We performed primary excision of the ulnar head on 23 patients over 70 years of age with severe comminuted fractures of both the distal radius and ulna. The distal radius fracture was fixed rigidly with a volar locking plate, and the ulnar head was resected at the fracture site. All the distal radial fractures united without major complications. The mean wrist flexion/extension arc was 122°, the mean pronation/supination arc was 164°, and grip strength was 69% of that on the contralateral side. All patients returned to their daily activities within a short time without any additional surgical treatment. For elderly patients, primary excision of the ulnar head is an effective treatment for comminuted distal radius and ulna fractures.

We hypothesized that interindividual variations in the teardrop, which represents the volar projection of the lunate facet of the distal radius, cause unsatisfactory fitting of the volar locking plate to the bone. This can cause flexor tendon ruptures. Herein, we conducted a cross-sectional study and measured the ratio of teardrop height and the teardrop inclination angle as parameters of teardrop configuration for 200 standardized lateral radiographs (average age of the patients, 51 years). We also quantified the influence of the teardrop morphology by analyzing the fit of three locking plates to three radii with differing teardrop inclination angles using a three-dimensional computer-aided design system. The average ratios of the teardrop height and teardrop inclination angle were 0.42( 0.30-0.56˚) and 28.8˚(9.9-44.9˚), respectively. The teardrop inclination angle was moderately correlated with age in men but not in women. In the plate-to-bone fit analyses, the fit of all the plates was significantly different between bones, with the configuration of the radius with the lowest teardrop inclination angle being the closest approximation to that of each plate. We demonstrated the interindividual variation in the shape of the teardrop and its influence on the fit of the volar plate, highlighting the importance of careful plate selection for achieving osteosynthesis of bones with a high teardrop inclination angle. Keywords: distal radius fracture; locking plate; plate-to-bone fit; teardrop morphology; three-dimensional computer-aided designThe treatment of distal radius fractures, including those in osteoporotic patients, has improved remarkably with the use of volar locking plates for osteosynthesis. The plates are installed on the anterior surface of the distal radius, which is concave and palmarly directed, and the ulnar distal end of the slope has a steep projection. As it has a U-shaped outline on lateral radiographs, it is called a teardrop, and it functions as a mechanical buttress for subluxation of the lunate. 1 This projection is higher on the ulnar side, where the flexor tendons are in close proximity to the bone compared to the radial side; therefore, to avoid flexor tendon injury, locking plates should not be placed distal to the watershed line, which Orbay called the distal ridge of the pronator fossa on the palmar surface. 2 Most available locking plates for the distal radius are precontoured to its standard morphology. However, the plates do not always fit well to the bone surface. Therefore, it became apparent that there are interindividual differences in the bony configuration of the distal radius, especially in the height and inclination of the slope to the teardrop. These interindividual differences have not been discussed in the anatomical description of the distal radius. [2][3][4][5] The discrepancy between the shape of the plate and the configuration of the teardrop leads to insufficient plate contact in some cases, which in turn causes complications such as flexor tendon injuries....

BACKGROUND:The upper extremity disability in patients with carpal tunnel syndrome (CTS) is related to dysfunction due to the median nerve damage. However, there is no report on which dysfunctions affect the upper extremity disability. PURPOSE: This study aimed to investigate which clinical factors influence upper extremity disability in women with CTS. METHODS: We analyzed 60 hands of women with bilateral idiopathic CTS. Upper extremity disability was assessed using Hand10, a validated and self-administered tool. Pain intensity was measured using the Japanese version of the Short-Form McGill Pain Questionnaire (SF-MPQ-J). We performed nerve conduction studies, assessed physical and psychological parameters, and collected demographic data. Physical parameters comprised grip strength, pinch strength, tactile threshold, static 2-point discrimination sensation, and severity of numbness. Psychological parameters include depression, pain anxiety, and distress. RESULTS:The bivariate analysis revealed that Hand10 was significantly correlated with age, symptom duration, SF-MPQ-J, grip strength, pain anxiety, and distress. Multiple regression analysis demonstrated that SF-MPQ-J and grip strength were related to Hand10 score. CONCLUSIONS: Pain intensity and grip strength were dysfunctions affecting the upper extremity disability in women with bilateral idiopathic CTS. Rehabilitation approaches for CTS should be considered based on the adaptive activities of the neural networks.

III.

We previously created a prosthetic hand with a tacit learning system (TLS) that automatically supports the control of forearm pronosupination. This myoelectric prosthetic hand enables sensory feedback and flexible motor output, which allows users to move efficiently with minimal burden. In this study, we investigated whether electroencephalography can be used to analyze the influence of the auxiliary function of the TLS on brain function. Three male participants who had sustained below-elbow amputations and were myoelectric prosthesis users performed a series of physical movement trials with the TLS inactivated and activated. Trials were video recorded and a sequence of videos was prepared to represent each individual's own use while the system was inactivated and activated. In a subsequent motor imagery phase during which electroencephalography (EEG) signals were collected, each participant was asked to watch both videos of themself while actively imagining the physical movement depicted. Differences in mean cortical current and amplitude envelope correlation (AEC) values between supplementary motor areas (SMA) and each vertex were calculated. For all participants, there were differences in the mean cortical current generated by the motor imagery tasks when the TLS inactivated and activated conditions were compared. The AEC values were higher during the movement imagery task with TLS activation, although their distribution on the cortex varied between the three individuals. In both S1 and other brain areas, AEC values increased in conditions with the TLS activated. Evidence from this case series indicates that, in addition to motor control, TLS may change sensory stimulus recognition.