Surgery (St Vincent's) - Research Publications

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    Static force dependency of bone conduction transducer as sensory feedback for stump-socket based prosthesis
    Mayer, RM ; Mohammadi, A ; Alici, G ; Choong, P ; Oetomo, D (Australian Robotics and Automation Association, 2018-01-01)
    The dependency of a novel sensory feedback for stump-socket based prosthesis on the static force is presented using a bone conduction transducer as feedback source. The stimulation was induced onto the bony landmarks of the elbow, specifically the Ulna and presented in an interval halving method. The perception threshold in the range of tactile and auditory perception at three different force levels has been tested. The inter subject variability is bigger than the intra subject variation. The small static force variation suggests a similar approach as in bone conduction hearing aids and therefore a static force bigger than 6N should be applied to perceive a constant stimulation. A mechanical design to include such a novel feedback into a stump-socket needs to account for this requirement. The inter subject variability needs to be addressed by incorporate some kind of person to person calibration of the gain.
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    Sham surgery: justified but practical? A systematic review of sham surgery trials in orthopaedics
    Bunzli, S ; Dowsey, MM ; Choong, PF (Academy of Science of South Africa, 2018)
    BACKGROUND: An increasing trend for sham surgery trials in minor orthopaedic procedures has been observed. Trial outcomes have changed the practice landscape of these procedures. However, there has been no sham surgery trial in a major orthopaedic procedure. The aims of this systematic review were to consider the ethics of sham surgery trials; to describe orthopaedic sham surgery trials conducted to date; and to consider the challenges that will need to be overcome in order to conduct sham surgery trials for major orthopaedic procedures in the future. METHODS: A systematic review of the literature and clinical trial registries was undertaken. Trials with a published main findings paper underwent a risk of bias assessment using the Cochrane Collaboration risk of bias tool, in addition to an ethical assessment based on the work of Horng and Miller. RESULTS: We identified 22 sham surgery trials for minor orthopaedic procedures that have been completed, terminated, or are currently in process. Among the ten trials with a published main findings paper, only one was free from risk of bias; all others were at risk of bias. According to the ethical assessment, the benefits of a sham control were outweighed by the risks in all but two of the ten trials. Across the 22 trials with published and unpublished main findings, participant recruitment within reasonable timeframes, as well as the low threshold for crossover from the sham were recurring challenges. CONCLUSIONS: Researchers are obliged to carefully consider the feasibility of conducting a sham surgery trial in a major orthopaedic procedure, before drawing on limited research funds. Exploring the conditions under which patients and surgeons would find participation in a sham surgery trial acceptable, and simulating trial costs based on patient and surgeon preferences may assist funders, assessors and ethics boards to determine whether to support the conducting of future sham surgery trials in major orthopaedic procedures.
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    Reconstructive options for large back free flap donor sites
    Azizeddin, A ; Choong, PFM ; Grinsell, D (WILEY, 2018-10)
    BACKGROUND: Reconstruction of posterior thoracic and trunk defects can prove challenging even to the most seasoned surgeons. Many commonly used techniques for closing back defects include primary closure and split skin grafts. Often times, however, other techniques are needed in order to give the patient the best aesthetic and functional outcome. In this study, we focus on and evaluate donor site closure techniques for defects in the back created by harvesting scapular and parascapular flaps. METHODS: Twenty patients were operated on to remove pathologically diagnosed sarcomas using a wide local excision. The defects, ranging from 5 to 22 cm in width, were closed using donor flaps from the scapular/parascapular region. Nine donor sites were then closed primarily with wide undermining, while 11 donor sites were closed using multiple techniques, such as large transposition flaps, large rotation advancement flaps, keystone neurovascular island flaps, latissimus dorsi advancement flap and large Y-V advancement flaps. RESULTS: All recipient and donor flaps survived with good aesthetic and functional outcome. Patient satisfaction was high and only two of 20 donor site flaps required further surgery due to wound dehiscence. No other complications were seen during the follow-up period. CONCLUSION: The proposed advanced techniques for donor site closure in back defects have shown that primary wound healing can be achieved with the use of a variety of different techniques and the avoidance of the complications of a skin graft.
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    In situ handheld three-dimensional bioprinting for cartilage regeneration
    Di Bella, C ; Duchi, S ; O'Connell, CD ; Blanchard, R ; Augustine, C ; Yue, Z ; Thompson, F ; Richards, C ; Beirne, S ; Onofrillo, C ; Bauquier, SH ; Ryan, SD ; Pivonka, P ; Wallace, GG ; Choong, PF (WILEY, 2018-03)
    Articular cartilage injuries experienced at an early age can lead to the development of osteoarthritis later in life. In situ three-dimensional (3D) printing is an exciting and innovative biofabrication technology that enables the surgeon to deliver tissue-engineering techniques at the time and location of need. We have created a hand-held 3D printing device (biopen) that allows the simultaneous coaxial extrusion of bioscaffold and cultured cells directly into the cartilage defect in vivo in a single-session surgery. This pilot study assessed the ability of the biopen to repair a full-thickness chondral defect and the early outcomes in cartilage regeneration, and compared these results with other treatments in a large animal model. A standardized critical-sized full-thickness chondral defect was created in the weight-bearing surface of the lateral and medial condyles of both femurs of six sheep. Each defect was treated with one of the following treatments: (i) hand-held in situ 3D printed bioscaffold using the biopen (HH group), (ii) preconstructed bench-based printed bioscaffolds (BB group), (iii) microfractures (MF group) or (iv) untreated (control, C group). At 8 weeks after surgery, macroscopic, microscopic and biomechanical tests were performed. Surgical 3D bioprinting was performed in all animals without any intra- or postoperative complication. The HH biopen allowed early cartilage regeneration. The results of this study show that real-time, in vivo bioprinting with cells and scaffold is a feasible means of delivering a regenerative medicine strategy in a large animal model to regenerate articular cartilage.
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    Importance of preoperative diagnosis for management of patients with suspected retroperitoneal sarcoma
    Gyorki, DE ; Choong, PFM ; Slavin, J ; Henderson, MA (WILEY, 2018-04)
    Soft tissue sarcoma is an umbrella term which encompasses over 60 histological tumour types. Approximately 15% of soft tissue sarcomas arise in the retroperitoneum. This complex group of tumours poses unique management challenges due to their often large size, histological heterogeneity and complexity of anatomical relationships. This review discusses the management of retroperitoneal tumours including the need for preoperative diagnosis, the evidence for neoadjuvant radiotherapy, the role of multivisceral resection and the importance of a multidisciplinary team approach.
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    Shoulder to knee: lessons learnt
    Choong, PFM (WILEY, 2017-05)
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    Diagnostic accuracy of computed tomography-guided biopsy in pathological fractures
    Stokes, CM ; Elsewaisy, O ; Pang, G ; Slavin, JL ; Schlicht, SM ; Choong, PFM (WILEY, 2017-07)
    BACKGROUND: Obtaining a histological diagnosis is essential for appropriate management of pathological fractures. Computed tomography (CT) is an accurate method of obtaining diagnosis for musculoskeletal tumours. We analysed whether diagnostic accuracy was maintained in the evaluation of pathological fractures. METHODS: A retrospective review of 101 consecutive patients presenting to our tertiary musculoskeletal tumour centre with pathological fracture was performed. Patients underwent core needle biopsy under CT guidance of pathological fractures diagnosed by plain radiography and either CT or magnetic resonance imaging. The histopathology of the CT-guided biopsy was compared with the sample obtained from open biopsy or definitive surgery to determine diagnostic accuracy. RESULTS: The mean age at diagnosis was 52 ± 20 years (range: 18-85) in a cohort of 46 men and 55 women. Diagnostic accuracy of CT-guided biopsy was 82.18%. There were 65 malignant and 36 benign tumours with diagnostic accuracy of 86.15% and 80.56%, respectively. The positive predictive value for a malignant tumour was 98.21% whilst it was 93.1% for benign tumours. The femur (53 cases) and humerus (25 cases) were the commonest bones fractured. The most frequent diagnoses were metastasis (20.79%), giant cell tumour (17.82%), osteosarcoma (9.90%) and myeloma (9.90%). There were no complications of CT-guided biopsy. CONCLUSION: Pathological fracture does not confound the diagnosis of musculoskeletal tumours. CT-guided biopsy is an accurate diagnostic tool in the evaluation of pathological fractures. Final diagnosis and management should be made in the context of appropriate anatomical and functional imaging using a multidisciplinary approach.
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    Engineering skeletal muscle - from two to three dimensions
    Ngan, CGY ; Quigley, A ; Kapsa, RMI ; Choong, PFM (WILEY, 2018-01)
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    Review of knee arthroscopic practice and coding at a major metropolitan centre
    Lisik, JP ; Dowsey, MM ; Petterwood, J ; Choong, PFM (WILEY, 2017-05)
    BACKGROUND: Arthroscopic knee surgery has been a topic of significant controversy in recent orthopaedic literature. Multiple studies have used administrative (Victorian Admitted Episodes Dataset and Centre for Health Record Linkage) data to identify trends in practice. This study explored the usage and reporting of arthroscopic knee surgery by conducting a detailed audit at a major Victorian public hospital. METHODS: A database of orthopaedic procedures at St Vincent's Hospital Melbourne was used to retrospectively identify cases of knee arthroscopy from 1 December 2011 to 1 April 2014. Procedures were categorized as diagnostic or interventional, and native and prosthetic joints were analysed separately. Procedure codes were reviewed by comparing a registrar, auditor and hospital coders for agreement. RESULTS: Of the 401 cases for analysis, 375 were conducted in native knees and 26 in prosthetic joints. Of native knees, 369 (98.4%) were considered interventional. The majority of these were conducted for meniscal pathology (n = 263, 70.1%), osteoarthritis (OA) (n = 25, 6.7%) and infection (n = 28, 7.6%). Comparison of codes assigned by different parties were found to be between 57% (k = 0.324) and 70% (k = 0.572) agreement, but not statistically significant. CONCLUSIONS: In this study, the most common indication for arthroscopy was meniscal pathology. Arthroscopy was rarely performed for OA in the absence of meniscal pathology. Diagnostic arthroscopy was rarely performed in the native knee, and fair to moderate agreement existed between parties in assigning Medicare Benefits Schedule procedure codes.