Current strategies to treat volumetric muscle loss use primarily pedicle or free muscle transfers, but these grafts fail to adequately regenerate functional tissue. Decellularized soft tissue grafts possess physical and chemical cues to promote muscle regeneration, suggesting their potential for use in large muscle defects. In this study, we developed a decellularized muscle matrix (DMM) graft using rat gastrocnemius. Anisotropy and chemical components of the extracellular matrix were retained, including laminin, fibronectin, and collagen. We compared the ability of DMM, autologous muscle grafts (clinical standard), and type I collagen plugs (negative control) to support muscle regeneration. DMM supported regeneration over a 56-day period in 1 × 1 cm and 1.5 × 1 cm gastrocnemius defects in rats. Muscle function tests demonstrated improved muscle recovery in rats with DMM grafts when compared to collagen. Histological sections were assessed using morphometrics and immunostaining. DMM supported muscle regeneration with less fibrosis and more de novo neuromuscular receptors than either autograft or collagen. Overall, our results indicate that DMM may be used as a muscle replacement graft based on its ability to improve muscle function recovery, promote muscle regeneration, and support new neuromuscular junctions.

Accurate sizing of nerve conduits to the nerve-stump diameter improves nerve recovery.

Background The transfer of patients for hand and microsurgical emergencies to level I trauma centers is a common practice. Many of these transfers do not actually require a hand specialist and could be taken care of at most regional hospitals. In this study, we will evaluate the appropriateness of patient transfers for hand trauma and determine if there is a correlation between inappropriate transfers and undesirable factors, such as insurance status and off-hour's presentation. Methods A retrospective chart review was performed in all patients transferred to a level I trauma center for hand and microsurgical trauma over a 22-month period. Collected data included indication for transfer, mode of transfer, time and day of the week, patient demographics, insurance status, and whether the transferring facilities had surgical coverage available. A synopsis, including treatment details, of each transfer was created, and a survey was sent to a review committee who rated the appropriateness of the transfers. Statistical analysis was performed to determine whether appropriateness of transfers was influenced by nonmedical variables. Results Over a 22-month period, a total of 95 hand or microsurgical patients were transferred to a single tertiary referral center. Of these, 66 % of the transfers were considered inappropriate by the surveyed physicians. Inappropriate transfers were statistically more likely to be under insured or transferred during nonbusiness hours. Conclusion A large percentage of patients are being transferred to tertiary care centers for reasons other than medical necessity, generating a large burden on already strained medical resources.

Background Denervation atrophy is one factor contributing to suboptimal motor recovery following major nerve repair. The hypertrophic effects of anabolic steroids may have a potential role in improving reinnervated muscle strength after delayed repair. Methods Forty-five immature female Sprague-Dawley rats underwent three surgeries and final testing. The tibial nerve was transected in the hind limb of the experimental (n=13) and control (n=14) animals and exposed, but not transected in the sham (n=15) group animals. Three months later, once denervation atrophy was established, all transected nerves underwent repair using an autograft from the contralateral limb. After waiting an additional month to allow axonal regeneration to the gastrocnemius muscles, the rodents were implanted with a subcutaneous infusion pump. For the experimental group, nandrolone was administered over the next 30 days via this pump, while the control and sham group pumps were filled with carrier only. Results Final testing, 6 weeks later, showed improved muscle contraction strength in the steroid-treated animals (72% of sham group strength) compared to control animals (57% of sham group strength, p<0.5). A trend towards increased weight and muscle belly diameter in the steroidtreated group was not statistically significant. Conclusions These findings support the potential role of anabolic steroids in improving recovery of atrophic muscle after delayed reinnervation.