A single Level I study evaluated the effect of preserving cutaneous nerves in the path of a skin incision made in the customary location for a carpal tunnel release. Preservation was compared to a standard approach to making a skin incision, which did not seek to preserve any nerve branches encountered as the wound was deepened down to the palmar fascia. The Patient Evaluation Measure (PEM) indicated a slight advantage in favor of the standard approach at the three-month assessment. The PEM is a broader evaluation of outcome than the VAS suggesting that the advantages for a standard carpal tunnel release incision refer to a domain other than pain.
Epineurotomy was studied in a systematic review and in a single Level II study. In the systematic review 97 the outcome was described as “overall improvement” at 12 months and, in the single Level II study, 34 the outcomes were “nocturnal pain” and “paraesthesia” at three months following surgery. Both studies indicated a mild effect favoring no epineurotomy.
Tenosynovectomy and internal neurolysis were compared in a systematic review 97 and the data were inconclusive. Lengthening of the flexor retinaculum was studied in a Level I study 49 that used the Boston Carpal Tunnel Questionnaire as the outcome measure. The results were inconclusive because the study had too little power to allow for statistically meaningful comparison. A single Level I study 53 examining ulnar bursa preservation, with VAS and PEM as the outcome measures at 8 weeks, also had too little power to allow for meaningful statistical comparisons. The study was therefore inconclusive.
See Evidence Tables 23-37 and Evidence Report (PDF Pages 88-95, Figures 82-88)
The physician has the option of prescribing pre-operative antibiotics for carpal tunnel surgery.
(Grade C, Level III)
Our searches indicated that the current literature rarely reports whether pre-operative antibiotic treatment was used in carpal tunnel release. Of forty-five studies analyzed for this recommendation, forty-four did not report whether pre-operative antibiotics were used. The study that did report antibiotic use reported that 6.03% of patients developed a post-operative infection, even though all patients received antibiotics.
An examination of the various trials addressing carpal tunnel syndrome treatment did not provide insight on whether there are conditions or comorbidities that predispose patients to post-surgical infection. Patients with diabetes mellitus, for example, were excluded from the trials. A single Level IV study looked at rates of post-operative infections in persons with and without diabetes and found that the rate was similar in the two groups.
See Evidence Tables 38-41 and Evidence Report pages 96-100.
We suggest that the wrist not be immobilized postoperatively after routine carpal
(Grade B, Level II)
We make no recommendation for or against the use of postoperative rehabilitation.
(Inconclusive, Level II)
The wrist should not be immobilized postoperatively after routine carpal tunnel release. Post-operative splinting for longer than two weeks did not offer any specific benefit in terms of grip or lateral pinch strength, bowstringing, complication rates, subjective outcome and patient satisfaction.
Clinicians may wish to provide protection for the wrist in a working environment or for temporary protection. However, the evidence does not provide objective criteria for these situations. Clinicians should be aware of the detrimental affects including adhesion formation, stiffness and prevention of nerve and tendon movement which may compromise the carpal tunnel release results in achieving another objective such as early release to work.
For postoperative rehabilitation, one study examined supervised hand therapy. The applicability of the outcome measure (return to work) was questioned because it was not considered to be critical to determining whether supervised hand therapy was beneficial to postoperative rehabilitation. The grade of recommendation was downgraded because the evidence was inconclusive.
There were no included studies that looked at work hardening and the role of various modalities for post-operative carpal tunnel management. The role of supervised therapy after carpal tunnel release in the work-related population will need further evaluation to determine if there is any advantage to work hardening, work simulation, or routine strengthening.
See Evidence Tables 42-51 and Evidence Report (PDF Pages 101-110, Figures 92-101)
We suggest physicians use one or more of the following instruments when assessing patients’ responses to CTS treatment for research:
Boston Carpal Tunnel Questionnaire (disease-specific)
DASH – Disabilities of the arm, shoulder, and hand (region-specific; upper limb)
MHQ – Michigan Hand Outcomes Questionnaire (region-specific; hand/wrist)
PEM (region-specific; hand)
SF-12 or SF-36 Short Form Health Survey (generic; physical health component for global health impact)
(Grade B, Level I, II, and III)
All measurement instruments, whether they are aimed at diagnosis, evaluation of disease activity or outcome, must be judged on their key psychometric characteristics: reliability, validity, interpretability and responsiveness. Reliability was generally measured in these studies by assessing the internal consistency and reproducibility of the study.
Per Jenkinson 67, “validity is assessed in relation to a specific purpose and setting.” Validity is established statistically for an instrument by measuring construct validity, convergent and divergent validity, and/or criterion validity. Instruments having construct validity are summarized in the table below.
Convergent and divergent validity measures can be found in the Evidence Tables (Tables 69-85). More information concerning interpretation of these measures can be found in the Evidence Report but an inclusive discussion is beyond the scope of the guideline. These values were not graphed and were provided to illustrate the direction and magnitude of relationships. Criterion validity was not summarized.
While adequate reliability and validity are concepts that are, for the most part, clear to clinicians, the capacity for interpretability and responsiveness may be less familiar. Interpretability refers to the fundamental meaning of the measure. Instruments that encompass items that are meaningful to patients and/or clinicians will have good interpretability and users can easily understand the meaning of these measures. Few studies measured interpretability therefore they are not summarized in the table below.
Responsive measures reflect small changes in a given condition. This may be important where subtle differences could be clinically important. Responsive measures are helpful in the planning of trials where the objective may be to demonstrate a small difference between, for example, treatments.
Generally speaking, generic measures, like the Short Form 36 (SF-36), look at a broadly based assessment of health and, as a result may not be very responsive to changes in status related to a relatively minor condition such as CTS.
Disease-specific instruments such as the Boston Carpal Tunnel Questionnaire (BCTQ) are most responsive.The BCTQ shows excellent responsiveness for the measurement of disease activity in CTS. Wherever possible the full instrument should be used because this gives the most comprehensive evaluation of both function and symptoms in CTS without any loss of responsiveness. The subscales of this instrument also have satisfactory responsiveness but give a more narrow view of disease activity. The BCTQ is fully validated in the treatment of carpal tunnel syndrome.
The region-specific instrument, The Disabilities of the Arm, Shoulder and Hand (DASH) was moderate to highly responsive and the Michigan Hand Outcomes Questionnaire (MHQ) was highly responsive in three of five subscales.
The Patient Evaluation Measure (PEM), (MHQ) and DASH are more broadly based region-specific instruments that can be considered to be responsive for the evaluation of CTS. The responsiveness of the DASH is slightly below the acceptable threshold (standardized response mean (SRM) = 0.80) but should be considered if the goal of the evaluation is a focus on disability because it has been evaluated in three key domains: internal consistency, reproducibility and responsiveness.
See Evidence Tables 52-101 and Evidence Report (PDF Pages 111-125, Figures 102-120)
Although we make every effort to find studies of the highest quality, such evidence is not readily available for carpal tunnel syndrome treatment at this time. This guideline has been hindered by a relative lack of power in the studies even though these studies were of Level I and II evidence. The recommendations of this guideline therefore depend to some degree on lesser evidence, including expert opinion.
To achieve a high-quality literature base, academic authors and scientists should invest their time and effort in studies designed to avoid bias (e.g., blinded and properly randomized controlled trials of sufficient power to address the outcome of interest). Future studies should, from the onset, be based on improved study design that includes a priori power calculations. Risk stratification studies are also needed to detect when antibiotics might be justified on the basis of co-morbidities and co-interventions.
We recognize that the issue of carpal tunnel syndrome in the workplace is important. Studies identified by the literature search commonly analyze risk, prevalence, and predictability of carpal tunnel syndrome in specific job categories but good evidence to address the effectiveness of workplace modifications was not available. Working patients, payors, and physicians clearly lack the evidence base to determine “best options”. Physicians and patients must first decide the desired outcome. Should the goal be permanent modification of activities for the worker or proceed to surgery and return to normal activities? Future research must rigorously address this subpopulation to determine if activity modification will result in positive outcomes such as ultimately avoiding surgery.