Protocol for the BONE-RECON trial: a single-arm feasibility trial for critical sized lower limb BONE defect RECONstruction using the mPCL-TCP scaffold system with autologous vascularised corticoperiosteal tissue transfer.

INTRODUCTION: Reconstruction of critical bone defects is challenging. In a substantial subgroup of patients, conventional reconstructive techniques are insufficient. Biodegradable scaffolds have emerged as a novel tissue engineering strategy for critical-sized bone defect reconstruction. A corticoperiosteal flap integrates the hosts' ability to regenerate bone and permits the creation of a vascular axis for scaffold neo-vascularisation (regenerative matching axial vascularisation-RMAV). This phase IIa study evaluates the application of the RMAV approach alongside a custom medical-grade polycaprolactone-tricalcium phosphate (mPCL-TCP) scaffold (Osteopore) to regenerate bone sufficient to heal critical size defects in lower limb defects. METHODS AND ANALYSIS: This open-label, single-arm feasibility trial will be jointly coordinated by the Complex Lower Limb Clinic (CLLC) at the Princess Alexandra Hospital in Woolloongabba (Queensland, Australia), the Australian Centre for Complex Integrated Surgical Solutions (Queensland, Australia) and the Faculty of Engineering, Queensland University of Technology in Kelvin Grove (Queensland, Australia). Aiming for limb salvage, the study population (n=10) includes any patient referred to the CLLC with a critical-sized bone defect not amenable to conventional reconstructive approaches, after discussion by the interdisciplinary team. All patients will receive treatment using the RMAV approach using a custom mPCL-TCP implant. The primary study endpoint will be safety and tolerability of the reconstruction. Secondary end points include time to bone union and weight-bearing status on the treated limb. Results of this trial will help shape the role of scaffold-guided bone regenerative approaches in complex lower limb reconstruction where current options remain limited. ETHICS AND DISSEMINATION: Approval was obtained from the Human Research Ethics Committee at the participating centre. Results will be submitted for publication in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: ACTRN12620001007921.

Wrist fusion using an induced membrane technique for forearm salvage in a patient with an infected open injury with segmental bone loss: A case report.

This case report describes the management of a 27-year-old male who, after a quadbike accident, presented with an open, infected, segmental both bone forearm injury with significant bone and soft tissue loss including the radio-carpal joint. Limb salvage was accomplished in the form of a single bone forearm fusion utilising Masquelet's two-stage induced membrane technique to reconstruct the segmental bone defect. The patient proceeded to uneventful bony union by 6 months and returned to driving and riding a quadbike. Despite significant deep infection, successful salvage was achieved using the induced membrane technique. Critical to success was aggressive, repeated debridement alongside restoration of vascular supply and reconstruction of soft tissue defects. We highlight the multidisciplinary approach to management including relevant specialists with a particular interest in limb reconstruction.

Managing soft tissues in severe lower limb trauma in an ageing population.

PURPOSE: With an ageing population, the incidence of trauma in those aged over 65 years is increasing. Strategies for dealing with these patients must be developed. At present the standard management of open tibial fractures in the UK is described by the BOAST4 guidelines (from the British Orthopaedic Association and British Association of Plastic & Aesthetic Surgeons). It is not clear to what extent these are appropriate for older patients. We describe our experience of managing elderly patients presenting with open tibial fractures. METHOD: Patients were identified via prospectively collected national and departmental databases. These data were supplemented by review of the patient records and radiographs. Data collated included patient demographics, injury details, orthopaedic and plastic surgery operative details, and long-term outcomes. RESULTS: Between January 2013 and June 2016, 74 patients aged over 65 years were admitted with open lower limb fractures. 54 of these were open tibial fractures and these patients formed the study group. 19 patients required soft-tissue reconstruction for Gustilo and Anderson IIIB tibial fractures (age range, 67-95 years). In these patients, there were 7 midshaft (AO 42), 1 proximal (AO 41), and 11 distal (AO 43) fractures. 13 patients were treated with internal fixation and 6 with circular frames. The median length of hospital stay was 27 days (range, 4-85). 14 patients received loco-regional flaps and 5 underwent free tissue transfer with one requiring preoperative femoral angioplasty. There were no flap losses. Four patients had fasciocutaneous flaps, 3 tibialis anterior transposition, 2 an extensor digitorum brevis flap, 1 a hemisoleus flap, and 4 were skin grafted. All patients went on to unite and return to their premorbid weight-bearing status (4 using walking frames, 3 using sticks, and 12 walking independently). CONCLUSION: Although the literature suggests a significantly higher complication rate in elderly patients with open fractures, we have demonstrated comparable rates of flap survival and bony union to those observed in younger patients. Challenges are presented in terms of patient physiology and these must be carefully managed pre- and postoperatively. These challenges are reflected in prolonged hospital stays.