Total knee replacement: should it be cemented or hybrid? (1/476)

OBJECTIVE: To compare the complication rates associated with total knee arthroplasty against the types of fixation (hybrid or cemented), using a single total knee design (the anatomic modular knee [AMK] prosthesis). DESIGN: A prospective, nonrandomized, controlled trial. SETTING: University Hospital in London, Ont., a tertiary care teaching centre. PATIENTS: Two groups made up of 484 knees in 395 patients (89 bilateral). INTERVENTIONS: In 260 knees a hybrid configuration (cemented tibia and noncemented femur) was used (group 1). In 224 knees the femoral and tibial components were cemented (group 2). All patellae were cemented in both groups. MAIN OUTCOME MEASURES: Clinical results were assessed by The Knee Society Clinical Rating Scores at 3 months, 6 months and yearly intervals. Radiographic results were determined by 3-foot standing radiographs and at each follow-up visit standing knee radiographs, lateral and skyline views. Radiographs were analysed for alignment, presence or absence of radiolucent lines or changes in the position of the implant. All reoperations and nonoperative complications were recorded. RESULTS: At an average follow-up of 4.8 years, 8 knees (1.6%) required reoperation. An analysis of the complications leading to reoperation demonstrated no difference between the 2 groups. CONCLUSIONS: There was no difference in outcome whether the femoral component was cemented or not. Medium-term results of the AMK are excellent with a very low reoperation rate.  (+info)

Osteonecrosis of the hip in sickle-cell disease associated with tuberculous arthritis. A review of 15 cases. (2/476)

We report a study of 15 cases of tuberculous hips with sickle-cell disease who presented during 1991-1993. Although the osteonecrosis was long-standing, biopsy was nearly always required to reveal the more recent tuberculous infection. Management consisted of 6 months of anti-tuberculous chemotherapy with appropriate palliative surgery 5-8 weeks after the start of drug treatment. The operative techniques which we used are described. The results were good both post-operatively, and in 12 patients followed-up at an average of 3 years. We recommend this combined management for the treatment of secondary tuberculous infections of hips previously damaged by sickle-cell disease.  (+info)

Disseminated thrombosis and bone infarction in female rats following inhalation exposure to 2-butoxyethanol. (3/476)

Groups of 10 male and 10 female F344/N rats were exposed to 0, 31, 62.5, 125, 250, and 500 ppm of 2-butoxyethanol (BE) by inhalation, 6 hr/day, 5 days/wk, for 13 wk. Four moribund female rats from the 500 ppm group were sacrificed during the first 4 days of exposure, and 1 moribund female from the same group was sacrificed during week 5. Dark irregular mottling and/or loss of the distal tail were noted in sacrificed moribund rats. Similar gross lesions were noted in the terminally sacrificed females exposed to 500 ppm BE. Histologic changes noted in the day 4 sacrificed moribund rats included disseminated thrombosis involving the coccygeal vertebrae, cardiac atrium, lungs, liver, pulp of the incisor teeth, and the submucosa of the anterior section of the nasal cavity. Alterations noted in coccygeal vertebrae from the 500 ppm sacrificed moribund rats included ischemic necrosis and/or degeneration of bone marrow cells, bone-lining cells, osteocytes (within cortical and trabecular bone), and chondrocytes (both articular and growth plate), changes that are consistent with an infarction process. The moribund female rat that was sacrificed during week 5 and those female rats treated with 500 ppm and sacrificed following 13 wk of treatment lacked thrombi, but they had coccygeal vertebral changes consistent with prior infarction and transient or complete bone growth arrest. No bone lesions or thrombi were noted in the male rats treated with the same doses of BE. In conclusion, exposure to 500 ppm BE vapors caused acute disseminated thrombosis and bone infarction in female rats. Possible pathogenic mechanisms are discussed.  (+info)

Treatment of autoimmune premature ovarian failure. (4/476)

There is no known immunosuppressive therapy for autoimmune premature ovarian failure that has been proven safe and effective by prospective randomized placebo-controlled study. Nevertheless, immunosuppression using corticosteroids has been used on an empirical basis for this condition. Here we present two cases of young women with premature ovarian failure who were treated with glucocorticoids in the hopes of restoring fertility. The first case illustrates the potential benefit of such therapy, and the second case illustrates a potential risk. The first patient with histologically proven autoimmune oophoritis was treated with alternate day glucocorticoid treatment. She had return of menstrual bleeding six times and ovulatory progesterone concentrations four times over a 16 week period. The second patient with presumed but unconfirmed autoimmune ovarian failure was referred to us after having been treated with a 9 month course of corticosteroids. During that treatment her menses did not resume. The corticosteroid treatment was complicated by iatrogenic Cushing syndrome and osteonecrosis of the knee. Identifying patients with autoimmune premature ovarian failure presents the opportunity to restore ovarian function by treating these patients with the proper immune modulation therapy. On the other hand, potent immune modulation therapy can have major complications. Corticosteroid therapy for autoimmune premature ovarian failure should be limited to use in placebo-controlled trials designed to evaluate the safety and efficacy of such treatment.  (+info)

Fat conversion of femoral marrow in glucocorticoid-treated patients: a cross-sectional and longitudinal study with magnetic resonance imaging. (5/476)

OBJECTIVE: To study the changes in hematopoietic marrow in patients given glucocorticoid (steroid) therapy. METHODS: In a cross-sectional study, high-resolution T1-weighted magnetic resonance imaging (MRI) images of the proximal femur were obtained in an unselected series of 29 premenopausal female patients with systemic lupus erythematosus (SLE) and in a series of 29 age-matched healthy female subjects. In a longitudinal analysis, 2 MRI studies were performed 19 months apart in 11 patients with SLE (including 9 patients from the cross-sectional study who were evaluated before treatment) and in 7 patients with rheumatoid arthritis (RA). The percentage of fat marrow and the index of marrow conversion (IMC) were derived from the MRI images to estimate the degree of transformation of hematopoietic into fatty marrow in the area of the femoral neck. Values observed in the cross-sectional study and their changes over time were correlated with treatment data. RESULTS: The cross-sectional study performed in SLE patients indicated that their mean (+/- SD) percentage of fat marrow (48+/-36%) and IMC (82+/-12) were significantly more elevated than those in the healthy control subjects (18+/-16% and 75+/-6, respectively) (P<0.01). The magnitude of fat conversion correlated positively with the mean daily dose of oral prednisolone, and was higher in patients with ischemic bone lesions. The longitudinal study performed in SLE and RA patients revealed that IMC changes over time correlated positively with daily prednisolone intake (r = 0.71; P = 0.001), fat conversion occurring exclusively in patients receiving a mean prednisolone dose < or =7.5 mg/day. CONCLUSION: MRI indicates that fat conversion occurs in the proximal femur of steroid-treated patients. The magnitude of fat conversion correlates with steroid intake and is higher in patients with ischemic bone lesions.  (+info)

Unusual complications in an inflammatory abdominal aortic aneurysm. (6/476)

An unusual case of an inflammatory abdominal aortic aneurysm (IAAA) associated with coronary aneurysms and pathological fracture of the adjacent lumbar vertebrae. The associated coronary lesions in cases of IAAA are usually occlusions. In the present case, it was concluded that a possible cause of the coronary aneurysm was coronary arteritis and the etiology of the pathological fracture of the lumbar vertebrae was occlusion of the lumbar penetrating arteries due to vasculitis resulting in aseptic necrosis. Inflammatory AAA can be associated with aneurysms in addition to occlusive disease in systemic arteries. The preoperative evaluation of systemic arterial lesions and the function of systemic organs is essential.  (+info)

Subchondral insufficiency fracture of the femoral head: a differential diagnosis in acute onset of coxarthrosis in the elderly. (7/476)

OBJECTIVE: To document subchondral insufficiency fracture (SIF) of the femoral head and investigate its frequency. METHODS: The study was based on a retrospective review of 464 removed femoral heads (from 419 patients) with both radiologic and histologic evidence of subchondral collapse. Gross photographs, specimen radiographs, and histologic sections were reevaluated in all cases. Available clinical notes and imaging studies were also reviewed. RESULTS: Ten cases previously diagnosed as osteonecrosis were reinterpreted as SIF on a histopathologic basis. All of these patients were women over 65 years old (average age 75) with osteopenia. The initial symptom was acute onset of hip pain. Radiologically, a subchondral collapse, mainly in the superolateral segment of the femoral head, was noted. Magnetic resonance imaging, available in 3 cases, showed diffuse low intensity on T1-weighted images and high intensity on T2-weighted or fat-suppressed images. Bone scintigraphy, available in 4 cases, showed increased uptake in the femoral head. Histopathologically, a 1.0-2.5-cm long linear whitish gray zone, comprising fracture callus and granulation tissue, was found beneath the subchondral bone end plate. There was no evidence of antecedent osteonecrosis. CONCLUSION: The results of this study indicate that SIF should be included in the differential diagnosis of acute onset of coxarthrosis in the elderly.  (+info)

Use of magnetic resonance imaging to diagnose common wrist disorders. (8/476)

Magnetic resonance imaging is being used more frequently to diagnose and plan treatment of wrist disorders. This article reviews the common pathologic lesions of the wrist: avascular necrosis, triangular fibrocartilage complex tears, ligamentous tears, ganglion cysts, carpal tunnel syndrome, and osteoarthritis. The typical magnetic resonance imaging characteristics of these lesions is discussed.  (+info)