II. Pathophysiology
- Radial Nerve tracks follows the spiral groove down the medial Humerus
III. Causes
- Mid-shaft Humerus Fracture
- Direct injury to the Radial Nerve as it lies in spiral groove
- Does not typically affect elbow extension (triceps)
- Axilla compression (Saturday Night Palsy, Crutch Palsy)
- Falling asleep with arm over the back of a chair or bench, often inebriated (Saturday Night Palsy)
- Results in loss of elbow extension (triceps) and a Wrist Drop
- Honeymooner's Wrist Drop
- Shoulder and upper arm compressed under the arm/body of their partner resulting in local compression
IV. Signs
- Weak elbow extension
- Occurs if Radial Nerve injury at the axilla
- Wrist Drop
- Weak wrist and digit extensors
- Sensory loss
- Dorsal hand numbness (including lateral 3.5 digits)
V. Management
- Avoid repeat compression
- Physical Therapy
- Highly effective after 6 months
- Cock-Up Wrist Splint
- Maintains normal hand function when Wrist Drop present
- Surgery indications
- Humerus Fracture with Radial Nerve compromise