Table 1.

Patient demographics, failure rates, component details, and metal ion concentrations

Variable	Overall	THA	Resurfacing
Number of hips	190	149	41
Primary	143	122	41
Revision	27	27
Number of patients	172	131	41
Followup (months)*	40 (12–74)	36 (12–61)	54 (12–74)
Male:female (number of hips)	126:64	93:56	33:08
Age (years)*	50 (17–78)	50 (17–78)	50 (33–65)
Harris hip score (points)*	92 (24–100)	91 (24–100)	93 (56–100)
VAS pain score (points)*	1.9 (0–8)	2.0 (0–8)	1.7 (0–8)
Cup inclination (°)*	46 (35–61)	46 (34–61)	47 (39–59)
Femoral head diameter (mm)*	49 (40–57)	49 (40–55)	50 (45–57)
Number of patients with known metal ion levels	93	78	15
Cobalt (μg/L)*	13 (0–150)	14 (0–150)	12 (0–126)
Chromium (μg/L)*	6 (0–87)	5 (0–87)	7 (0–60)
Revisions (number of hips)	24	19	5
Revision rate (%)	13	13	12
Time to revision (months)*	45 (12–75)	43 (12–65)	49 (24–75)
Failure mode (number of hips)
Metallosis	9 (4.7%)	9 (6.0%)
Aseptic cup loosening	8 (4.2%)	6 (4.0%)	2 (4.9%)
Periprosthetic fracture	2 (1.1%)		2 (4.9%)
Infection	2 (1.1%)	2 (1.3%)
Cup malposition	1 (0.5%)	1 (0.7%)
Aseptic femoral loosening	1 (0.5%)		1 (2.4%)
Heterotopic ossification	1 (0.5%)	1 (0.7%)

* Values are expressed as mean, with range in parentheses.