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J Parvizi

Publications and source records attributed to J Parvizi.

24 records · Page 2Linked to original sources

The Frank Stinchfield Award. Sudden death during primary hip arthroplasty.

The records of 23 patients who died intraoperatively during hip arthroplasty at the authors' institution were reviewed. Of the 38,488 hip arthroplasties in 29,431 patients performed between 1969 and 1997, there were 23 deaths during surgery. There were 15 women and eight men with a mean age of 80.9 years. Preoperative diagnoses were acute hip fracture (13 patients), pathologic fracture (four patients), femoral neck nonunion (one patient), osteoarthritis (four patients), and rheumatoid arthritis (one patient). Eleven patients undergoing cemented total hip arthroplasty died and 12 patients undergoing cemented hemiarthroplasty died. All deaths occurred because of irreversible cardiorespiratory disturbances that were initiated during cementing. There were no deaths among 12,551 patients receiving 15,411 uncemented hip arthroplasties during the 28-year period under review. Autopsy was performed in 13 patients. Bone marrow microemboli were seen in the lungs of 11 of 13 patients in whom an autopsy was performed and methylmethacrylate particles were seen in the lungs of three of 13 patients. These data suggest that elderly patients with preexisting cardiovascular conditions undergoing cemented arthroplasty, especially for fracture diagnosis, are at increased risk for intraoperative death compared with patients undergoing elective hip arthroplasty. In the latter years of the current study, modifications of the operative techniques designed to minimize intramedullary hypertension were associated with a reduction greater than three-fold in overall intraoperative mortality rate. These changes in surgical technique should be considered when cement fixation is used in patients thought to be at risk for having cardiopulmonary disturbances develop from venous embolization of marrow contents.

Age Distribution↗

Development of postoperative fibromatosis after resection of an intraspinal meningioma. Case report.

The authors report the case of an adult female patient who developed a paraspinous thoracic fibromatosis (desmoid tumor) after undergoing resection of an intraspinal thoracic meningioma that was complicated by postoperative wound infection. To the best of the authors' knowledge, this is the first report of such a tumor occurring after resection of a spinal meningioma. Awareness of the development of postoperative fibromatosis and recognition of its association with wound sepsis is important. Although rare, this distinctive lesion should be considered in the differential diagnosis of the apparent rapid regrowth of otherwise indolent lesions including meningioma.

Female↗

Severe pathological changes of parabrachial nucleus in Alzheimer's disease.

In the first of a series of studies aimed at mapping brain stem pathological changes in patients with Alzheimer's disease (AD), we report a new finding regarding the parabrachial nucleus (PBN), a unit of paramount importance in the relay and integration of visceral and nociceptive information as well as in homeostatic control. The brains of 20 patients with AD were surveyed. The PBN contained pervasive neuropathological changes in 100% of the brains from those with early-onset dementia and in 80% from those with late-onset dementia. These changes were entirely absent in all 10 normal controls. The pathological changes of PBN, would cause autonomic dysfunction in patients with AD and perhaps contribute to the disproportionate mortality encountered in these patients.

Age of Onset↗

Combining the clinical signs improves diagnosis of scaphoid fractures. A prospective study with follow-up.

This is a prospective study evaluating the efficacy of four clinical signs believed to be useful in the diagnosis of scaphoid fracture. Two hundred and fifteen consecutive patients with suspected scaphoid fracture were examined on two separate occasions to evaluate tenderness in the anatomical snuff box (ASB), tenderness over the scaphoid tubercle (ST), pain on longitudinal compression of the thumb (LC) and the range of thumb movement (TM). At the initial examination ASB, ST and LC were all 100% sensitive for detecting scaphoid fracture with specificities of 9%, 30% and 48% respectively. These clinical signs used in combination, within the first 24 hours following injury, produced 100% sensitivity and an improvement in the specificity to 74%. TM had 69% sensitivity and 66% specificity. Our results suggest that these clinical signs are inadequate indicators of scaphoid fracture when used alone and should be combined to achieve a more accurate clinical diagnosis.

Adolescent↗

Exposure to low-intensity ultrasound increases aggrecan gene expression in a rat femur fracture model.

The effects of ultrasound stimulation on various parameters of bone repair after diaphyseal injury were assessed in a standard rat femur fracture model. Bilateral closed femoral fractures were made in 79 skeletally mature male Long-Evans rats. An ultrasound signal consisting of a 200 microsecond burst sine wave of 0.5 MHz repeating at 1 kHz, with an intensity of 50 or 100 mW/cm2 spatial and temporal average, was applied to one fracture in each animal. The contralateral fracture was not exposed to ultrasound and served as a control. Mechanical testing of the healing fracture was performed 3 weeks after injury. In fractures treated with a 50 mW/cm2 ultrasound signal, the average maximum torque (223.5 +/- 50.5 Nmm compared with 172.6 +/- 54.9 Nmm, p = 0.022, paired t test) and average torsional stiffness (13.0 +/- 3.4 Nmm/degree compared with 9.5 +/- 2.9 Nmm/degree, p = 0.017) were significantly greater in treated than in control fractures. In animals treated with a 100 mW/cm2 ultrasound signal, the average maximum torque and torsional stiffness were greater in treated than in control fractures, but this trend did not reach statistical significance. Biochemical analysis of callus in ultrasound-treated and control fractures failed to demonstrate significant differences in cell number, collagen content, or calcium content. Evaluation of gene expression in fractures treated with 50 mW/cm2 ultrasound demonstrated a shift in the expression of genes associated with cartilage formation; aggrecan gene expression was significantly higher on day 7 after fracture and significantly lower on day 21 (p = 0.033 and 0.035, respectively). alpha 1(II) procollagen gene expression was similarly modified, but this trend did not reach statistical significance. Expression of genes coding for bone-related proteins, including alpha 1(I) procollagen, bone gamma-carboxyglutamic acid protein, alkaline phosphatase, and transforming growth factor-beta 1, did not differ between ultrasound-treated and control fractures. These data suggest that ultrasound stimulation increased the mechanical properties of the healing fracture callus by stimulating earlier synthesis of extracellular matrix proteins in cartilage, possibly altering chondrocyte maturation and endochondral bone formation.

Aggrecans↗