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Published 4/1/2016
Terry Stanton

Academy Updates Clinical Practice Guideline on Carpal Tunnel Syndrome

New CPG increases array of strong recommendations
At its March meeting, the AAOS Board of Directors approved an updated Clinical Practice Guideline (CPG) on carpal tunnel syndrome (CTS) that represents a substantive update to the CTS guidelines originally issued in 2008 and revised in 2011. The new CPG carries the endorsement of the American Society for Surgery of the Hand (ASSH), the American College of Radiology, and the American College of Surgeons.

Among other things, the guideline:

  • Supports the use of diagnostic scales (eg, CTS-6 and Katz Hand Diagram) to aid in the diagnosis of CTS
  • Supports a greater treatment benefit for those patients who are treated surgically, as compared to those patients who are treated with splinting, NSAIDs, or steroid injections

Nine recommendations are characterized as "strong" (see box below), including one stating that thenar atrophy is strongly associated with ruling in CTS, but poorly associated with ruling it out. For treatment, the guideline recommends surgery, when necessary, to release the transverse carpal ligament to relieve symptoms and improve hand function. There was not strong evidence to recommend supervised over unsupervised postsurgical therapy.

"These guidelines should help doctors make an accurate diagnosis of CTS more easily and with fewer tests," said Brent Graham, MD, chair of the AAOS Diagnosis and Treatment of Carpal Tunnel Syndrome Work Group. "An innovation of the current guideline is that we studied some of the clinical instruments that are now available, and these include both a series of questions related to the history of symptoms and some important physical examination maneuvers; taking those as a group is a lot more powerful in identifying the diagnosis accurately than would be any one of these clinical factors taken by itself.

"What has become clear is that no one symptom or physical examination finding has actually been shown to be a sine qua non for the condition," he said.

Among the noteworthy recommendations in the new CPG is the statement that moderate evidence supports the use of diagnostic questionnaires and/or electrodiagnostic studies to diagnose CTS. Instruments such as the CTS-6 or the Katz Hand Diagram may be used to confirm or rule out CTS without the use of more costly investigations such as electrodiagnostic testing, Dr. Graham said.

"What the literature shows is that if you do a proper history and clinical evaluation effectively, then the role and importance of electrodiagnostic tests is much less. Where the diagnosis is so clearly present or not present based on the clinical evaluation, the 'value added' of electrodiagnostic testing is limited," said Dr. Graham. "What it does add is time and expense—and these tests are unpleasant for the patient. They hurt. It is a step forward to have the Academy, and now the ASSH, the American College of Radiology, and the American College of Surgeons sponsoring or endorsing a guideline that says you can diagnose CTS either using electrodiagnostic tests, using a clinical tool, or both."

The CPG itself should be seen as a tool for facilitating an accurate diagnosis and an effective course of treatment.

"When carpal tunnel is not effectively treated," said Dr. Graham, "there are generally only two causes: Either the diagnosis was correct but the surgery was done ineffectively, or the patient simply didn't have carpal tunnel syndrome. An incorrect diagnosis is not an uncommon scenario. There is a burden of incorrect diagnosis that contributes to poor results after treatment for CTS, and limiting that is the point of this CPG."

Risk factors
The new guideline addresses risk factors for CTS, citing strong evidence in support of an association with increased body mass index and high hand/wrist repetition rate, and moderate evidence pointing to a number of other risk factors, including assembly line or computer work, gardening, rheumatoid arthritis, and psychosocial factors. Dr. Graham urged caution in interpreting these statements.

"This is a controversial area," he explained, "especially where some of these factors relate to the workplace. There is concern about what it means to say that exposure to something like keyboard use is related to CTS. There is very little data to clearly link a true cause-and-effect relationship—in other words, of a certain exposure and a certain result. There are no prospective studies that show the disease showing up more in one group or another."

Overall, Dr. Graham said, the new CTS guideline reflects an advance in what is known about the evaluation and treatment of CTS.

"With each succeeding round, the evidence has been getting better," he said. "Clinical researchers are becoming more sophisticated about how to perform effective research that answers real questions. We noticed that the tenor of the previous recommendations was more timid than it is now because the quality of the evidence was that much less than it was for the current CPG. The quality of the evidence has clearly improved, and that allowed us to make more meaningful recommendations.

"This CPG was a bit different from dealing with other orthopaedic conditions, because in addition to orthopaedic surgeons, the doctors who look after this include plastic surgeons, general surgeons, neurosurgeons, physiatrists, and primary care physicians. We had a good cross-section of contributors. That speaks to the terrific planning and insight of the Academy in producing these guidelines."

View all AAOS CPGs at www.aaos.org/guidelines

Terry Stanton is the senior science writer for AAOS Now. He can be reached at tstanton@aaos.org

Evidence: Strong
The number of studies in the orthopaedic literature backed by high-quality evidence continues to mount, and the number of strong recommendations in each new Academy Clinical Practice Guideline (CPG) reflects this trend. Of the 35 recommendations in the new CPG on Carpal Tunnel Syndrome, nine are classified as "strong"—having evidence from two or more "high"-quality studies with consistent findings for recommending for or against an intervention—and an additional 13 as "moderate." Recommendations backed by strong evidence offer guidance as follows:

  • Thenar atrophy is strongly associated with ruling in carpal tunnel syndrome, but poorly associated with ruling out carpal tunnel syndrome.
  • Use of the Phalen Test, Tinel Sign, Flick Sign, or Upper Limb Neurodynamic/nerve Tension test criterion A/B as independent physical examination maneuvers to diagnose carpal tunnel syndrome is not recommended, because alone, each has a poor or weak association with ruling in or ruling out carpal tunnel syndrome.
  • Body mass index and high hand/wrist repetition rate are associated with the increased risk of developing carpal tunnel syndrome.
  • The use of immobilization (brace/splint/orthosis) should improve patient-reported outcomes.
  • The use of steroid (methylprednisolone) injection should improve patient-reported outcomes.
  • Evidence does not support magnet therapy for the treatment of carpal syndrome.
  • Surgical release of the transverse carpal ligament should relieve symptoms and improve function.
  • Surgical treatment of carpal tunnel syndrome should have a greater treatment benefit at 6 and 12 months as compared to splinting, NSAIDs/therapy, and a single steroid injection.
  • No benefit is seen for routine postoperative immobilization after carpal tunnel release.