Objective To study the mechanism of compound of calcium phosphate(TCP) and platelet-rich plasma(PRP) in the treatment of femoral head necrosis.Methods The left femoral heads of 48 New Zealand white rabbits were frozen by liquid nitrogen as to make themodel of femoral head necrosis.Twenty-four rabbits were randomly chosen as theexperimental group and their femoral heads were filled with TCP/PRP. The other 24 rabbits were used as the control group and their femoral heads were filled only with TCP. They were sacrificed at 2, 4,8,12 weeks after operation. The specimens were examined with X-ray and histological study.Results At 2 weeks after operation,there was no significant difference in femoral headdensity between the two groups. Four weeks after operation, femoral head density decreased in both groups, while it decreased more in the control group. At 8,12 weeks after operation, the density of the femoral heads in both groups increased, and it was higher in the experimental group. Histology examination showed thatthere was no difference between the two groups 2 weeks after operation. The head became flat at 4 weeks. Control group had more defects. At 4,8,12 weeks, more repairs were observed in the experimental group than that in the control group. The amount and maturity of osteogenesis in experimental group were much more greaterthan those in control group．Bone histomorphometry showed that the volum of thetrabecular was larger in the experimental group (36.65%±7.22%,38.29%±4.28%，39.24%±3.42%) than that of control group(P＜0.05). Conclusion TCP/PRP does not only provide osteoblasts scaffold, butalso promotes bone formation and the head repair. TCP/PRP is a good biomaterialfor the treatment of femur head necrosis.
Forty cases of intertrochanteric fractures of femur were treated with percutaneous nonmetallic external fixator. The patients were followed up for 6 months to 3 years, and the fractures were all united without coxa vara or shirtening deformities. There was no mortality in this series. This method had the advantages ofbeing simple, save time and effort, less traumatic and early ambulation. The design of the apparatus tallied with the biomechanics of the neck and shaft of the femur.
To investigate the effects of augmentation with bone cement on the biomechanics of the dynamic hip screw (DHS) fixation in the intertrochanteric fracture specimen that has a normal bone density.MethodsTwentyfour matched pairs of the embalmed male upper femora (48sides) were used to make the specimens of the intertrochanteric fracture of Type A2. All the specimens were fixed with DHS. The right femur specimen from each pair was fixed by augmentation with DHS (the augmentation group) and the left femur specimen was fixed with the conventional fixation (the control group). Thebiomechanical tests on the bending stiffness and the torsional stiffness were performed with the servohydraulic testing machine in the two groups.ResultsThe maximum load and the maximum torque were 3 852.160 2±143.603 1 N and 15.5±2.6 Nm in the augmentation group and 3 702.966 7±133.860 1 N and 14.7±3.4 Nm in the control group. There was no significant difference in the biomechanical effects between the two groups (P＞0.05). Conclusion The augmenting fixation with bone cement in the intertrochanteric fracture specimen with a normal bone density has no significant effect on the strength of the DHS augmentation or on the overall stability of the fractured bone.
ObjectiveTo design an auto-compressive and anti-circumrotate intramedullary nail( ACACIN) and to evaluate the preliminary clinical efficacy on fixing adult femur fracture. Methods From January 1998 to June 2001, 23 patientswith femur fracture were stabilized with auto-compressive and anti-circumrotateintramedullary nail. 2-4 elastic blocks were installed into the proximal and distal different distance of quincunx nail to defend circumrotate and axis compress. Results Fracture healing were obtained in all 23 patients treated with auto-compresseiveand anti-circumrotate intramedullary nail, the time of fracture healing was 6-13 weeks in 21 cases and 15-22 weeks in 2 cases of old fracture. There was no complication related to infection, nail break, abnormal union and joint ankylosis. The results were excellent in 19 cases, good in 3 cases, and moderate in 1 case according Kolmert’s criterion for function ; the effective rate was 95.7%. Conclusion Auto-compressive and anti-circumrotate intramedullary nail has a suitable radian for adult femur, can afford stable fixation, anti-circumrotate andaxis compress.
Objective To discuss the method of constructingbiomechanical model of rabbit femur.Methods The sample of rabbit femur was prepared as follows:firstly，femur section images were obtained，then the image wasput into the computer and processed to get the boundary contour line; secondly, through programming the contour line coordinate for modeling was obtained, then the data were put into the model software to find the threedimensional entity model. Results Whole three-dimensional model of rabbit femur was constructed. It simulated actually dissection form of femur. Conclusion The establishment of the model lays a foundation for ascertaining optimal parameter of vibration improving bone minerydensity by finite element analysis.
Objective To evaluate the effect of composite (bFGF/PDPB) of basic fibroblast growth factor（bFGF） and partially deproteinized bone (PDPB) on the repair of femoral head defect. Methods Forty-eight femoral heads with defect derived from 24 New Zealand rabbits were divided into 3 groups at random, which were implanted with bFGF/PDPB(group A), PDPB(group B) and nothing(group C) respectively.The rabbits were sacrificed at 2,4,and8 weeks after operation, and then the femoral heads were obtained. The specimens injected with Chinese ink were created. Then X-ray examination, histopathological and morphological examination of blood vessel, and image analysis were made. Results The bone defects healed completely 8 weeks after operation in group A. The implants in the repaired tissue were not substituted completely in group B. The bone defects did not heal completely in group C. Two weeks after operation, affluent newly formed vessels were seen in repaired areas in groupA. No significant difference between group A and group B was observed 8 weeks after operation. In group C, newly formed vessels were scarce 2, 4, and 8 weeks after operation. There were 3 sides rated excellent, 2 good and 1 fair in group A; 1 excellent, 2 good, 2 fair and 1 poor in group B; and 1 fair and 5 poor in group C according to the X-ray evaluation 8 weeks after operation. Eight weeks after operation, the volume fraction of bone trabecula in repaired tissue was higher in group A than that in group B (Plt;0.05), and the fraction in group C was thelowest among the 3 groups (Plt;0.05). Conclusion The composite ofbFGF and PDPB can effectively promote the repair of femoral head defect of rabbit.
Objective To investigate the possibility of using extendible distal femoral replacements in the treatment of osteosarcoma in growing individuals. Methods From December 1999 to March 2003, 3 cases (2 were typeⅡB, 1 was type ⅡA) with osteosarcoma were treated byextendible distal femoral replacements. Of the 3 cases, 2 underwent prosthesis extention operation, 1 was not operated. Results After the removal of tumor, the extremities of 2 patients were shortened by 4 to 5 cm within 2 to 3 years. After the lengthening procedure, the affected extremities were of equal length to the unaffected extremities and no drag symptoms of blood vessel and nerves were observed. Follow-up was done for 2 months to 3 years. There was no aseptic loosening. The function of joints was fairly good. Conclusion Extendible distal femoral replacements is an easy, convenient, and effective way to treat osteosarcoma.
ObjectiveTo investigate the clinical outcome of application of joint prosthesis in limb salvage treatment of mildmalignant tumor at the articular ends of femurs, with severe osteolysis. Methods The treatment of 15 cases of mildmalignant tumor at the articular ends of femurs with severe bone destruction, from 1978 to 1999, was reviewed. There were 10 cases of giant-cell bone tumor and 5 cases of chondrosarcoma, among which there were 5 cases at the stage ofⅠA, 9 cases at ⅠB, and 1 case at ⅡA, with 4 cases at the proximal end and 11cases at the distal end. The tumor was totally removed, with a massive bone defect left at the foci, and then the prosthesis replacement was performed to reconstruct the articular joint. All of the 15 patients were followed up for 9 monthsto 20 years, 4 years and 3 months on average, before clinical evaluation. Results All of the wound healed well, with primary healing. Local relapse occurred in one case and the patient died of lung metastasis; the amputation of the replaced knee joint was performed in one case due to severe infection after trauma; radiograph showed there was slight sunk of the prosthesis in 2 cases after replacement. The other 11 cases recovered well with satisfactory function. Conclusion The limb salvage treatment of mildmalignant tumor at the articular ends of femurswould be available, especially for those with massive bone destruction, when the tumor is removed by whole and rationally marginal resection, followed by properlyutilization of prosthesis and general post-operative exercise.
ObjectiveTo design a new type of short femoral intertrochanteric nail (FITN) with anterior curvature (19.5 cm in length and 120 cm in radius) and observe the geometric match with medullary cavity of the femur. MethodsBetween November 2015 and June 2016, 25 geriatric patients with femoral intertrochanteric fractures were treated with the newly designed FITN. There were 7 males and 18 females with an average age of 82.3 years (range, 65-94 years). According to AO/OTA fracture classification, 3 cases were rated as A1.2, 2 cases as A1.3, 5 cases as A2.1, 8 cases as A2.2, and 7 cases as A2.3. The interval between injury and operation was 3.2 days (range, 2-7 days). Postoperatively, the nail entry point position (anterior, central, and posterior) on sagittal plane, the nail tip position (6-grade scale) and the nail tail level (3-grade scale) were measured using fluoroscopy and X-ray films to evaluate the geometric match of the nail with medullary cavity of the femur. ResultsOne patient with Parkinson disease died of asphyxia and pulmonary infection. The other 24 patients were followed up 1-8 months (mean, 4 months). Fracture union time was 6-10 weeks (mean, 8 weeks). The mean Parker-Palmer mobility score was 5.5 (range, 4-8). No patient had hip-thigh pain. The nail entry point was positioned anterior in 2 cases (8%), central in 18 cases (72%), and posterior in 5 cases (20%). The distal nail tip located at the central canal axis (grade 0) in 15 cases (60%), at anterior without contact with the anterior inner cortex (grade 1) in 8 cases (32%), at posterior (grade -1) in 1 case (4%), and at anterior with slight nail-tip impingement with the anterior cortex (grade 2) in 1 case (4%). The proximal nail tail level did not protrude out beyond the greater trochanter (grade 0) in 13 cases (52%), protruded out less than 5 mm (grade 1) in 9 cases (36%), and more than 5 mm (grade 2) in 3 cases (12%). ConclusionThe newly designed FITN has a good geometric match with the femur medullary canal in Chinese population, which may reduce the nail related complications.
Objective To compare heterotopic ossification between femoral head reconstruction and total hip arthroplasty(THA) in patients with ischemic necrosis of femoral head(INFH). Methods Between June 1994 and December 2004, the femoral heads were repaired in 1 005 patients with INFH,the total hip was replaced in 485 patients with INFH. The rate of heterotopic ossification was observed in 74 (Ficat Ⅲ to Ⅳ stages) of 1 005 patients and 80 of 485 patients given THA to compared the results of the two methods. Results These patients were followed up 2 to 10 years(6.5 years on average). The rates of heterotopic ossification were 5.4%(4/74) and 22.5%(18/80), respectively. There was statistically significant difference between two operative methods (Plt;0.01). Conclusion The rate of heterotopic ossification of femoral head reconstruction is lower than that of THA, so femoral head reconstruction is a better operative method for young patients and THA is suitable for old patients.