (p = 0.646), although the change ranged from -2.7 to + 4.0 %Body weight × height (-80% to +315%). Preoperative gait, clinical factors and patient characteristics predicted up to 33% of the variability in postoperative gait. Notably, greater preoperative abductor strength was associated with higher postoperative adduction and external rotation moments (R = 0.197-0.266, p < 0.05) after adjusting for age, sex, BMI and preoperative gait.

CONCLUSION

Preoperative clinical factors predicted several specific aspects of objectively-characterized postoperative gait function. Physical exam findings can augment the predictive ability of clinical outcome measures, and potentially help guide rehabilitation plans.

Are Harris hip scores and gait mechanics related before and after THA?

BACKGROUND

Discordance between subjective and objective functional measures hinders the development of new ways to improve THA outcomes.

QUESTIONS/PURPOSES

We asked if (1) any kinematic or kinetic gait variables are correlated with preoperative Harris hip scores (HHS), (2) any kinematic or kinetic gait variables are correlated with postoperative HHS, and (3) pre- to postoperative changes in any kinematic or kinetic gait variables are associated with the change in HHS?

METHODS

For this retrospective study, an institutional review board-approved data repository that included all individuals who participated in motion analysis research studies was used to identify subjects evaluated before (n=161) and at least 6 months after primary unilateral THA (n=156). Selected kinematic (sagittal plane dynamic hip ROM and kinetic (peak external moments about the hip in the sagittal, frontal, and transverse planes) gait variables were collected at subjects' self-selected normal walking speeds. We used first-order partial correlations to identify relationships between HHS and gait variables, controlling for the influence of speed.

RESULTS

Preoperative HHS correlated with hip ROM (R|speed=0.260; p<0.001) and the peak extension moment (R|speed=0.164; p=0.038), postoperative HHS correlated with the peak internal rotation moment (R|speed=0.178; p=0.034), and change in HHS correlated with change in hip ROM (R|speed=0.288; p=0.001) and peak external rotation moment (R|speed=0.291; p=0.002). Similar associations were seen when the HHS pain and function were analyzed separately.

CONCLUSIONS

This study identified relationships between a common clinical outcome measure and specific, modifiable gait adaptations that can persist after THA-ROM and transverse plane gait moments. Addressing these aspects of gait dysfunction through focused rehabilitation could be a new strategy for improving clinical outcomes. Prospective studies are needed to evaluate this concept.

LEVEL OF EVIDENCE

Level III, diagnostic study. See the Instructions for Authors for a complete description of levels of evidence.