At What Time Interval After a Sharp Nerve Laceration Is Primary Nerve Repair No Longer Possible?

Purpose: The timeframe after a sharp nerve injury when nerve grafting becomes required remains unclear. A retrospective analysis was performed to determine the timeframe when primary repair of a sharp nerve laceration can no longer be performed and grafting becomes necessary.

Methods: All sharp nerve injuries in three regions of the hands and upper extremity-major nerves, common digital nerves, and proper digital nerves-treated between 2016 and 2021 were reviewed. Time from injury to repair, need for nerve grafting, length of graft, age, and associated injuries were collected and analyzed.

Results: A total of 313 nerve lacerations were included. Predictors of the need for grafting included time from injury to repair and level of injury. The odds ratio of time from injury in predicting the need for grafting was 1.04 for proper digital nerves, 1.05 for common digital nerves, and 1.18 for major nerves. Age and other injuries were not associated with increased rates of grafting. Only level of injury was associated with length of graft needed.

Conclusions: Patients with sharp major nerve injuries required grafting more frequently after several days from injury, whereas primary repair of common and proper digital nerves could be achieved up to two weeks or greater after injury. This suggests that the window for primary neurorrhaphy may be as short as two days after injury for major nerve injuries, much shorter than for common and proper digital nerve injuries.

Type Of Study/level Of Evidence: Prognostic IV.