Table 2.
Baseline characteristics of propensity score–matched patients
| HRA (n = 251) | THA (n = 251) | All (n = 502) | |||||
|---|---|---|---|---|---|---|---|
| Variable | Mean | SD | Mean | SD | p value | Mean | SD |
| Age at surgery | 53.6 | 6.0 | 54.1 | 6.2 | 0.353 | 53.9 | 6.1 |
| BMI | 28.6 | 4.7 | 28.5 | 4.2 | 0.779 | 28.6 | 4.5 |
| Charlson Comorbidity Index score | 0.1 | 0.5 | 0.1 | 0.5 | 0.652 | 0.1 | 0.5 |
| Baseline LEAS | 11.8 | 3.1 | 11.9 | 3.1 | 0.667 | 11.8 | 3.1 |
| Baseline HOOS pain | 49.3 | 13.9 | 49.8 | 14.8 | 0.685 | 49.6 | 14.3 |
| Baseline HOOS stiffness | 49.6 | 16.0 | 50.1 | 17.7 | 0.775 | 49.8 | 16.8 |
| Baseline HOOS ADL | 54.9 | 16.7 | 55.5 | 16.6 | 0.664 | 55.2 | 16.6 |
| Baseline HOOS sports and recreation | 32.8 | 20.1 | 33.0 | 20.9 | 0.913 | 32.9 | 20.5 |
| Baseline HOOS QOL | 27.0 | 16.3 | 27.3 | 17.0 | 0.823 | 27.2 | 16.6 |
| Baseline SF-12 PCS | 36.9 | 8.5 | 37.3 | 8.1 | 0.640 | 37.1 | 8.3 |
| Baseline SF-12 MCS | 52.6 | 11.2 | 53.6 | 10.1 | 0.290 | 53.1 | 10.7 |
| N | % | N | % | p value | N | % | |
| Valvular disease | 11 | 4.4 | 10 | 4 | 0.824 | 21 | 4.2 |
| Pulmonary circulation disease | 1 | 0.4 | 0 | 0 | 0.999 | 1 | 0.2 |
| Peripheral vascular disease | 2 | 0.8 | 0 | 0 | 0.499 | 2 | 0.4 |
| Other neurological disorder | 1 | 0.4 | 0 | 0 | 0.999 | 1 | 0.2 |
| Chronic pulmonary disease | 14 | 5.6 | 12 | 4.8 | 0.687 | 26 | 5.2 |
| Diabetes | 7 | 2.8 | 6 | 2.4 | 0.779 | 13 | 2.6 |
| Hypothyroidism | 9 | 3.6 | 9 | 3.6 | 0.999 | 18 | 3.6 |
| Renal failure | 0 | 0 | 2 | 0.8 | 0.499 | 2 | 0.4 |
| Liver disease | 1 | 0.4 | 0 | 0 | 0.999 | 1 | 0.2 |
| Lymphoma | 1 | 0.4 | 0 | 0 | 0.999 | 1 | 0.2 |
| Solid tumor without metastasis | 0 | 0 | 1 | 0.4 | 0.999 | 1 | 0.2 |
| Coagulopthy | 4 | 1.6 | 2 | 0.8 | 0.686 | 6 | 1.2 |
| Obesity | 40 | 15.9 | 34 | 13.5 | 0.450 | 74 | 14.7 |
| Fluid and electrolyte disorder | 4 | 1.6 | 5 | 2 | 0.999 | 9 | 1.8 |
| Deficiency anemia | 8 | 3.2 | 7 | 2.8 | 0.793 | 15 | 3 |
| Alcohol abuse | 0 | 0 | 1 | 0.4 | 0.999 | 1 | 0.2 |
| Psychosis | 3 | 1.2 | 2 | 0.8 | 0.999 | 5 | 1 |
| Depression | 14 | 5.6 | 11 | 4.4 | 0.538 | 25 | 5 |
| Hypertension | 83 | 33.1 | 81 | 32.3 | 0.849 | 164 | 32.7 |
| ASA score | 0.652 | ||||||
| 1 | 48 | 19.1 | 56 | 22.3 | 104 | 20.7 | |
| 2 | 188 | 74.9 | 182 | 72.5 | 370 | 73.7 | |
| 3–4 | 15 | 6 | 13 | 5.2 | 28 | 5.6 | |
| Charlson Comorbidity Index score | 0.380 | ||||||
| 0 | 222 | 88.4 | 228 | 90.8 | 450 | 89.6 | |
| 1+ | 29 | 11.6 | 23 | 9.2 | 52 | 10.4 | |
| Laterality | 0.858 | ||||||
| Right | 128 | 51 | 130 | 51.8 | 258 | 51.4 | |
| Left | 123 | 49 | 121 | 48.2 | 244 | 48.6 | |
| Year of surgery | 0.973 | ||||||
| 2007 | 27 | 10.8 | 30 | 12 | 57 | 11.4 | |
| 2008 | 64 | 25.5 | 60 | 23.9 | 124 | 24.7 | |
| 2009 | 65 | 25.9 | 69 | 27.5 | 134 | 26.7 | |
| 2010 | 73 | 29.1 | 72 | 28.7 | 145 | 28.9 | |
| 2011 | 22 | 8.8 | 20 | 8 | 42 | 8.4 | |
| Implants | |||||||
| Implant outer diameter, mm | – | ||||||
| 48 | 30 | 12 | 0 | 0 | 30 | 6 | |
| 50 | 98 | 39 | 0 | 0 | 98 | 19.5 | |
| 52 | 50 | 19.9 | 0 | 0 | 50 | 10 | |
| 54 | 60 | 23.9 | 56 | 22.3 | 116 | 23.1 | |
| 56 | 10 | 4 | 107 | 42.6 | 117 | 23.3 | |
| 58 | 2 | 0.8 | 43 | 17.1 | 45 | 9 | |
| 60 | 1 | 0.4 | 35 | 13.9 | 36 | 7.2 | |
| 62 | 0 | 0 | 6 | 2.4 | 6 | 1.2 | |
| 64 | 0 | 0 | 3 | 1.2 | 3 | 0.6 | |
| 66 | 0 | 0 | 1 | 0.4 | 1 | 0.2 | |
| Bearing surface | – | ||||||
| C on C | 0 | 0 | 23 | 9.2 | 23 | 4.6 | |
| C on XP | 0 | 0 | 133 | 53 | 133 | 26.5 | |
| M on XP | 0 | 0 | 90 | 35.9 | 90 | 17.9 | |
| Missing parts | 0 | 0 | 5 | 2 | 5 | 1 | |
| Resurfacing | 251 | 100 | 0 | 0 | 251 | 50 | |
HRA hip resurfacing arthroplasty, THA total hip arthroplasty, SD standard deviation, BMI body mass index, LEAS Lower Extremity Activity Scale, HOOS Hip Disability and Osteoarthritis Outcome Score, ADL activities of daily living, QOL quality of life, SF-12 12-item Short Form Health Survey, PCS physical component summary, MCS mental component summary, ASA score American Society of Anesthesiologists physical status classification system score, C on C ceramic on ceramic, C on XP ceramic on polyethylene, M on XP metal on polyethylene