The study was carried out on 30 elderly female patients above 60 years with DRF who developed signs and symptoms (either night or day and night symptoms) suggestive of DCTS within 6 months of fracture. Patients were recruited from those attending the outpatient clinic either for rehabilitation or for electrophysiological evaluation.

Exclusion criteria were: (1) patients with clinical signs and symptoms suggestive of carpal tunnel syndrome before the date of fracture, (2) patients with peripheral neuropathy, (3) patients with violent trauma of the upper limb suggestive of direct nerve injury, (4) patients with associated traumatic nerve injury, (5) patients with history of median nerve release, (6) patients with diabetes mellitus, and other metabolic disorders, (7) patients with rheumatological disorders.

History was taken regarding time of onset of the neurological symptoms. The demographic data and anthropometric measures were documented from all the participants [weight, height, and body mass index (BMI)]. All patients in the symptomatic group had paresthesia in the median nerve distribution of the fractured wrist and positive findings in neurological examinations, including the Tinel sign test and Phalen test. CTS-6 score was recorded for each patient to assess the severity of symptoms [10].

For a case–control study design, 30 female patients of matched age and anthropometric measures who did not experience symptoms of CTS on the injured hand up to 6 months after injury were included as controls from among consecutive patients treated conservatively.

A sample of 30 patients in each group was enough to detect the effect of carpal malalignment on the development of DCTS if true at 0.005 alpha error and 0.90 power of the test, assuming an effect size of 1.0.

Radiological parameters, including the radiocapitate distance (RCD), volar prominence height (VPH), and volar tilt (VT) (Fig. 1), were measured using lateral view radiographs of the wrist at the time of onset of DCTS in the symptomatic group and at 6 months after injury in the control group.

Demonstrating VT, RCD, and VPH. R: radius, L: lunate, C: capitate

Carpal alignment is typically represented by the radiocarpal and intercarpal angles. The RCD was defined as the distance between the centre of the head of the capitate and the volar cortical line of the radial diaphysis, the VPH was defined as the distance between the vertex of the volar prominence of the distal radial epiphysis and the volar cortical line of the radial diaphysis, and the VT was the angle between the line connecting the dorsal and volar margins of the lunate facet of the distal radius and the line perpendicular to the volar cortical line of the radial diaphysis. A negative VT indicates dorsal angulation of the distal radial articular surface. The RCD is positive when the centre of the capitate's head is on the volar side from the volar cortical line of the radial diaphysis and negative when it is on the dorsal side [11].

The electrophysiological evaluation was done to all the participants. The studies were performed using Viking Quest (Nicolet ViaSys Healthcare, U.S.A.). The following electrophysiological studies were performed: median (APB) and ulnar (ADM) motor nerve conduction studies and median (index) and ulnar (little finger) sensory nerve conduction studies. Median versus ulnar comparative studies were done if there was no electrophysiological abnormality in the median sensory conduction study. The classification of neurophysiological severity of median entrapment across the wrist was according to the Padua neurophysiological classification scale [12].

Data were fed to the computer and analyzed using IBM SPSS software package version 20.0 (Armonk, NY: IBM Corp). Student t-test was used to compare both groups regarding the radiological parameters. Correlations between CST-6 score, Padua neurophysiological classification scale for CTS and the different radiological parameters were examined in the DCTS group. The threshold value and the odds ratio of each radiological parameter were examined using univariate logistic regression analysis. Significance of the obtained results was judged at the 5% level.