Objective:
Radial nerve injuries (RNI) cause loss of extension of the elbow, wrist, and digits, which significantly influence the upper limbs’ function. Nerve grafting is often necessary due to the extensiveness of the injury zone. Nerve allografts have become popular in recent years, and yet have still not achieved equivocal results as autografts. The aim of this study is to identify prognostic factors related to RNI and nerve grafting that predict successful outcomes.

Material and Methods:
We retrospectively reviewed patients who received nerve grafting after radial nerve injuries in a tertiary center from 2005 to 2020. Patients who received concomitant tendon transfers were excluded. 48 cases were included, grouped according to Chuang’s level I to IV classification. We defined the followings as successful outcomes: (1) wrist extension, (2) finger extension, (3) thumb extension reaching Medical Research Council's scale (MRC) grade 3. Comparisons were made with patients who failed to achieve the aforementioned outcomes.

Result:
4 patients had a level I injury, 21 patients with level II injury, 14 patients with level III injury, and 9 patients with level IV injury. 37 cases received nerve grafting without subsequent tendon transfer. In level I to III patients, 77% patients achieved wrist extension MRC≥3, where younger age (31.5±13 vs 42.1±23), significantly lower BMI (24.7±5 vs 29.95±5, p< 0.05), and shorter time from injury to reconstruction (157±90 vs 273±254) were found to be associated with successful outcomes. In level I to IV patients, only 43% patients achieved finger extension MRC≥3, and younger age (29±15 vs 37.5±17) was the only relatable factor. Interestingly, length of defect and number of cables did not show any significant difference in both wrist extension and finger extension outcomes

Conclusion:
Although nerve grafting has gradually shifted out of favor in comparison to tendon transfers or nerve transfers, it is still the most commonly performed surgical option in acute RNI. Patient demographics unexpectantly correlate more with functional outcomes than surgical factors and should be emphasized when considering nerve grafting for RNI.

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