Surgery (St Vincent's) - Research Publications
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ItemNo Preview AvailableThe relevance of ligament balancing in total knee arthroplasty: how important is it? A systematic review of the literature(PAGEPRESS PUBL, 2009)Ligament balancing affects many of the postoperative criteria for a successful knee replacement. A balanced knee contributes to improved alignment and stability. Ligament balancing helps reduce wear and loosening of the joint. A patient with a balanced knee is more likely to have increased range of motion and proprioception, and decreased pain. All these factors help minimize the need for revision surgery. Complications associated with ligament balancing can include instability caused by over-balancing and the possibility of neurovascular damage during or as a result of ligament balancing. This article attempts to summarize the literature, to define a balanced knee, and outline the benefits and possible complications of ligament balancing. Different techniques, sequences, and tools used in ligament balancing, and their relevance in correcting various deformities are reviewed.
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ItemNo Preview AvailableClinical applications of molecular imaging in sarcoma evaluation.(E-MED LTD, 2005-06-21)A wide range of molecular imaging techniques are available that can provide complementary information to conventional, anatomical imaging for the evaluation of known or suspected bone and soft tissue sarcomas. In particular, positron emission tomography (PET), particularly in the form of hybrid PET/CT technology, offers many potential advantages over current imaging approaches by delineating not only the extent of disease but also the biological heterogeneity that can exist both between and within sarcomas. This review discusses the clinical situations where nuclear medicine techniques can aid in the management of patients with sarcoma. These include biopsy guidance, whole body staging, therapeutic response assessment and evaluation of residual mass lesions after treatment.
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ItemBisphosphonates regulate cell growth and gene expression in the UMR 106-01 clonal rat osteosarcoma cell line(NATURE PUBLISHING GROUP, 2001-04-06)Local growth of osteosarcoma involves destruction of host bone by proteolytic mechanisms and/or host osteoclast activation. Osteoclast formation and activity are regulated by osteoblast-derived factors such as the osteoclast differentiating factor, receptor activator of NF-kappaB ligand (RANKL) and the inhibitor osteoprotegerin (OPG). We have investigated the in vitro effects of bisphosphonates on a clonal rat osteosarcoma cell line. The aminobisphosphonate pamidronate was added to UMR 106-01 cell cultures (10(-8)M to 10(-4)M up to 5 days). The non-aminobisphosphonate clodronate was administered for the same time periods (10(-6)M to 10(-2)M). Cell proliferation, apoptosis and mRNA expression was assessed. Both agents inhibited cell proliferation in a time- and dose-dependent manner. ELISA analysis demonstrated an increase in DNA fragmentation although there was no significant dose-related difference between the doses studied. Bisphosphonate-treated cultures had a greater subpopulation of cells exhibiting morphological changes of apoptosis. Expression of mRNA for osteopontin and RANKL was down-regulated by both agents, while the expression of mRNA for alkaline phosphatase, pro-alpha1(I) collagen and OPG was not altered. Out in vitro work suggests the bisphosphonates not only have direct effects on osteosarcoma cell growth and apoptosis, but also, by altering the relative expression of osteoclast-regulating factors, they may inhibit the activity of osteoclasts and their recruitment.
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ItemOutcome of patients with osteosarcoma over 40 years of age: is angiogenesis a marker of survival?(Springer Science and Business Media LLC, 2006-03-21)BACKGROUND: Osteosarcoma predominantly afflicts young people in their second and third decades of life. When osteosarcoma arises in patients older than 40 years, the prognosis is usually poorer compared to their younger counterparts. Although the clinical, histopathologic features and prognostic indicators are well defined for young patients, much less is known about affected adults. The purpose of this study is to describe our institution's experience with the management of osteosarcoma in patients greater than 40 years and also evaluate, by immunohistochemical analysis, the prognostic significance of microvessel density, as a marker of intratumoural angiogenesis. METHODS: A retrospective clinicopathological analysis was performed on 11 patients over the age of 40 years that were treated at our institution between 1996 and 2004. Archival pre-treatment biopsy tissue was retrieved for immunohistochemical staining against two endothelial cell markers (CD31 and CD34) and also against VEGF. Angiogenesis was assessed by determining the intratumoural microvessel density (MVD) and the degree of VEGF expression in these specimens. This was correlated with patient outcome in terms of local recurrence, metastasis and death. Histological results were also compared to a group of patients less than 40 years of age. RESULTS: Of the 11 patients, 9 were male and 2 were female and the mean age was 58 years (range, 42-85). In 7 patients, osteosarcoma arose secondarily from Paget's disease of the bone. The most common site involved was the humerus (7) followed by the femur (2) then pelvis (1) and ulna (1). At the time of diagnosis, 4 patients had metastatic disease. Preoperative chemotherapy was given to 4 patients, with a good response in 3 patients. Six patients underwent limb-sparing surgery, 4 had amputations and 1 was treated with radiotherapy alone. The mean follow up time was 31.5 months (range, 8-81). At this time, 4 patients (36%) had developed lung metastases and 5 patients (46%) had died. Overall survival was 54.5%. Intratumoural MVD was higher in patients over 40 years, although not statistically significant (p = 0.111, CD31; p = 0.134, CD34). VEGF was uniformly expressed in all sections, however no relationship was found between the degree of expression and patient age. CONCLUSION: The prognosis for older patients with osteosarcoma is generally poor. Initial presentation is commonly associated with metastatic disease and neoadjuvant chemotherapy is often avoided because of its side effects. Increased intratumoural vascularity may contribute to the poorer prognosis in these patients, however further studies are needed.
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ItemMyoepithelioma within the carpal tunnel: a case report and review of the literature.(Springer Science and Business Media LLC, 2009-09-09)Myoepitheliomas of the extremity are rare and usually benign, while a minority display malignant features. This case demonstrates the diagnosis and management of myoepithelioma within the carpal tunnel. Clinical and radiological tumour features were evaluated. Hematoxylin and eosin stained tumour sections were examined, and immunohistochemistry was performed. Histology revealed a nodular mass of epithelioid cells in clusters within a myxoid/chondroid stroma. No mitoses were noted. Cytokeratins, neuron-specific enolase, synaptophysin, glial fibrillary acidic protein, and S100 were positive on immunohistochemistry. A literature review revealed very few prior reports of myoepithelioma in the wrist, and limited data concerning any relationship between recurrence and quality of surgical margins. In this case, wide local excision would have significantly compromised dominant hand function, and therefore a marginal excision was deemed appropriate in the context of bland histological features. Surgical margins noted in future case reports will aid clinical decision making.
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ItemResearch: Is resection of tumours involving the pelvic ring justified? : A review of 49 consecutive cases.(Springer Science and Business Media LLC, 2005-04-09)INTRODUCTION: Pelvic surgery is challenging and impacts significantly on limb and visceral function, thus, raising the question "is heroic surgery justifiable". This study assessed the functional, oncologic and surgical outcomes following pelvis tumour resections. METHODS: Between 1996-2003, 49 patients (mean age 43 years) underwent pelvic tumour resections- 38 primary malignant tumours, 5 secondary tumours and 6 benign tumours. Bone tumours comprised 5 osteosarcomas, 5 Ewings sarcomas, and 12 chondrosarcomas. Of the soft tumours, 9 were of neural origin. Tumours involved the ilium, acetabulum, pubic bones, sacrum or a combination of these. Functional assessment was performed and no patient had metastases at presentation. RESULTS: There were 41 limb sparing resections and 8 hindquarter amputations. Surgical margins were intralesional (1), marginal (13), wide (26), and radical (3). Of limb sparing surgery, prosthetic reconstructions were performed in 10 patients, biologic reconstructions in 6, a combination of these in 3 and no reconstruction in others. There was 1 intraoperative death, 7 local recurrences and 19 metastases. Death from disease occurred at a mean of 14.2 months with a mean followup of 27 (1-96) months. Amputation and periacetabular resections had worse functional outcomes. Emotional acceptance was surprisingly high. CONCLUSION: Pelvic resections are complex. Functional outcome is significantly affected by surgery. Disease control is similar to limb tumours. Emotional acceptance of surgery in survivors was surprisingly high. Major pelvic resection for malignancy appears justified.
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ItemAn interesting diagnosis for a presacral mass: case report.(Springer Science and Business Media LLC, 2009-11-08)A presacral mass can present a diagnostic dilemma for the surgical oncologist. Differential diagnoses include congenital causes such as teratoma or chordoma, neurological causes such as neurilemoma or neurofibroma or other malignancies such as lymphoma or sarcoma. Diagnosis usually requires imaging such as CT and MRI and tissue biopsy. We present an unusual cause of a presacral mass being extramedullary haematopoiesis, found incidentally in a 71 year old female. Extramedullary haematopoiesis is defined as the production of myeloid and erythroid elements outside of the bone-marrow. This diagnosis is extremely rare in the presacral area especially in a patient with no haematological abnormalities. A review of the literature is presented.
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ItemSafety of rFVIIa in hemodynamically unstable polytrauma patients with traumatic brain injury:: Post hoc analysis of 30 patients from a prospective, randomized, placebo-controlled, double-blind clinical trial(BMC, 2007)BACKGROUND: Trauma is a leading cause of mortality and morbidity, with traumatic brain injury (TBI) and uncontrolled hemorrhage responsible for the majority of these deaths. Recombinant activated factor VIIa (rFVIIa) is being investigated as an adjunctive hemostatic treatment for bleeding refractory to conventional replacement therapy in trauma patients. TBI is a common component of polytrauma injuries. However, the combination of TBI with polytrauma injuries is associated with specific risk factors and treatment modalities somewhat different from those of polytrauma without TBI. Although rFVIIa treatment may offer added potential benefit for patients with combined TBI and polytrauma, its safety in this population has not yet been assessed. We conducted a post hoc sub analysis of patients with TBI and severe blunt polytrauma enrolled into a prospective, international, double-blind, randomized, placebo-controlled study. METHODS: A post hoc analysis of study data was performed for 143 patients with severe blunt trauma enrolled in a prospective, randomized, placebo-controlled study, evaluating the safety and efficacy of intravenous rFVIIa (200 + 100 + 100 microg/kg) or placebo, to identify patients with a computed tomography (CT) diagnosis of TBI. The incidences of ventilator-free days, intensive care unit-free days, and thromboembolic, serious, and adverse events within the 30-day study period were assessed in this cohort. RESULTS: Thirty polytrauma patients (placebo, n = 13; rFVIIa, n = 17) were identified as having TBI on CT. No significant differences in rates of mortality (placebo, n = 6, 46%, 90% confidence interval (CI): 22% to 71%; rFVIIa, n = 5, 29%, 90% CI: 12% to 56%; P = 0.19), in median numbers of intensive care unit-free days (placebo = 0, rFVIIa = 3; P = 0.26) or ventilator-free days (placebo = 0, rFVIIa = 10; P = 0.19), or in rates of thromboembolic adverse events (placebo, 15%, 90% CI: 3% to 51%; rFVIIa, 0%, 90% CI: 0% to 53%; P = 0.18) or serious adverse events (placebo, 92%, 90% CI: 68% to 98%; rFVIIa, 82%, 90% CI: 60% to 92%; P = 0.61) were observed between treatment groups. CONCLUSION: The use of a total dose of 400 (200 + 100 + 100) microg/kg rFVIIa in this group of hemodynamically unstable polytrauma patients with TBI was not associated with an increased risk of mortality or with thromboembolic or adverse events.
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ItemIntraosseous angiosarcoma with secondary aneurysmal bone cysts presenting as an elusive diagnostic challenge.(Springer Science and Business Media LLC, 2008-05-20)Angiosarcoma of bone is an exceedingly rare primary bone malignancy that can present as an aggressive osteolytic lesion. Histological diagnosis can be extremely challenging, as the pathological features often resemble that of aneurysmal bone cysts. We report an interesting and peculiar case of an intraosseous angiosarcoma that presented as a diagnostic dilemma and discuss the relevant radiological and pathologic findings.
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ItemReconstruction after external hemipelvectomy using tibia-hindfoot rotationplasty with calcaneo-sacral fixation.(Springer Science and Business Media LLC, 2008-01-21)BACKGROUND: External hemipelvectomy is associated with high post operative morbidity and a poor functional outcome. We aim to explore a reconstruction technique to improve function and post operative appearance for patients who undergo external hemipelvectomy. CASE PRESENTATION: We present a Case where extensive cancer involvement of pelvis and femur was managed with a novel surgical technique, which involved a calf sparing modified anterior flap hemipelvectomy combined with rotationplasty of the spared calf and fixation of calcaneus to the sacrum, thereby recreating a new thigh stump. CONCLUSION: Tibia-hindfoot rotationplasty result in good functional outcome and appearance for selected patients undergoing external hemipelvectomy with unaffected external iliac and femoral vessels.