Atroshi I, Hofer M, Larsson G, Ranstam J. Extended Follow-up of a Randomized Clinical Trial of Open vs Endoscopic Release Surgery for Carpal Tunnel Syndrome. JAMA. 2015;314(13):1399-1401. doi:10.1001/jama.2015.12208
In the United States, carpal tunnel release (open or endoscopic) was performed more than 577 000 times in 2006.1 A survey of hand surgeons found 52% used only open release, 36% used mostly endoscopic release, and 12% used both in 2011.2 Randomized trials have shown these methods have similar short-term efficacy, but no previous studies have adequate follow-up beyond 5 years.3 Longer-term follow-up is important because disease progression or scar formation could occur.
We conducted a randomized trial comparing open and endoscopic release and found modestly lower postoperative pain following endoscopic surgery, but no differences in symptom and function scores up to 5 years.4,5 This extended follow-up compared outcomes 11 to 16 years after surgery.
Patients aged 25 to 60 years with carpal tunnel syndrome (CTS) were randomized in the operating room of a regional hospital in Sweden to conventional open or 2-portal endoscopic release (surgeons were experienced in both techniques).4 The trial and follow-up were approved by the regional ethical review board of Lund University. Participants provided written informed consent. Evaluations were performed the week before surgery and again at 3, 6, 12, and 52 weeks’ postsurgery as well as 5 years after surgery.
In this extended follow-up, a questionnaire, which included the validated Levine-Katz 11-item CTS symptom severity scale and 8-item functional status scale,6 also used at baseline, 1 year, and 5 years, was mailed to the patients (score range, 1 [best] to 5 [worst]). The questionnaire also included (1) a pain scale (used in prior evaluations), (2) the 11-item disabilities of the arm, shoulder and hand (DASH) scale, (3) the treatment satisfaction visual analog scale, and (4) questions about height and weight, smoking, medical conditions, and subsequent surgery on the hands (verified through medical records). Patients reporting current numbness and/or tingling were interviewed by a blinded researcher via telephone.
The primary outcome was change in symptom severity score from baseline and 1 year. The secondary outcomes were change in functional status score from baseline and 1 year, current pain, DASH scale and satisfaction scores, and repeat surgery. The sample was adequate to detect a between-group symptom severity score difference (absolute) of 0.4; smaller differences are unlikely to be clinically important.
We compared the 2 groups regarding changes in symptom severity and functional status scores with analysis of covariance (adjusting for age, sex, study hand dominance, and baseline scores), other scores with the t test, and categorical outcomes with the χ2 test (relative risks were calculated). We used Stata version 13.0 (StataCorp) and a 2-sided threshold of .05 for statistical significance.
Of 128 patients originally randomized (65 to the open group and 63 to the endoscopic group), 3 died and 1 refused participation (all 4 were in the open group). From October 2013 through September 2014, 124 patients (97%) provided complete data for all outcome measures between 11.3 and 15.7 years after surgery (mean [SD], 12.8 [1.2] years). Patient characteristics at follow-up were similar between groups (mean age, 57 years; 75% were women; body mass index [calculated as weight in kilograms divided by height in meters squared] of 27.5; 15% were smokers). Six percent had undergone further surgery on the same hand and 40% on the contralateral hand.
Improvement in symptom severity score (similar in the 2 groups at 1 year) was maintained at follow-up (Table 1). In the open group, the symptom severity score was 3.1 at baseline, 1.4 at 1 year, and 1.4 at follow-up (mean [SD] change from baseline, 1.7 [0.7]; from 1 year, 0.04 [0.5]); in the endoscopic group, it was 3.2 at baseline, 1.4 at 1 year, and 1.4 at follow-up (mean [SD] change from baseline, 1.8 [0.8]; from 1 year, −0.003 [0.6]). Adjusted mean between-group difference in change from baseline was −0.03 (95% CI, −0.25 to 0.19; P = .79) and from 1 year was −0.03 (95% CI, −0.23 to 0.17; P = .76). No between-group differences were found in the secondary outcomes (Table 2).
To our knowledge, this is the first randomized trial to evaluate long-term outcomes of CTS surgery. After a mean follow-up of 12.8 years after CTS surgery, there were no significant differences between open and endoscopic carpal tunnel release. The large symptom and functional improvements and high level of patient satisfaction achieved with surgery were durable and few patients had undergone further surgery.
Study limitations include a single institution in Sweden and unknown generalizability. Our long-term follow-up was limited to patient-reported outcomes, which are central in CTS and were consistent across several measures with established reliability and validity. The results should help clinicians and patients in making treatment decisions.
Corresponding Author: Isam Atroshi, MD, PhD, Department of Orthopedics Hässleholm-Kristianstad, Clinical Sciences, Lund University, SE-22100 Lund, Sweden (firstname.lastname@example.org).
Author Contributions: Dr Atroshi had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: Atroshi.
Acquisition, analysis, or interpretation of data: All authors.
Drafting of the manuscript: Atroshi.
Critical revision of the manuscript for important intellectual content: All authors.
Statistical analysis: Atroshi, Ranstam.
Obtained funding: Atroshi.
Administrative, technical, or material support: Atroshi, Hofer, Larsson.
Study supervision: Atroshi.
Conflict of Interest Disclosures: The authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest and none were reported.
Funding/Support: This research was supported by grants from Region Skåne.
Role of the Funder/Sponsor: Region Skåne had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.
Trial Registration: clinicaltrials.gov Identifier: NCT01887145
Additional Information: The trial protocol is available upon request from the authors.