CLINICAL QUESTION

Is surgery safe and effective for the treatment of carpal tunnel syndrome compared with nonsurgical treatment?

EVIDENCE-BASED ANSWER

Surgery for carpal tunnel syndrome probably results in some clinical improvement compared with splinting in the long term (more than 3 months), but it does not appear to lead to clinically significant improvement in symptoms or hand function. Similarly, surgery does not appear to result in clinically meaningful improvement compared with corticosteroid injection in the long term. It is not clear whether there are any differences in adverse effects between surgical and nonsurgical interventions.¹ (Strength of Recommendation: B, inconsistent or limited-quality patient-oriented evidence.)

PRACTICE POINTERS

Carpal tunnel syndrome is a compression neuropathy of the median nerve at the wrist.¹ Common symptoms are numbness, tingling, and pain within the median nerve distribution. In more severe cases, skin sensation can be permanently diminished, and axonal injury results in atrophy of the thenar muscles.^1,2 Carpal tunnel syndrome is a clinical diagnosis, but there are no universally accepted diagnostic criteria or treatment guidelines.^1,3 Management is often guided by disease severity and symptom duration. Those with severe symptoms or objective findings of thenar atrophy or positive electrodiagnostic changes are often referred for surgical evaluation. Those with mild or early symptoms are often treated with nonsurgical interventions, such as splinting or corticosteroid injection. The authors of this Cochrane review evaluated the outcomes of various nonsurgical treatment modalities vs. various surgical therapies.

A total of 14 randomized trials and 1,231 participants (1,293 wrists) were included in the review.¹ The mean age of participants in the studies ranged from 32 to 53 years, and the mean duration of symptoms varied from 31 weeks to 3.5 years. Studies were conducted in nine countries from Asia, Europe, and North America. Heterogeneity was found in the diagnosis of carpal tunnel syndrome within studies and in nonsurgical and surgical techniques used. The review compared surgery with several nonsurgical treatments—including splinting, corticosteroid injection, splinting combined with corticosteroid injection, platelet-rich plasma injection, manual therapy, multi-modal nonoperative treatment, unspecified medical treatment, and hand support—and surgery plus corticosteroid injection vs. corticosteroid injection alone. Outcomes were measured with several validated scales, including the Boston Carpal Tunnel Questionnaire Symptom Severity Scale. The authors of this review drew conclusions only about splinting and corticosteroid injections as nonsurgical techniques vs. surgery.

The primary outcome was clinical improvement in the long term (i.e., more than 3 months of follow-up).¹ Clinical improvement was a qualitative measure defined by significant relief of symptoms and pain or improvement in function from baseline, as defined by the respective study authors. The criteria for clinical improvement varied across studies. Secondary outcomes were symptoms, function, pain, health-related quality of life, adverse effects, and need for surgery.

The heterogeneity of the study designs and outcomes made it challenging to draw any broad conclusions, but the authors concluded that surgery probably resulted in a greater chance of clinical improvement at long-term follow-up compared with splinting (risk ratio = 2.1; 95% CI, 1.04 to 4.24).¹ However, outcome comparisons using the Boston Carpal Tunnel Questionnaire Symptom Severity Scale revealed that no clinically meaningful differences were found in long-term symptom improvement or hand function between participants who underwent surgery or splinting. Further, there was no significant difference in improvement in health-related quality of life or pain. Similar conclusions were drawn regarding the comparison between surgery and corticosteroid injection.

It is worth noting that 40% of participants in the nonsurgical treatment groups opted for surgery during the study before the long-term follow-up measurement.¹ This may underestimate the benefit of surgery. There were no significant differences in adverse effects between surgical and nonsurgical treatments.

Clinical practice guidelines recommend that patients with severe symptoms or objective findings of thenar atrophy or positive electrodiagnostic changes should be referred for surgical evaluation.⁴ Additional guidelines state that surgical treatment of carpal tunnel syndrome probably has a greater benefit at 6 and 12 months compared with splinting, nonsteroidal anti-inflammatory drugs, physical or occupational therapy, or a single corticosteroid injection.⁵

PATIENT PERSPECTIVE

The physician must be prepared to address patient questions and preferences. Shared decision-making necessitates patience as the physician elicits how long the condition has persisted and whether any home remedies have been attempted, as well as patient expectations. A clear and unbiased description of treatment options should be provided, along with risks and benefits of each approach. The physician should not be afraid to respond to patient questions by saying that a clear answer is not available, as is often the case. Patients will undoubtedly have questions about what they have found online about treatment options.

Editor’s Note: The patient perspective is the opinion of the patient perspective author and, although peer reviewed, does not represent evidence-based conclusions.

The practice recommendations in this activity are available at https://www-cochrane-org.lib3.cgmh.org.tw:30443/CD001552.

The opinions and assertions contained herein are those of the authors and are not to be construed as official or as reflecting the views of the U.S. Department of Defense or the Uniformed Services University of the Health Sciences.