What is the best course of treatment for a patient with a recent needle injury to the forearm, no erythema, no middle finger drop, and weak wrist movement 1 week after the incident?

Management of Weak Wrist Following Forearm Needle Injury

You should obtain urgent hand surgery consultation within 24-48 hours and high-resolution ultrasound of the radial nerve within 48-72 hours, as this presentation suggests iatrogenic peripheral nerve injury requiring early evaluation to prevent permanent disability. 1

Immediate Actions

• Remove any remaining IV access immediately and refer urgently to hand surgery within 24-48 hours, as delays beyond 72 hours can compromise outcomes and lead to permanent disability 1
• The absence of middle finger drop (which has resolved) but persistent wrist weakness suggests partial radial nerve injury, likely affecting the posterior interosseous nerve (PIN) branch, which requires specialist evaluation 2
• Early surgical consultation is critical because nerve injuries may require exploration, decompression, or repair, and timing directly impacts functional recovery 1

Diagnostic Imaging Protocol

• Obtain high-resolution ultrasound of the radial nerve from upper arm through forearm within 48-72 hours to identify the exact site and nature of injury 1
• If ultrasound is equivocal or surgical planning requires more anatomical information, proceed to MRI with dedicated neurography sequences for superior soft-tissue detail 1
• Plain radiographs are not indicated unless there is concern for associated fracture or foreign body 1

Immediate Symptomatic Management

• Immobilize the wrist in neutral position (20-30 degrees extension) with a volar splint to prevent contractures and avoid overstretching of potentially denervated muscles 1
• Apply topical NSAIDs (diclofenac gel) to the injection site three times daily as first-line treatment for localized pain and inflammation, with superior safety profile compared to systemic agents 1

Physical Therapy Initiation

• Begin aggressive physical therapy within 48-72 hours focusing on passive range of motion exercises for wrist and fingers to prevent contractures 1
• Initiate active-assisted exercises for any preserved motor function and nerve gliding exercises (radial nerve glides) once acute pain subsides, typically after 3-5 days 1
• The fact that middle finger drop has already resolved suggests neuropraxia rather than complete transection, but persistent wrist weakness requires ongoing monitoring 3, 2

Critical Clinical Pearls

• The absence of erythema does not exclude nerve injury—nerve damage can occur without visible skin changes or infection 2
• Wrist extension weakness with preserved finger extension suggests PIN injury distal to the radial nerve's superficial sensory branch, which may require surgical exploration if no improvement occurs 2
• Complete transection of the PIN can occur even with seemingly minor penetrating injuries and may only be discovered on surgical exploration 2

Follow-Up Protocol

• Schedule follow-up at 2 weeks, 6 weeks, 3 months, and 6 months to document recovery trajectory, as peripheral nerve recovery may take weeks to over 12 months depending on severity 1
• If no improvement occurs within 3 months, or if motor function deteriorates, urgent repeat surgical consultation is mandatory 1
• Recovery is more likely with shorter duration of compression and early intervention, making timely specialist referral essential 4

Common Pitfalls to Avoid

• Do not delay specialist referral waiting for "spontaneous recovery"—the 24-48 hour window for optimal surgical evaluation is critical 1
• Do not assume that resolution of one symptom (middle finger drop) means complete recovery—persistent weakness indicates ongoing nerve dysfunction requiring investigation 3, 2
• Do not rely solely on clinical examination—electrodiagnostic studies and imaging are essential for determining the extent and location of nerve injury 3, 2