BACKGROUND:Col um Femoris Preserving prosthesis is developed by Pipino, an Italian surgeon, and LINK (Germany). Whether the femoral osteotomy plane recommended in the surgical manual is suitable for Chinese people and whether the osteotomy method can cause stress changes of the prosthesis and femur has not been yet reported.
OBJECTIVE:Based on clinical reviews and three-dimensional finite element model, to analyze the clinical efficacy of total hip arthroplasty with Col um Femoris Preserving prosthesis and relevant stress distribution.
METHODS:We retrospectively analyzed 36 patients undergoing total hip arthroplasty with neck-retaining femoral prosthesis and 36 patients receiving total hip arthroplasty with biotype prosthesis in terms of Harris scores, visual analog scale scores, preoperative and postoperative measurements of eccentricity changes, IDES-Engh radiological evaluation and the incidence of complications. Two different osteotomy plane finite element analysis models were created to analyze the eccentricity difference and changes in the stress distribution of prosthesis and femur when the osteotomy plane was set 1.5 cm above the intertrochanteric fossa or at the junction of femoral head and neck.
RESULTS AND CONCLUSION:Neck-retaining total hip arthroplasty with the osteotomy plane set at the junction between the head and neck achieved good short-term outcomes, showing no difference from total hip arthroplasty with normal biological prosthesis. The finite element analysis showed that the eccentricity increased and the stress on the prosthesis and femur also increased when the osteotomy plane was set at the junction of femoral head and neck compared with that set 1.5 cm above the intertrochanteric fossa. But there was no difference in stress distribution between two osteotomy planes.

[Objective]To investigate the effects of bone marrow stromal stem cells(MSCs) on the bone defect around the implant and the osteointegration of implant-bone interface.[Method]Fifteen healthy clean New Zealand rabbits were studied.MSCs were separated,cultured and induced to osteoblasts.Cancellous bone defects(0.6?1.2 cm)were created in bilateral femur condyle in rabbits.Titanium alloy columns(0.3?1.0 cm)were implanted into both defects.Tissue engineering bone was implanted around the left titanium alloy implant,but only hydroxyapatite ceramic in the right.The biological characteristics were evaluated by X-ray examination,SEM,energy dispersive X-ray analysis and histologic studies at 4,8,and 12 weeks postoperatively.[Result] X-ray examination showed the density of bone tissue around the implant was aequalis.The interspace between implant and bone was filled with lots of bone trabeculae in the experimental group at 12 weeks postoperatively.The density of bone tissue was inhomogeneous,and low-density umbra existed in the interspace in the control group.Energy dispersive X-ray analysis showed the content of the Ca and P in the experimental group was statistically higher than that in the control group at different time points(P0.05.The ratio of Ca to P became higher and reaching the peak level at 8 week.Histological study showed the bone defects around the implant were repaired by new mature bone in the left at 12 weeks postoperatively,while in the right no new bone was found at any time point.[Conclusion]The compounds of hydroxyapatite ceramic and osteoblasts induced by MSCs can repair the bone defect around the implant and improve the osteointegration of implant-bone interface.

[Objective]To dynamically monitor revascularization and metabolism of tissue-engineered bone graft in repairing bone defects by radionuclide bone imaging.[Method]Twenty-four healthy New Zealand rabbits were studied.Mesenchymal stem cells(MSCs) were separated and cultured from bone marrow.Cancellous bone defects(0.6 cm?1.2 cm) were created on bilateral femoral condyles in rabbits.The compound of coral hydroxyapatite ceramic(CHA) and defects were treated with the induced osteoblasts inplanted into the left defects(experimental group).While CHA alone was used for the right(control group).The counts of regions of interest(ROI) was evaluated by radionuclide bone imaging at 4,8 and 12 weeks postoperatively.[Result]ROI in the experimental group was significantly higher than that of control group at 4,8 and 12 weeks postoperatively.ROI in either group had a tendency to increase with time.Eight weeks postoperatively,ROI in experimental group tended to increase at a lower speed,while ROI in control group had a tendency to increase at a higher speed.ROI in either group reached a peak at 12 weeks postoperatively.[Conclusion]The tissue-engineered bone graft is an effective method for repairing cancellous bone defects.Radionuclide bone imaging can dynamically monitor the changes of revascularization and metabolism of tissue-engineered bone graft.

BACKGROUND: Some studies have shown that bone marrow mesenchymal stem cells and al ograft bone have a certain role for repairing bone defects, but the effectiveness on cancel ous bone defects is seldom reported so far. OBJECTIVE: To observe the effectiveness of bone marrow mesenchymal stem cells combined with al ogeneic bone on cancel ous bone defects. METHODS: The models of cancel ous bone defects (0.6 cm×1.2 cm) were made artificial y in both condylus lateralis femoris of New Zealand white rabbits: one side served as model group implanted with combination of bone marrow mesenchymal stem cells and al ogeneic bone, and the other side was considered as control group implanted with al ogeneic bone. RESULTS AND CONCLUSION: The model group was better than the control group in new bone growth and defect repair at 4, 8, 12 weeks after implantation, which was confirmed by general observation, X-ray examination and hematoxylin-eosin staining. There was a large amount of trabecular bone formation and mature lamel ar bone tissue in bone defects of model group by histological observation at 12 weeks after implantation, and bone defects of the model group were repaired basical y; while there were only abundant woven bones in the control group, and bone defects in the control group were not repaired effectively. Scores on Lane-Sandhu’s X-ray combined with histological observation were higher in the model group than the control group (P < 0.05). Biomechanical test showed that the maximum pressure load of the femoral condyle and load/strain ratio in the model group were significantly higher than those in the control group at 12 weeks after implantation (P < 0.05),while the maximum strain and displacement of the model group was lower than that of the control group (P < 0.05). These findings suggest that the combination of bone marrow mesenchymal stem cells and al ogeneic bone is superior to simple al ogeneic bone implantation in the repair of cancel ous bone defects of the femoral condyle.

Objective To investigate technique and effect of reconstruction with alcohol-inactivated autograft-prosthesis composite after en bloc resection of giant cell tumor of bone around the knee.Methods From January 2007 to October 2008,8 patients with Campanacci grade Ⅲ giant cell tumor of bone around the knee underwent en bloc resection of tumor and reconstruction with alcohol-inactivated autograft-prosthesis composite in our hospital.There were 5 males and 3 females,aged from 20 to 43 years (average,31years).The tumor located in distal femur in 5 cases and proximal tibia in 3 cases.There were 4 cases of primary tumor and 4 cases of recurrent tumor.Two patients combined with pathological fracture.The Musculoskeletal Tumor Society (MSTS) score was used to evaluate limb function,and the International Society of Limb Salvage (ISOLS) score was used for radiographic evaluation.Results All patients were followed up for 38 to 67 months (average,54 months).No recunrence,metastasis,prosthesis loosening were found.The mean healing time of autograft and host bone was 5.5 months.At final follow-up,the MSTS score ranged from 25 to 29 [average,26.3 (88％)]; the ISOLS score ranged from 28 to 35 [average,32.8 (88.5％)].Creeping substitution was possibly the main way of bone union.The healing time in femoral lesion was faster than that in tibial lesion.Conclusion For Campanacci grade Ⅲ giant cell tumor of bone around the knee,en bloc resection and reconstruction with alcohol-inactivated autograft-prosthesis composite is an effective method,which can provide satisfactory results.

BACKGROUND: Limb salvage operations with preservation of the epiphysis (LSPPE) had been used clinically in order to overcome discrepancy of affected limb and poorer limb function, but more post-operation complications existed, including infection, grafting bone resorption, fracture and internal fixation cinch.OBJECTIVE: To study the clinical related matters of inactivated bone replantation with preservation of the epiphysis in children limb salvage with osteosarcoma.DESIGN: Clinical observation regularly.SETTING: General Hospital of Jinan Military Area Command of Chinese PLA.MATERIALS: Eleven patients corresponded selected standard and accepted treatment from January 1999 to January distal metastasis was found with lung X-ray check and CT scanning, the patient would be excluded this study. There were 5 males, 6 females, and the mean age of (8±2) years old (4-11 years). The disease history was 1-6 months.FO) were adopted. After 2 weeks of chemotherapy, the operations of inactivated bone replantation with preservation of the epiphysis were performed. The operation was performed under epidural or general anesthesia. The patient lied on operating table. The knee anteriomedialis incision was adopted. Firstly, femur periosteum was opened beyond proximal end 2-3 cm from tumor, subperiosteum stripping was done to the proximal femur, descend femur with wire saw, separated and disconnected aboral periosteum, blunt dissecting femur aboral blood vessel and nerves to the popliteal fossa,deligating blood vessel around the tumor. Attachment of gastroenemius was cut off. Epiphyseal plate was identified carefully. According to pre-operation MR, the distal femur descend level was determined and the femur was descend with electro-saw. It was determined with cytology that no tumor cell existed in descend level, and reconstruction of bone de-fect with inactivated tumor-bone shell with 95% alcohol and bone cement containing ADR (20 g bone cement: 10 mg ADR), the diaphysis was fixed by intramedullary nail and screws were inserted in the residual epiphysis for the osteosynthesis of the distal osteotomy. One drainage tube was placed into and closed incision The affected limb was protected with plaster cast. Post-operative treatment: Regular usage of antibiotics was adopted to prevent infection. The drainage tube was pulled out when drainage amount ＜ 50 Ml/24 hours. The progressive passive exercise was initiated during the protection of affected limb with plaster cast for 8 weeks. Twelve to 14 days after operation, stitches were taken out. The postoperative chemotherapy then initiated, drug and dosage were identified on the response to the preoperative chemotherapy. Eight weeks after operation, patients were permitted to walk with the protection of double crutches and ery analysis: To observe ncision healing and existing of nerve and blood vessel injure, or not. During follow-up, patient recoveries were determined with affected knee function, limb length, distal metastasis, post-operative complications and dynamic imaging inspection of bone healing.imaging inspection of bone healing.MAIN OUTCOME MEASURES: ① The response to chemotherapy was evaluated with tumor cell necrosis rate. ② Post-operative recovery was determined with parameters such as knee function, limb length, distal metastasis, etc. ③ Dynamic imaging inspection of bone healing.MAIN OUTCOME MEASURES: ① The response to chemotherapy was evaluated with tumor cell necrosis rate. ② Post-operative recovery was determined with parameters such as knee function, limb length, distal metastasis, etc. ③ Dynamic imaging inspection of bone healing.RESULTS:All patients in this study were done follow-up.①The histological response of 11 patients to preoperative chemotherapy were classified as 7 in gradeⅣ,4 ingrade Ⅲ.②Post-operation recovery:No nerve and blood vessel injury existed and all incision healed well,there was not incision infection and healing.Eleven patients were followed-up from 10 to 72 months.Three patients could flexed affected knee joint ≥110,90-110 in 3 cases,60-90 in 4 cases,＜60 in one patient .The length of both lower extremity equaled in 4 cases,the length of affected limb was shorter than 2.0 cm in 5 cases,2.0-3.0 cm in 2 cases. One patient with recurrence,two with metastasis,three died.Screw cinch in one patient and one patient with inactivated bone fracture. ③Dynamic imaging inspection: No recurrence was found around epiphysis. Essential bone healing existed between the inactivated bone and epiphysis,callus formation between the inactivated bone and diaphysis at 2 months after operation; more callus formed and 4 months; 6 months after operation,bone complete healing was found between the inactivated bone and diaphysis.④Post-operation recovery:During follow-up, a screw cinch was found in one patient, and dislodged the screw because of bone healing well. One patient underwent open reduction, bone grafting and internal fixation with encircle device because of inactivated bone fracture.four months of the operation, grafting bone healed well. At post-operative 24 months, the length of both lower extremities equaled and the affected knee flexed to 110°.CONCLUSION: Inactivated bone replantation with preserving epiphysis for osteosarcoma in children was propitious to recover limb function and keep limb length.