Back to Annual Meeting Program

Introduction: Peripheral nerve injuries resulting in an insurmountable gap require reconstruction with a bridging material to regain continuity. As the use of autograft alternatives such as conduits and processed nerve allografts are becoming more conventionally accepted, clinical outcomes data with respect to treated gap length is of interest.  In 2008, a multicenter, retrospective study was initiated to capture data on outcomes of processed nerve allografts in today's clinical practice. As the length of a nerve defect is one essential contributing factor for outcomes, here we report our findings on the relationship of nerve gap lengths for injuries between 5 mm and 50 mm.   

Methods: The IRB approved study enrolled 12 sites with 25 contributing surgeons. Standardized data collection forms were completed for 132 individual nerve injuries. The aggregate data was separated by treated gap length and subsequent subgroup analysis was performed including injury and repair demographics and response rates. Quantitative assessment included: MRCC scale for sensory and motor nerves, 2-point discrimination (2-PD), Semmes-Weinstein Monofilaments (SWMF), grip/strength testing and range-of-motion. 

Results: Fifty one nerve repairs reported sufficient quantitative follow-up to assess for outcomes analysis. Repairs were divided up into three gap groups: A (5- 14mm) n = 11, B (15 - 29mm) n =21, C (30-50mm) n= 19. Characteristics of each subgroup are listed in Table 1. Lacerations were the most prevalent mechanism of injury for all three groups. Group B contained significantly more chronic injuries than Group A. 

Meaningful recovery, defined as S3-S4/M3-M5 on the MRCC scales, was reported in 88% of all repairs. One hundred (100) percent of the repairs in Group A reported meaningful recovery with 76.2% and 94.7% in the mid and long gap groups. Recovery by Group is listed in Table 1.  There were no reported nerve adverse events; however 4 revision surgeries were required due to complications from the original injury.

Conclusion: We found that processed allografts performed reliably well across short and longer gap lengths.

Length is a contributing factor to outcomes and should be considered as part of a nerve repair strategy.  Continuation of this study will provide additional insight into nerve repair outcomes.