Cadaveric investigation on radial nerve strain using different posterior surgical exposures for extraarticular distal humeral ORIF: merits of nerve decompression through a lateral paratricipital exposure.

Objective: To determine whether the type of posterior surgical approach for distal humeral fracture open reduction and internal fixation influenced radial nerve strain during simulated operative retraction in a cadaveric model.

Methods: Three different posterior surgical exposures: triceps splitting, lateral paratricipital, and paratricipital with release of the lateral intermuscular septum were used. Radial nerve strain was measured using a microDVRT, while traction was applied with a digital force gauge at forces 0.1-0.3 kg.

Results: The lateral paratricipital with nerve decompression was superior to both the triceps splitting approach (P < 0.048) and paratricipital method without decompression (P < 0.036). There was no significant difference between the triceps splitting method and paratricipital exposure without intermuscular septum release.

Conclusions: Radial nerve decompression through release of the lateral intermuscular septum through a lateral paratricipital exposure ideally decreases nerve strain during humeral open reduction and internal fixation in our cadaveric model.