The Current State of Outcome Measurements After Peripheral Nerve Injury: A Systematic Review

The manner in which outcomes are reported after peripheral nerve injury (PNI) varies tremendously and often centers on surgeon-manual muscle testing. The purpose of our systematic review was to quantify the use of outcome measures after PNI in the contemporary literature (published in 2008 and beyond) and to evaluate which domains of recovery are assessed most frequently.

With the assistance of a medical librarian, we performed a systematic review of the literature published in or after 2008 (to represent the last 15 years) for patients with upper-extremity PNI. We excluded articles with <5 participants, minors, brachial plexus or digital nerve injuries, compressive neuropathies, or <6 months of follow-up. Data were extracted to identify which outcome measures were used in each study, categorizing the outcome measures under the domains of motor, sensory, function, and pain.

Of the 4 outcome domains (pain, motor, sensory, and function), motor was reported the most frequently, followed by function. Within the motor category, more than two-thirds of the studies used manual muscle testing for assessment. Half of the articles reported outcomes in 2 of the 4 assessed domains. Pain was the least assessed domain, reported in 11 of 68 articles.

While there has been incorporation of functional outcomes, the majority of the literature in the last 15 years remains focused on surgeon-reported muscle testing and does not adequately reflect the multiple domains affected by PNI. Pain is the least frequently reported domain, despite being an issue that frequently vexes PNI patients.

There is a need for clinicians and researchers to agree upon a common set of outcome measures for PNI that (A) encompass perspectives of clinicians and patients and (B) reflect multiple domains affected by PNI. This will improve the quality of outcome reporting and facilitate future comparative effectiveness studies.