Carpal tunnel syndrome (CTS) is the most common peripheral compression neuropathy of the upper extremity. Repetitive wrist and finger motion has been suggested as a major factor of pathogenesis of CTS. However, little is known about the pathomechanics of CTS. We aimed to evaluate the movement of the median nerve in the carpal tunnel during wrist and finger motions using transverse ultrasound in 21 patients with CTS (5 men and 16 women with mean age 69.0 years). We examined quantitatively the median nerve location as a coordinate within the carpal tunnel at varied wrist positions with all fingers full extension and flexion respectively in the affected and unaffected sides. We thus found that at all wrist positions during finger motion, the median nerve moved significantly more ulnopalmarly in the affected side compared to the unaffected side (p < 0.05). Especially, at the wrist palmar-flexion position as a provocative test, the nerve moved significantly (p < 0.05) the most ulnopalmarly among all wrist positions in the affected side. The nerve was the most strongly compressed against the transverse carpal ligament by the flexor tendons. Additionally, the displacement amount of the nerve in the dorsal-palmar direction was significantly smaller in the affected side than in the unaffected side. These findings indicate that such a pattern of nerve movement has the potential to distinguish affected from unaffected individuals. This ultrasound information could be useful in better understanding of the pathomechanics of CTS, and in further improvement of diagnosis and treatment for CTS.

This study showed that the wrist dorsal flexion position with finger flexion could be the appropriate position to examine FPL tendon irritation after plating. Moreover, it would be effective for preventing FPL rupture to cover the FPL transverse gliding area approximately 10 mm radial to the vertex of the palmar bony prominence of the distal radius with the pronator quadratus and the intermediate fibrous zone.

Background:We compared the clinical results of a newly modified abductor pollicis longus (APL) suspension arthroplasty with trapeziectomy procedure (modified Thompson procedure) with those of the original APL suspension arthroplasty with trapeziectomy procedure (original Thompson procedure) for treatment of advanced osteoarthritis of the thumb carpometacarpal (CMC) joint and assessed the effectiveness of the modified Thompson procedure for thumb CMC osteoarthritis.Methods: Ten hands of 10 patients (Group 1) were treated with the original Thompson procedure.Twenty hands of 16 patients (Group 2) were treated with the modified Thompson procedure, in which the bone tunnel positions were rearranged for a more dorsoradial passage of the transferred APL.Results: Significant differences between values before and after surgery were noted in thumb palmar and radial abduction angles, pinch power, grip strength, Quick Disability of Arm, Shoulder, and Hand questionnaire (Quick DASH) score, and visual analog scale (VAS) score. There was no statistically significant difference in thumb palmar abduction angle, pinch power, grip strength, Quick DASH score, or VAS score between Groups 1 and 2. However, range of motion of radial abduction in the thumb was significantly better for patients in Group 2 than for those in Group 1. Conclusions:The modified Thompson procedure is a simple, effective technique that results in greater improvement in thumb radial abduction angle, as compared with the original technique, in patients with advanced thumb CMC osteoarthritis. Additionally, the modified technique is as useful as the original procedure for early restoration of thumb function and pain relief. (J Nippon Med Sch 2019; 86: 269 278)

Purpose: The second dorsal metacarpal (SDMC) perforator flap has been widely used for the soft tissue reconstruction of the hand. However, it is difficult to identify the depth and branches of the perforators of the second dorsal metacarpal artery (SDMA) using only handheld acoustic Doppler flowmetry (HADF), which is the most common method. The purpose of this study was to compare the results of examination by color Doppler ultrasonography (CDU) with those of HADF and to evaluate the efficacy of CDU for detection of the perforators to be used in the design of the SDMC flap. Methods: Twenty-two healthy volunteers (42 hands) were examined using both CDU and HADF. All locations identified as the perforators of the SDMA by the two examinations were mapped respectively. Results: The total perforator arteries detected with CDU in all hands were 111 branches, 49 branches of which could not be identified with HADF. The average number of perforators of the SDMA per hand found with CDU was 2.8 branches, while that for HADF was only 1.8 branches. The detection rates of the cutaneous perforators of the SDMA by CDU were 100% in the proximal onethird of the second metacarpal and 95% in the distal one-fourth of the second metacarpal. Conclusion: This study demonstrated the superiority of CDU compared with HADF for detection of the perforators of the SDMA. The CDU examination could easily identify the locations of the cutaneous perforators and help in the useful assessment of vascularity for the SDMC flap.

Purpose: The purpose of this study was to investigate the displacement of the median nerve in the carpal tunnel during finger motion at varied wrist positions using transverse ultrasound in healthy volunteers, in order to clarify the appropriate position of a wrist splint in treating carpal tunnel syndrome.