OBJECTIVE: To evaluate the clinical effect of drilling procedure following the hydroxyapatite orbital implantation. METHODS: From February 1996 to April 2000, 146 consecutive patients who received hydroxyapatite orbital implant were drilled and inserted a motility peg 6 to 16 months after hydroxyapatite implantation. Among them, there were 97 males and 49 females, aged from 18 to 60 years old, of the 146 motility pegs, 36 were sleeved pegs and 110 were nonsleeved. Goldman visual field analyzer was applied to measure the degree of artificial eye’s movement before and after drilling. RESULTS: Followed up for 1 to 40 months, no secondary infection occurred. The mobility of the prosthesis increased from (18.7 +/- 3.8) degrees preoperatively to (42.3 +/- 3.7) degrees postoperatively. CONCLUSION: The delayed drilling procedure and motility peg insertion improve the range of movement and the sensitivity of the artificial eye with a low rate of complications.
In order to study the Titanium-bone interaction and integration mechanism, the titanium implant was implanted in the tibia of 9 Newzealand rabbits, and the Ti-bone interface performed for 1, 3, and 6 months were examined and analyzed by fluorescence microscope and advanced TOF-SIMS techniques. The results showed that Ti-bone tissue was integrated closely in a very reactive manner. Both physical and chemical integration occurred in the Ti-bone interface. The Ti-bone could diffuse into the bone tissue though the diffusion was very limited. It was up to 100 microns in depth during the early period. The diffusion density was high, and later in a smooth distribution. Furthermore, while Ti+ diffused into the bone tissue, other elements such as Ca+, OH-, O-, etc, could also diffuse into titanium in exchange. The growth pattern around the bone tissue was in two fashions, one was implantefugal and the other was implantopetal. In this study, based on the ionic distribution, osmosis and impurity elements distribution, the Ti-bone integration mechanism was discussed at molecular and atomic level.
The aim of this experiment was to study the osteogenesis in vivo of allogenic osteoblast combined culture with calcium phosphate composites. The osteoblasts were obtained by enzymatic digestion of periosteum from fibula subcultured to 13 generations, the cells were combined culture with hydroxyapatite and biphasic calcium phosphate. Subseguently, the composite was implanted into rabbits subcutaneously or intramuscularly. The blank material was implanted in the contralateral side as control. Four weeks later, all animals were sacrificed. All the implants were examined by gross observation, histological examination and EDXA. The results showed: 1. obvious ingrowth of connective tissue with very little inflammatory reaction; 2. new bone formation in the composites with deposit of Ca and P on the surface of osteoblast, but none in the blank materials; 3. no significant difference of new bone formation between the different sites of implantation or different materials, but those implanted intramuscularly had lamellae form of new bone while those implanted subcutaneously had only mineralization of extracellular matrix. The conclusion were: 1. the composites are biocompatible with prior osteogenesis property; 2. periosteal-derived allogenic osteoblasts obatined by enzymatic digestion could survive following implantation with bioactivity; 3. rich blood supply might be advantageous to new bone formation and its maturation.
From the results of this experiment, it showed that the implanted tendon was gradually extruded from the tibia hole and attached to the periosteum. The dominant breeding of tissue cells, cytodynamics, the perimeter ratio of tendon/bone and the effect of revascularization were discussed in detail.
Objective To study the immunological rejection occurred in different period after the in vivo implantation of vitreous-cryopreservation tissue engineered tendons for the repair of tendon defect and investigate its influences on the hepatic, renal, and cardiovascular function of rats. Methods Tenocytes obtained from tail tendon of one-weekold SD rats were cultured in vitro. The tenocytes at passage 2-4 (5 × 106 cells/mL) were co-cultured with 1.5 cm bio-derived tendon material to reconstruct tissue engineered tendon. The 21% DMSO was used as cryopreservation protection solution andthe Eurocoll ins solution served as basic solution for pre-frozen solution (4 ) and eluent. The cell-scaffold composites were vitreous-cryopreserved by self-designed method. Seventy-two healthy SD rats (male and/or female) weighing 210-230 g were randomly divided into three groups: group A (n=32), group B (n=32), and group C (n=8). The 0.5 cm tendon defect model was establ ished in the middle part of Achilles tendon in groups A and B. The defect in group A and B was repaired by the transplantation of tissue engineered tendon with and without vitreous-cryopreservation, respectively. At 2, 4, 6, and 8 weeks after transplantation, the general observation and the detection of hepatic function, renal function, and cardiovascular function were conducted. At 2, 4, and 6 weeks after transplantation, serum immunology test was conducted. Results There were no tissue necrosis, hydrops, and suppurative infection in groups A and B. The adhesion was evident in groups A and B 2 weeks after transplantation, improved gradually during 4-6 weeks, and disappeared at 8 weeks. The neonatal tissue had full integration and continuity, and the bridging region of the tendon healed and was similar to the normal tendon. For serum IgG and IgM content, there was no significant difference when group A or B was compared with group C, and between group A and group B 2, 4, and 6 weeks after transplantation (P gt; 0.05). Hepatic function: aspartate aminotransferase (AST) content of group A was less than that of group C 4 weeks after transplantation (P lt; 0.05); AST content of group B was less than that of group C 4 and 6 weeks after transplantation (P lt; 0.05); but there was no significant difference when group A or B was compared with group C in terms of other indexes 8 weeks after transplantation (P gt; 0.05). Renal function: serum albumin and creatinine in groups A and B were decreased obviously, and significant difference was evident when compared with group C (P lt; 0.05). Cardiovascular function: there was no significant difference between group A and group C in terms of blood glucose, triglyceride, and cholesterol (P gt; 0.05);there was a significant difference between group B and group C in terms of triglyceride 8 weeks after transplantation (P lt; 0.05). Conclusion Repairing tendon defect with the implantation of vitreous-cryopreservation tissue engineered tendons results in no obvious immunological rejection and exerts no obvious influences on hepatic, renal, and cardiovascular function.
A mechanical study on the bones of 29 rabbits following implantation of carbontendon was carried out. The rabbits were divided into seven groups according to the observation time (2,4,6,8,12,20 and 30 weeks after operation). A bundle of artificial tendon composed of 7,000 carbon fibers was passedthrough a tunnel in the tibia, and both ends of the artificial tendon were ligated to the muscle fibers. The mechanical strength and histological structure of the carbonbone junction and their relationship were studied in each group. Carbon fiberwas split and degradated in six to eight weeks after operation. The tensile strength of carbontendon in the soft tissue was decreased from 82±4.6N in the second week to 27±5.31N and6.3±1.81N in the sixth and eighth week respectively. The tensile strength of carbontendon increased from 3.01±1.2N to 6.1±2.01N at the carbon -tendon-bone junction in the bone. The tensile strength of carbon-tendon was unsatisfactory for implantation into bone. The carbon-tendon was split and degradated and the tensile strength was not b enough to cope with the early functional exercises.
Objective To investigate the feasibility and characteristic of tissue engineered testicular prosthesis with highdensity polyethylene(HDPE，trade name: Medpor) and polyglycolic acid(PGA). Methods The chondrocytes were isolated from the swine articular.The PGA scaffold was incorporated with medpor which semidiameters were 6mmand 4mm respectively.Then, the chondrocytes (5×10 7/ml) were seeded onto Medpor-PGA scaffold and cultured for 2 weeks. The ten BALB／C mice were divided into two groups randomly(n=5). In the experimental group, the cell-scaffold construct was implanted into subcutaneous pockets on the back of nude mice. In the control group, the Medpor-PGA scaffold was implanted. The mice of two groups were sacrificed to harvest the newly formed cartilage prosthesis after 8 weeks. Macroscopy, histology and immunohistochemistry observations were made. Results The gross observation showed that on changes were in shape and at size, the color and elasticity were similar to that of normal cartilage and that the cartilage integrated with Medpor in the experimental group; no cartilage formed and fiberlike tissue was found in the control group. HE staining showed that many mature cartilage lacuna formed without blood vessel and some PGA did not degradated completely. Toluidine blue staining showed extracellular matrix had metachromia. Safranin O-fast green staining showed that many proteoglycan deposited and collagen type Ⅱ expression was bly positive. In the control group, Medpor was encapsulated by fiber tissue with rich blood vessel. Conclusion The newly formed complex of Medpor-PGA and cells was very similar to testicle in gross view and to normal cartilage in histology. This pilot technique of creating testicular prosthesis by incorporating tissue-engineered cartilage with Medpor demonstrated success.
OBJECTIVE: To investigate the method and clinical effect of temporal fascia flap, free forearm flap, free iliac bone transfer and immediate implant on reconstruction of maxillary defect. METHODS: From February 1999 to July 2002, 8 cases of maxillary defects due to excision of cancer were repaired immediately with temporal fascia flap, free forearm flap, free iliac bone transfer and implant. Out of 8 patients, there were 6 males and 2 females, aged 32-49 years, with a disease course of 3 months to 2 years. RESULTS: Free iliac bone and forearm flap survived in all 8 cases. Osseo-integration could be seen and the implants could be used for denture repair and chew function. After 6-12 months, X-ray examination showed iliac bone healing; facial shape and functional restoration were satisfactory. CONCLUSION: Temporal fascia flap, free forearm flap, free iliac bone transfer and immediate implant is an ideal method to repair maxillary defect immediately and reconstruct its function.
Large sample-size registries have become a necessary complement to randomized controlled trials. This study introduced the registries in the field of clinical application of implantable cardioverter defibrillator, especially the two large registries of the US NCDR ICD and Boston Scientifićs ALTITUDE, described the current status and future direction, thus to guide such registry researches in China.
Objective To overview the theoretical basis and research status of prepectoral implant-based breast reconstruction. Methods The domestic and foreign researches on the application of prepectoral implant-based breast reconstruction in breast reconstruction were retrospectively analyzed. The theoretical basis, clinical advantages, and limitations of this technique were summarized and the future development trend in this field was discussed. Results The recent advances in breast cancer oncology, the development of materials and the concept of oncology reconstruction have provided a theoretical basis for prepectoral implant-based breast reconstruction. The selection of patients and the experience of surgeons are crucial for postoperative outcomes. Ideal thickness and blood flow of flaps are the most important considerations for the selection of prepectoral implant-based breast reconstruction. However, its long-term reconstruction outcomes and clinical benefits and risks in Asian populations still need to be confirmed by more studies. Conclusion Prepectoral implant-based breast reconstruction has a broad application prospect in breast reconstruction following mastectomy. However, the evidence is limited at present. Randomized study with long-term follow-up is urgently in need to provide sufficient evidence to evaluate the safety and reliability of prepectoral implant-based breast reconstruction.