Multiple myeloma: evaluation by CT

Although patients who have multiple myeloma usually have straightforward clinical symptoms and corroborative radiographs, in some instances, these patients will present atypically, with symptoms suggesting active disease but radiographs that are normal or nonspecific. We reviewed the records of 32 patients who had documented multiple myeloma and had undergone CT examinations, assessing the value of those examinations. Although CT is not indicated in all patients who have multiple myeloma, it is especially useful in patients who have bone pain and normal or nonspecific radiographs. CT provided confirmatory information in all cases in which lesions were seen on radiographs. CT also frequently demonstrated a greater extent of disease than could be appreciated on the radiographs.     

Supraacetabular insufficiency fractures

Insufficiency fractures in the supraacetabular region were identified in five women, aged 55-83 years. Factors contributing to the diminished resistance of their bones included postmenopausal osteoporosis, steroid therapy, radiation therapy, and rheumatoid arthritis. The supraacetabular fractures were seen on routine radiographs as hazy bands of sclerosis located immediately above and parallel to the acetabular roof. All five patients had additional fractures in the spine or pelvis. Supraacetabular insufficiency fractures may be an unsuspected cause of hip pain, especially in older women.     

Reliability and validity of static knee strength measurements obtained with a chair-fixed dynamometer in subjects with hip or knee arthroplasty

OBJECTIVES: To evaluate the reliability (intertrial, interevaluator) and the concurrent validity of strength measurements obtained with a chair-fixed dynamometer and to recommend a clinical protocol that minimizes standard error of measurement (SEM). DESIGN: Within-session repeated measures of maximal static strength of knee flexors and extensors at 30 degrees and 60 degrees of flexion on the chair-fixed and Cybex dynamometers. SETTING: Ambulatory physiotherapy department of a rehabilitation hospital. PARTICIPANTS: Convenience sample of 50 subjects with total hip (n=25) or knee (n=25) arthroplasty. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Reliability was quantified by indices of dependability and corresponding SEMs estimated with the generalizability theory, whereas coefficients of correlation were used to assess the validity. RESULTS: Indices of dependability confirmed excellent intertrial (0.98-1.00) and a very good interevaluator (.92-.99) reliability for the strength measures obtained for different movements and positions. An average of 3 trials minimized the magnitude of the SEMs (>2 Nm for all measurements). When comparing the strength values obtained with the Cybex dynamometer to those measured with the chair-fixed dynamometer, strongest relations were attained when the tested knee was positioned at 60 degrees compared with 30 degrees for subjects with a total knee (.78-.92 vs .87-.93) or hip (.73-.85 vs .86-.91) arthroplasty. CONCLUSIONS: A clinical protocol averaging 3 trials with the knee positioned at 60 degrees after a familiarization period, both for knee flexors and extensors, performed by a trained therapist is recommended to minimize measurement errors on strength values measured with the chair-fixed dynamometer.     

Ferromagnetic materials in patients: detection before MR imaging

A number of surgical clips and other metallic materials embedded within patients have ferromagnetic properties that present a potential hazard when in the strong fields associated with magnetic resonance imaging. Several types of magnetometers and metal detectors were investigated as possible pre-imaging screening devices. The sensitivities and costs of these devices are given.