Objective To compare the effect of calcium sulfate pellets made by different methods in repair of segmental radial defect of rabbits. Methods Eighty white New Zealand rabbits were sub-jected to defects of middle part of the left radial bone and divided into four groups according to repair ma-terials: control group (Group A, implanted with no artificial bone substitute), uncoated pressed calcium sulfate pellets (Group B), coated pressed calcium sulfate pellets (Group C) and coated pressed calcium sulfate pellets combined with rhBMP-2 (Group D). Histologic examination and biological test were done at 4, 8 and 12 weeks after operation. The data were processed with mono-factor variance analysis. Re-sults New bone formation was found on the defected bone in Group D and Group C, with better in Group D. The bone strength test showed that the anti-bending strength was (39.6±1.7) % in Group C and (47.5±2.1) % in Group D, which were higher than (21.3±2.7) % in Group A and (23.6±3.3) % in Group B, with higher anti-bending strength in Group D than that in Group C (F = 125.3 ,P <0.01). Conclusions For restoration of segmental bone defects, chitosan-coated pressed calcium sulfate pellet shows relatively high density and slightly slow resorption, which closely coincides with the growth rate of new bone. The coated pellet combined with rhBMP-2 can enhance its osteogeneais in restoring segmental Done defects.

[Objective]To explore the effects on surrounding tissue and bone regeneration by citrated calcium sulphate(CCaS) and Ostesset~.[Method]Bilateral or lateral femoral condyles were drilled into defects in 18 rabbits,and divided into 3 groups: A,12 rabbits,left defect filled with CCaS cylinder,right defect with osteoset~;B,3 rabbits,left defect with CCaS,right defect blank;C,3 rabbits,left defect with osteoset~GFDA3,right defect blank.The rabbits were sacrificed at 3 wks,6 wks and 13 wks,and defect samples were taken for histological exam,roengenographic observation and bone tissue calculation by image-plus CCD system.[Result]The defects that were not grafted were filled with bone marrow and there was minimal new bone,only at the margen of the defects CCaS and osteoset~GFDA3 implanted in the defects were gradually absorbed,and substituted by new bone trabecula,which became more mature and thicker.The area fraction and trabecula thickness of new bone in defects treated with CCaS were not significantly different from defects treated with osteoset~ after 3,6,13 wks.However,the degradation velocity of CCaS was slower than that of osteoset~.No inflammatory and foreign body response was observed.[Conclusion]Just like osteoset~,CCaS is more benefitial to new bone formation compared with osteoset~,because CCaS has relatively slower degradation velocity.

[Objective]To probe the efficacy of total hip arthroplasty(THA)in the treatment of patients with ankylosing spondilitis(AS).[Method]Ninety-eight THA were performed in 56 patients who had AS,and 42 patients(76 hips)were analyzed retrospectively with an average follow-up period of 5.6 years(ranged,2.5 to 5.5 years).The clinical results were evaluated by the Harris hip scoring system and radiographic analysis.[Result]For the latest follow-up,the average Harris hip score improved from 26.8 points(ranged,4 to 51 points)preoperatively to 85.2 points(ranged,55 to 94 points)at the final postoperatively evaluation.89.5% of the patients had an excellent or good results evaluated by Harris hip scoring system postoperatively.One patient was revised for infection,fissured fracture of neck of femur or calcar femorale above the lesser trochanter happended in two patients,one patient had footdrop and recovered 3 months later,1 patient had deep vein thrombosis.There was no sign of loosening,dislocation or fracture of the prosthesis.According to the system of Brooker,the incidence of heterotopic ossification was 9.2 %(7 hips).[Conclusion]THA can greatly relieve the pain of the patients who have AS and reconstruct the function of hip joint.Compared with THA operated for other cause of disease,THA in AS leads to no high risk.

Periosteal autograft from different sources have been used to repair 1 5cm bone defects of radius in 10 rabbits.On the left side,sharp dissected grafts were implanted and the animals were sacrificed 4,8,14,30 and 60 days after operation.Bone formation was studied with X ray and histologic technique.The results showed that the way of sharp dissecting can preserve the periosteum completely,and good bone formation was found in this group.It suggested that the sharp dissecting of the periosteum is the important key for periosteal graft.

In order to determine the efficacy of mannitol and anisodamine in the treatment of compartment syndrome, a new animal model of compartment syndrome was used to observe the changes in CPK, MDA, tissue pressure and pathology before and after the use of the drugs. The results showed that the values of CPK, MDA and intracompartmental pressure declined and pathological changes improved after the therapy. The result indicated that this new animal model is reproducible and successful. Mannitol is useful in the treatment of compartment syndrome, and at the same time it acts as a free radical scavenger, so that it can prevent reperfusion injury. Anisodamine can improve the limb's microcirculation. CPK can be an index for judging the therapeatic effect in the treatnent of compartment syndrome.

Bi-polar,bi-pedicled separation delayed flaps were designed on the backs of New Zealand rabbits with the application of a medical silicon membrane as the separation material. Values of glucose and lactic acid, PtcO 2 were measured separately at proximal,middle and distal areas of the flaps after the distal pedice was cut at 0,1,4,7,14,21 days,respectively, after the formation of flaps. After flap delaying,PtcO 2 in separated flap was always lower than that of the mormal control,accompanied with glucose decrease and lactic acid increase, although there were significant differences in different areas of the flap. The survived area of the flap increased after 7 days. Furthermore,all the length of the flap survived after 21 days,although the level of glucose in the flap was still lower and lactic acid was still higher.The results suggested that by separation and delaying the flap may adapt gradually to hypoxia via lowered metabolism.For flap survival,the threshold value of glucose in flap is 0 01mmol/L , lactic acid is 0 47mmol/L,and PtcO 2 is 3mmHg .

Relation between change of capillary pressure, survival length in bi pedicled separation delay flap was observed. Bi polar, bi pedicled separation delay flaps were designed on the backs of New Zealand rabbits. Medical silicon membrane was used as separative material. Values of capillary pressure were measured at proximal, middle and distal points. Survival length increased with delayed time, capillary pressure at middle was lower in the bi pedicled separation delay flap. It is concluded that capillary pressure is increased greatly by separation delay, and there is a linear relation between capillary pressure and survival length of flaps.

Objective To evaluate the causes,clinical manifestations and diagnosis of tarsal tunnel syndrome. Methods Operation was performed for 18 patients ( 21 sides) with tarsal tunnel syndrome. Preoperative Takakura index was 3-7 points with an average of 6.4 points. Ganglion was found in 15 cases (17 sides), varicosity in 2 cases (3 sides) and lipoma in 1 case. Results The symptoms disappeared without recurrence in 0.5 to 17 years' follow-up (average 7.3). Postoperative Takakura index was 9-10 points (average 9.7). Conclusion Tarsal tunnel syndrome is rare in the clinical practice with varied causes and different clinical manifestations. Operation can be performed with satisfactory results for the patients unsuitable for conservative treatment.

Objective A retrospective study of the results of surgical or non-operative treatment in patients with herniation of lumbar disc 10 years or longer before,in order to evaluate the efficacy of different therapeatic strategies for lumbar disc herniation. Method Definite diagnosis of lumbar disc herniation was made in all cases before treatment,and the follow-up period was 10 to 38 years. The patients were divided into three groups according to different treatment methods: non-operative group,simple nucleus resection group,and nucleus resection combined with space fusion group. The long term therapeutic effects and image change of the three groups were observed. The difference of height of intervertebral space at the herniation site was measured before treatment and at the latest follow-up. Adjacent spaces were also observed. The data were analyzed statistically by t -test and ? 2 -test. Results Among 98 cases in non-operative group,85 cases enjoyed almost a normal life and work;vertebral canal decompression was performed for the rest 13 cases because of intermittent claudication. The protruded space was narrowed for 3.17?1.65mm in height in average after non-operative treatment,and there was degeneration of adjacent spaces in 13 cases. Among the 84 cases in simple nucleus resection group,relative good outcome was seen in 71 patients,and the remaining 13 cases had to receive a second operation because of symptom relapse. The protruded space was decreased 5.50?1.51mm in height in average as measured at the latest follow-up comparing with that of before operation. The degeneration of the adjacent space was observed in 15 cases. In 71 patients who received nucleus resection combined with space fusion experienced a good relief of symptoms. The space,where disc herniation had occurred,fused very well and no re-narrowing occurred. Degeneration of the adjacent space was observed in 39 cases,but the patients were symptomless. Conclusions The effect of either non-operative therapy or operation for patients with lumbar disc herniation was good after a long-term follow-up if the indication was chosen properly. We suggest that non-operative therapy should be the first choice for the lumbar disc herniation. The relatively normal nucleus should be preserved as much as possible when nucleus resection was performed. Intervertebral fusion was a relative better treatment comparing with the other two treatments.

Objective The complications of internal fication for calcaneal fracture were summarized and discussed to increase awareness of these complications, and to improve decision making and efficacy of the treatment. Methods The patients admitted to our hospital from October 1997 to June 2003 were followed up. The fracture in 68 feet (66 patients) was treated with open reduction and internal fixation (ORIF) using steel plate. The complications associated with ORIF were analyzed and discussed as to etiology, incidence, diagnosis, prevention and treatment. Results The patients were followed up for 7 to 57 months. Complications were found in 14 cases, including postoperative wound dehiscence in 5 (infection in 2), malunion (failure to achieve reduction) and arthritis in 9, accompanied by nerve injury in 6. The percentage of complication was 20 6%. With timely treatment, good function was regained in most of the patients. Conclusion Should attention be paid to the operation, many complications could be avoided. ORIF with plate is one ot the options for the treatment of this fracture, but the operative technic and the device should be improved. As the anatomy of the calcaneus is different from a long bone, it is unsuitable to apply the principle and device that are used in the internal fixation of a long bone to this fracture. The plate and screws used in the fixation of the calcaneal fracture can not give enough support