Determinants of pain and functioning in hip osteoarthritis - a two-year prospective study

Prognostic Factors and Changes in Pain, Physical Functioning, and Participation in Patients With Hip and/or Knee Osteoarthritis: A Systematic Review

OBJECTIVE

This study aimed to systematically synthesize literature on prognostic factors of changes in either direction (ie, worsening or improvement) in pain, physical functioning, and participation in patients with knee and/or hip osteoarthritis (OA).

METHODS

Studies included in two preceding reviews underwent full-text screening for inclusion in the current review. Additionally, an extensive literature search was conducted in five databases. Title/abstract screening was performed using an active learning program. Inclusion criteria comprised patients diagnosed with knee and/or hip OA, with the dependent variable assessing pain, physical functioning, or participation. Potential associated prognostic factors were measured as independent variables. The methodologic quality of studies was assessed with the Hayden criteria.

RESULTS

A total of 31 studies were included in this systematic review. In patients with knee OA, pain worsening was associated with lower physical functioning (strong evidence) and with higher body mass index, ethnicity, and a higher comorbidity count (moderate evidence). Also, in patients with knee OA, pain improvement was associated with less pain at baseline (moderate evidence). In patients with knee and/or hip OA, worsening of physical functioning exhibited associations with higher body mass index, more pain, more hip pain, a higher comorbidity count, higher avoidance of activities (strong evidence), and ethnicity (moderate evidence). In patients with knee OA, improvement in physical functioning showed an association with higher vitality (moderate evidence). Regarding the remaining prognostic factors, there is weak, inconclusive, or inconsistent evidence for an association with the outcomes. In patients with hip OA, only weak evidence was found for three factors predicting a change in physical functioning.

CONCLUSION

This review encompasses prognostic factors associated with changes in either direction (ie, worsening or improvement) in pain, physical functioning, and participation. The results are consistent with other reviews. Future research should place a stronger emphasis on patients with hip OA and participation as an outcome.

Risk Factors and Population-Attributable Fractions for Incident Hip Osteoarthritis

Background

Despite the huge burden of hip osteoarthritis (OA) and the lack of effective treatment, research into the primary prevention of hip OA is in its infancy.

Purpose

We sought to evaluate risk factors for incident clinical and incident radiographic hip OA among middle-aged and older adults, to evaluate the importance of risk factors from a preventive perspective, and to estimate the percentage of new cases attributable to these risk factors.

Methods

We retrospectively reviewed data from the Rotterdam study, an open-population cohort study of individuals aged 55 years or older. Data including baseline age, sex, body mass index, smoking status, education level, diagnosis of diabetes, C-reactive protein (CRP), cam morphology, acetabular dysplasia, radiographic thumb OA, radiographic hip OA, and hip pain were assessed for their association with incident clinical hip OA and incident radiographic hip OA separately, after 11 years of follow-up. The population-attributable fractions (PAFs) of statistically significant modifiable risk factors were calculated, as well.

Results

New onset of clinical hip OA was seen in 19.9% (544 of 2729) and incident radiographic hip OA in 9.9% (329 of 3309). Female sex, education level below average (PAF 21.4%), and radiographic hip OA (PAF 3.4%) were statistically significantly associated with incident clinical hip OA. Female sex, age, overweight (PAF 20.0%), cam morphology (PAF 7.9%), acetabular dysplasia (PAF 3.6%), and radiographic thumb OA (PAF 4.7%) were statistically significantly associated with radiographic hip OA.

Conclusions

Our retrospective analysis suggests that, from a primary prevention perspective, the most important modifiable risk factors among middle-aged and older individuals may be low educational level for incident clinical hip OA and overweight for incident radiographic hip OA. Further study is warranted.

Comorbidities in people with hand OA and their associations with pain severity and sensitization: Data from the longitudinal Nor-Hand study

Objective

To determine whether the comorbidity burden and co-existing comorbidities are cross-sectionally and/or longitudinally associated with pain and pain sensitization in a cohort study of people with hand OA.

Design

We examined whether comorbidity burden and individual comorbidities based on the self-administered Comorbidity Index (range: 0-42) at baseline were associated with pain outcomes at baseline and 3 years follow-up. Pain outcomes included hand and overall bodily pain (range: 0-10) as well as pressure pain thresholds at the tibialis anterior muscle (kg/cm²) and temporal summation (distal radioulnar joint) as measures of central pain sensitization. We performed linear regression analyses adjusted for age, sex, body mass index, physical exercise and education.

Results

We included 300 and 196 participants in cross-sectional and longitudinal analyses, respectively. Using baseline data, the burden of comorbidities was associated with greater pain in hands (beta ​= ​0.61, 95% CI 0.37, 0.85) and overall body (beta ​= ​0.60, 95% CI 0.37, 0.87). Similar strength of associations was found between comorbidity burden (baseline) and follow-up pain. Among the individual comorbidities, back pain and depression were associated with nearly one unit higher pain score in hands and overall body at both baseline and follow-up. Only back pain was related to lower pressure pain thresholds at follow up (beta ​= ​-0.24, 95% CI -0.50, -0.001).

Conclusion

People with hand OA and greater comorbidity burden, co-existing back pain or depression reported greater pain severity than their counterparts, also 3 years later. These results acknowledge the relevance of accounting for comorbidities in the pain experience in people with hand OA.

Effects of physical exercise and body weight on disease-specific outcomes of people with rheumatic and musculoskeletal diseases (RMDs): systematic reviews and meta-analyses informing the 2021 EULAR recommendations for lifestyle improvements in people with RMDs

BACKGROUND

A European League Against Rheumatism (EULAR) taskforce was convened to develop recommendations for lifestyle behaviours in rheumatic and musculoskeletal diseases (RMDs). This paper reviews the literature on the effects of physical exercise and body weight on disease-specific outcomes of people with RMDs.

METHODS

Three systematic reviews were conducted to summarise evidence related to exercise and weight in seven RMDs: osteoarthritis, rheumatoid arthritis, systemic lupus erythematosus, axial spondyloarthritis (axSpA), psoriatic arthritis, systemic sclerosis and gout. Systematic reviews and original studies were included if they assessed exercise or weight in one of the above RMDs, and reported results regarding disease-specific outcomes (eg, pain, function, joint damage). Systematic reviews were only included if published between 2013-2018. Search strategies were implemented in the Medline, Embase, Cochrane Library of systematic reviews and CENTRAL databases.

RESULTS

236 articles on exercise and 181 articles on weight were included. Exercise interventions resulted in improvements in outcomes such as pain and function across all the RMDs, although the size of the effect varied by RMD and intervention. Disease activity was not influenced by exercise, other than in axSpA. Increased body weight was associated with worse outcomes for the majority of RMDs and outcomes assessed. In general, study quality was moderate for the literature on exercise and body weight in RMDs, although there was large heterogeneity between studies.

CONCLUSION

The current literature supports recommending exercise and the maintenance of a healthy body weight for people with RMDs.

The Management between Comorbidities and Pain Level with Physical Activity in Individuals with Hip Osteoarthritis with Surgical Indication: A Cross-Sectional Study

Background and Objectives: The degenerative pathology of the hip joint appears in young age groups, related to fem-oroacetabular impingement, and in advanced age, due to other inflammatory causes, with greater potential for severity in the presence of comorbidities. Objectives: To evaluate the participation of the main causes of osteoarthritis in relation to physical activities, s Body Mass Index (BMI) and television time (TV). Materials and Methods: 54 patients with surgical indication treated at an orthopedic referral university hospital were stratified into groups (Impact: I, Osteonecrosis/rheumatic: II, Infectious/traumatic: III), and the influence of comorbidities on physical activity performance, relative to BMI and TV time. Results: It was observed that the impact group was the most frequent (51.8%), with 79.6% under the age of 60 years. This group followed the general mean (p < 0.05), using the variables of comorbidity and the level of physical activity. Pain intensity, TV time, BMI showed no correlation with physical activity. Conclusion: Morphostructural changes (group I) represented the most frequent etiological group, and severe pain was common in almost the entire sample. Unlike BMI, comorbidity showed a significant relationship with the level of physical activity.

PROMIS PF correlates with HOOS, JR in patients with hip pain

Background

Patient-reported outcome measures (PROMs) are increasingly integrated into reporting requirements tied to reimbursement. There may be advantages to computer adaptive tests that apply to many different anatomical regions and diseases, provided that important information is not lost.

Questions

1) Does the Patient-Reported Outcomes Measurement Information System Physical Function (PROMIS PF) computer adaptive test correlate with the Hip injury and Osteoarthritis Outcome Score for Joint Replacement (HOOS, JR: a hip-specific PROM); 2) Is there any difference in the amount of variation explained by various factors (e.g. age, BMI, presence of concomitant knee pain) for both measures?

Methods

In this prospective, cross-sectional study of 213 patients, we assessed the Pearson correlation of PROMIS PF and HOOS, JR. To investigate the variation explained by various patient-level factors, we constructed two multivariable linear regression models.

Results

We found a large correlation between PROMIS PF and HOOS, JR (r 0.58, P < 0.001). Disabled or unemployed status was independently associated with both lower PROMIS PF and HOOS, JR scores (regression coefficient [β] -3.4; 95% confidence interval [CI] -5.8 to -1.0; P = 0.006 and β -11; 95% CI -17 to -5.0; P < 0.001, respectively). Private rather than public insurance was associated with both higher PROMIS PF and HOOS, JR scores (β 4.5; 95% CI 2.2 to 6.8; P < 0.001 and β 6.4; 95% CI 0.49 to 12; P = 0.034, respectively). No floor or ceiling effects were observed for PROMIS PF. HOOS, JR scores showed 4.2% floor and 0.5% ceiling effect.

Conclusions

This study adds to the evidence that general measures of physical limitations may provide similar information as joint- or region-specific measures.

Level of evidence

Level III.

Prognostic factors for progression of osteoarthritis of the hip: a systematic review

Background

Predicting which patients with hip osteoarthritis are more likely to show disease progression is important for healthcare professionals. Therefore, the aim of this review was to assess which factors are predictive of progression in patients with hip osteoarthritis.

Methods

A literature search was made up until 14 March 2019. Included were cohort and case-control studies evaluating the association between factors and progression (either clinical, radiological, or THR). Excluded were studies with a follow-up < 1 year or specific underlying pathologies of osteoarthritis. Risk of bias was assessed using the QUIPS tool. A best-evidence synthesis was conducted.

Results

We included 57 articles describing 154 different factors. Of these, a best-evidence synthesis was possible for 103 factors, separately for clinical and radiological progression, and progression to total hip replacement. We found strong evidence for more clinical progression in patients with comorbidity and more progression to total hip replacement for a higher Kellgren and Lawrence grade, superior or (supero) lateral femoral head migration, and subchondral sclerosis. Strong evidence for no association was found regarding clinical progression for gender, social support, pain medication, quality of life, and limited range of motion of internal rotation or external rotation. Also, strong evidence for no association was found regarding radiological progression for the markers CTX-I, COMP, NTX-I, PINP, and PIIINP and regarding progression to total hip replacement for body mass index.

Conclusion

Strong evidence suggested that 4 factors were predictive of progression of hip osteoarthritis, whereas 12 factors were not predictive of progression. Evidence for most of the reported factors was either limited or conflicting.

Protocol registration

PROSPERO, CRD42015010757

Electronic supplementary material

The online version of this article (10.1186/s13075-019-1969-9) contains supplementary material, which is available to authorized users.

Gait- and Posture-Related Factors Associated With Changes in Hip Pain and Physical Function in Patients With Secondary Hip Osteoarthritis: A Prospective Cohort Study

OBJECTIVE

To identify gait- and posture-related factors associated with changes in hip pain and physical function in patients with hip osteoarthritis (OA).

DESIGN

Prospective cohort study.

SETTING

Clinical biomechanics laboratory of a university.

PARTICIPANTS

Consecutive sampling of female patients with mild-to-moderate secondary hip OA (N=30).

MAIN OUTCOME MEASURES

Hip pain (visual analog scale) and physical function (physical component summary of the Medical Outcomes Study 36-Item Short-Form Health Survey) were measured at baseline and 12 months later. With changes in hip pain and physical function as dependent variables, linear regression analyses were performed with gait- and posture-related factors as independent variables with and without adjustment for age, joint space width, and hip pain or physical function at baseline. Posture-related factors included angles of thoracic kyphosis, lumbar lordosis, sacral inclination, spinal inclination, and spinal mobility. Gait-related factors were walking speed, steps per day, joint angles, external hip joint moment impulses, and daily cumulative hip moments.

RESULTS

Multiple linear regression analyses showed that limited hip extension (adjusted standardized B coefficient [95% confidence interval]: -0.52 [-0.88 to -0.17]) and limited external rotation angles (-0.51 [-0.85 to -0.18]) during walking were associated with the worsening of hip pain. An increased thoracic kyphosis (-0.54 [-0.99 to -0.09]), less sacral anterior tilt (0.40 [0.01-0.79]), reduced thoracic spine mobility (0.59 [0.23-0.94]), less steps per day (0.53 [0.13-0.92]), and a slower walking speed (0.45 [0.04-0.86]) were associated with deterioration in physical function.

CONCLUSIONS

Gait- and posture-related factors should be considered when assessing risk and designing preventive interventions for the clinical progression of secondary hip OA.

The application of mechanical diagnosis and therapy on hip osteoarthritis: A case report

Background: The prevalence and cost of hip osteoarthritis (OA) is rising. Mechanical diagnosis and therapy (MDT) is an orthopedic classification and treatment system based on mechanical and symptomatic response to repeated and sustained end-range movements. There has been no investigation of the association between MDT and patients diagnosed with hip OA. Case Description: This case report presents a 71-year-old female diagnosed with hip OA and matching the currently accepted clinical prediction rule (CPR) for symptomatic hip OA. The patient was classified and treated by a Diplomat of MDT and co-examiner using MDT. Outcomes: Short- and long-term (13 months) outcomes were excellent, demonstrating rapid abolishment of symptoms and improvement in function in 5 visits over 21 days. The patient demonstrated the ability to prevent and manage reoccurrence of symptoms independently; nevertheless, she received a total hip replacement which was not in accordance with current guidelines and recommendations. Conclusion: This case report raises questions about whether or not pathologies traditionally associated with the etiology of hip OA are actually at fault. Moreover, it raises questions about the utility of special tests and CPRs typically utilized to identify those structures. The case report provides preliminary evidence from one patient that MDT may be capable of providing effective short- and long-term outcomes in the management of hip OA.

Health enhancing physical activity in patients with hip or knee osteoarthritis - an observational intervention study

Background

Osteoarthritis is one of the leading causes of inactivity worldwide. The recommended level of health enhancing physical activity (HEPA) is at least 150 min of moderate intensity physical activity per week. The purpose of this study was to explore how the proportion of patients, who reached the recommended level of HEPA, changed following a supported osteoarthritis self-management programme in primary care, and to explore how reaching the level of HEPA was influenced by body mass index (BMI), gender, age and comorbidity.

Methods

An observational study was conducted using data from a National Quality Registry in which 6810 patients in primary care with clinically verified hip or knee osteoarthritis with complete data at baseline, 3 and 12 months follow-up before December 31^st 2013 were included. HEPA was defined as self-reported physical activity of at least moderate intensity either a) at least 30 min per day on four days or more per week, or b) at least 150 min per week. HEPA was assessed at baseline, and again at 3 and 12 months follow-up. Cochran’s Q test was used to determine change in physical activity over time. The association between reaching the level of HEPA and time, age, BMI, gender, and Charnley classification was investigated using the generalized estimation equation (GEE) model.

Results

The proportion of patients who reached the level of HEPA increased by 345 patients, from 77 to 82%, from baseline to 3 months follow-up. At 12 months, the proportion of patients who reached the level of HEPA decreased to 76%. Not reaching the level of HEPA was associated with overweight, obesity, male gender and Charnley category C, i.e. osteoarthritis in multiple joint sites (hip and knee), or presence of any other disease that affects walking ability.

Conclusions

Following the supported osteoarthritis self-management programme there was a significant increase in the proportion of patients who reached the recommended level of HEPA after 3 months. Improvements were lost after 12 months. To increase physical activity and reach long-lasting changes in levels of physical activity, more follow-up sessions might be needed.

The rate of joint replacement in osteoarthritis depends on the patient's socioeconomic status

Background and purpose - Assessment of potential disparities in access to care is a vital part of achieving equity in health and healthcare. We have therefore studied the effect of socioeconomic status (SES) on the rates of knee and hip replacement due to osteoarthritis. Methods - This was a cohort study in Skåne, Sweden. We included all residents aged ≥ 35 years with consultations between 2004 and 2013 for hip or knee osteoarthritis. We retrieved individual information on income, education, and occupation and evaluated the rates of knee and hip replacement according to SES, with adjustment for age and sex. Professionals, legislators, senior officials, and managers, and individuals with the longest education, served as the reference group. Results - We followed 50,498 knee osteoarthritis patients (59% women) and 20,882 hip osteoarthritis patients (58% women). The mutually adjusted rate of knee replacement was lower in those with an elementary occupation (hazard ratio (HR) = 0.81, 95% CI: 0.72-0.92), in craft workers and those with related trades (HR = 0.88, CI: 0.79-0.98), and in skilled agricultural/fishery workers (HR = 0.83, CI: 0.72-0.96), but higher in the 2 least educated groups (HR = 1.2 in both). The rate of hip replacement was lower in those with an elementary occupation (HR = 0.77, 95% CI: 0.68-0.87), in plant and machine operators/assemblers (HR = 0.83, CI: 0.75-0.93), and service workers/shop assistants (HR = 0.88, CI: 0.80-0.96). The rate of hip replacement was higher in the highest income group (HR = 1.1, 95% CI: 1.0-1.2). Interpretation - There was a lower rate of joint replacement in osteoarthritis patients working in professions often associated with lower socioeconomic status, suggesting inequity in access to care. However, the results are not unanimous, as the rate of knee replacement was higher in the least educated groups.

Stiffness, pain, and hip muscle strength are factors associated with self-reported physical disability in hip osteoarthritis

BACKGROUND

Physical disability (PD) is common among patients with osteoarthritis (OA) of the hip. Exercise therapy is proposed to be a potential intervention to reduce PD. However, the optimal targets of an exercise program are not known.

PURPOSE

The aim of the present study was to identify factors that explain the level of self-reported PD in patients with hip OA. Knowledge of these factors will help develop specific and effective exercise programs.

METHODS

Data from 149 patients with hip OA (85 men and 64 women) were analyzed. Self-reported PD was quantified using the physical function subscale of the Western Ontario and McMaster index. A stepwise regression analysis was conducted to identify significant factors associated with self-reported PD.

RESULTS

Stiffness, pain, and hip muscle strength were found to be significant factors related to the level of self-reported PD in hip OA. These factors explained 59% (r adjusted = 0.59) of the variance. Body mass index, gender, age, and passive internal hip rotation and flexion range of motion explained only minor parts of the dependent variable self-reported PD.

DISCUSSION AND CONCLUSION

Stiffness, pain, and hip muscle strength are associated with self-reported PD in hip OA. It is imperative that exercise treatments for hip OA include strategies to modify these factors. Further research should evaluate their role in preventing hip OA.

Relationship between strength, pain, and different measures of functional ability in patients with end-stage hip osteoarthritis

OBJECTIVE

Performance tests and self-reported questionnaires capture different domains of function in patients with lower extremity osteoarthritis, but the impairments related to each of these domains have not been elucidated. The purpose of this study was to determine how strength and joint pain influence performance-based tests and self-reported questionnaires of functional ability of individuals with end-stage hip osteoarthritis.

METHODS

Fifty-six patients scheduled to undergo unilateral total hip arthroplasty were included in this cross-sectional analysis. Subjects completed the Hip Outcome Survey (HOS) and pain in the affected hip was quantified on a scale from 0-10. Performance-based tests included the Six-Minute Walk Test (6MWT), the Timed Up & Go (TUG), and the Stair Climbing Test (SCT). Isometric strength of the hip abductors and knee extensors was tested and recorded. Hierarchical linear regressions were created to determine the contributions of pain, knee extensor strength, and hip strength for each outcome measure (TUG, 6MWT, SCT, and HOS). Height and body mass index were entered first, followed by pain, then knee extensor strength, and then hip abduction strength.

RESULTS

Greater pain significantly predicted lower HOS scores, but hip strength did not significantly improve the model. Hip pain was also significantly related to TUG, SCT, and 6MWT values, but hip and knee strength explained additional variance for these performance-based measures.

CONCLUSION

Self-report and performance-based measures capture different aspects of disability and are influenced by different underlying impairments. Both types of outcome measures should be used in studies that evaluate functional changes in patients with hip osteoarthritis.

Education attainment is associated with patient-reported outcomes: findings from the Swedish Hip Arthroplasty Register

BACKGROUND

Age, sex, and medical comorbidities may be associated with differences in patient-reported outcome scores after THA. Highest level of education may be a surrogate for socioeconomic status, but the degree to which this is associated with patient-reported outcomes after THA is not known.

QUESTIONS/PURPOSES

We investigated the national Swedish Hip Arthroplasty Register for the association of education attainment on patient-reported outcomes 1 year after THA; specifically, we evaluated level of education attainment against health-related quality of life (HRQoL), pain reduction, and satisfaction with treatment 1 year after THA.

METHODS

All THAs for osteoarthritis performed from 2005 through 2007 with complete patient-reported outcome measures (representing 49% of the THAs performed for this diagnosis) were selected from the Swedish Hip Arthroplasty Register. These cases were merged with national databases containing education attainment, marital status, and comorbidities (n = 11,464; mean age of patients, 64 years). The patient-reported outcome measure protocol included the HRQoL measure EuroQol five-dimension scale (EQ-5D), a VAS for pain, the Charnley classification survey, and a VAS addressing THA satisfaction. Linear regression analyses determined the association of preoperative patient factors with patient-reported outcomes.

RESULTS

High education attainment was associated with higher HRQoL (EQ-5D index ß(high) = 0.03 ± 0.01; EQ VAS ß(high) = 2.6 ± 0.5) after THA, whereas those with low and medium education were at risk for lower HRQoL. High education was associated with less pain after treatment (ß(high) = -3.3 ± 0.05). Individuals with low or medium education were at risk for less satisfaction with THA (p < 0.001).

CONCLUSIONS

Our results suggest clinicians should support patients with low and medium education to a greater extent. Identification of patients who will benefit most from THA and educating those at risk for poorer outcomes, like patients with low and medium education, ultimately may improve patient satisfaction, HRQoL, pain, and the cost utility of THA.

LEVEL OF EVIDENCE

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

Independent associations of socioeconomic factors with disability and pain in adults with knee osteoarthritis

BACKGROUND

The purpose of this study is to explore the relationship between function, pain and stiffness outcomes with individual and community socioeconomic status (SES) measures among individuals with radiographic knee osteoarthritis (rOA).

METHODS

Cross-sectional data from the Johnston County Osteoarthritis Project were analyzed for adults age 45 and older with knee rOA (n = 782) and a subset with both radiographic and symptomatic knee OA (n = 471). Function, pain and stiffness were measured using the Western Ontario and McMasters Universities Index of Osteoarthritis (WOMAC). Individual SES measures included educational attainment (<12 years, ≥12 years) and occupation type (managerial, non-managerial), while community SES was measured using Census block group poverty rate (<12%, 12-25%, ≥25%). SES measures were individually and simultaneously examined in linear regression models adjusting for age, gender, race, body mass index (BMI), occupational physical activity score (PAS), comorbidity count, and presence of hip symptoms.

RESULTS

In analyses among all individuals with rOA, models which included individual SES measures were observed to show that occupation was significantly associated with WOMAC Function (β =2.91, 95% Confidence Interval (CI) = 0.68-5.14), WOMAC Pain (β =0.93, 95% CI = 0.26-1.59) and WOMAC Total scores (β =4.05, 95% CI = 1.04-7.05), and education was significantly associated with WOMAC Function (β =3.57, 95% CI = 1.25-5.90) and WOMAC Total (β =4.56, 95% CI = 1.41-7.70) scores. In multivariable models including all SES measures simultaneously, most associations were attenuated. However, statistically significant results for education remained between WOMAC Function (β =2.83, 95% CI = 0.38-5.28) and WOMAC Total (β =3.48, 95% CI = 0.18-6.78), as well as for the association between occupation and WOMAC Pain (β =0.78, 95% CI = 0.08-1.48). In rOA subgroup analyses restricted to those with symptoms, we observed a significant increase in WOMAC Pain (β =1.36, 95% CI = 0.07-2.66) among individuals living in a block group with poverty rates greater than 25%, an association that remained when all SES measures were considered simultaneously (β =1.35, 95% CI = 0.06-2.64).

CONCLUSIONS

Lower individual and community SES are both associated with worse function and pain among adults with knee rOA.

Strength and functional deficits in individuals with hip osteoarthritis compared to healthy, older adults

PURPOSE

Hip osteoarthritis (OA) compromises quality of life for many individuals. This study quantified deficits in functional capacity for use in rehabilitation goal setting by combining assessments of muscle strength, function and physical activity in patients with hip OA and healthy adults.

METHOD

Twenty-six patients with end-stage hip OA and 18 healthy adults participated. Isometric muscle strength around the hip and knee was measured. Function was assessed using stair climbing, five-time-sit-to-stand, timed-up-and-go and 6-minute walk tests. The UCLA activity rating scale assessed physical activity. Analyses of covariance (ANCOVA) were used to assess differences between groups.

RESULTS

Patients had 30% less knee extensor (p < 0.001), 38% less knee flexor (p < 0.001), 10% less hip flexor (p = 0.47), 23% less hip extensor (p = 0.24) and 17% less hip abductor strength (p = 0.23) than healthy adults. Hip adductor strength was equal between groups (p = 0.93). Patients were 50% slower on the stair climbing test (p = 0.001), 34% slower on the timed-up-and-go test (p = 0.004), 34% slower on the five-time-sit-to-stand test (p = 0.001), and walked 28% less during the 6-min walk test (p < 0.001). Patients were less physically active (p = 0.001).

CONCLUSIONS

Patients had deficits in muscle strength, function and physical activity compared to healthy adults. Quantifying these deficits provides benchmarks for improvement during rehabilitation.

IMPLICATIONS FOR REHABILITATION

Hip osteoarthritis (OA) affects up to 28% of adults over the age of 65 and many individuals report functional and activity limitations directly related to their arthritic condition, posing a risk for future morbidity Total hip arthroplasty (THA) is the treatment of choice for decreasing pain and improving function, however, some individuals suffering from end-stage hip OA are not candidates for THA, and effective rehabilitation interventions to improve physical function are crucial Establishing estimates of the deficits in muscle strength, physical function and physical activity in people with and without hip OA can aid rehabilitation professionals in their goal setting and intervention planning Rehabilitation interventions should not only consist of muscle strengthening and functional training, but interventions to improve physical activity levels are required to improve overall physical functioning and to decrease risks for additional health complications.