Table 4.
Demographics, wear, histology, MRI, and intraoperative data for hip resurfacings and THAs presenting with unexplained pain
| Variable | Hip resurfacing | THA | p value |
|---|---|---|---|
| Number of hips | 10 | 24 | |
| Age (years)* | 49 (33–60) | 54 (42–66) | 0.32 |
| BMI (kg/m2)* | 24 (22–37) | 27 (19–40) | 0.48 |
| Male:female | 3:7 | 15:9 | 0.13 |
| Time to revision (months)* | 23 (18–50) | 45 (18–103) | 0.01 |
| Head size (mm)* | 45 (40–54) | 46 (38–53) | 0.90 |
| Acetabular inclination (°)* | 47 (33–51) | 46 (33–51) | 0.56 |
| Acetabular anteversion (°)* | 16 (7–21) | 20 (5–25) | 0.14 |
| Implant type | 0.15 | ||
| ASR (DePuy, Warsaw, IN, USA)† | 1 (10) | 12 (48) | |
| BHR (Smith & Nephew, Memphis, TN, USA)† | 7 (70) | 8 (32) | |
| Conserve Plus (Wright Medical, Memphis, TN, USA)† | 1 (10) | 2 (8) | |
| Cormet (Corin Group, Cirencester, UK)† | 0 (0) | 1 (4) | |
| Durom (Zimmer, Warsaw, IN, USA)† | 0 (0) | 1 (4) | |
| M2a (Biomet, Warsaw, IN, USA)† | 1 (10) | 1 (4) | |
| TLWR (μm/year)* | 3.3 (0–128.2) | 2.2 (0–85.6) | 0.45 |
| TVWR (mm3/year)* | 0.3 (0–26.2) | 0.3 (0–29.3) | 0.83 |
| ALVAL score* | 6 (3–10) | 7 (2–10) | 0.45 |
| Metallic particles (Grade 2–3)† | 2 (20) | 2 (8) | 0.56 |
| Tissue damage score (Grade 2–3)† | 6 (60) | 17 (68) | 0.71 |
| MRI synovial volume (mm3)* | 13,917 (0–198,100) | 24,663 (0–645,575) | 0.25 |
| MRI synovial thickness (mm)* | 8 (1–29) | 9 (1–45) | 0.82 |
* Values are expressed as median, with range in parentheses; †values are expressed as number, with percentage in parentheses; BMI = body mass index; ASR = Articular Surface Replacement; BHR = Birmingham Hip Resurfacing.