This document addresses the use of carpal tunnel release surgery for the treatment of carpal tunnel syndrome, which is a condition brought on by increased pressure on the median nerve at the wrist. Symptoms may include numbness, tingling, and pain in the arm, hand, and fingers. When symptoms are severe or do not respond to conservative treatment options, such as wrist splint use and steroidal injections, surgery to enlarge the "tunnel" and reduce pressure on the nerve is sometimes necessary.

Note:  For information related to the medical necessity criteria for use of conventional electromyography and nerve velocity studies (EMG/NCS), see the following document:

• CG-MED-24 Electromyography and Nerve Conduction Studies (EMG/NCS).

Note:  For information to the use of automated nerve conduction testing with portable devices, such as the NC-stat^® system, see the following document:

• MED.00092 Automated Nerve Conduction Testing.

Medically Necessary: 

Carpal tunnel release surgery is considered medically necessary without the need for a trial of conservative treatment measures if there is documentation of both the diagnosis of carpal tunnel syndrome and thenar atrophy or carpal tunnel syndrome following significant acute trauma.

Carpal tunnel release surgery is considered medically necessary when conservative medical treatment has been ineffective at relieving the symptoms of significant pain or functional impairment with numbness in the distribution of the median nerve which is:

• refractory to adequate wrist splinting of at least 4 weeks duration; or
• unresponsive to additional conservative treatment measures, such as anti-inflammatory medications,  of at least 4 weeks duration, or steroid injections, etc; and
• confirmed by electrodiagnostic testing (nerve conduction velocity studies/electromyography) unless thenar atrophy is present; and
• not associated with other treatable or time-limited conditions, such as current pregnancy, treatment-responsive arthritis, or hypothyroidism.

Diagnostic Testing:

• A detailed history should be obtained prior to any surgical planning, to include information about any medical conditions, prior hand/wrist injuries, and how the hands have been used during work and leisure activities.
• Hand/wrist x-rays may be indicated to rule out other causes, such as arthritis or fracture.
• Nerve conduction velocity studies (NCV) showing positive motor or sensory delay confirm the diagnosis. (Conduction velocity changes are late effects of carpal tunnel syndrome. An additional assessment measure is abnormal motor and sensory latencies. Conduction velocity changes, particularly in multiple nerves, may be a sign of peripheral neuropathy, rather than carpal tunnel syndrome).
• Electromyogram (EMG) may be necessary if prior testing yields inconclusive or discordant results. 

Note:  NCV/EMG testing is not considered necessary if obvious thenar atrophy is present.

Not Medically Necessary:

Carpal tunnel release surgery is considered not medically necessary when the criteria listed above are not met.

Note:  The severity of symptoms and the degree of abnormal test findings (on nerve conduction velocity studies) indicate the appropriate initial therapeutic approach. Surgery is generally not a first line treatment in the absence of significant clinical findings.

The following codes for treatments and procedures applicable to this document are included below for informational purposes.  Inclusion or exclusion of a procedure, diagnosis or device code(s) does not constitute or imply member coverage or provider reimbursement policy.  Please refer to the member's contract benefits in effect at the time of service to determine coverage or non-coverage of these services as it applies to an individual member.

Carpal tunnel syndrome is the most common entrapment neuropathy and carpal tunnel surgery is the most commonly performed surgery of the hand. The syndrome is related to the bony anatomy of the wrist where the area, known as the carpal tunnel, is bound dorsally and laterally by the carpal bones and ventrally by the tranverse carpal ligament. Through this contained space run the nine flexor tendons and the median nerve. Any space-occupying lesion or inflammation can compress the median nerve and produce the typical symptoms of carpal tunnel syndrome, i.e., pain, numbness and tingling in the distribution of the median nerve. Severe symptoms include hypoesthesia, clumsiness, loss of dexterity, and weakness of finger pinch capability. In the most severe cases, marked sensory loss and significant functional impairment with thenar atrophy may be experienced.

A variety of etiologies have been associated with carpal tunnel syndrome, including pregnancy (due to hormone-related edema), inflammatory arthritis, Colles' fracture, amyloidosis, hypothyroidism, diabetes mellitus, acromegaly and history of corticosteroid/estrogen use. Nonspecific flexor tenosynovitis is the most common cause and is typically associated with occupational repetitive motion of the hand and wrist.

Conservative treatment options may include wrist splinting, local steroid injections, oral steroids, ultrasound, and nonsteroidal anti-inflammatory drugs (NSAIDs). The American Academy of Orthopaedic Surgeons (AAOS) (2008) Clinical Practice Guideline for the Treatment of Carpal Tunnel Syndrome recommendations include that a course of non-operative treatment is an option in patients diagnosed with carpal tunnel syndrome and another non-operative treatment or surgery is suggested when the current treatment fails to resolve the symptoms within 2 to 7 weeks. Carpal tunnel release surgery is not considered a first-line treatment option, in most cases.

Current approaches to carpal tunnel release surgery include open carpal tunnel release and endoscopic carpal tunnel release. Open carpal tunnel release surgery requires an incision in the palm and wrist and allows the surgeon to visualize more of the inner tissues. Endoscopic carpal tunnel release surgery requires a smaller incision at the wrist (single-portal technique) or at the wrist and palm (two-portal technique). A recent study, Atroshi (2009) compared open carpal tunnel release with endoscopic carpal tunnel release and demonstrated that the efficacies of both techniques are equivalent.

Thenar atrophy:  significant weakness in the palm of the hand and the base of the thumb, which is associated with decreased function, due to compression of the median nerve

Flexor tenosynovitis:  this condition refers to swelling of the lining of the flexor tendons in the wrist area, which results in pressure being exerted on the median nerve

Peer Reviewed Publications: 

1. Aroori S, Spence RA. Carpal tunnel syndrome. Ulster Med J. 2008; 77(1):6-17.
2. Atroshi I, Hofer M, Larsson GU, Ornstein E, Johnsson R, Ranstam J. Open compared with 2-portal endoscopic carpal tunnel release: a 5-year follow-up of a randomized controlled trial. J Hand Surg Am. 2009; 34(2):266-272.
3. Katz JN, Simmons BP. Carpal tunnel syndrome. N Engl J Med. 2002; 346(23):1807-1812.
4. Keith MW, Masear V, Amadio PC, et al. Treatment of carpal tunnel syndrome. J Am Acad Orthop Surg. 2009; 17(6):397-405
5. Scholten RJ, Mink van der Molen A, Uitdehaag BM. Surgical treatment options for carpal tunnel syndrome. Cochrane Database Syst Rev. 2007; (4):CD003905.

Government Agency, Medical Society, and Other Authoritative Publications:

1. American Academy of Orthopaedic Surgeons. Clinical practice guideline on the treatment of carpal tunnel syndrome. 2008. Available at: http://www.aaos.org/Research/guidelines/CTSTreatmentGuideline.pdf. Accessed on December 14, 2009.

1. American Association for Hand Surgery. Carpal Tunnel Syndrome. FAQ. Available at: http://www.handsurgery.org/. Accessed on December 14, 2009.
2. American Society for Surgery of the Hand. Carpal Tunnel Syndrome. Available at:  http://www.assh.org/Public/HandConditions/Pages/CarpalTunnelSyndrome.aspx. Accessed on December 18, 2009.
3. National Institute of Neurological Disorders and Stroke (NINDS). Carpal Tunnel Syndrome Fact Sheet. Updated April 10, 2008. Available at: http://www.ninds.nih.gov/disorders/carpal_tunnel/detail_carpal_tunnel.htm. Accessed on December 14, 2009.