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Background In a previous study concerning 1,660 ScanHip THAs that were followed for up to 12 years, the cumulative revision rate was not found to be dependent on whether a 22-mm or a 32-mm head size had been used. We have re-examined these patients to see whether a longer follow-up time (9-21 years) would disclose an effect of head size on the revision rate. Patients and methods We analyzed the cumulative revision rate for 1,720 Scan Hip arthroplasties with either 22-mm or 32-mm femoral heads. The patients were followed for 9-21 years. Results Arthroplasties with 32-mm head had 2.8-times higher cumulative revision rate than those with a 22-mm head. Older age reduced the risk of revision while male sex increased the risk. Interpretation We found that head size affects revision risk, but that even in a reasonably large material a long follow-up time is required to disclose the effects of head size-and thus wear-on survival. [ABSTRACT FROM AUTHOR]

BACKGROUND: Cementing technique is a crucial factor in prosthesis fixation. No randomized studies have been published, however, comparing the outcome of conventional fingerpacking with the outcome of pressurization of the cement prior to cup insertion. PATIENTS AND METHODS: We randomized 50 THAs to either fingerpacking or sequential pressurization (including individual pressurization of each anchorage hole) and followed the patients with RSA for 5 years. The penetration of cement into the anchorage holes was measured on digital radiographs. Postoperative radiolucent lines around the cup were correlated to later RSA results. For clinical evaluation, we used SF-36 and HHS. RESULTS: The pressurized group of THAs was more stable regarding changes in inclination. We found no other difference in the migratory behavior. The cement penetration into the anchorage holes was deeper with the pressurization technique than with fingerpacking. For the whole group taken together, there was a strong relation between the presence of radiolucent lines as measured on the postoperative radiograph and later migration observed by RSA at 2 and 5 years. INTERPRETATION: Pressurization of the cement produced better cement penetration and increased the cup stability in terms of changes in inclination. Early findings of radiolucent lines can predict later unfavorable cup migration. [ABSTRACT FROM AUTHOR]

We analyzed the radiographic and clinical outcome of the ScanHip total hip arthroplasty in 70 patients after 10 years. The Swedish National Hip Register, in which the end-point of the survival analysis is defined as revisions, reported a 10-year survival rate of 94% with the ScanHip, but in the present series 13% of the femoral stems and 29% of the sockets met the criteria for aseptic loosening. Focal osteolysis was found around 8 sockets (11%) and 23 stems (32%) and had occurred significantly oftener around loose sockets, but not around femoral stems. Linear polyethylene wear was significantly increased in loose sockets, but no relationship was noted between polyethylene wear and stem loosening or was there a correlation between clinical symptoms or patients' satisfaction and component loosening. Therefore precise serial long-term radiographic follow-up is the only satisfactory method for detecting aseptic loosening of total hip arthroplasty. It gives the surgeon more detailed information about each case than survival analysis alone. [ABSTRACT FROM AUTHOR]