Radial Nerve Hydrodissection at the Spiral Groove Following Humeral Shaft Fracture with Severe Radial Neuropathy

Case Diagnosis: Severe radial neuropathy secondary to comminuted humeral shaft fracture

Case Description or Program Description: 79 yo M suffered fall onto his right arm two weeks after shoulder replacement, suffering comminuted humeral shaft fracture. Closed reduction performed in ER. Patient noted to have no active wrist or finger extension on arrival to ED. Also diminished sensation in radial nerve distribution. Managed non-operatively initially with bracing and therapy. Serial x-rays of the humerus showed progressive callus formation of the fracture. EMG 6 weeks after injury showed 1-2+ fibrillations and positive sharp waves in the distal triceps, with no actively firing motor units in brachioradialis and all distal radially-innervated muscle including 4+ fibrillations. Radial nerve visualized under ultrasound distal to the fracture showed an large and edematous nerve that appeared to dive into the callus. Patient was agreeable to an experimental attempt to hydrodissect the radial nerve out of the callus using platelet lysate.

Setting: Sports Medicine Clinic

Assessment/Results: Severe radial neuropathy secondary to comminuted humeral shaft fracture treated with platelet lysate hydrodissection. Unfortunately, more than 6 weeks following the procedure, patient has had no return of radial nerve motor or sensory function. Patient is in process of scheduling tendon transfer surgery.

Discussion (relevance): Hydrodissection is a useful intervention in certain nerve entrapments. In this case, the nerve injury was too severe to successfully treat the injury. Consideration to alternative injectate options should also be considered and discussed with patients.

Conclusions: Complete radial nerve transection and entrapment was unable to be managed with platelet lysate hydrodissection. Hydrodissection is a strong option in other nerve entrapments with less severe nerve injuries.