Characteristics of the study sample.
| Characteristics | Hip Defect Absent, n = 48 | Grade 1 Hip Defect Present, n = 66 | p | Grade 2 Hip Defect Present, n = 80 | p |
|---|---|---|---|---|---|
| Age, yrs, mean (SD) | 64.1 (6.73) | 64.1 (6.84) | 0.95 | 65.5 (7.70) | 0.01 |
| BMI, kg/cm2, mean (SD) | 27.2 (3.99) | 28.2 (4.43) | 0.02 | 27.5 (4.20) | 0.53 |
| Hip pain† | |||||
| Presence‡ | 40% | 48% | 0.14 | 46% | 0.81 |
| Men | 22% | 44% | 0.002 | — | — |
| Women | 62% | 53% | 0.2 | — | — |
| Interaction p value, p = 0.003 | |||||
| Severity §, mean (SD) | 1.32 (3.14) | 2.10 (4.20) | 0.07 | 2.60 (5.11) | 0.03 |
| Leg strength, kg, mean (SD) | 101 (53.0) | 99 (53.0) | 0.71 | 98.0 (48.7) | 0.73 |
| Steps per day, mean (SD) | 7970 (3526) | 7444 (3245) | 0.15 | 7127 (3507) | 0.04 |
| Any BML | 5% | 20% | 0.003 | 23% | 0.009 |
| Presence of high cartilage signal | 42% | 60% | 0.002 | 62% | 0.009 |
| Men | 40% | 70% | < 0.001 | — | — |
| Women | 44% | 46% | 0.81 | — | — |
| Interaction p value, p = 0.008 | |||||
| Hip effusion† | |||||
| Presence* | 10% | 18% | 0.07 | 20% | 0.09 |
| Effusion CSA**, mean (SD) | 1.05 (0.79) | 1.16 (0.96) | 0.31 | 1.30 (1.01) | 0.02 |
| Presence of radiological hip OA | 28% | 30% | 0.94 | 40% | 0.002 |
| Men | 22% | — | — | 50% | 0.001 |
| Women | 27% | — | — | 27% | 0.97 |
| Interaction p value, p = 0.007 |
Significant data are in bold face. Results of t tests (continuous variables) and chi-squared tests (categorical variables), with standard errors of means calculated with clustering of observations on subjects at phase 2 and phase 3 taken into account. Two-way ANOVA test was used for estimating sex interactions.
↵† Pain score calculated using Western Ontario and McMaster Universities Osteoarthritis index.
↵‡ Presence of hip pain defined as grade 0 = no hip pain and grade 1 = pain score > 0.
↵§ For subjects with hip pain score > 0.
↵* Presence of hip effusion dichotomized as grade 0 = no effusion or/and effusion CSA ≤ 2.0 cm2, and grade 1 = effusion ≥ 2.0 cm2.
↵** Mean effusion and SD obtained using t test including only subjects with effusion CSA > 0. BMI: body mass index; BML: bone marrow lesions; CSA: cross-sectional area; OA: osteoarthritis.