What is the recommended follow-up and management plan for a patient with improved wrist drop, no finger pain, intact tactile sensation, and mild numbness in the subcutaneous tissue near the injection site, which is stiff but not tender?

Management of Improving Wrist Drop with Injection Site Complications

Continue the current conservative management with active finger motion exercises, maintain wrist splinting during functional activities, and monitor the injection site for resolution over the next 2-4 weeks, as the clinical picture indicates favorable recovery from a radial nerve injury. 1

Immediate Management Priorities

Wrist Support and Positioning

• Apply or continue using a dorsal cock-up splint positioning the wrist in 20-30 degrees of extension to facilitate functional hand use, as this is the standard orthotic management for wrist drop 1
• Ensure the splint is padded and comfortably tight but not constrictive to avoid compromising circulation or causing additional nerve compression 1
• The splint should only stabilize the wrist and must not restrict finger motion 1

Critical Active Motion Protocol

• Perform active finger motion exercises multiple times daily from this point forward to prevent finger stiffness, which is one of the most functionally disabling adverse effects 1, 2
• Active finger motion does not adversely affect the nerve injury and provides significant impact on patient outcome 1, 2
• All unaffected joints (shoulder, elbow, fingers) should maintain full active range of motion throughout the treatment period 1
• Hand stiffness can be very difficult to treat after it develops, requiring multiple therapy visits and possibly surgical intervention 1, 2

Injection Site Management

Local Tissue Care

• The stiffness and subcutaneous thickening near the injection site likely represents localized inflammatory reaction or mild fibrosis that should resolve with time 3
• Monitor the injection site for signs of infection including increased redness, warmth, purulent drainage, or worsening pain, though current non-tender status is reassuring 3
• Gentle range of motion exercises for the wrist (within pain-free limits) can help prevent adhesions and promote tissue remodeling 3

Expected Recovery Timeline

• Mild numbness in subcutaneous tissue that is improving suggests resolving local inflammation rather than significant nerve damage 3
• Most injection-related soft tissue reactions resolve within 2-4 weeks with conservative management 3

Monitoring and Follow-Up Schedule

Short-Term Assessment (2-3 Weeks)

• Reassess wrist extensor strength to document continued improvement of the wrist drop 1
• Evaluate finger range of motion to ensure no stiffness has developed 1, 2
• Examine the injection site for resolution of thickening and numbness 3
• If symptoms plateau or worsen, consider nerve conduction studies to assess the degree of radial nerve injury 4, 5

Medium-Term Follow-Up (4-6 Weeks)

• If wrist drop has not significantly improved by 4 weeks, obtain nerve conduction studies and electromyography to assess for axonal injury versus neurapraxia 4, 5
• Consider high-resolution nerve ultrasound if available, as it can visualize nerve pathology and guide management decisions 5
• Re-evaluate injection site; if subcutaneous thickening persists beyond 4 weeks, consider ultrasound evaluation to rule out organized hematoma or abscess 3

Imaging Considerations

• MRI of the wrist without IV contrast is appropriate if there is concern for structural complications at the injection site, such as tendon injury or deep soft tissue pathology 3
• Plain radiographs are not indicated unless there is concern for underlying bony pathology 3

Red Flags Requiring Urgent Re-Evaluation

Neurological Deterioration

• Worsening wrist drop or development of complete finger extension weakness suggests progressive nerve injury requiring urgent electrodiagnostic studies 4, 5
• New sensory loss beyond the current mild subcutaneous numbness, particularly in the radial nerve distribution (first dorsal web space), warrants immediate assessment 4
• Development of pain in the fingers (currently absent) could indicate nerve compression or ischemia 4

Injection Site Complications

• Development of tenderness, erythema, or warmth at the injection site suggests infection requiring urgent evaluation 3
• Rapidly expanding swelling could indicate hematoma or abscess formation 3
• Increasing stiffness rather than improvement suggests developing fibrosis or compartment syndrome 3

Common Pitfalls to Avoid

• Do not rigidly immobilize the fingers, as this leads to unnecessary stiffness and poor functional outcomes 1, 2
• Avoid assuming all wrist drops are peripheral nerve injuries; central causes (stroke affecting the motor cortex) can present with isolated wrist drop, though the improving course and injection site findings make this unlikely in this case 6, 7, 8
• Do not delay active motion exercises waiting for "complete healing," as early mobilization is crucial for optimal outcomes 1, 2
• Avoid over-treating the injection site with topical agents or aggressive manipulation, as most inflammatory reactions resolve spontaneously 3

Prognosis and Expectations

• The combination of improving wrist drop, intact tactile sensation, and absence of pain suggests a favorable prognosis consistent with neurapraxia (temporary nerve dysfunction without axonal damage) 4, 5
• Most cases of neurapraxia recover within 6-12 weeks with conservative management 4
• The improving subcutaneous numbness indicates resolving local inflammation rather than permanent nerve damage 3
• Continued improvement over the next 2-4 weeks would support conservative management without need for surgical intervention 1, 4