ABSTRACT
BACKGROUND: Inappropriate size of tibia prosthesis wil affect the stability and long term curative effect of knee joint. Raising the tibia prosthesis bone coverage through preoperative analysis may further reduce the incidence of loosing and sinking of tibia prosthesis. OBJECTIVE: To select the appropriate prosthesis and maximize the tibia prosthesis bone coverage rate through the three dimensional reconstruction of CT and preoperative tibia osteotomy simulation among the patients preliminarily treated with total knee arthroplasty. METHODS: Total y 76 (84 knees) patients treated with total knee arthroplasty were enrol ed and randomly divided into test group (38 cases, 41 knees) and control group (38 cases, 43 knees). Al the patients in the test group were underwent CT scan and three-dimensional reconstruction of CT before operation. Preoperative tibia osteotomy was stimulated. The most appropriate tibia prosthesis was selected by comparatively analyzing the data of tibia osteotomy, and maximizing the tibial plateau prosthesis bone coverage. Three-dimensional reconstruction of CT was absence in the control group by contrast. Tibia plateau bone coverage of patients in these two groups after replacement was evaluated. The repair effect was evaluated during the fol ow-up. RESULTS AND CONCLUSION: Total y 75 patients were fol owed up for 13 to 56 months. One patient in the test group withdrew from the study because of periprosthetic fractures. Analyzing from the fol ow-up after replacement, tibia plateau prosthesis coverage rates of test group and control group were (89.87±4.14)%, (83.15±5.21)%respectively; New York Hospital for Special Surgery scores were respectively (87.48±8.69) points and (82.37±10.14) points, the difference was statistical y significant (P 0.05). These results suggest that choosing the most appropriate type of tibia prosthesis by applying three-dimensional reconstruction of CT and preoperative tibia osteotomy on patients treated with total knee arthroplasty can improve tibial plateau prosthesis bone coverage rate and is conductive to achieve a satisfactory repair effect.
ABSTRACT
BACKGROUND:Implantation of bone morphogenetic protein (BMP) or vascular endothelial growth factor (VEGF) alone, without support vectors, is easy to be flushed away by the blood flow, and thus limits the osteogenesis and angiogenesis. OBJECTIVE: To observe the effects of combination of calcium phosphate cement (CPC), BMP-6/VEGF in bone defect repair. METHODS:Defect models of the bilateral medial femoral condyle were prepared in New Zealand white rabbits. Then, the medial femoral condyle was filed with CPC/BMP-6/VEGF, CPC/BMP-6, and CPC, respectively, in the left side, but nothing in the right side as control. After 8 and 16 weeks of implantation, the hard tissue slices were prepared for histological observation and scanning electron microscope observation. RESULTS AND CONCLUSION:Al three kinds of materials showed good biocompatibility, and no obvious inflammation was found. After 8 weeks of implantation, the junction of the CPC/BMP-6/VEGF and bone tissue was almost completely covered by newly formed trabecular bone. With the development of cement degradation, abundant osteoblasts could be found in the surface of newborn trabecular bone. After 16 weeks of implantation, an ongoing cement degradation and bone formation was seen. Moreover, newly formed bone tissue increased and became thicker. The cement in the interface was separated into smal pieces and closely interconnected with the surrounding tissues, and newly formed bone showed a mesh-like ingrowth into the cement. This newly formed bone was mature and could not be distinguished from the original trabecular bone. Both the degradation and osteogenesis of CPC and CPC/BMP-6 were much slower than that of CPC/BMP-6/VEGF (P < 0.05). This study demonstrates angiogenesis and osteogenesis in vivo through the additive effects of VEGF and BMP-6. CPC/BMP-6/VEGF can be an ideal bone substitute in bone repair.