Delayed vascularization and resultant resorption limits the clinical use of tissue engineered bony constructs. The objective of this study is to develop a strategy to accelerate the neovascularization of tissue-engineered bony constructs using endothelial differentiated adipose-derived stem cells (ASC). The authors harvested ASC from inguinal fat pads of male Lewis rats (n = 5) and induced toward endothelial and osteoblastic lineages. The authors created critical size calvarial defects on male Lewis rats (n = 30) and randomized the animals into 4 groups. For the repair of the defects the authors used hydroxyapatite/poly(lactide-co-glycolide) [HA-PLG] scaffolds in group I, HA-PLG scaffolds seeded with ASC in group II, HA-PLG scaffolds seeded with ASC-derived endothelial cells in group III, and HA-PLG scaffolds seeded with ASC-derived osteoblasts in group IV. The authors evaluated the bone healing histologically and with micro-computed tomography (CT) scans 8 weeks later. Adipose-derived stem cells exhibited the characteristics of endothelial and osteogenic lineages, and attached on HA-PLG scaffolds after differentiation. Micro-CT analysis revealed that highest bone mineral density was in group IV (1.46 ± 0.01 g/cm) followed by groups III (1.43 ± 0.05 g/cm), I (1.42 ± 0.05 g/cm), and II (1.3 ± 0.1 g/cm). Hematoxylin-Eosin and Masson Trichrome staining revealed similar results with the highest bone regeneration in group IV followed by groups II, III, and I. Regenerated bone in group IV also had the highest vascular density, but none of these differences achieved statistical significance (P > 0.05). The ASC-derived endothelial cells and osteoblasts provide a limited increase in calvarial bone healing when combined with HA-PLG scaffolds.

AlloDerm RTU and AlloMaxTM are two acellular dermal matrices (ADMs) used in implant-based breast reconstruction. In this study, we examined whether different processing methods for the ADMs lead to a disparity in histologic, clinical, and financial outcomes after breast reconstruction. Thirty patients undergoing implant-based breast reconstruction were randomized into AlloMax or AlloDerm arms (n = 15, each). ADM was placed at the time of immediate reconstruction. Patients were evaluated for complications on postoperative days 7, 14, and 30. During implant exchange, ADM biopsies were taken and compared histologically for vascular and cellular infiltration. Patient satisfaction was evaluated using the BRECON-31 questionnaire 1 year after implant exchange. A cost analysis was performed comparing the two ADMs. Patient demographics and complication rates were similar between the two groups (p > 0.05). Histologically, vessel density and fibroblast/inflammatory cell infiltrate were greater on the dermal side than on the implant side (p < 0.01) in both ADMs, suggesting greater vascular and cellular in-growth from the dermal side. Vessel density in the middle portion of the Allomax biopsies was significantly higher than the same site in the Alloderm biopsies (p < 0.05). The extent of fibroblast/inflammatory cell infiltration was similar in both arms (p > 0.05). The BRECON-31 satisfaction questionnaire yielded similar responses across all metrics between the two study arms. The negotiated price was slightly different when comparing the two ADMs, with no significant difference in ADM reimbursement. In this study, AlloDerm RTU and AlloMax were successfully used for implant-based breast reconstruction with comparable outcomes.

Elbow arthroplasty in the setting of active infection may be accomplished by means of free tissue muscle transfer. Elimination of infection and acceptable joint function may be possible with this form of reconstruction.

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