OBJECTIVETo measure the changes of plantar pressure of the first tarsometatarsal joint fracture and dislocation by three different implants to provide experimental reference in selecting implants.

METHODSEight fresh foot specimens were made into the models of the first tarsometatarsal joint fracture and dislocation, which were fixed with 3.5 mm cortical screw, 1/4 tubular plate and compressive staple in turn. After the loading of 600 N, the changes of the plantar pressure in forefoot were measured by the method of the F-scan plantar pressure system.

RESULTSAfter first tarsometatarsal joint fracture and dislocation, the peak pressure under the first metatarsal head would decrease, while the pressure under the second metatarsal head would increased,whose differences were statistically significant (P<0.05). When the first tarsometatarsal joint was fixed with screw or plate respectively; the peak pressure under the two metatarsal heads would tend to be normal. However,the staple fixation showed the statistical significant difference compared with normal state, although the peak pressure under the first and second metatarsal heads were recovered in some extent(P<0.05).

CONCLUSIONAfter the first tarsometatarsal joint fracture-dislocation, the plantar pressure might be compensated partly by the adjacent metatarsal heads according to the regulation of the load transfer mechanism. While the first tarsometatarsal joint fracture-dislocation was fixated by screw or plate, the plantar pressure of the forefoot would return to the normal state. However,if the joint was fixated by the staple, it would still be difficult to return the plantar pressure to be normal.

Foot Joints ; injuries ; surgery ; Forefoot, Human ; physiology ; Fracture Fixation, Internal ; methods ; Fractures, Bone ; surgery ; Humans ; Joint Dislocations ; surgery ; Pressure

Humans ; Ion Channels ; Myocytes, Smooth Muscle ; metabolism ; physiology ; Pulmonary Artery ; metabolism ; physiology

Pulmonary artery hypertension (PAH) is a combination of factors caused abnormal pulmonary hemodynamics.Pulmonary vascular resistance (PVR) progressive as clinical features of PAH.In recent years,studies had shown that pulmonary artery smooth muscle cell membrane potassium channels at the time of PAH and pulmonary vasoconstriction (HPV) and vascular remodeling were closely related to potassium channel in the article on the role of PAH in progress of the study review.

Objective To investigate the effects of penehyclidine on respiratory mechanics after tracheal intubation in patients with chronic obstructive pulmonary disease. Methods Sixty-six patients with chronic obstructive pulmonary disease were divided randomely into two groups. Group Ⅰ (penehyclidine group, 33 cases) was intravenously injected 1 mg of penehyclidine before intubation, group Ⅱ (control group, 33 cases)was not given bronchodilator. Lung-chest walt compliance, airway pressure, and resistance were measured at 1 h,4 h,and 6 h after tracheal intubation. Results Patients in group Ⅰ had significantly both lower airway pressure and resistance and higher lung-chest wall compliance than group Ⅱ (P < 0. 05). Conclusion Penehyclidine produces higher lung-chest wall compliance and lower airway pressure and resistance in patients with chronic obstructive pulmonary disease.

Objective To explore the features of clinical manifestations and electrophysiology of spinal muscular atrophy(SMA) in children.Methods The clinical features and laboratory data were analyzed in 32 children with SMA,electromyography tests were carried out in 28 patients and the muscle biopsy were performed in 24 cases.Results The 32 cases were subdivided into 3 clinical groups,15 cases were SMAⅠ,12 cases were SMAⅡ,5 cases were SMAⅢ.They were all characterized by progressive muscle weakness associated with hyptonia and atrophy.The clinical distinction between SMAⅠto SMAⅢ reflected different age of onset and disease severity.All cases of SMAⅠhad symptoms of respiratory disability,only 1 case of SMAⅡ had paradoxical breathing and none of SMAⅢ had similarly symptoms.Electromyographic studies showed a pattern of denervation with no sensory involvement.The rate of spontaneous potential was 87%,with gentle strain,the duration of motor unit was extended(30%-150%) and the amplitude of it was increased(90%-450%),the motor nerve conduction velocity was reduced slightly in 28% patients.The muscle biopsy provided evidence of skeletal muscle denervation with groups of atrophy.Conclusions The clinical features,the changes of electromyography and the muscle biopsy are valuable for diagnosis of SMA.Respiratory management will prolong survival and improve the quality of life for these patients.

Objective To evaluate the safety and efficacy of nephron sparing surgery (NSS) for renal angiomyolipoma (RAML). Methods Thirty-nine patients of RAML were underwent NSS. Tumor enucleation was done in 23, partial nephrectomy in 16, and selective arterial embolization in 2. Results The average diameter of enucleated tumor was 5.8 cm(from 3.0 to 14.0 cm), the average of blood loss was 190 ml(from 75 to 800 ml),none of the patients developed hemorrhage or urinary fistula. The average follow-up of 38 patients was 48 months(from 1 to 120 months). Postoperative serum level of creatinine was stable, no patients had a local recurrence. Conclusions NSS can be performed with satisfactory result in RAML. Effective control of hemorrhage and conservancy of renal function are the key points.

Femoral head necrosis and nonunion is a common complication after surgery of femoral neck fracture.Recently,femoral neck shortening have caused attentions which can impact the function of hip.Incidence,mearsurement,influence factor,prevention and treatment of femoral neck shortening have been retrospective reviewed.Amount of femoral neck shortening with sliding compression system is significantly more than length of stability system,which is result from its own mechanism.However,effcacy of length of stability system still need a large scale of sample.It uses radiography to diagnose shortening.The present measurement methods include displacement of femoral head,xyz-axis measurement,the length of exposed screw,the collapse of femoral head.However,position,the angle of screen and the defect of the method would increase deviation.A measurement with simple,wide application and accuracy need to continue to explore.Apart from patients' condition,shortening also affected by the pattern and quality of surgery.Overall,older women,displacement fracture,unsatisfactory reduction will increase the risk and shrinkage of shortening.In addition,the pattern of the internal fixation becomes the research focus in the field of orthopedic clinical research.Including the transformation of sliding compression system device and design of novel device.How to combine them together organically could be a future development direction.Meanwhile,there are still in exploratory stage to decide whether biological combined with internal fixation can prevent shortening.Intertrochanteric osteotomy can achieve union and correct the limblength discrepancy,However,it did not restore the length of femoral neck.So,it is unknown that whether the method can solve the slight shortening which have impacted the hip function.

Objective: To study the origin, morphological structure, and functional regulation of osteoclast(OC) for further investigation on the mechanism and regulation of bone resorption. Methods: The OCs were isolated by two kinds of traditional method. Osteoclasts were isoclated from neonatal rat long bones. The cytochemistry was observed. The osteoclast-like cells (OLC) were derived from the mouse bone marrow cells in the presence of 1,25(OH)2VitD3 in vitro. Results: Both morphological and functional studies showed that the isolated cells shared some of the typical characteristics of osteoclasts, that is A. multinuclearity; B. developing spreading and pseudopodial activity when cultured on glass; C. high tartrate-resistant acid phosphatase (TRAP); D. resorption lacunae could be found when the cells were cocultured with devitalized bone slices and the number was increased as the time followed. OLC had the same histological and structural traits as the OCs by the former method. The concentration of Ca 2+ and acid phosphatase (ACP) increased gradually. Conclusion: Different kinds of method fit different experiments. The OC obtained by the first method has more activity of bone resorption. The OLC by the second method has more in quantity and can be used in the study of cell differentiation.