So far there are studies that report the benefits of physiotherapy treatment in carpal tunnel syndrome, but none on the treatment of dry needling. Recently, an ultrasound validation study has been published in which the results indicate that the application of dry needling with "fascial winding technique" in the carpal tunnel, following the "four-pole carpal dry needling" model, is valid for reaching and traction of the transverse carpal ligament. Stretching over this ligament could lead to new therapeutic possibilities for dry needling at this level. The objective of this project is to demonstrate the clinical efficacy of this technique in patients affected by carpal tunnel syndrome, determining the proportion of patients who can be avoided surgery, and quantifying the improvement in the clinic related to pain, strength and functionality of the hand and the median nerve.

The study is a randomized clinical trial on a sample of 86 patients diagnosed with carpal tunnel syndrome, who have been prescribed surgery at this level. The degree of involvement of the median nerve will be mild or moderate, according to electromyographic results. The dry needling with fascial winding technique will be applied to the intervention group following the model of "four-pole carpal dry needling" during a period of 6 weeks, at the rate of one weekly session. The control group will remain within the normal course of their waiting list status for STC surgery, without receiving any extraordinary treatment to what is normally practiced in this situation. The main variables contemplated are: need for surgery at the end of the study, level of involvement of the median nerve (according to electromyographic result), transverse area of the median nerve at the entrance of the carpal tunnel and relationship between the area of the median nerve at the wrist and the forearm (both recorded by ultrasound study), pain intensity (using visual analog scale), symptom intensity, functional capacity and quality of life (according to the Boston Carpal Tunnel Questionnaire), and degree of muscular strength to the grip manual and digital.

INTRODUCTION:

Dry Needling (DN) is an invasive technique widely used in the Physiotherapy field, on which numerous studies have recently been published. The vast majority of these studies focus on the action of DN on the muscular element: the well-known myofascial trigger points. According to what Dunning proposed in 2014, it should not ignore and/or underestimate its action on the connective-fascial tissue, the other aspect of a single, unique and indivisible functional whole: the myofascia.

In the field of acupuncture, numerous studies have been conducted to determine the role played by the fascia in the therapeutic phenomenon that begins when working with a needle. Among these, mention in particular the studies of Dr. H. M. Langevin, pioneers in the contribution of scientific evidence to the phenomenon known as "needlegrasp". When the acupuncture needle (the same as the one used in DN) is rotated, the fascial connective tissue winds around to the point where it is fastened and trapped.

With the intention of demonstrating the benefit of treatment with DN on connective-fascial tissue, the investigators present this research project. In the same, it is proposed to apply DN in a pathology such as carpal tunnel syndrome (CTS), in which surgical treatment is currently considered principally.

There are previous studies that describe the benefits of physiotherapy treatment in the CTS, but none on the treatment of DN. Recently, it has been validated using ultrasound image how DN needles, applied following the original model proposed and described as "four-pole carpal dry needling" (FCDN), reach the transverse carpal ligament (TCL) in 93.1%. In turn, if these needles are manipulated in the form of unidirectional rotation, named in this work as "fascial winding technique" (FWT), a traction-stretching of this ligament can be observed via ultrasound. It was possible to observe in 80.6% of the occasions. The results obtained indicate that DN with FWT in the carpal tunnel (CT), following the FCDN model, is valid to reach and traction the TCL. Similarly, the same study also shows this treatment as safe in terms of not injuring the median nerve and/or the ulnar artery. The level of pain and/or superficial bleeding produced is very slight and only at the time of performing the technique, without causing painful discomfort or residual bruising.

In affected patients with CTS there is a decrease in the sliding movement of the median nerve with respect to the TCL, located just above it. If, as has already been verified, a traction-stretching of the TCL can be performed using the DN technique with FWT applied according to the FCDN model, a relaxation of the tension and flexibility in this same ligament can also be achieved . It is logical to think that this decrease in the tension of the TCL leads to an improvement in the sliding movement of the median nerve, restricted in patients with CTS. On the other hand, this relaxation of the TCL (one of the walls of the case that forms the CT) could also lead to a decrease in the pressure existing inside the tunnel, thus decreasing the compression on the median nerve, established as one of the main causes of the symptoms of sensory and motor disturbance in these patients.

If it is possible to demonstrate the clinical efficacy of DN treatment with FWT in patients with CTS, important benefits will be achieved. In the first place, a new therapeutic tool would be provided, full of competence for the physiotherapist, in the treatment of this pathology. In addition, the combination of this treatment with other medical and physiotherapeutic types already existing could increase the therapeutic benefits for patients with CTS. It is even contemplated that it is shown to be effective enough to be considered as an alternative to surgery in cases of mild or moderate medium nerve involvement, thus avoiding all the risks and possible complications that this entails. For all this, the economic burden derived from the current treatment in these patients, as well as the time of convalescence and/or sick leave, would be significantly reduced.

HYPOTHESIS:

Dry needling with fascial winding technique applied in patients with carpal tunnel syndrome in a level of mild or moderate median nerve involvement, avoids surgery, at this level, to a significant proportion of patients with indication of it.

OBJECTIVES:

PRINCIPAL:

o To determine the proportion of patients with carpal tunnel syndrome and level of mild or moderate median nerve involvement in which the application of dry needling with a fascial winding technique avoids surgery at this level.

ESPECIFIC:

• To determine the improvement in the clinic related to pain, strength and functionality of the hand and the median nerve, in patients with carpal tunnel syndrome treated with dry needling with fascial winding technique.
• Determine if there are adverse or undesirable effects when applying dry needling with fascial winding technique in patients with carpal tunnel syndrome and, if so, specify what they are and how often they occur. In this same line, the intensity of pain associated with the application of the "four-pole carpal dry neeling" approach will be determined.

METHODOLOGY:

The study is a randomized single-blind clinical trial (RCT).

Sample. The individuals of the sample will be recruited by sampling of consecutive cases of the Orthopedic Surgery and Traumatology Service of Hospital de Bellvitge, once the carpal tunnel surgery is considered indicated.

Sample size:

The calculation of the number of individuals required has been made taking into account that currently the percentage of success of open surgery ranges between 70-98%, so it is expected to avoid such surgery at a percentage of 84 ± 12.5%. Setting a power of 80% and a level of significance of 5% in the ratio comparison formula for cases of bioequivalence, we obtain that the sample size is 34 individuals per group. Assuming a maximum loss percentage of 20% it will be necessary to recruit 43 individuals per group.

Assignment to groups. To the extent that the sample is recruited, subjects will be randomly distributed into two groups (intervention and control) using a software-generated randomization system. Each subject will be assigned a numbered, sealed and opaque envelope where their inclusion in the intervention or control group will be specified. The evaluating staff will be blinded to the assignment to the groups.

STATISTICAL ANALYSIS OF THE DATA:

First, a descriptive analysis of the sociodemographic characteristics (age, sex and profession) and anthropometric characteristics (BMI, wrist perimeter, dominant hand) for each of the groups and for all response variables (EMG, CSA-M , WF-R, pain intensity, BCTQ, muscle strength of grip, and intensity of pain that causes the FCDN approach model) for each of the groups and for each of the assessments. For this, the percentage for the qualitative variables and the mean and standard deviation for the quantitative ones will be calculated.

Secondly, the evolution of each one of the response variables will be evaluated and they will be compared between both groups with a two-factor ANOVA test and with repeated measures. The level of significance set is 5%. The statistical analysis will be carried out with the SPSS 21.0 software.

ETHICAL ASPECTS:

Note that this project complies with the principles established in the Declaration of Helsinki, and will be submitted for approval to the Clinical Research and Ethics Committee of Bellvitge Hospital.

All participating subjects will sign an informed consent, with free and voluntary acceptance of participation in the study.

Inclusion Criteria:

The study population are individuals with a clinical and electromyographic diagnosis of CTS, and levels of mild median nerve involvement (focal demyelination without axonal degeneration) or moderate (focal demyelination with sensory but non-motor axonal degeneration) according to electromyogram (EMG).

Exclusion Criteria:

Will not be included those subjects with previous surgery in the CT, to whom the involvement of the median nerve is attributable to another type of neuropathy (diabetic, uraemic, deficiency, ...), to those who present a previous pain in the region, attributable to arthritis and not to CTS, to individuals suffering from fibromyalgia and/or chronic pain syndrome, to those who suffer from aversion or phobia to needles, to pregnant patients, to those with intellectual disability to understand the procedure, methodology and object of the study (mental, psychiatric disorders, low level of IQ, ...), and/or those patients who show little collaboration to the correct performance of the study.

For the time being it is expected to analyze the data obtained for the elaboration of the study that we present. It is to be determined if in the future these data can be used for other studies.

Assignment to groups. To the extent that the sample is recruited, subjects will be randomly distributed into two groups (intervention and control) using a software-generated randomization system. Each subject will be assigned a numbered, sealed and opaque envelope where their inclusion in the intervention or control group will be specified.

The evaluating staff will be blinded to the assignment to the groups.