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Beta-particle dosimetry of various radionuclides used in the treatment of rheumatoid arthritis was estimated using Monte Carlo radiation transport simulation coupled with experiments using reactor-produced radionuclides and radiachromic film dosimeters inserted into joint phantoms and the knees of cadavers. Results are presented as absorbed dose factors (cGy-cm2/MBq-s) versus depth in a mathematical model of the rheumatoid joint which includes regions of bone, articular cartilage, joint capsule, and tissue (synovium) found in all synovial joints. The factors can be used to estimate absorbed dose and dose rate distributions in treated joints. In particular, guidance is provided for those interested in (a) a given radionuclide's therapeutic range, (b) the amount of radioactivity to administer on a case-by-case basis, (c) the expected therapeutic dose to synovium, and (d) the radiation dose imparted to other, nontarget components in the joint, including bone and articular cartilage.

Ten cases are described of catastrophic failure of the polyethylene liner of three different designs of uncemented acetabular component. Failure occurred as a result of either 'wearthrough' to the metal backing, liner fracture or a combination of both, at a mean of 4.6 years after implantation (2 to 7.6). At revision there was metallosis in all hips and osteolysis of the femur or the pelvis in six. Catastrophic failure was seen only in cups with a minimum polyethylene thickness of less than 5 mm.

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We compared combined B-mode/Doppler (duplex ultrasonic scanning and venography in routine preoperative and postoperative screening for major proximal deep vein thrombosis in 78 patients undergoing total hip or knee arthroplasty. Of 309 extremity examinations, duplex scanning had an overall sensitivity of 85.7% (12/14) and a specificity of 97.3% (287/295). The preoperative prevalence and postoperative incidence of major deep vein thrombosis were 2.5% and 14.1% of patients, respectively, despite intensive mechanical and pharmacologic prophylaxis. In addition, venography documented a preoperative prevalence and postoperative incidence of isolated calf deep vein thrombosis in 2.5% and 16.7% of patients, respectively. Whereas such disease extended proximally even in the absence of anticoagulation in only 18% of patients studied by serial duplex scans, calf deep vein thrombosis accounted for the only two instances of pulmonary embolism in this study. There were no deaths related to pulmonary embolism. This study suggests that duplex scanning is useful in screening for perioperative deep vein thrombosis in patients undergoing total hip or knee arthroplasty, which carries a significant risk of venous thromboembolism despite routine prophylaxis.

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Previously, we reported a prospective study of 30 patients with unicompartmental osteoarthritis of the knee treated nonoperatively with an unloader brace and average follow-up of 2.7 years. Although the initial study suggested short-term benefit according to pain and function measures, the objective of the current study was to evaluate these same patients via telephone questionnaire to determine the status of their brace use and any surgical procedures on the affected limb. Because we noted that even at 2.7 years, some patients opted for surgical management despite good response to bracing, our hypothesis was that these patients would not opt for long-term brace wear. Twenty-four of 30 patients were available for reporting based on telephone interview; in addition, we talked with family members of 5 patients who had died. When evaluated at 2.7 years, 41% of the 30 patients were still using the brace, 35% had discontinued brace use, and 24% had undergone arthroplasty. When contacted for the follow-up survey at an average of 11.2 years, 17 (58.6%) of the 29 patients had undergone arthroplasty. The mean interval between initial evaluation and arthroplasty was 3.9 years. In addition, 7 patients had undergone arthroscopic surgery. Importantly, none of the patients were still wearing the brace. The use of an unloader brace is effective in providing short-term pain relief and improved function; however, most patients subsequently opt for total knee replacement on the symptomatic knee.