Bisphosphonate-induced Osteonecrosis of the Jaws: Review, Clinical Implications and Case Report

The introduction of bisphosphonates has increased in the last decade following their indication for metastatic bone diseases, osteoporosis, hypercalcaemia of malignancy and Paget’s disease. Although bisphosphonates have been used clinically for more than three decades there have been no documented long-term complications of their effects on the jaws until recently, where there is now growing evidence of the influence of bisphosphonates on osteonecrosis of the jaws. The aim of this paper is to report a case of this newly described complication, to review this phenomenon, including the clinical implications and to reiterate current clinical guidelines for management of patients in which bisphosphonate therapy is indicated. To the best of our knowledge this is the first reported case of bisphosphonate-induced necrosis of the jaw in South Africa.     

Lymph Node Mesenchymal and Endothelial Stromal Cells Cooperate via the RANK-RANKL Cytokine Axis to Shape the Sinusoidal Macrophage Niche

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Corynebacterium jeikeium endocarditis: a systematic overview spanning four decades

Skin flora is an important source of microorganisms that cause infective endocarditis. While staphylococcal and beta-hemolytic streptococcal species are well-recognized components of skin flora that can cause infective endocarditis, other skin flora rarely produce endocardial infection. One species of Corynebacterium has received the most attention, Corynebacterium jeikeium. This bacterium, a gram-positive rod that is a strict aerobe, is known to cause mechanical prosthetic valve infection and vancomycin is generally required for treatment of this multidrug-resistant organism. Following treatment of an unusual case of bioprosthetic valve endocarditis due to C. jeikeium, a Medline search for English-language articles published from January 1966 to October 2004 was performed. Reports of C. jeikeium endocarditis cases with culture of either blood or cardiac surgery tissue samples positive for C. jeikeium and with clinical and echocardiographic findings of infective endocarditis were reviewed. Clinical data and results of diagnostic procedures were examined. All 38 patients with C. jeikeium endocarditis reported in the literature had at least one predisposing condition for the development of infective endocarditis. The majority of patients (74%) had involvement of a prosthetic heart valve. The mortality attributed to C. jeikeium endocarditis was 33% and was similar in patients who did and did not undergo valve replacement. This relatively high mortality rate mandates that clinicians be aware of this rare endocardial infection. C. jeikeium is a rare cause of endocarditis and it more commonly infects prosthetic valves. Careful scrutiny is required when C. jeikeium is isolated from a blood culture, particularly in patients with underlying prosthetic cardiac valves.     

Primary myocutaneous flap closure following resection of locally advanced pelvic malignancies

BACKGROUND: Perineal wounds, created at the time of extended resection for locally advanced malignancy and following chemoradiation, are at risk of serious complications. METHODS: To determine whether immediate myocutaneous flap closure prevents complications, 57 patients treated with multimodality therapy and proctectomy (35 perineal wounds) or sacrectomy (22 posterior wounds) were studied. Patients were categorized according to whether they underwent primary skin and pelvic closure (group 1; ,n = 20); primary skin and omental pelvic closure (group 2; n = 24); or immediate myocutaneous flap closure (group 3; n = 13). RESULTS: Groups were similar with respect to age and sex; however, group 1 had more primary tumours and required less radical surgery and chemoirradiation than groups 2 and 3. Groups 1 and 2 experienced more complications overall (eight of 20, nine of 24 and three of 13 patients in groups 1, 2 and 3 respectively), more acute wound complications (seven of 20, nine of 24 and two of 13), delayed wound healing (three of 20, six of 24 and one of 13) and more reoperations for perineal wound problems (five of 20, seven of 24 and zero of 13). Patients in group 2 had a significantly longer hospital stay than those in group 1. Flap closure (group 3) did not increase the length of stay. The routine use of primary flap closure reduced overall wound complications (eight of 31 versus ten of 26 patients) and length of hospitalization (13 versus 17 days). CONCLUSION: Complete wound healing was achieved in all patients; however, immediate myocutaneous flap closure reduced the need for readmission and reoperation.     

Biomechanics of femoral interlocking nails

Today there is a variety of different interlocking intramedullary nail designs available for the femur. We compared different nail types in the bone implant complex (BIC) of four unreamed solid nails and a slotted reamed nail with simulated comminuted mid shaft fractures to see if there are major differences in stiffness for axial load, bending and torsion. The fractures were simulated by a 2 cm defect osteotomy in paired human cadaver femora. Each bone was tested intact in a universal testing machine, osteotomy and osteosynthesis were performed, and the BIC was tested. Relative stiffness was calculated. In torque testing the unslotted solid nail showed significantly more stiffness (0.6-1.8 Nm/degrees) compared to the slotted nail (0.2 Nm/degrees). Compared to intact bone (6.9 Nm/degrees), both groups of nails were significantly less stiff (relative stiffness 2-20%). In axial load and bending testing the large diameter unreamed nail showed significantly higher stiffness (32-68%). This study shows that stiffness of bone implant complex in interlocking femoral nails is more dependent on nail profile than on the pressfit of nails in the medullary canal.