The relationship of severity of carpal tunnel syndrome with body fat distribution and hand anthropometric parameters: Digit ratio (2d:4d), hand/wrist ratio and handgrip strength

Carpal tunnel syndrome (CTS), which occurs as a result of compression of the median nerve (n.) within the carpal tunnel, is the most common entrapment neuropathy. It is very important to have knowledge about the morphometric anatomy of the hand and wrist circumference, which is associated with the carpal tunnel and n. medianus, in determining the diagnosis and treatment options for CTS. In our study, we aimed to evaluate the relationship between CTS symptoms, the parameters showing body fat distribution, grip strength of the hand, and these morphometric parameters. In our study, 90 female and 10 male patients who applied to Karaman Medical Center with the suspicion of CTS were recorded by making electromyography (EMG) measurements in the neurology policlinic. The 2nd digit length (2D), 4th digit length (4D), 2D/4D and other anthropometric measurements were made for the hand and wrist. In addition, in order to obtain information about the body fat distribution of the patients, body mass index (BMI) and WC/HC were calculated by measuring height, weight, arm circumference (AC), waist circumference (WC), and hip circumference (HC). Hand grip strength (HGS) measurement, Visual analog scale (VAS) for pain, and Likert (L) scale for numbness severity were used to detect changes after CTS. The patients were divided into three groups according to age and BMI. The data obtained were analyzed according to gender, lateralization, age groups, body mass index, affected hand, EMG grade, and Likert scale, and also the correlations between these parameters were determined. A statistically significant difference was found between anthropometric measurements, especially wrist depth (WD), wrist width (WW), WD/WW, palm length (PL), and WD/PL parameters, according to the EMG degree indicating the severity of CTS. Although normally 2D is higher than 4D in women, in our study, 4D value was measured as higher than 2D due to compression of n. medianus. It was determined that body fat ratio increased with age and CTS degree. The BMI of the patients in the 3rd age group (62-83 years) was found to be the highest as 30.39±3.83, and the mean age of the group with the most severe EMG level was determined as 62.21±14.25. A significant negative correlation was found, indicating that the grip strength decreased as the severity of CTS increased. In addition, a strong positive correlation was found between EMG grade and VAS and Likert scale findings. The data we obtained show that the occurance of CTS causes changes by affecting the normal anatomical structure of the hand and wrist. In addition, it was observed that the increase in the measurement values of the parameters showing the body fat distribution caused an increase in the data showing the severity of this syndrome. Depending on the data obtained, this significant relationship between the severity of CTS and the changes in the anatomical structure of the hand and wrist after this entrapment neuropathy should be considered in the diagnosis and treatment of CTS. In addition, we believe that body fat distribution should be taken into account in addition to hand and wrist anthropometric measurements. We hope that the data we obtained will be a database for more comprehensive studies including high sample size and more diverse patients in this field. We believe that it will guide clinicians in the early diagnosis of CTS in terms of determination of the factors affecting the course of the disease and treatment options. Keywords: Body mass index, carpal tunnel syndrome, electromyography grade, grip strength, wrist anthropometry.