A preclinical large-animal model for the assessment of critical-size load-bearing bone defect reconstruction.

Critical-size bone defects, which require large-volume tissue reconstruction, remain a clinical challenge. Bone engineering has the potential to provide new treatment concepts, yet clinical translation requires anatomically and physiologically relevant preclinical models. The ovine critical-size long-bone defect model has been validated in numerous studies as a preclinical tool for evaluating both conventional and novel bone-engineering concepts. With sufficient training and experience in large-animal studies, it is a technically feasible procedure with a high level of reproducibility when appropriate preoperative and postoperative management protocols are followed. The model can be established by following a procedure that includes the following stages: (i) preoperative planning and preparation, (ii) the surgical approach, (iii) postoperative management, and (iv) postmortem analysis. Using this model, full results for peer-reviewed publication can be attained within 2 years. In this protocol, we comprehensively describe how to establish proficiency using the preclinical model for the evaluation of a range of bone defect reconstruction options.

Assessment of morbidity following regional nodal dissection in the axilla and groin for metastatic melanoma.

BACKGROUND: This study assessed and compared the morbidity of nodal dissection in the axilla and groin including sentinel lymph node biopsy (SLNB), completion lymph node dissection for a positive SLNB (CLND) and therapeutic lymph node dissection (TLND) with and without adjuvant radiotherapy (RT). METHODS: Patients who had nodal dissection in the axilla or groin for cutaneous melanoma over an 18-year period (1995-2013) were prospectively documented on a database. The median follow-up was nearly 3 years. Early complications and clinically relevant lymphoedema were retrospectively analysed to assess the incidence and differences between the region and type of nodal surgery. RESULTS: Included were 1521 patients following nodal dissection in the axilla (916 patients) and groin (605 patients). Less early complications occurred following SLNB in the axilla compared with the groin (5% versus 14%, P = 0.0001). Early complications were similar for CLND and TLND in the groin (49% versus 43%, P = 0.879) and axilla (28% versus 33%, P = 0.607). Moderate to severe lymphoedema rates were similar following axillary SLNB and CLND (6% versus 8%, P = 0.407). The lymphoedema rate for groin SLNB was lower than CLND (10% versus 20%, P = 0.063). No significant difference in lymphoedema rates followed CLND and TLND in each region. Following TLND, RT increased lymphoedema rates. CONCLUSIONS: Morbidity may occur following SLNB with the groin having a higher rate of early complications and lymphoedema compared with the axilla. The morbidity following CLND and TLND were similar. Lymphoedema rates were increased following RT.