Assessment of Disability Related to Hip Dysplasia Using Objective Measures of Physical Performance

Abstract

Background: Lower extremity physical performance measures (PPMs), which can objectively quantify functional ability, are an attractive adjuvant to patient-reported outcome (PRO) instruments. However, few tests have been validated for use in hip instability. Purpose: To evaluate 4 different PPMs for their ability to differentiate between young adults with hip dysplasia indicated for treatment with periacetabular osteotomy (PAO) and asymptomatic controls and to test inter- and intratest reliability and relationship with popular hip PRO instruments. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: A total of 24 symptomatic patients aged 15 to 39 years (100% female) with hip dysplasia (lateral center-edge angle <25°) indicated for treatment with PAO completed the visual analog scale (VAS) for pain, Hip disability and Osteoarthritis Outcome (HOOS) Pain subscale, HOOS Short Version (HOOS PS), International Hip Outcome Tool Short Version (iHOT-12), modified Harris Hip Score (mHHS), Patient Reported Outcome Measurement Information System (PROMIS) physical function (PF) and pain interference (PI), and 4 physical function tests: (1) self-selected walking speed (SSWS), sit-to-stand 5 times (STS5), (3) 4-square step test (FSST), and (4) timed stair ascent (TSA). A further 21 young, asymptomatic adults aged 18 to 39 years (91% female) also underwent testing. Between-group comparisons were made with unpaired t test with Bonferroni-Holm correction. Inter- and intrarater reliability was assessed in 38 participants by repeating PPMs at a second visit and using 2 raters. Spearman rank correlation coefficients were used to determine associations between PPMs and PRO instruments. Results: Significant differences between patients with hip dysplasia and controls were observed for all PRO instruments (HOOS Pain, 47.8 vs 99.2; HOOS PS, 61.9 vs 99.2; iHOT-12, 32.2 vs 99.2; mHHS, 54.5 vs 90.6; PROMIS PF, 41.4 vs 65.6; and PROMIS PI, 62.0 vs 39.1 [all P < .001]), and all PPMs (SSWS, 1.21 vs 1.53 m/s; STS5, 10.85 vs 5.95 s; FSST, 6.59 vs 4.03 s [all P < .001]; and TSA, 4.58 vs 3.29 s [ P = .002]). All 4 PPMs demonstrated excellent intra- and intertest reliability (intraclass correlation coefficient, 0.83-0.99). STS5, FSST, and TSA were correlated highly ( r > 0.5) with physical function PRO instruments, including PROMIS PF, mHHS, and iHOT-12. Conclusion: Patients with symptomatic hip dysplasia demonstrated significant impairment on functional testing compared with asymptomatic controls, and performance measure testing demonstrated excellent test-retest reliability. Timed stair ascent and sit-to-stand testing in particular were correlated strongly with physical function PRO instruments. PPMs may be a viable and well-received adjuvant to PRO instrument administration for patients with nonarthritic hip conditions, and investigation of the ability of PPMs to assess surgical outcomes for hip dysplasia is warranted.

Test–retest reliability for performance-based outcome measures among individuals with arthrogryposis multiplex congenita

“…Our between-days, test–retest reliability findings for performance-based tests are generally similar to reports among other patient populations [ 23 , 24 , 28 , 29 , 34 – 37 , 39 , 40 , 51 , 52 ]. For example, among adolescents and young adults with hip dysplasia and controls ( n = 34), Scott et al reported self-selected gait speed test–retest reliability over 10 timed meters of a 14-m course (ICC 2,1 = 0.93; 95%CI: 0.87-0.96), [ 23 ] similar to our 10mWT reliability results (ICC 3,k = 0.95; 95%CI: 0.90-0.97). Among children with neurological conditions, Graser et al also reported similar between-days reliability using 10-timed meters over a 14-m course (ICC 2,1 = 0.90; 95%CI: 0.80-0.95).…”

“…Among typically-developing children and young adults, ‘self-selected’ gait speeds for 11–30 year olds are, on average, 1.28–1.36 m/sec, [ 49 ] which is significantly faster than speeds obtained in our participants with AMC (i.e., 1.01–1.02 m/sec). Further, Scott et al found gait speeds of 1.2 ± 0.2 m/sec among adolescents and young adults with hip dysplasia ( n = 24), suggesting gait speeds with AMC, where multiple lower-limb regions are typically involved, are worse [ 23 ]. Collectively, results highlight the importance of evaluating and addressing reduced gait speed among individuals with AMC, particularly since ‘self-selected’ gait speed is better correlated to perceived gait quality when compared to other performance-based measures, like the 6-Minute Walk Test, in young adults with congenital, mobility-limiting conditions [ 50 ].…”

“…Collectively, results highlight the importance of evaluating and addressing reduced gait speed among individuals with AMC, particularly since ‘self-selected’ gait speed is better correlated to perceived gait quality when compared to other performance-based measures, like the 6-Minute Walk Test, in young adults with congenital, mobility-limiting conditions [ 50 ]. Scott et al also reported adolescents and young adults with hip dysplasia ( n = 24) had FSST times of 6.6 ± 2.5 s, as compared to controls ( n = 21; 4.0 ± 0.7 s) [ 23 ]. Individuals with AMC in our study had mFSST times that were double that of individuals with single-joint involvement and triple that of controls.…”

“…2 ) [ 22 ]. For some children, adolescent, and adult populations, such as those with neurological conditions and hip dysplasia, between-days test–retest reliability for the 10mWT has been reported [ 23 , 24 ]. The 10mWT, using ≥ 2 trials, is included in a core set of rehabilitation outcome measures recommended for adults with neurological conditions based on its established psychometric properties and clinical utility [ 22 ].…”

“…In various pediatric and adult populations, Four Square Step Test (FSST) test–retest reliability has been reported, as has concurrent, construct, and predictive validity for falls among adults [ 23 , 38 – 40 ]. With the FSST, individuals complete multi-directional stepping (i.e., forwards, lateral, and backwards) over canes arranged in a ‘ + ’ in a specified sequence [ 38 ].…”