64721

Neuroplasty and/or transposition; median nerve at carpal tunnel

CPT code 64721 describes a surgical procedure known as carpal tunnel release, which involves the neuroplasty and/or transposition of the median nerve within the carpal tunnel. The carpal tunnel is a narrow passageway on the palm side of the wrist surrounded by bones and ligaments. The median nerve, which provides sensation to the palm side of the thumb and fingers (except the little finger) and provides nerve signals to move the muscles around the base of the thumb, passes through this tunnel. Carpal tunnel syndrome occurs when this nerve is compressed, often due to thickening of the transverse carpal ligament (flexor retinaculum). During the procedure, the surgeon makes an incision in the palm of the hand to access the transverse carpal ligament. This ligament is then carefully divided or released to increase the space within the carpal tunnel, thereby relieving the pressure on the median nerve. Neuroplasty refers to the decompression of the nerve from surrounding restrictive tissue, while transposition involves moving the nerve to a new location, though the latter is less common in standard carpal tunnel surgery. The goal of the surgery is to restore normal blood flow to the nerve and stop the progression of nerve damage, alleviating symptoms such as numbness, tingling, and hand weakness. This code specifically refers to the open surgical technique. If the procedure is performed endoscopically, a different code (29848) should be utilized. The surgery is typically performed under local, regional, or general anesthesia and is often conducted in an outpatient setting.

Clinical Indications

  • Confirmed Carpal Tunnel Syndrome (CTS) via Electromyography (EMG) or Nerve Conduction Studies (NCS)
  • Persistent numbness or paresthesia in the median nerve distribution
  • Thenar muscle atrophy or weakness
  • Failure of conservative treatments such as splinting, NSAIDs, or corticosteroid injections
  • Severe symptoms interfering with sleep or activities of daily living
  • Chronic pain in the wrist and hand associated with median nerve compression

Procedure Steps

  1. The patient is positioned supine, and the operative extremity is prepped and draped in a sterile fashion.
  2. Anesthesia is administered (local with MAC, regional, or general).
  3. A longitudinal incision is made in the palm, typically along the line of the third web space or the ulnar border of the thenar crease.
  4. Dissection is carried down through the subcutaneous fat to expose the palmar fascia.
  5. The transverse carpal ligament (flexor retinaculum) is identified and carefully divided longitudinally to decompress the carpal tunnel.
  6. The median nerve is inspected to ensure it is fully released and to check for any anatomical variations or mass lesions.
  7. Neuroplasty is performed if the nerve is adhered to surrounding tissues.
  8. Hemostasis is achieved using cautery or pressure.
  9. The skin incision is closed with sutures, and a sterile dressing is applied.

Coding Guidelines

  • Code 64721 is used for the open release of the carpal tunnel.
  • For endoscopic carpal tunnel release, use code 29848.
  • If the procedure is performed bilaterally, append modifier 50 or use RT and LT modifiers as per payer preference.
  • Internal neurolysis (64727) is generally bundled into 64721 and should not be reported separately unless it is a significantly more complex procedure requiring the use of an operating microscope.
  • This procedure has a 90-day global period.
  • Synovectomy of the flexor tendons (25115 or 25116) may be reported separately if performed and documented, but only if it is not a routine part of the decompression.
  • Do not report 64721 in conjunction with 29848 for the same hand.

Associated ICD-10 Codes