This study was aimed to estimate the effect of different ProDisc-C arthroplasty designs after it was implanted to C5-C6 cervicalspine. Finite element (FE) model of intact C5-C6 segments including the vertebrae and disc was developed and validated. Ball-and-socket artificial disc prosthesis model (ProDisc-C, Synthes) was implanted into the validated FE model and the curvature of the ProDisc-C prosthesis was varied. All models were loaded with compressed force 74 N and the pure moment of 1.8 Nm along flexion-extension and bilateral bending and axial torsion separately. The results indicated that the variation in the curvature of ball and socket configuration would influence the range of motion in flexion/extension, while there were not apparently differences under other conditions of loads. The method increasing the curvature will solve the stress concentration of the polyethylene, but it will also bring adverse outcomes, such as facet joint force increasing and ligament tension increasing. Therefore, the design of artificial discs should be considered comprehensively to reserve the range of motion as well as to avoid the adverse problems, so as not to affect the long-term clinical results.
Arthroplasty ; Biomechanical Phenomena ; Finite Element Analysis ; Humans ; Intervertebral Disc ; Pressure ; Prostheses and Implants ; Range of Motion, Articular ; Spine ; Zygapophyseal Joint

This study investigated the effect of prolonged walking with load carriage on body posture, muscle fatigue, heart rate and blood pressure of the tested subjects. Ten healthy volunteers performed 30 min walking trials on treadmill (speed = 1.1 m/s) with different backpack loads [0% body weight (BW), 10% BW, 15% BW and 20% BW]. The change of body posture, muscle fatigue, heart rate and blood pressure before and after walking and the recovery of muscle fatigue during the rest time (0, 5, 10 and 15 min) were collected using the Bortec AMT-8 and the NDI Optotrak Certus. Results showed that the forward trunk and head angle, muscle fatigue, heart rate and blood pressure increased with the increasing backpack loads and bearing time. With the 20% BW load, the forward angle, muscle fatigue and systolic pressure were significantly higher than with lighter weights. No significantly increased heart rate and diastolic pressure were found. Decreased muscle fatigue was found after removing the backpack in each load trial. But the recovery of the person with 20% BW load was slower than that of 0% BW, 10% BW and 15% BW. These findings indicated that the upper limit of backpack loads for college-aged students should be between 15% BW and 20% BW according to muscle fatigue and forward angle. It is suggested that backpack loads should be restricted to no more than 15% BW for walks of up to 30 min duration to avoid irreversible muscle fatigue.
Blood Pressure ; Body Weight ; Exercise Test ; Healthy Volunteers ; Heart Rate ; Humans ; Muscle Fatigue ; Posture ; Walking ; physiology ; Weight-Bearing

Objective To investigate a more pedect method for a nice outward appearance of a reconstructed thumb.Methods A free one-stage plasty second toe transfer for thumb reconstruction by interchanging the whole skin-nail flap from the great toe with another one from the second toe.Results There were 12 cases in this group,following-up 6-9 months in 8 cases,7 cases was excellent and 1 cases was good.The reconstructed thumb got a nice looking and more normal function while no blight to the great toe occurred.Conclusion It is an effective new procedure in ameliorating outward appearance of the reconstructed thumb by transferring the free moulded second toe.

Objective To investigate the risk factors associated with epididymitis after transurethral resection of prostate.Methods A retrospective analysis of 352 patients with benign prostatic hyperplasia (BPH) who underwent transurethral resection of prostate in X'an Aerospace General Hospital from January 2015 to December 2017 was performed.There were 14 cases of epididymitis and 338 cases of nonepididymitis.Measurement data were expressed as ((x) ± s),t test was used for comparison between groups;count data was expressed by rate (％),and chi-square test was used for comparison between groups.Univariate and multivariate logistic regression analyses were used for factors that may lead to post-urethral epididymitis.Results Univariate logistic regression analysis showed that preoperative leukocytic positive,urine glucose positive and prostate volume had significant effects on postoperative epididymitis (P ＜ 0.05).Multivariate logistic regression analysis showed that prostate volume increased (OR =0.182,P =0.005)was an independent risk factor for postoperative epididymitis.Conclusion The enlargement of prostate volume is an independent risk factor for postoperative epididymitis.For large-volume prostate surgery,the purpose of relieving obstruction can be achieved.