Results of Conserve Plus Hip Resurfacing: prospective clinical, radiographic and ion study

We report the 3- to 5-year clinical, radiographic and serum ion level results of a prospective consecutive cohort of 42 hip resurfacing arthroplasties using the Conserve Plus implant in 39 male patients that were operated on by a single surgeon in a community hospital. Average age was 53 years (range 34-67) at surgery. There was one revision for a subcapital neck fracture. There were no surgery related complications. The survival of the implant was 95%. Clinical evaluation showed excellent results with a modified Charnley score of 17.6/18, Harris Hip Score of 96.2/100, WOMAC of 95.1/100, Oxford Score 15.3, and UCLA-Activity Score of 8/10. Radiographic analysis showed no implant at risk, no migration or signs of loosening, no neck narrowing and no osteolysis at final follow-up. Average cup inclination angle was 43.5° with 2 outliers (34° and 57°). Ion level study showed average cobalt in serum 1.04 µg/l (range 0-4) for the whole group, 0.7 µg/l (range 0-3) in patients with unilateral resurfacing and 2.0 µg/l (range 0-4) in patients with bilateral resurfacing. All patients had ion levels within the safe zone. This independent series of Conserve Plus HRA confirms good results at short- to mid-term with excellent wear characteristics. Results for avascular necrosis were equal to those for osteoarthritis.