BACKGROUND:Usual mechanics experiment approach cannot be applied directly to human body and the inter-comparability of models is low.Therefore finite element numerical simulation to mechanical behavior of human body has become an effective method for better understanding of the human body.OBJECTIVE:To establish a three-dimensional finite element model of femoral osteoporosis.METHODS:According to the average Chinese femur parameters,1 male patient with severe osteoporosis,aged 86 years,with no hip joint diseases,was selected.The data of femoral osteoporosis was obtained by means of spiral CT scanning.The graphical data were processed by the Mimics 11.1 (a graph processing software),and the outline curve data of femoral bone cortex inside and outside surface were obtained.The curve data were imported into the Unigraphic NX4.0 for solid modeling.The femur three-dimensional model composed of the cortical bone,cancellous bone and medullary canal was obtained.The model data were imported into the Ansys 11.0 for operations such as assigning,meshing,and contact interactions to establish three-dimensional finite element model of osteoporotic femur.RESULTS AND CONCLUSION:Three-dimensional finite element model of femur of osteoporosis was successfully established,which provides a reliable method for the construction of finite element model of femoral osteoporosis,and creates conditions for investigating femoral osteoporosis fracture fixation method and joint replacement.

Objective To observe the effect of two reverse pedicle flap repaired soft tissue defect of the finger.Methods From April,2011 to March,2015,46 patients were randomly divided into two groups.Twenty-eight cases were performed by dorsal metacarpal artery flaps with cutaneous branches as pedicle and the 18 cases were performed by reverse the proper palmar digital artery dorsal branches island flap.The complication,survival rate,hand function and appearance were analyzed.Results The dorsal metacarpal artery flaps with cutaneous branches as pedicle and reverse the proper palmar digital artery dorsal branches island flap were an average follow-up of 18 and 15 months,all flaps survived.For fingertip defects,8 cases were repaired with as pedicle as the dorsal metacarpal artery flaps with cutaneous branches as pedicle while 16 cases were repaired with reverse the proper palmar digital artery dorsal branches island flap.Among them,complication included 2 cases of early venous congestion and 2 cases of superficial skin necrosis.One case of reverse the digital artery dorsal branches island flap blistered;the flap sensibility was good recovery.The two-point discrimination testing of dorsal metacarpal artery flaps with cutaneous branches as pedicle was from 6.0 to 9.0 mm (average of 7.1 ± 0.5 mm);the two-point discrimination testing of dorsal metacarpal artery flaps with cutaneous branches as pedicle was from 4.0 to 7.0 mm (average of 5.2 ± 0.4 mm),but there were differences in two-point discrimination and there was statistically significant (P ＜ 0.05).There was no significant difference between the two groups each finger interphalangeal joint activity compared with the healthy side.The study found that 10 cases of dorsal metacarpal artery flaps appearance was 5 mm higher than normal skin and 1 patient of reverse the digital artery dorsal branches island flap appearance was 5 mm higher than normal skin,the difference was statistically significant (P ＜ 0.05),the latter was better than the former,especially repaired fingertip defect.Conclusion Dorsal metacarpal artery flaps with cutaneous branches as pedicle and reverse the proper palmar digital artery dorsal branches island flap were safe and reliable,it is the ideal flap finger defects.For finger fingertip defect repaired reverse the proper palmar digital artery dorsal branches island flap is superior dorsal metacarpal artery flaps with cutaneous branches as pedicle.

Objective: To evaluate the surgical technique and the effectiveness of the free superficial palmar branch of the radial artery flap to repair soft tissue defect of fingers. Methods: Between June 2014 and June 2017, 10 cases (10 fingers) of soft tissue defects of fingers were repaired with the free superficial palmar branch of the radial artery flaps. There were 8 males and 2 females with an average age of 29.8 years (range, 23-42 years). The causes of injury included the chainsaw cutting injury in 6 cases, the machine crush injury in 2 cases, and the glass scratching in 2 cases. The time from injury to admission was 1-8 hours with an average of 3 hours. The locations were the volar of the middle of index finger in 3 cases, the volar of the distal of index finger in 1 case, the volar of the distal of middle finger in 3 cases, the ulnar side of distal interphalangeal joint of ring finger in 1 case, and the volar of the distal of the little finger in 2 cases. The area of soft tissue defect ranged from 1.8 cm×0.9 cm to 2.8 cm×2.1 cm, and the area of flap ranged from 2.0 cm×1.0 cm to 3.0 cm×2.3 cm. The donor sites were sutured directly. Results: All flaps survived after operation, and the wounds healed by first intention. The incisions of donor site also healed by first intention with a linear scar. All cases were followed up 6-12 months (mean, 9 months). The appearance and texture of the flaps were satisfactory. The pain sensation, warm sensation, and touch sensation of the flap recovered. At last follow-up, the two-point discrimination of the flap was 6-13 mm (mean, 7.5 mm). According to the assessment of the upper limb function issued by tha Hand Surgery Society of Chinese Medical Association, the results were graded as excellent in 8 cases and good in 2 cases. Conclusion: The free superficial palmar branch of the radial artery flap is easy to harvest and anastomose and has small injury. It is an ideal method in repairing of soft tissue defects of fingers.