PATIENTS AND METHODS
rheumatoid arthritis, infection, dementia, aseptic loosening)
RHEUMATOID ARTHRITIS, SYSTEMIC DISEASE, DISEASE, OSTEOARTHRITIS OF THE HIP, INFECTION, SECONDARY, MALIGNANT DISEASE
Between November 2004 and June 2007, 150 patients with primary or secondary osteoarthritis of the hip were included in a randomized study investigating polyethylene wear of five different articulations and migration of the implants. The randomization, surgical procedure, post‐operative treatment and method of wear measurement has previously been described in detail.The patients were randomized into five groups of cemented THAs with Participant flow diagram describing the original five study groups based on the different head‐cup articulations and the final three groups based on head material (stainless steel, CoCrMo, and Oxinium). Exclusions after 10 years follow‐up are sorted after revision causes (infection or aseptic loosening) and reasons for drop out (deceased or lost to follow‐up). The gender distribution, age and Harris Hip Score (median and range) in the three study groups are specified(A) Charnley flanged 40 monoblock, oval, 316 L stainless steel, matte surface (Ra 0.8 μm) femoral stem with a 22.2 mm head, which articulated with a Charnley Ogee UHMWPE acetabular cup. (B) Spectron EF CoCrMo femoral stem with a 28 mm CoCrMo modular femoral head, retrieved from study case n° 819, with abrasive marks on the stem‐cement interface, mainly on the posterior‐distal‐medial side. The collared Spectron EF stem was fabricated with a matte distal surface (Ra 0.7 μm) and a grit blasted roughened surface (Ra 7.3 μm) on the proximal third of the stem. The neck and collar are highly polished.Exclusion criteria were BMI > 35, uncompensated cardio‐pulmonary disease, malignant disease, dementia, rheumatoid arthritis or other serious systemic diseases.Of the 150 patients in the original study, 19 patients had deceased and 38 patients withdrew from the study and could therefore not provide a blood sample at 10 years follow‐up (not able or willing to participate) (Figure After 10‐year follow‐up, the remaining 81 patients (54 females and 27 men from the original five groups were regrouped into three groups, depending on the femoral head material used at the time of surgery) (Figure 