Bishop, Allen T.

Background: The objective of this study was to review the outcomes of patients who underwent one-bone forearm (OBF) reconstruction. Methods: A retrospective review of patients who underwent OBF surgery between 1994 and 2014 was undertaken. Patient demographics, etiology, associated injuries, number of surgeries prior to OBF surgery, surgical details, and postoperative information were collected. A telephone interview was conducted at final follow-up, including a Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) questionnaire, a 10-point scoring system used by Peterson et al, and a series of questions concerning pain and patient satisfaction. Results: There were 6 males and 2 females with a mean age of 44 years (range, 20-66 years). All patients had traumatic etiology, with 6 having open wounds and 2 having closed wounds. All patients had union with a mean follow-up of 83.6 months (range, 16-218 months). The mean pain score was 3 (range, 0-8), of which 3 were painless (score 0). The mean QuickDASH score was 39 (range, 7-75), and 4 patients had good or excellent results according to the 10-point score system used by Peterson et al. All patients were satisfied with the result. Five of 8 had complications related to soft tissues that were residual from their prior injuries and surgeries. One patient had post healing fracture requiring revision fixation and 1 had a postoperative infection requiring parenteral antibiotics. Conclusions: OBF surgery is an effective salvage procedure for complicated forearm instability, particularly after trauma. While union rates are high, complications are typically related to pain and soft tissue secondary to the previous injury and reconstructive procedures.

Processed nerve allografts have become an alternative to repair segmental nerve defects, with results comparable with autografts regarding sensory recovery; however, they have failed to reproduce comparable motor recovery. The purpose of this study was to determine how revascularizaton of processed nerve allograft would affect motor recovery. Eighty‐eight rats were divided in four groups of 22 animals each. A unilateral 10‐mm sciatic nerve defect was repaired with allograft (group I), allograft wrapped with silicone conduit (group II), allograft augmented with vascular endothelial growth factor (group III), or autograft (group IV). Eight animals from each group were sacrificed at 3 days, and the remaining animals at 16 weeks. Revascularization was evaluated by measuring the graft capillary density at 3 days and 16 weeks. Measurements of ankle contracture, compound muscle action potential, tibialis anterior muscle weight and force, and nerve histomorphometry were performed at 16 weeks. All results were normalized to the contralateral side. The results of capillary density at 3 days were 0.99% ± 1.3% for group I, 0.33% ± 0.6% for group II, 0.05% ± 0.1% for group III, and 75.6% ± 45.7% for group IV. At 16 weeks, the results were 69.9% ± 22.4% for group I, 37.0% ± 16.6% for group II, 84.6% ± 46.6% for group III, and 108.3% ± 46.8% for group IV. The results of muscle force were 47.5% ± 14.4% for group I, 21.7% ± 13.5% for group II, 47.1% ± 7.9% for group III, and 54.4% ± 10.6% for group IV. The use of vascular endothelial growth factor in the fashion used in this study improved neither the nerve allograft short‐term revascularization nor the functional motor recovery after 16 weeks. Blocking allograft vascularization from surrounding tissues was detrimental for motor recovery. The processed nerve allografts used in this study showed similar functional motor recovery compared with that of the autograft. © 2014 Wiley Periodicals, Inc. Microsurgery 36:134–143, 2016.

OBJECT Transfer of the triceps motor branch has been used for treatment of isolated axillary nerve palsy in the adult population. However, there are no published data on the effectiveness of this procedure in the pediatric population with traumatic injuries. The authors reviewed demographics and outcomes in their series of pediatric patients who underwent this procedure. METHODS Six patients ranging in age from 10 to 17 years underwent triceps motor branch transfer for the treatment of isolated axillary nerve injuries between 4 and 8 months after the inciting injury. Deltoid muscle strength was evaluated using the modified British Medical Research Council (MRC) grading system. Shoulder abduction at last follow-up was measured. RESULTS The mean duration of follow-up was 38 months. The average postoperative MRC grading of deltoid muscle strength was 3.6 ± 1.3. The median MRC grade was 4. One patient who did not achieve an MRC grade of 3 suffered multiple injuries from high-velocity trauma. Unlike in the adult population, age, body mass index of the patient, and delay from injury to surgery were not significant factors affecting the outcome of the procedure. CONCLUSIONS In the pediatric population with traumatic injuries, isolated axillary nerve injury treated with triceps motor branch transfer can result in good outcomes.

BackgroundVascular endothelial growth factor (VEGF) induces angiogenesis and osteogenesis in bone allotransplants. We aim to determine whether bone remodeling in VEGF‐treated bone allotransplants results from repopulation with circulation‐derived autogenous cells or survival of allogenic transplant‐derived cells.MethodsVascularized femoral bone transplants were transplanted from female Dark Agouti rats (DA;RT1a) to male Piebald Viral Glaxo (PVG;RT1c). Arteriovenous bundle implantation and short‐term immunosuppression were used to maintain cellular viability. VEGF was encapsulated in biodegradable microspheres and delivered intramedullary in the experimental group (n = 22). In the control group (n = 22), no VEGF was delivered. Rats were sacrificed at 4 or 18 weeks. Laser capture microdissection of bone remodeling areas was performed at the inner and outer cortex. Sex‐mismatched genes were quantified with reverse transcription‐polymerase chain reaction to determine the amount of male cells to total cells, defined as the relative expression ratio (rER).ResultsAt 4 weeks, rER was significantly higher at the inner cortex in VEGF‐treated transplants as compared to untreated transplants (0.622 ± 0.225 vs. 0.362 ± 0.081, P = 0.043). At 4 weeks, the outer cortex in the control group had a significantly higher rER (P = 0.038), whereas in the VEGF group, the inner cortex had a higher rER (P = 0.015). Over time, in the outer cortex the rER significantly increased to 0.634 ± 0.106 at 18 weeks in VEGF‐treated rats (P = 0.049). At 18 weeks, the rER was >0.5 at all cortical areas in both groups.ConclusionsThese in vivo findings suggest a chemotactic effect of intramedullary applied VEGF on recipient‐derived bone and could imply that more rapid angiogenesis of vascularized allotransplants can be established with microencapsulated VEGF. © 2014 Wiley Periodicals, Inc. Microsurgery 35:45–51, 2015.

The purpose of this study was to evaluate the effect of wrapping bioabsorbable nerve conduit around primary suture repair on motor nerve regeneration in a rat model. Forty rats were randomly divided into two experimental groups according to the type of repair of the rat sciatic nerve: group I had primary suture repair; group II had primary suture repair and bioabsorbable collagen nerve conduit (NeuraGen® 1.5 mm, Integra LifeSciences Corp., Plainsboro, NJ) wrapped around the repair. At 12 weeks, no significant differences in the percentage of recovery between the two groups were observed with respect to compound muscle action potentials, isometric muscle force, and muscle weight (P = 0.816, P = 0.698, P = 0.861, respectively). Histomorphometric analysis as compared to the non‐operative sites was also not significantly different between the two groups in terms of number of myelinated axons, myelinated fiber area, and nerve fiber density (P = 0.368, P = 0.968, P = 0.071, respectively). Perineural scar tissue formation was greater in primary suture repair group (0.36 ± 0.15) than in primary repair plus conduit wrapping group (0.17 ± 0.08). This difference was statistically significant (P < 0.001). Wrapping bioabsorbable nerve conduit around primary nerve repair can decrease perineural scar tissue formation. Although the scar‐decreasing effect of bioabsorbable nerve wrap does not translate into better motor nerve recovery in this study, it might have an effect on the functional outcome in humans where scar formation is much more evident than in rats. © 2014 Wiley Periodicals, Inc. Microsurgery 34:562–567, 2014.

Object Choline acetyltransferase (ChAT) is an enzyme synthesized within the body of a motor neuron whose role is to form the neurotransmitter acetylcholine. Quantification of ChAT levels in motor or mixed nerves has been proposed to provide information regarding the viability of a proximal nerve stump for motor neurotization following brachial plexus injury. To do so requires information regarding normal ChAT levels and those in injured nerves, as well as the correlation of ChAT level determined at surgery with eventual motor recovery. The purpose of this study was to determine ChAT activity in the normal and injured sciatic/peroneal nerve in a rat model, evaluate the correlation between ChAT and motor recovery, find the relationship between ChAT activity and isometric muscle force, and elucidate the parallel between ChAT activity and acetylcholinesterase (AChE) activity. Methods Sixty animals were divided into 3 groups. The sciatic nerves in Group 1 were transected without repair. Nerves in Group 2 were transected and repaired. Nerves in Group 3 sustained a crush injury followed by transection and reconstruction. All animals were allowed 12 weeks of recovery followed by evaluation of ChAT levels in the peroneal nerve, correlated with measures of maximal isometric tibialis anterior muscle force and muscle weight (the operated side normalized to the control side). Karnovsky AChE staining of peroneal nerve segments was also compared with radiochemical assay of ChAT activity in the same nerve. Results A significant difference in the tibialis anterior isometric tetanic force and the tibialis anterior muscle weight index (TAMI) was noted between Group 1 and Groups 2 and 3 (p < 0.0001); no significant difference was found comparing Group 2 with Group 3. The correlation between the force measurement and the TAMI was 0.382. Both AChE measurement and ChAT activity demonstrated significantly fewer fibers in the operated nerve compared with the contralateral nerve. Intergroup variability could also be illustrated using these tests. The correlation coefficient between the isometric tetanic force measurement and the ChAT analysis in Groups 1 and 2 was 0.468. The correlation for the AChE staining and the isometric tetanic force measurement was 0.111. The correlation between the TAMI and the ChAT levels was 0.773. The correlation between the TAMI and the AChE-stained fibers was 0.640. Correlating AChE staining to the ChAT analysis produced a correlation of 0.712. Conclusions The great variability in all groups and weak correlations to the functional muscle assessments and the ChAT radiochemical assay made this technique an unreliable method of determining motor nerve viability.