Tetanic force measurements of rat tibialis anterior (TA) muscles have been described, but with a variety of stimulation parameters. This study presents a novel functional method of force measurement of the rat TA muscle and describes the optimization of stimulation parameters. Bilateral TA muscles in 10 male Lewis rats were attached to a force transducer after the corresponding hindlimb was fixed. Preload, stimulus intensity, duration, and frequency were optimized for each individual muscle and the isometric maximal tetanic muscle force was measured. The mean left side tetanic force as a percentage of the right was 100.0 +/- 4.4% and was statistically equivalent. Large standard deviations between sides (35-50%) were observed in the optimized parameters (preload, stimulus intensity, duration, and frequency). Optimization of the variables affecting isometric tetanic force resulted in reproducible and reliable side-to-side measurements of the TA muscle in the rat model.

The peroneus brevis is a valuable flap for defect closure around the ankle and lower leg. It can be harvested together with a vascularized split fibula segment, representing a simple alternative to several free composite flaps. Its complication rate can be lowered significantly if the proximal 3 cm of the muscle origin (i.e., the flap tip in distally pedicled flaps) is discarded during dissection and delicate hemostasis is performed.

The purpose of this study was to demonstrate that living bone allotransplants can incorporate, remodel, and maintain mechanical properties without long-term immunosuppression in a fashion comparable to living autotransplants. For this, viability is maintained by repair of nutrient vessels and neovascularization from implanted host-derived vasculature. Microsurgically revascularized femoral diaphysis allotransplants were transferred from young male New-Zealand-White (NZW) into 4 groups of male Dutch-Belted (DB) rabbits. Short-term immunosuppression by tacrolimus (IS, groups 4 and 5) and host-derived neovascularization (NV) from implanted fascial flaps was used to maintain viability (groups 3 and 5) as independent variables. Group 2 received neither IS nor NV. Vascularized pedicled autotransplants were orthotopically transplanted in group 1. After 16 weeks, transplants were evaluated using radiologic, histologic, biomechanical, and histomorphometric parameters. Vascularized bone allotransplants treated with both short-term IS and host-derived NV (group 5) healed in a fashion similar to pedicled autotransplants (group 1). Their radiographic scores were higher than other groups. Groups with patent fascial flaps (3 and 5) showed significantly greater neoangiogenesis than ligated controls (2 and 4). Tacrolimus administration did not affect neoangiogenesis. Elastic modulus and ultimate stress were significantly greater in autogenous bone than in allotransplanted femora. Biomechanical properties were not significantly different among allotransplants. Bone turnover was decreased with IS, but increased with NV by the implanted fascial flaps. Living allogeneic femoral allotransplants treated with short-term IS and host-derived neoangiogenesis can lead to stable transplant incorporation in this rabbit model. The reconstruction of skeletal defects remains a challenging reconstructive problem, for which vascularized bone autotransplants are among the best options. They heal more reliably and quickly, remodel more effectively, and resist infection better than nonviable allografts. 1 Limited donor sites, potential donor site morbidity, and poor geometric matching to defects create surgical challenges. 2 Prosthetic replacement and distraction osteogenesis also have significant rates of hardware failure or sepsis. 2 Avascular structural bone allografts do not fully incorporate and demonstrate little remodeling.Living bone allotransplantation is intriguing, given absence of donor morbidity, close geometric matching, and potentially similar healing/remodeling to living autotransplant bone. A few reports of clinical use, however, have demonstrated poor viability and mechanical properties, and problems with infections. [3][4][5] The need to maintain long-term immunosuppression (IS) raises concerns for potential severe side-effects, which are difficult to justify for extremity-preserving procedures.We previously have described a method of living allogeneic bone transplantation in the rat not requiring long-term IS, made poss...

Functional and esthetic reconstruction of the bony and tendinous structures with a stable, sensate soft tissue integument after complex posttraumatic defects of the heel is demanding. Cases are rare in the literature and hardly comparable due to their heterogeneity. The reconstructive approach has to consider both patient profile and the reconstructive tree, with free microvascular flaps playing a primary role. The goals are the reconstruction of both osteotendinous structures and slender soft tissue lining for proper shoe fitting for ambulation and mechanical and thermal protection. The flap should be sensate in weightbearing areas to optimize gait and to prevent long-term complications by ulcers. The osteofasciocutaneous deep inferior circumflex artery (DCIA) flap is especially suitable for complex heel defects with subtotal or total loss of the calcaneal bone as all components (iliac bone, groin skin, and fascia lata) can have a wide range of size and shape. We operated on 2 cases with this variable composite flap. One patient had a complete heel defect by war shrapnel. The complete calcaneus, soft heel, and Achilles tendon were reconstructed. The second patient had an empty os calcis after a comminuted fracture and a lateral crush-induced soft tissue defect. In both patients, a stable wound closure, osseous integration, and weightbearing ambulation could be achieved.