We reviewed 96 consecutive cementless total hip replacements with four different designs; 21 PCA, 25 Harris Galante Porous/Harris Galante I (stem/cup), 25 Profile Porocoat/Tri-Lock Plus (stem/cup) and 25 Profile HA-coated/Tri-Lock Plus (stem/cup). The operations were performed in the period 1984 to 1991. Median follow-up ranged from 12 to 16 years in the four groups. Mean linear wear rates ranged from 0,17 to 0,21 mm/year in the four groups, and there were no statistically significant differences between the groups (p=0,9). Moderate or extensive osteolysis was found in 46 of the 96 included hips. The association between wear and extent of osteolysis was statistically significant (p=0,006). We found poor twelve-year survival of the primary prostheses in all four groups (50–70%), mainly due to revisions because of wear of the polyethylene liner and/or osteolysis. The sparsely documented Profile/Tri-Lock Plus systems did not perform statistically significantly better than the PCA and the HG. The poor long term results with these uncemented total hip arthroplasties illustrate the necessity of regular radiographic evaluation in order to detect osteolysis and liner-failure which both generally are asymptomatic until catastrophic failure appears.

Aims: To assess the influence of hip disease on the risk of revision, we studied different disease groups among 53 698 primary total hip replacements (THRs) reported to the NAR between 1987 and 1999. Methods: the revision rate in the 8 most common hip diseases were compared by kaplan-meier survival analyses and cox multiple-regression. To eliminate the influence of prosthesis type a subgroup of 16217 charnley prostheses were analysed. Results: we found statistically significant differences in prosthesis survival among the hip diseases, but after adjustment for prosthesis type most of the differences disappeared. In patients ≤60 years, 59% of the prostheses were uncemented and 33% could be defined as inferior uncemented prostheses. In the charnley subgroup only complications after fracture of the femoral neck had an increased risk for revision compared to primary osteoarthritis (rr 1.5, p=0.005). 10 years survival for cemented charnley prostheses with osteoarthritis was 92.0% for patients ≤60 years and 93.5% for patients > 60 years. Conclusions: after adjustment the results for all disease groups were good. The results of thrs in disease-groups where patients are operated on at a young age were less good because these patients had often been given inferior uncemented prostheses.

Aims: The mid- and long-term results of uncemented cups are uncertain. The aim of this study was to assess their results and to compare them with the most common cemented cup, the Charnley. Material and methods: In the study we included only patients under the age of 60 that had been operated with one of the 10 most common uncemented cup brands or the Charnley cup. Only brands that had been in use for at least 6 years were included. There were only minor differences among the brands concerning age, gender and diagnosis. Survival percentages were calculated with the Kaplan-Meier method. Results: With all cup revisions (change of cup or polyethylene liner) as end-point, the overall 5 year survival probability was 97% (95% CI: 96.3 97.3) which decreased to 86% (95% CI: 84.4 Ð 87.5) at 10 years. The 10 years survival varied from 74% for the Atoll cup to 88% for the Optiþx and the Harris-Galante cup, whereas for the cemented Charnley cup the 10 years survival probability was 94%. For the uncemented cups the increase in revision risk after 6 years was mainly due to wear and osteolysis. For the HA-coated cups also aseptic loosening increased after 6 years of follow-up. Conclusion: Uncemented cups in young patients had good short-term results. At 10 years of follow-up for the investigated uncemented cup brands, the results were inferior to the Charnley cup.

Aims: We wanted to investigate the association between risk factors recorded prospectively before primary hip replacement, and the risk for later revision hip surgery. Methods: During the years 1977–83 The National Health Screening Service in Norway conducted an investigation of risk factors for cardiovascular disease. 56,818 persons born 1925–42 were invited, and 92% participated. We matched these screening data with data from the Norwegian Arthroplasty Register concerning primary and revision hip arthroplasty. Results: We identified 504 men and 834 women who had received a primary total hip replacement after the screening. Of these 75 and 94 were revised during follow-up. Mean age at screening was 49 years; mean age at primary hip replacement was 62 years. Mean age at censoring was 68 years. Men vs women had a relative risk of 1.9 of undergoing hip revision during follow-up (95% CI 1.3–2.8). For each years increase in age at primary hip arthroplasty, the risk of revision surgery during follow-up decreased with 14% for men and 17% for women. Men who at screening had the highest level of physical activity during leisure had 5.5 times the risk of later revision, relative to those with the lowest level of physical activity (95% CI 1.0–31.9). Conclusions: Men have a higher risk for revision hip surgery. There is less risk of revision the older the patient is at primary hip arthroplasty. Men with intense physical activity at middle age are at increased risk of undergoing revision hip surgery before they are 70 years old.

Purpose: The outcome of primary total hip arthroplasty (THA) after a previous paediatric hip disease was studied in data from the Norwegian Arthroplasty Register (NAR).

Materials and Methods: 72,301 primary THAs were reported to the NAR for the period 1987 – February 2002. Of these, 5,459 (7.6%) were performed because of sequela after developmental dysplasia of hip (DDH), 737 (1.0%) because of DDH with dislocation, 961 (1.3%) because of Perthes’/ slipped femoral capital epiphysis (SFCE) and 50,369 (70%) because of primary osteoarthritis (OA). Prosthesis survival was calculated by the Kaplan-Meier method and relative risks for revision in a Cox model with adjustments for age, gender, type of systemic antibiotic, operation time, type of operating theatre and brand of prosthesis.

Results: Without any adjustments the THAs for all three groups of paediatric hip diseases had 1.4 – 2.0 times increased risk for revision compared to that of OA (p< 0.001). Due to huge differences in the studied groups, a more homogenous subset of the data had to be analysed. In this subset, only THAs with well documented prostheses, high-viscosity cements and antibiotic prophylaxis both systemically and in the cement were included (16,874 THAs). In this homogenous subset, no differences in the survivals could be detected for DDH without dislocation and for Perthes’/SFCE compared to OA. For DDH with dislocation the revision risk with all reasons for revisions as endpoint in the analyses was increased 3.3 times compared to OA (p< 0.001), 2.7 times with aseptic loosening as endpoint (p< 0.01) and 10 times with infection as endpoint (p< 0.001).

Conclusions: If well-documented THAs are used after paediatric hip diseases the results are just as good as after osteoarthritis, except for DDH with dislocation where increased revision risk is found.

The Norwegian Arthroplasty Register recorded 24,408 primary total hip replacements from 1987 to 1993; 2907 of them (13%) were performed with uncemented femoral components. We have compared the results of eight different designs, each used in more than 100 patients. Survivorship of the components was estimated by the Kaplan-Meier method using revision for aseptic loosening of the femoral component as the end-point. At 4.5 years, the estimated probability of revision for aseptic loosening for all implants was 4.5%, for the Bio-Fit stem 18.6% (n = 210) and for the Femora stem 13.6% (n = 173). The PM-Prosthesis and the Harris/Galante stem prostheses needed revision in 5.6% and 3.6%, respectively. The clockwise threaded stem of the Femora implant needed revision in 20% of right hips, but in only 4% of left hips. The short-term results of the four best uncemented femoral components (Corail, LMT, Profile and Zweimuller) were similar to those for cemented stems, with revision for loosening in less than 1% at 4.5 years. The importance of the control of innovative designs and the registration of early results is discussed.