Interest of the "compress test" in diagnosis of nerve injury in hand wounds.

Introduction: Hand wounds are a common cause of emergency department admission. Digital nerve lesions are found in 5% of palm wounds. Early diagnosis reduces the risk of morbidity, sequelae and litigation. Screening for digital nerve injury by the usual tests is difficult in an emergency context. We assessed the diagnostic value of the simple "compress test" to screen for pulp sensibility disorder and the factors that may influence the value of this examination, with a view to validating routine use.

Material And Method: A retrospective study included 821 palm wounds treated between January 2014 and May 2016. There were 605 male and 216 patients; mean age, 42.8 years (range: 18-90 years). The dominant hand was involved in 307 cases (37.4%). Sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios of the compress test were calculated. Diagnostic value was also calculated according to age, gender, affected digit, dominant side and examiner's experience.

Results: Clinical deficit was found in 412 cases (50.2%). A digital nerve lesion was found intraoperatively in 277 cases (33.6%). Test sensitivity was 87.3%, specificity 68.6%, positive predictive value 58.5%, negative predictive value 91.4%, positive likelihood ratio 2.78 and negative likelihood ratio 0.18. The test was more effective for thumb wounds and for examination by a junior surgeon. There were no differences according to injured side, innervation territory or gender.

Conclusion: This clinical test is reliable, with very good negative predictive value and good sensitivity, allowing its use in routine clinical practice. Nevertheless, surgical exploration of deep palm injuries should remain the rule.