In the present paper, the contribution of the largest principal component and the number of principal component needed for accumulative contribution 95% are selected as indices of electroencephalogram (EEG) in mental fatigue state in order to investigate the relationship between these parameters and mental fatigue. The experimental results showed that the contribution of the largest principal component of EEG signals increased in the prefrontal, frontal and central areas, while the number of principal component needed for accumulative contribution decreased by 95% with the increasing mental fatigue level. The parameters of singular system of EEG signals can be regarded as useful features for the estimation of mental fatigue and have larger application value in the study of mental fatigue.
ObjectiveTo investigate the effectiveness of butterfly shaped locking compression plate for the treatment of complex distal radius fractures. MethodsBetween June 2011 and January 2013, 20 cases of complex distal radius fractures were treated with butterfly shaped locking compression plate fixation. There were 11 males and 9 females with an average age of 54 years (range, 25-75 years). Injury was caused by falling in 10 cases, by traffic accident in 7 cases, and by falling from height in 3 cases. All of fractures were closed. According to AO classification system, there were 8 cases of type C1, 8 cases of type C2, and 4 cases of type C3. Of them, 9 cases had radial styloid process fracture, 4 cases had sigmoid notch fracture, and 7 cases had both radial styloid process fracture and sigmoid notch fracture. The mean interval between injury and operation was 5.2 days (range, 3-15 days). ResultsAll incisions healed by first intention; no complications of infection and necrosis occurred. All cases were followed up 14 months on average (range, 10-22 months). All factures healed after 9.3 weeks on average (range, 6-11 weeks). No complications such as displacement of fracture, joint surface subsidence, shortening of the radius, and carpal tunnel syndrome were found during follow-up. At last follow-up, the mean palmar tilt angle was 10.2°(range, 7-15°), and the mean ulnar deviation angle was 21.8°(range, 17-24°). The mean range of motion of the wrist was 45.3°(range, 35-68°) in dorsal extension, 53.5°(range, 40-78°) in palmar flexion, 19.8°(range, 12-27°) in radial inclination, 26.6°(range, 18-31°) in ulnar inclination, 70.2°(range, 45-90°) in pronation, and 68.4°(range, 25-88°) in supination. According to the Dienst scoring system, the results were excellent in 8 cases, good in 10 cases, and fair in 2 cases, and the excellent and good rate was 90%. ConclusionTreatment of complex distal radius fractures with butterfly shaped locking compression plate can reconstruct normal anatomic structures, especially for radial styloid process and sigmoid notch fractures, and it can get good functional recovery of the wrist and the distal radioulnar joint.
ObjectiveTo discuss the clinical result of extrinsic radioulnar tether combined with anchoring nail fixation for treating chronic dorsal instability of the distal radioulnar joint (DRUJ). MethodsBetween July 2011 and December 2012, 6 patients with chronic dorsal instability of the DRUJ were treated with extrinsic radioulnar tether combined with anchoring nail fixation. There were 1 male and 5 females with the average age of 27.3 years (range, 22-35 years). All of 6 patients had a wrist trauma history. The average disease duration was 4.8 years (range, 6 months to 15 years). Radiographs were taken postoperatively to observe the anchoring nail loosening. The stress test and forearm rotation test were used to evaluate the function of DRUJ. The complications, the grip power, range of motion, and visual analogue scale (VAS) scores were recorded at last follow-up. And the joint function was evaluated by disability of arm, shoulder, and hand (DASH) score. ResultsPrimary healing of incision was obtained in all cases, without any complications such as infection and ulnar neck fracture. All 6 patients were followed up 6-24 months (mean, 13.7 months). Stability was achieved in all patients. Radiographs showed that the joint space was widened and dislocation of the ulnar head was improved at 3 and 6 months after operation. The results of the stress test and forearm rotation test were negative. At last follow-up, the grip power, DASH score, VAS score, and range of motion of the wrist were significantly improved when compared with preoperative ones (P<0.05). ConclusionExtrinsic radioulnar tether combined with anchoring nail fixation is an easy method of surgical revision to treat chronic dorsal instability of DRUJ, which can maintain the stability and protect the blood supply of triangular fibrocartilage complex.