Objective?To observe the changes of force bearing area and pressures of the rabbit tibiofemoral contact area and the biomechanical reconstruction level of joint after meniscal allograft.?Methods?A total of 28 Japanese rabbits were involved, weighing 3.0-3.5 kg, male or female. Of 28 rabbits, 7 were selected as meniscus donors, the remaining 21 rabbits were randomized into group A (n=7), group B (n=7), and group C (n=7). Group A underwent single knee opening and suturing, group B underwent medial meniscus excision and suturing, and group C underwent medial meniscus allograft after medial meniscus excision and suturing. The rabbits were sacrified at 12 weeks after operation for biomechanical observation through biomechanical machine and color imaging system. The meniscus tissue specimens were harvested from groups A and C to perform histological and immunohistochemical staining.?Results?After operation, all rabbits in 3 groups survived to the end of experiment. There were significant differences in the force bearing area and pressures at 0-90° flexion between group B and groups A, C (P lt; 0.05) at 12 weeks, showing no significant difference between group A and group C (P gt; 0.05); and there were significant differences in the force bearing area and pressures at 120° flexion among 3 groups (P lt; 0.05). The histological observation showed that the number of cartilage cells and collagen fibers returned to normal in group C, and the immunohistochemical staining showed that transplanted meniscus of group C contained large amounts of collagen fibers consisting of collagen type I and collagen type II. After 12 weeks of operation, the collagen type I contents were 0.612 5 ± 0.059 8 in group A and 0.587 2 ± 0.063 9 in group C, showing no significant difference (t=0.765, P=0.465); the collagen type II contents were 0.772 4 ± 0.081 5 and 0.814 3 ± 0.051 7, respectively, showing no significant difference (t= —0.136, P=0.894).?Conclusion?The allograft of rabbit meniscus can significantly increase the force bearing area of the tibiofemoral contact area and reduce the average pressure. Therefore, biomechanically speaking, the meniscus allograft can protect the articular cartilage and reconstruct the biomechanical balance.
OBJECTIVE: To investigate the styles and affecting factors of bone union after massive frozen allografting for skeletal reconstruction owing to excision of bone tumor. METHODS: From 1992 to 1999, 85 patients suffering from bone malignant tumor were given the excision of large bone segment and treated with allografting in different methods of operation: large bone allografts with condylar articular surface in 16 cases, osteoarticular allografts in 57 cases, bone allografts in combination with prosthetic replacement of hip in 9 cases, and prosthetic replacement of knee in 3 cases. The average follow-up was 2 years and 9 months. The union time and styles of host-donor junction were determined by X-ray characters, and the results of operations were assessed according to Enneking’s functional evaluation system of reconstructive procedures after surgical treatment of tumors for the musculoskeletal system. RESULTS: There were 4 kinds of basic bone union styles by the X-ray characters, there were no significant difference in the time span of bone union after fixation with different methods. Of the 85 fresh-frozen allografting procedures, more than 80% of the patients were treated with interlocked intramedullary nail and allograft-prosthesis combination, and the overall result was excellent and good. Sufficient blood supply was important for host-donor junction healing, but the function of immune response was uncertain. CONCLUSION: There were different styles of bone union after massive allografting. The recommended operative methods for massive allografts are stable internal fixation, sufficient blood supply, soft tissue repair and periosteal flap coverage.
Objective To review the recent research progress of base and clinical application of tracheal replacement. Methods Literature concerning tracheal prosthesis and the current achievements were extensively and comprehensively reviewed. Results Most tracheal lesions can be resected and achieve primary reconstruction, but the resectable length was limited.Tracheal replacement was an efficient and feasible way to substitutethe defects resulting from extended resection. Conclusion Newtechniques such as tissue engineering, tracheal transplantation, new tracheal prosthesis of biomaterials break fresh ground for the more rapid development of tracheal surgery.
ObjectiveTo review the current status and progress of sterilization and preservation for allograft in anterior cruciate ligament reconstruction.MethodsThe related literature about the sterilization and preservation of allografts in anterior cruciate ligament reconstruction was extensively reviewed and summarized.ResultsThere are many sterilization methods for allografts, the most commonly used method is γ-ray irradiation, but the optimal irradiation dose is still unclear. Electron beam irradiation is also available, but excessive dose is harmful to graft shaping. A combined sterilization method combining physics and chemistry methods is still being explored. Cryopreservation is the most commonly used method of preservation. In order to reduce the influence of crystals, the principle of " slow cooling and rapid rewarming” should be adhered to as far as possible.ConclusionThe processing methods of allograft can affect the effectiveness of anterior cruciate ligament reconstruction. The clinical doctors should consider the sterilization and preservation methods in practice.
Objective To investigate the promotion effect of neurotropic reinnervation with chemically extracted acellular nerve allograft. Methods The sciatic nerves of 5 healthy adult SD rats, regardless of gender and weighing 270-300 g, were collected to prepare chemically extracted acellular nerve allograft. Eighteen healthy adult Wistar rats, regardless of genderand weighing 300-320 g, were made the model of left sciatic nerve defect (10 mm) and randomly divided into 2 groups: autograft (control group, n=9) and allograft group (experimental group, n=9). The defects were bridged by acellular nerve allograft in experimental group and by autograft by turning over the proximal and distal ends of the nerve in control group. At 3 months after transplantation, dorsal root ganglion (DRG) resection operation was performed in 6 rats of 2 groups. At 3 weeks after operation, the sural nerves were harvested to calculate the misdirection rate of nerve fibers with pathological staining and compute-assisted image analysis. Cholinesterase staining and carbonic anhydrase staining were performed in the sural nerve of 3 rats that did not undergo DRG resection at 3 months. Results The results of chol inesterase staining and carbonic anhydrase staining showed that experimental group had less brown granules and more black granules than control group. After DRG resection, count of myelinated nerve fiber were 4 257 ± 285 in the experimental group and 4 494 ± 310 in the control group significant (P lt; 0.05). The misdirection rate was 2.27% ± 0.28% and 7.65% ± 0.68% in the experimental group and in the control group respectively, showing significant difference (P lt; 0.05). Conclusion Chemically extracted acellular nerve allograft can not only act as a scaffold in the period of nerve defects repair, but markedly enhance the effects of neurotropic reinnervation.
Objective
To investigate the risk factors of early allograft dysfunction (EAD) following C-Ⅱ donation after cardiac death (DCD) liver transplantation.
Methods
The data of 46 donors and recipients of C-ⅡDCD liver transplantation between March 2012 and August 2015 were retrospectively analyzed. The baseline data such as democracy, death cause, donor warm ischemic time (DWIT) and cold ischemic time (CIT) in EAD group and the non-EAD group (control group) was compared, and whether these factors were risk factors of EAD was investigated by univariate and multivariate analyses. Statistical cut-off values for significant factors of the unfavorable analysis were defined by receiver operating characteristics (ROC) analysis. The 6-month and 1-year graft survival rate were compared.
Results
The EAD group had a longer DWIT compared with the group [(17.6±4.7) and (12.7±6.2) minutes, P=0.009]; meanwhile, the EAD group had a longer CIT compared with the control group [(13.7±4.7) and (11.0±3.5) hours, P=0.020]. The other factors in both groups showed no statistical significance (P>0.05). The ROC curve revealed the cut-off values of DWIT and CIT were 17.50 minutes [area under the curve (AUC)=0.713, P=0.020] and 9.85 hours (AUC=0.723, P=0.015), respectively. The multivariate logistic regression analysis showed the DWIT [odds ratios (OR)=1.340, 95% confidence interval (CI)(1.042, 1.654), P=0.008] and CIT [OR=1.396, 95% CI (1.075, 1.698), P=0.015] were all independent risk factors of EAD. The 6-month and 1-year graft survival rate of the EAD group and the control group was 85.7% vs. 92.3% (P=0.607) and 71.4% vs. 84.6% (P=0.587), respectively.
Conclusions
EAD may occured in C-Ⅱ donors with DWIT≥17.50 minutes or CIT≥9.85 hours in DCD liver transplantation. The livers can be used as a resource for clinical use and also have a good outcome.
Objective To investigate the rat model of cardiac allograft vasculopathy after heart transplantation in rat abdominal cavity. Methods Forty Wistar rats and 40SDrats were divided into control group and experiment group randomly pair-matching. Rat model ofheterotopic heart transplantation was developed. Low doseCyclosporine A were injected into the abdominal cavity in experiment group, while the control group had not received the Cyclosporine A. Transplant hearts were harvested at two weeks and four weeks post-operatively and changes of coronary artery were observed by light microscope. Results There were no alteration of tunica intima of coronary artery in control group at two weeks and four weeks post-transplantation. Tunica intima of coronary artery increased in thickness at two weeks post-transplantation in experiment group and concentric circular change occurred at four weeks post-transplantation. Lumen of coronary artery constricted transparent and cardiac allograft vasculopathy occurred. Conclusion This animal model is reliable of cardiac allograft vasculopathy.
Objective To investigate the efficacy of freeze-driedcancellous allograft in the treatment of spinal tuberculosis. Methods From January 1999 to August 2004, there were 31 cases of spinal tuberculosis who underwent surgery. The freeze-dried cancellous allograft was used as grafting material in all the cases.The cancellous allograft was packed in a titanium mesh cage or an artificial vertebrae, and then used as a strut graft anteriorly to implant into the bone defect after the redical debridement, and the instrumentation was done. Results Twenty-three cases were followed up 1.5 years to 5 years (3.7 years on average), and bonyfusion was achieved in 21 cases 6 months later. In 2 cases ceasing antituberculous therapy after 2 months of operation, the local recurrence was obvious. The loosened screw was noticed in one of these two cases, who had tuberculosis in lumbar spine. When antituberculous therapy continued, the bony fusion was observed in these two cases 12 months later. No further position change of the instrument wasnoticed in the patient carrying loosened screw, but the kyphosis of the thoracolumbar spine aggravated. Conclusion Freeze-dried cancellous allograft could be usedin the treatment of spinal tuberculosis. To achieve good results of allograft incorporation and remodeling, the rigid instrumentation should be performed, postoperative antituberculous therapy is also important.
ObjectiveTo summarize the mid-term effectiveness of arthroscopic anterior cruciate ligament (ACL) reconstruction combined with meniscus allograft transplantation.MethodsA clinical data of 21 patients treated with arthroscopic ACL reconstruction and meniscus allograft transplantation and followed up more than 5 years between February 2007 and December 2014 was retrospectively analyzed. There were 12 males and 9 females, aged from 18 to 45 years, with an average age of 23.5 years. The cause of injury was sport sprain in 15 cases, falling in 4 cases, and traffic accident in 2 cases. The time from injury to operation ranged from 2 to 36 months, with an average of 12 months. Among them, 15 patients underwent previous meniscectomy, with an average interval of 1.6 years (range, 3 months to 6.5 years). All patients were primary ACL reconstruction. Preoperative anterior drawer test, Lachman test, and pivot shift test were positive. Lysholm score was 43.6±10.2. International Knee Documentation Committee (IKDC) score was 60.50±14.06. Of the 21 patients, 10 were gradeⅠ-Ⅱcartilage injuries and 11 were grade Ⅲ cartilage injuries according to MRI. ResultsAll patients were followed up 5.1-7.8 years, with an average of 5.5 years. There were 2 cases of numbness of lower extremity, 3 cases of slight exudation of incision, 2 cases of articular movement bounce, 5 cases of mild joint swelling and pain after exercise. At last follow-up, Lachman tests were negative in 18 cases and positive in 3 cases; anterior drawer tests were negative in 19 cases and positive in 2 cases; pivot shift tests were negative in all cases. Lysholm score was 84.5±16.5 and IKDC score was 85.25±4.60, which were significantly higher than those before operation (P<0.01). The flexion and extension of the affected knee joint were (128±13) and (3±7)°, respectively, which were smaller than those of the healthy knee joint [(133±15), (0±5)°] (P<0.01). The results of KT-1000 test showed that when knee flexion was 30 and 90°, tibial anterior displacement of affected side [(2.35±1.20), (1.60±1.15) mm] were not significantly different from those of healthy side [(1.20±1.10), (1.10±1.03) mm] (P>0.01). MRI showed that the ACL graft was in normal position and meniscus survived well. Cartilage injuries were gradeⅠ-Ⅱ in 18 cases and grade Ⅲ in 3 cases. ConclusionFor patients with severe meniscus injury and ACL rupture, ACL reconstruction combined with meniscus allograft transplantation can restore the stability of the joint, recover the meniscus function which is conducive to the protection of articular cartilage and obtain satisfactory mid-term effectiveness.
Objective To explore the effect of tri pterygium glycoside (TG) on the skeletal muscle atrophy and apoptosis after nerve allograft. Methods Twenty Wistar male rats were adopted as donors, weighing 200-250 g, and the sciatic nerves were harvested. Fifty SD male rats were adopted as recipients, weighing 200-250 g. Fifty SD rats were made the models of10 mm right sciatic nerve defect randomly divided into five groups (n=10): group A, group B, group C, group D and group E.groups A and B received fresh nerve allograft, groups C and D received sciatic nerve allograft pretreated with TG, and group E received autograft. The SD rats were given medicine for 5 weeks from the second day after the transplantation: groups A and E were given physiological sal ine, groups B and D TG 5 mg/ (kg·d), and group C TG 2.5 mg/ (kg·d). At 3 and 6 weeks, respectively, after nerve transplantation, general observation was performed; the structure of skeletal muscles was observed by HE staining; the diameter of skeletal muscles was analyzed with Image-Pro Plus v5.2; the ultrastructure of skeletal muscles was observed by TEM; the expressions of Bax and Bcl-2 were detected by immunohistochemical staining; and the apoptosis of skeletal muscles was detected by TUNEL. Results All rats survived to the end of the experiment. In general observation, the skeletal muscles of SD rates atrophied to different degrees 3 weeks after operation. The muscular atrophy in group A was more serious at 6 weeks, and that in the other groups improved. The wet weight, fiber diameter and expression of Bcl-2 in group A were significantly lower than those in groups B, C, D and E (P lt; 0.01)；those in groups B, C and D were lower than those in group E (P lt; 0.05); and there were no significant differences among groups B, C and D (P gt; 0.05). The apoptosis index and expression of Bax in group A were significantly higher than those in groups B, C, D and E (P lt; 0.01)；those in groups B, C and D were higher than in groupE (Plt; 0.05); and there were no significant differences among groups B, C and D (P gt; 0.05). Three weeks after nerve allograft, under the l ight microscope, the muscle fibers became thin; under the TEM, the sarcoplasmic reticulum was expanded. Six weeks after nerve allograft, under the l ight microscope, the gap of the muscle fibers in group A was found to broaden and connective tissue hyperplasia occurred obviously; under the TEM, sarcomere damage, serious silk dissolution and fragmentary Z l ines were seen in group A, but the myofibrils were arranged tidily in the other groups, and the l ight band, dark band and sarcomere were clear. Conclusion TG can decrease the skeletal muscle atrophy and apoptosis after nerve allograft. The donor’s nerve that is pretreated with TG can reduce the dosage of immunosuppressant for the recipient after allograft.
