Abstract: Objective To study the preventive effect of n-3 polyunsaturated fatty acids on allograft arteriosclerosis. Methods Arterial homeotransplant model were created with 480 rats which were divided into four groups. Control group, no n-3 lyunsaturated fatty acids were taken. Group A, n-3 polyunsaturated fatty acids were taken for two weeks before operation with the dose of EPA 600mg/kg. Group B, 300 mg/kg and group C 150 mg/kg were taken respectively. The recipient’s transplanted vessel was excised after 1,7,14,21and 28 days respectively. The tissue pathological variations, ultrastructure variations and expression variations of intercellular adhesion molecule-1(ICAM-1), vascular cell adhesion molecule-1（VCAM-1）, nuclear factorkappa B（NF-κB） had been observed. Results The pathological changes occurred 7 days after operation in control group and were most prominent on the 28th day, blood vessels were obstructed and the expressions of ICAM-1, VCAM1,NF-κB were markedly intensified than those of group A, B, C (Plt;0.05). The pathological variations of transplanted vessel in group A, B, C occurred later than those in control group. The nonobstruction rates in group A, B, C were better than that in control group. The expressions of ICAM-1， VCAM-1， NF-κB in control group were ber than those in group A， B， C (Plt;0.05). The expressions of ICAM-1， VCAM-1， NF-κB after 1 day or 7 days demonstrated no statistically significant change in group A， B， C （Pgt;0.05）. The preventive effect for allograft vessel atheromatosis in group A and group B was ber than that in group C after 14, 21 and 28d (Plt;0.05). There were no significant difference between group A and group B (Pgt; 0.05). Conclusion The n-3 polyunsaturated fatty acids can prevent the allograft vessel atheromatosis, the most effective dose of n-3 polyunsaturated fatty acids is 300 mg/kg.
Objective To observe the systemic and local immune response after repair of nerve defect with acellular nerve xenograft laden with allogenic adipose-derived stem cells (ADSCs) in rhesus monkey so as to evaluate the safety of the proposed material for nerve reconstruction. Methods Bilateral tibial nerves were taken from a healthy adult male landrace (weighing 48 kg) to prepare acellular nerve xenograft by chemical extraction. ADSCs were isolated from a healthy adult male rhesus monkey (weighing 4.5 kg), and were seeded into the acellular nerve grafts. The radial nerve defect models with 25 mm in length were established in 10 healthy adult female rhesus monkeys (weighing 3-5 kg), and they were divided into cell-laden group (n=5) and non-cell-laden group (n=5) randomly. Defect was repaired with acellular nerve xenograft laden with allogenic ADSCs in cell-laden group, with acellular nerve xenograft only in non-cell-laden group. The blood samples were taken from peripheral vein preoperatively and at 14, 60, and 90 days after operation for lymphocyte analysis; at 5 months after operation, the grafts were harvested to perform histological examination for local immune response and nerve regeneration. The nerve autograft in rhesus monkey was used as control. Results In cell-laden group and non-cell-laden group, no significant difference was found in the count of lymphocytes and T lymphocytes, the percentage of T lymphocytes, CD8+ T lymphocytes, as well as the ratio of CD4+ T lymphocytes to CD8+ T lymphocytes between pre- and post-operation (P gt; 0.05); in cell-laden group, the percentage of CD4+ T lymphocytes at 14 days was significantly lower than that at 60 and 90 days postoperatively (P lt; 0.05). The percentage of CD4+ T lymphocytes in cell-laden group was significantly lower than that in non-cell-laden group at 14 days (P lt; 0.05), but no significant difference was found in the other indexes at the other time between 2 groups (P gt; 0.05). At 5 months after operation, mild adhesion was found on the surface of nerve xenografts; the epineurium of nerve xenografts was thicker than that of nerve autografts; and neither necrosis nor fibrosis was found. CD3+, CD4+, CD8+, CD68+, and CD163+ T lymphocytes were scattered within the grafts, in which regenerative axons were revealed. CD3+, CD4+, CD8+, CD68+, and CD163+ T lymphocytes were comparable in cell-laden group, non-cell-laden group, and autograft group. Conclusion Repair of nerve defect with acellular nerve xenograft elicits neither systemic nor local immune response in rhesus monkeys. Implantation of allogenic ADSCs might result in transient depression of CD4+ T lymphocytes proliferation early after surgery, no immune response can be found.
Objective The anterior cruciate l igament (ACL) is the important stable structure of the knee. To evaluate the method and outcome of bone-ACL-bone (B-ACL-B) allograft under arthroscope in reconstruction of ACL. Methods Between October 2007 and February 2010, arthroscopic ACL reconstruction with deep-freezing B-ACL-B allograft was performed on 22 patients with ACL ruptures. There were 15 males and 7 females with an average age of 27.6 years (range, 19-55 years). The causes of ACL rupture were sport trauma in 12 cases, fall ing injury in 1 case, heavy crush in 2 cases, and traffic accident in 7 cases. The locations were the left knee in 14 cases and the right knee in 8 cases. The disease durationwas 7 days to 12 months (median, 65 days). Nineteen patients showed the positive results of anterior drawer test and pivot shift test, and 21 patients showed the positive results of Lachman test. According to International Knee Documentation Committee (IKDC) criteria, there were 5 abnormal and 17 severely abnormal. The subjective IKDC score was 49.6 ± 6.9. The Lysholm score was 48.5 ± 5.3. The Tegner scale scores were 6.8 ± 1.2 before injury and 2.1 ± 0.5 before operation. The MRI showed the ACL injuries in 18 of 20 patients. Results The mean operative time was 75 minutes (range, 65-85 minutes); the mean blood loss was 110 mL (range, 80-150 mL). All incisions healed by first intention. No immunologic rejection and deep vein thrombosis of lower l imbs occurred. All patients were followed up 7-34 months (mean, 18 months). At last follow-up, the flexion of the knee ranged from 125 to 135° (mean, 130.5°). Two patients showed the positive results of anterior drawer test, 1 patient showed the positive result of pivot shift test, and 3 patients showed the positive results of Lachman test. According to the IKDC criteria, 10 patients rated as normal, 11 patients as nearly normal, 1 patient as abnormal. The subjective IKDC score was 90.0 ± 5.8, showing significant difference when compared with preoperative one (t=4.653, P=0.021). The Lysholm score was 91.6 ± 7.1, showing significant difference when compared with preoperative one (t=4.231, P=0.028). The Tegner scale score was 6.1 ± 1.5, showing no significant difference when compared with one before injury (t=1.321, P=0.070) and showing significant difference when compared preoperative one (t=3.815, P=0.033). The arthroscopic examination showed no rupture of grafts in 19 patients, 17 grafts showed normal tension, and 2 showed sl ight relaxation at 6 months after operation. Conclusion Reconstruction of the ACL with B-ACL-B allograft under arthroscope is a safe and effective method, which can anatomically reconstruct ACL and obtain a good recovery of the knee function after operation.
Objective To explore the biomechanic effects of multi ple freeze-thaw on human allograft tendons. Methods Thirty tendons (24 flexor digitorum superficial is tendons and 6 flexor poll icis longus tendons) were harvested from 3 fresh cadaver donors and were divided into 6 groups randomly (fresh group; 1 cycle, 2 cycle, 3 cycle, 5 cycle, and 10 cycle freeze-thaw groups). There was 4 flexor digitorum superficial is tendons and 1 flexor poll icis longus tendon in each group. The structural and mechanical properties as well as viscoelastic change were estimated. Results The results of the structural and mechanical properties in 1 cycle, 2 cycle, and 3 cycle freeze-thaw groups were similar to that of the fresh group (P gt;0.05). The tendons in 5 cycle and 10 cycle freeze-thaw groups showed a significantly lower ultimate load and maximum stress when compared with those of fresh group (P lt; 0.05), but there was no significant difference in maximum tensile or maximum strain (P gt; 0.05). Moreover, the tendons in 5 cycle and 10 cycle freeze-thaw groups had a significant increase in viscoelastic properties when compared with fresh group (P lt; 0.05). Conclusion In the cryopreservation of tendon allografts, the cycle of freeze-thaw should not exceed 3 times. Multiple cycle freeze-thaw will weaken the biomechanical properties of tendon allografts, which make grafts easier to fatigue or even rupture.
Objective To investigate the cl inical therapeutic results of allograft tendon for anatomical reconstruction of medial patellofemoral l igament (MPFL) in patellar dislocations. Methods From September 2005 to June 2008, 20 patientswith patellar dislocation underwent MPFL reconstructions. There were 4 males and 16 females, aged 13 to 31 years (19 years on average). Patellar dislocations occurred in 7 left and 13 right knees, including 6 cases of acute dislocation and 14 cases of recurrent dislocation. The disease course was 1 day to 2 years. The frequency of dislocation was 1-6 (4 on average). Affected knee joint showed pain, swell ing and patellar instabil ity; the range of action for patella obviously increased. The X-ray films showed patellar dislocation or medial margin avulsion fracture. The preoperative Q angle was (15 ± 3)°, the congruence angle was (10 ± 11)°. Reconstruction was performed via allograft tendon. Allograft tendon was anchored to the superomedial pole of the patella by two bone anchors, and the other end was fixed at the natural MPFL insertion site near the medial femoral condyle with an interference screw in a bone tunnel. All patients were evaluated postoperatively; Kujala patellofemoral scores, objective knee function, compl ications, and reoperations were assessed. Results Primary heal ing was achieved in 18 cases and secondary heal ing in 2 cases. No infection or necrosis and absorption of grafts was observed. All patients were followed up for an average of 25.6 months (range, 6-34 months) postoperatively. At last follow-up, other patients had no pain, swell ing and patellar instabil ity except 1 case; neither patella redislocation nor fracture occurred. The X-ray films showed good position of anchors and tunnel 6 months after operation, and the congruence angle was (3 ± 8)°, showed statistically significant difference when compared with preoperation (P lt; 0.05). The postoperative Q angle was (15 ± 2)°, the Kujala knee function score improvedsignificantly from 60.8 ± 7.2 to 83.4 ± 8.0 at last follow-up, showing statistically significant difference (P lt; 0.05). According to Insall et al. for function, the results were excellent in 12 cases, good in 6 cases, and fair in 2 cases, the excellent and good rate was 90%. Conclusion MPFL reconstruction improves cl inical symptoms. Anatomical MPFL reconstruction is effective for patellar dislocation, and it offer good recovery of the pre-morbid patella mechanics. There would be l ittle bone loss when tendon is fixed by anchors, and there would be less patellar fracture than bone tunnel technique. The bone anchors also provide firm fixation. Allograft can avoid the graft harvest site morbidity, but it increases the cost of the surgery.
To analyze the effectiveness of anterior cruciate l igament (ACL) reconstruction with preserving the remnant ACL by allograft l igament. Methods Between January and July in 2008, 97 patients underwent ACL reconstruction with the allograft l igament. On the basis of the ACL’s condition, patients were divided into 2 groups. In the trial group (patients having remnant ACL, n=38), there were 27 males and 11 females with an average age of 24.3 years (range, 16-43 years); of them, 8 cases compl icated by menicus injury and 13 cases by Outbridge I degree cartilage injury; the time from injuryto operation was 3-20 weeks (mean, 8.6 weeks). In the control group (patients having no remnant ACL, n=59), there were 35 males and 24 females with an average age of 27.8 years (range, 18-48 years); of them, 16 cases compl icated by menicus injury and 23 cases by Outbridge I degree cartilage injury; the time from injury to operation was 4-44 weeks (mean, 12.7 weeks). All injuries were caused by sports in 2 groups. All patients had positive anterior drawer test and positive Lackman test. Before operation and 3, 8, 9, 15 months after operation, the function of the knee joint was evaluated by the International Knee Documentation Committee (IKDC) scale and Lysholm score. KT-2000 arthrometer was used to evaluate knee laxity. Results All incisions healed primarily, and no intraarticular infection occurred. Thirty-seven cases and 57 cases were followed up 15 months in the trial group and the control group, respectively. Knee instabil ity disappeared; the patients showed negative anterior drawer test and negative Lackman test. By the evaluation of KT-2000, the joint sl ippage of 2 groups were less than 2 mm at 3 and 6 months after operation, but it was more than 2 mm in 2 cases of the trial group and in 3 cases of the control group at 9 months after operation; and it was no change in the trial group and 2.5-4.0 mm (mean, 3.4 mm) in the control group at 15 months after operation. Both the IKDC scale and Lysholm score were higher in the trial group than in the control group 3 months after operation, but the differences were not significant (P gt; 0.05). Both the IKDC scale and Lysholm score were
Objective To observe the revascularization process of chemically extracted acellular allogeneous nerve graft in repairing rat sciatic nerve defect. Methods Eighty adult male SD rats were selected. The sciatic nerve trunks from ischial tuberosity to the ramus of tibiofibular nerve of 16 SD rats were obtained and were prepared into acellular nerve stents by chemical reagent. Sixty-four SD rats were used to prepare the models of sciatic nerve defect (1.0 cm) and thereafter were randomized into two groups (n=32): experimental group in which acellular allogeneous nerve grafts were adopted and control group in which orthotopic transplantation of autologous nerve grafts were adopted. Postoperatively, the general conditions of all rats were observed, and the gross and ALP staining observation were conducted at 5, 7, 10, 14, 21, 28 days and 2, 3 months, respectively. Results All the incisions were healed by first intention. Trail ing status and toe’s dysfunction in extension happened to the right hindl imb of rats in two groups and were improved 6 weeks after operation. General observation showed that the grafts of two groups connected well to the nerves, with appearances similar to that of normal nerve. ALP staining demonstrated that the experimental group had no ingrowth of microvessel but the control group had ingrowth of microvessel 5 days after operation; the experimental group had ingrowth of microvessel but both groups had no microvessel 7 days after operation; few longitudinal microvessel throughout the grafts were observed in both groups 10, 14 and 21 days after operation; no obvious difference in capillary network of grafts was observed between two groups 28 days after operation; and the microvascular architecture of grafts in both groups were similar to that of normal nerve 2 and 3 months after operation. Conclusion When the chemically extracted allogeneous nerve graft is adopted to repair the peripheral nerve defect, new blood microvessels can grow into grafts timely and effectively.
Objective To evaluate the feasibil ity and effectiveness of allograft osteochondral transplantation with arthroscopic assistance for osteochondritis dissecans (OCD) associated with large osteochondral defects. Methods From January 2004 to May 2007, 13 patients with OCD with large osteochondral defects were treated. There were 7 males and 6 females, aged 18-59 years with an average of 35.8 years. The locations were left side in 8 cases and right side in 5 cases. The disease course was 7 days to 20 years with the median duration of 42 months. Four cases had obvious sprained history. The involved locations were lateral portion of the medial femur condyle (MFC) in 5 cases, thochlea area of MFC in 2 cases and lateral femur condyle in 6 cases. The range of motion was (95.0 ± 13.5)° and the Lysholm score was 62.23 ± 7.79. According to International Cartilage Repair Society classification system and the Guhl classification of OCD under arthroscopy, all the patients were type IV. Defect areas were 3-7 cm2 with an average of 4.32 cm2. The depths of defects were 0.8-2.0 cm with an average of 1.55 cm. Allograft osteochondral transplantation combining with adsorbable screw was appl ied for the lesions. The patients were closely instructed to do exercise through following up. Results The wounds all healed by first intention Thirteen cases were followed up for 2.2 years (14 months to 4 years) after operation. Three months after operation, 2 cases had pain after continuous exercise for 1 hour, they were directed in the methods of functional exercise and to strengthen their quadriceps femoris. Medicine was given in 2 patients who had sign of friction feel ing of joint 6 months after operation. The range of motion at the last follow-up was (137.0 ± 9.8)°, showing statistically significant difference when compared with that before operation (P lt; 0.05). The X-rays and EMRI examinations at following-up indicated that bone healed well and articular facet was integrity. The Lysholm score was 92.08 ± 7.64 one year after operation, showing statistically significant difference when compared with that before operation (P lt; 0.05). Conclusion Allograft osteochondral transplantation with arthroscopic assistance is a useful method in treatment of OCD with large osteochondral defects of the knees.
To research the operative method and the cl inical efficacy of repairing and reconstructing tendon and l igament with allograft tendon. Methods From September 2000 to May 2007, 164 cases with tendon and l igament injuries were treated, including 116 males and 48 females aged 21-47 years old (average 31.5 years old). There were 126 cases of anterior cruciate l igament injury, 18 cases of complete acromioclavicular dislocation, 10 cases of old dislocation of radialhead, 4 cases of Achilles tendon rupture, 2 cases of tibial is anterior muscle rupture, 2 cases of patellar tendon rupture, and 2 cases of rectus femoris rupture. Time interval between injury and hospital admission was 4-345 days (average 75 days). Allograft tendon 10-26 cm in length with suture anchor or absorbable interference screw was used to reconstruct the l igament and tendon. Results All wounds healed by first intention, except one case of rectus femoris rupture. All patients were followed for 10-36 months (average 21 months). The international knee documentation commitee and the Lysholm score of patients with anterior cruciate l igament injury 12 months after operation were significantly higher than that of before operation (P lt; 0.01). According to the Lazzcano and Karlsson score standard, 13 cases of complete acromioclavicular dislocation at 10-12 months after operation were graded as excellent and 5 cases were good. According to Arner Lindholm score standard, 3 cases of Achilles tendon rupture at 8-16 months after operation were graded as excellent and 1 case was good. For the patients with tibial is anterior muscle rupture, at 10-17 months after operation, the limitation of dorsal extension in ankle joint was 5°, and the muscle strength in the anterior tibial is muscle was decreased. For the patients with patellar tendon rupture, one completely restored the motion range of the knee joint 14 months after operation, the other had knee extension l imitation of 10° at 13 months after operation. For the patients with rectus femoris rupture, one had 15° of extension limitation at 18 months after operation, the other suffered limitation of both extension and genuflex at 12 months after operation. According to the Broberg-Morrey score standard, 7 caseswith old dislocation of radial head were graded as excellent and 3 cases were good at 3-36 months after operation. Conclusion Allograft tendon is a good material for repairing and reconstructing tendon and ligament injuries, but attention should be paid to postoperatively early exercise under appropriate protection and early management of local rejection.
Objective To investigate the effect of tetramethylpyrazine (TMP) with a certain concentration added to vitrification solution on peripheral nerve allografts regeneration. Methods Forty-eight healthy clean SD male rats were selected as donors, and 96 healthy clean Wistar male rats as recipients, all rats being 3 months old and weighing 200-250 g. The sciatic nerves segments of 15 mm were removed from the donors, then randomly divided into 4 groups according to vitrificationsolution containing TMP. No TMP was used in group A as the control group; 100 mg/L, 200 mg/L and 400 mg/L TMP were used in group B, group C and group D, respectively. Then them were cryo-preserved at — 196 ℃ for 3 weeks. Nerve defect of 10 mm in length was made in the sciatic nerves of recipients. After rewarming, the allografts were transplanted to the corresponding rats. The gross appearance, the morphological and electrophysiological changes, the image analysis of axons and motor end-plate were detected at 4, 8, 12 and 16 weeks. Results All rates survived to the end of the experiment. The adhesion and edema of allografts in group A and group B were obvious 4 weeks after operation; then adhesion and edema was obvious in group A and were improved in the other groups 8 weeks after operation. Adhesion was observed in groups A and B; no adhesion was observed in groups C and D at 12 weeks. The number of regeneration nerve, the latent, the ampl itude, the nerve conduction velocity, the medullary sheath/μm2, the medullary sheath density/μm2 and the image analysis of axons and motor end-plate in groups A and B were significantly lower than those in groups C and D (P lt; 0.01); and there were no significant differences between groups C and D (P gt; 0.05). The observation of transmission electron microscope showed that medullated nerve fibers and myel in sheath of groups C and D were thicker than groups A and B, layers of groups C and D were clear. Conclusion The vitrification solution with 200 mg/L tetramethylpyrazine has protective effect on regeneration of peripheral nerve allografts．