Is open carpal tunnel release surgery (CPT code 64721) medically necessary for a patient with a 3-year history of numbness and paresthesia in the hands, who has undergone chiropractic treatment with minimal improvement, and has bilateral carpal tunnel syndrome confirmed by electrodiagnostic testing?

Medical Necessity Determination for Open Carpal Tunnel Release

Direct Answer

Open carpal tunnel release (CPT 64721) is NOT medically necessary at this time because the patient has not completed the standard conservative treatment pathway required by evidence-based guidelines, specifically failing to trial wrist splinting for 4 weeks or attempt corticosteroid injection. 1

Rationale and Clinical Context

Confirmed Diagnosis

The patient clearly meets diagnostic criteria for bilateral carpal tunnel syndrome:

• Electrodiagnostic confirmation showing moderately severe bilateral median neuropathies at the wrists with prolonged distal motor latencies and diminished sensory conduction velocities across the wrists 1
• Clinical symptoms of persistent pain, sensory loss, and paresthesia in median nerve distribution for 3 years 1
• Positive provocative testing with bilateral Tinel's and Durkan's compression tests

Missing Conservative Treatment Requirements

The American College of Surgeons guidelines establish that surgical decompression should follow failed conservative management. 1 The MCG criteria explicitly require demonstration that nonoperative treatment is unlikely to be successful, indicated by:

• Failed 4-week trial of splinting = NOT MET (patient has not tried braces)
• Failed local corticosteroid injection = NOT MET (no history of injections)

While the patient does have persistent symptoms meeting one criterion, both splinting and corticosteroid injection must be attempted or contraindicated before surgery can be considered medically necessary. 1

Why Conservative Treatment Cannot Be Bypassed

Surgical decompression is the most effective treatment for moderate to severe carpal tunnel syndrome, but guidelines universally require documentation of failed conservative measures first. 1 This is not arbitrary—it establishes:

• That symptoms are refractory to less invasive interventions
• Medical necessity documentation for payers
• Appropriate risk-benefit assessment (surgery carries risks of nerve injury, incomplete release, and need for revision) 2, 3

Chiropractic Treatment Does Not Substitute

The patient's chiropractic treatment with minimal improvement does not fulfill guideline requirements because:

• Chiropractic manipulation is not an evidence-based treatment for carpal tunnel syndrome
• It does not substitute for wrist splinting (which mechanically reduces median nerve pressure during sleep when symptoms are worst)
• It does not substitute for corticosteroid injection (which directly addresses inflammation within the carpal tunnel)

Clinical Pitfalls to Avoid

Do not confuse symptom severity with treatment urgency. While this patient has moderately severe disease by electrodiagnostic criteria, there is no evidence of axonal loss on EMG, meaning the nerve damage is still reversible with appropriate treatment. 1

The ulnar-distribution symptoms the patient describes are inconsistent with pure carpal tunnel syndrome and suggest either:

• Overlay of other pathology (the patient has documented flexor tendon tears requiring separate surgical attention)
• Symptom mislocalization by the patient
• Coexisting polyneuropathy 4

This diagnostic complexity makes it even more critical to complete conservative carpal tunnel treatment before proceeding to surgery, as surgery may not address all symptoms.

Required Next Steps Before Surgical Authorization

The patient must complete the following before open carpal tunnel release can be considered medically necessary:

1. Wrist splinting trial for minimum 4 weeks (preferably nighttime neutral position splints, as symptoms are worse at night) 1
2. Local corticosteroid injection if splinting fails or provides only partial relief 1
3. Re-evaluation after 4-6 weeks of each intervention to document treatment failure

Only after documented failure of both interventions (or clear contraindications to them) does the patient meet evidence-based criteria for surgical intervention. 1

Surgical Effectiveness When Indicated

When conservative treatment has failed and surgery becomes appropriate, both open and endoscopic carpal tunnel release provide equivalent symptom relief, with endoscopic allowing return to work approximately one week earlier. 1, 5, 6, 2 However, this decision point has not yet been reached for this patient.