Serum and Wound Vancomycin Levels After Intrawound Administration in Primary Total Joint Arthroplasty.

BACKGROUND: Periprosthetic joint infection is the most common cause of readmissions after total joint arthroplasty (TJA). Intrawound vancomycin powder (VP) has reduced infection rates in spine surgery; however, there are no data regarding VP in primary TJA. METHODS: Thirty-four TJA patients received 2 g of VP intraoperatively to investigate VP's pharmacokinetics. Serum and wound concentrations were measured at multiple intervals over 24 hours after closure. RESULTS: All serum concentrations were subtherapeutic (<15µg/mL) and peaked 12 hours after closure (4.7µg/mL; standard deviation [SD], 3.2). Wound concentrations were 922 µg/mL (SD, 523) 3 hours after closure and 207 µg/mL (SD, 317) at 24 hours. VP had a half-life of 7.2 hours (95% confidence interval, 7.0-9.3) in TJA wounds. CONCLUSIONS: VP produced highly therapeutic intrawound concentrations while yielding low systemic levels in TJA. VP may serve as a safe adjunct in the prevention of periprosthetic joint infection.

Use of a fibular strut allograft in an osteoporotic distal humerus fracture: a case report.

In 2004, nearly 120 000 fragility fractures of the humerus were reported. As the US population ages, this number is expected to increase. Fractures of the distal humerus can be treated in a closed or open fashion. Open treatment includes open reduction and internal fixation or total elbow arthroplasty. Open reduction and internal fixation typically involves dual plating for increased stability and early mobility. We present a case in which dual plating failed due to lack of screw purchase in osteoporotic bone. This patient's fracture was then revised with the use of a fibular strut allograft for improved stability and screw purchase. This method of fixation has not previously been described in the distal humerus and may prove useful in open fixation of osteoporotic distal humerus fractures.

Osteonecrosis of the femoral head after solid organ transplantation: a prospective study.

BACKGROUND: The reported prevalence of osteonecrosis of the femoral head in patients who have undergone a solid organ transplant has ranged from 3% to 41%. The wide variation is due to the retrospective nature of most studies and the inability to capture data on asymptomatic patients. The primary goals of this study were to determine the true prevalence of osteonecrosis of the femoral head following solid organ transplantation, the time to the development of the osteonecrosis, and whether findings on magnetic resonance imaging precede the onset of symptoms. METHODS: Beginning in 1997, patients who had undergone a solid organ transplant were asked to participate in a prospective study in which they would be screened for osteonecrosis of the femoral head. Inclusion criteria included an age of greater than fourteen years, a first-time transplant, and magnetic resonance imaging performed within six months after the transplant. Exclusion criteria were pre-existing osteonecrosis of the femoral head in the hip included in the study, a history of inflammatory arthritis, previous hip surgery, any contraindication to magnetic resonance imaging, a prior organ transplant, prior systemic corticosteroid treatment, and mental health issues preventing adequate follow-up. Screening magnetic resonance imaging was performed every four months. Survivorship analysis was used to determine the prevalence of osteonecrosis of the femoral head. RESULTS: Fifty-two patients (103 hips) were enrolled in the study. Their ages ranged from twenty-four to sixty-five years (mean, forty-three years). Sixteen patients were dropped from the study, but the data collected on them before they were dropped were included in the analysis. Osteonecrosis of the femoral head was diagnosed in eight of the 103 hips. Survivorship analysis revealed that, at one year after the transplant, 89% +/- 7% of the hips and 80% +/- 13% of the patients were free of osteonecrosis of the femoral head; thus the prevalence of osteonecrosis one year after transplantation was 11% or 20%, respectively. The mean duration of follow-up of the remaining hips was 2.3 years. In two hips the osteonecrosis of the femoral head was seen on the initial screening magnetic resonance imaging, and in the other six it developed after the initial magnetic resonance imaging revealed negative findings. All cases of osteonecrosis of the femoral head developed within ten months after the transplant. Seven of the eight hips were asymptomatic at the time of diagnosis. There was a significant difference in the one-year osteonecrosis-free survival rate between the patients who were less than forty years old (78%) and those who were at least forty years old (97%) (p = 0.011). Diabetes, smoking, and rejection episodes were not risk factors for osteonecrosis of the femoral head. CONCLUSIONS: Our study of patients who had had a solid organ transplant revealed that the true prevalence of osteonecrosis of the femoral head in such patients is lower than that reported in most previous studies, osteonecrosis of the femoral head develops prior to the onset of symptoms, an age of less than forty years is a risk factor for osteonecrosis of the femoral head, and osteonecrosis of the femoral head develops within one year after transplantation. We recommend that magnetic resonance imaging be used to screen for osteonecrosis of the femoral head within one year after transplantation. The utility of additional magnetic resonance imaging after one year has not been established.