Summary of the 4 osteoarthritis patients at the time of the primary operation, their failure mode and months to revision in whom the femoral head and the resurfacing implant were removed for analysis

Case no.	Age/Gender	Implant	Mode of failure	Months to revision	Side/Bilateral	Cement type/Viscosity
1	59/M	BHR 46-mm head, 52-mm cup	Fracture of the femoral neck	46	Right	Simplex/Low viscosity
2	62/M	Durom 54-mm head, 60-mm cup	Loosening of the femoral component	7	Right	Simplex/Low viscosity
3	55/F	ASR 40-mm head, 45-mm cup	Fracture of the femoral neck	2	Left/Bilateral	Palacos/High viscosity
4	58/M	BHR 50-mm head, 56-mm cup	Fracture of the femoral neck	24	Right/Bilateral	Simplex/Low viscosity

F: female; M: male; BHR: Birmingham Hip Resurfacing implant (Smith and Nephew, Memphis, TE), Durom (Zimmer, Winterthur, Switzerland); ASR = Articular Surface Replacement (DePuy, Leeds, UK).