Predictive Factors of Neurovascular and Tendon Injuries Following Dog Bites to the Upper Extremity.

Background: Dog bite injuries to the upper extremity can result in traumatic neurovascular and musculotendinous damage. Currently, there are no clear guidelines dictating which patients may benefit from early operative exploration. The purpose of this study was to identify clinical variables that were predictive of abnormal intraoperative findings in patients who sustained an upper extremity dog bite injury. Methods: All patients who presented to a level I trauma center between 2007 and 2015 with an upper extremity dog bite injury who underwent subsequent surgical exploration were retrospectively screened for inclusion in our study. Patients with inadequate documentation or preexisting neurovascular or motor deficits were excluded. Abnormalities on physical exam and injuries encountered during surgical exploration were recorded for each patient. Contingency tables were constructed comparing normal and abnormal nerve, tendon, and vascular physical exam findings with intact or disrupted neurovascular and musculotendinous structures identified during surgical exploration. Results: Between 2007 and 2014, 117 patients sustained a dog bite injury to the upper extremity, of which 39 underwent subsequent surgical exploration and were included in our analysis. Sixty-nine percent of patients with neuropraxia on exam had intraoperative nerve damage. Seventy-seven percent of patients with an abnormal tendon exam had intraoperative musculotendinous damage. One hundred percent of patients with an abnormal vascular physical exam had intraoperative arterial injury. Conclusions: To date, there are no clear guidelines on what clinical criteria indicate the need for operative exploration and possible repair of neurovascular structures in upper extremity dog bite injuries. In our study, nerve, tendon, and vascular abnormalities noted on physical exam were strongly predictive of discovering neurovascular and musculotendinous damage during surgical exploration.