Processed nerve allografts for peripheral nerve reconstruction: a multicenter study of utilization and outcomes in sensory, mixed, and motor nerve reconstructions.

PURPOSE: As alternatives to autograft become more conventional, clinical outcomes data on their effectiveness in restoring meaningful function is essential. In this study we report on the outcomes from a multicenter study on processed nerve allografts (Avance® Nerve Graft, AxoGen, Inc). PATIENTS AND METHODS: Twelve sites with 25 surgeons contributed data from 132 individual nerve injuries. Data was analyzed to determine the safety and efficacy of the nerve allograft. Sufficient data for efficacy analysis were reported in 76 injuries (49 sensory, 18 mixed, and 9 motor nerves). The mean age was 41 ± 17 (18-86) years. The mean graft length was 22 ± 11 (5-50) mm. Subgroup analysis was performed to determine the relationship to factors known to influence outcomes of nerve repair such as nerve type, gap length, patient age, time to repair, age of injury, and mechanism of injury. RESULTS: Meaningful recovery was reported in 87% of the repairs reporting quantitative data. Subgroup analysis demonstrated consistency, showing no significant differences with regard to recovery outcomes between the groups (P > 0.05 Fisher's Exact Test). No graft related adverse experiences were reported and a 5% revision rate was observed. CONCLUSION: Processed nerve allografts performed well and were found to be safe and effective in sensory, mixed and motor nerve defects between 5 and 50 mm. The outcomes for safety and meaningful recovery observed in this study compare favorably to those reported in the literature for nerve autograft and are higher than those reported for nerve conduits.

Analyzing glenohumeral torque-rotation response in vivo.

BACKGROUND: Because the human shoulder has many degrees of freedom that allow redundant means of producing the same net humerothoracic motion, there are many impediments to objective, repeatable assessment of shoulder function in vivo. Devices designed to date have suffered from poor reliability. In this study we introduce a new device and methods to evaluate human shoulder kinematics and evaluate its reproducibility from subject to subject and from day to day. METHODS: This was a controlled laboratory study. Using electromagnetic motion sensors to record the position and orientation of the thorax, scapula, and humerus, we quantified the kinematic response of twenty four normal shoulders in response to known internal-external torque application. A four-parameter logistic function was selected to characterize the strident features of the torque-rotation relationship. FINDINGS: Our analysis in conjunction with the measurement technique described herein, allowed the passive glenohumeral internal-external range of motion to be differentiated from other motion components and was determined to within 9.6% of full scale over three repeated trials. Range of motion was the most reliable biomechanical outcome, more so than computed indices of glenohumeral flexibility and hysteresis. The exact profile of the torque-rotation response, and therefore the repeatability of the calculated outcomes, was unique from shoulder to shoulder. INTERPRETATION: The development of the capacity for precise, non-invasive measurement of shoulder biomechanics over time is a requisite step towards optimizing treatment of shoulder injury and disease. Our current methods are superior to previous attempts at trying to non-invasively evaluate the biomechanics of the glenohumeral joint.