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 explore the situation of tendon-bone heal ing when allogenic tendon graft is wrapped with autologous periosteum around the tendon in rabbits. Methods Twenty healthy New Zealand white rabbits with the age of 4-5 months were used in the experiment, weighing 2.5-3.0 kg. One-side posterior l imb was selected randomly as the test, and thecontralateral l imb was served as the control at the same time. The allogenic tendon graft was designed as a tendon-bone model in the proximal tibial metaphysis of rabbits. The portion of tendon in the bone tunnel was wrapped with autologous periosteal graft in which the cambium layer was facing the bone tunnel in the experimental group, while the portion of tendon in the bone tunnel was not wrapped with autologous periosteal graft in the control group. The histologic examination of the tendon-bone interface (n=2) and the biomechanical test for maximal pullout load (n=8) were conducted 4 and 8 weeks after operation, respec tively. Results All specimens were observed with naked eyes 4 and 8 weeks after the operation. Many new bones around bone tunnel outlet were seen in the experimental group, while a few or few new bones were seen in the control group. Four weeks after operation, histological observation showed there were a lot of prol iferative mesenchymal cells in the periosteal germinal layer in the experimental group and conspicuous membrane bone formation was obvious. The arrangement of massive osteoblasts around newborn bone trabecula was similar to pal isade. The newborn bone trabecula was l inked with the periosteum. Some loose connective tissues and few newborn bones between the tendon graft and the bone tunnel were seen in the control group, and the connection of them was loose. Eight weeks after operation, the connection between the tendon graft and the bone tunnel was tight and no gap existed in the experimental group. The number of newborn bones was large and their arrangement was relatively regular. The tidemark l ine was seen between the tendon graft and the bone tunnel, which was similar to normal tendon-bone interface. The prol iferation of fibroblast was active in the periosteum, and there were many fibrous joints betweenthe periosteum and the tendon graft. Partial bone formation was seen between the tendon graft and the bone tunnel in thecontrol group, with disorderly arrangement, and there were many collagen fibrous joints between the tendon graft and the bone tunnel. Four and 8 weeks after operation, the pullout or pull and break loads of the experimental group were (35.03 ± 1.21) N/ cm and (42.36 ± 1.31) N/cm, respectively, and those of the control group were (26.14 ± 6.13) N/cm and (31.63 ± 6.87) N/ cm, respectively. There was significant difference between the two groups (P lt; 0.05). Conclusion The transplantation of autologous periosteum graft wrapping around allogenic tendon graft may shorten the time of osteochondral ossification between the tendon graft and the bone tunnel, improve heal ing strength and promote tendon-bone heal ing in the bone tunnel in rabbits.
ObjectiveTo study the effect of chemical extraction of allogeneic tendon and allogeneic chondrocytes for reconstruction of anterior labrum of shoulder joint in rabbits.MethodsThe body weight of 45 adult New Zealand white rabbits ranged from 2.5 to 3.0 kg. The Achilles tendons of 15 rabbits were taken and the allogeneic tendons were prepared by chemical extraction with antigen inactivation. The extracted tendons were compared with untreated tendons by HE and Masson stainings. Chondrocytes were isolated and cultured by trypsin method and identified by immunohistochemical staining of collagen type Ⅱ. The remaining 30 rabbits were used to prepare the model of anterior labrum defect of shoulder joint. After the allogeneic tendon was transplanted to the damaged labrum, the rabbits was randomly divided into two groups (15 in each group). In group A, the allogeneic chondrocytes were injected into the joint immediately after transplantation, while in group B, no treatment was made. At 4, 6, and 8 weeks after operation, 5 transplanted tendons of each group were taken. After general observation, HE staining was used to observe the number of nuclei, Masson staining was used to observe the expression of collagen fibers in muscle fiber tissues, and AB staining was used to detect the glycosaminoglycan level after transplantation, to evaluate the cell growth in the tissues of the two groups of allogeneic tendon.ResultsBy HE and Masson stainings, the allogeneic tendon antigen prepared by chemical extraction method was inactivated and the fibrous tissue structure was intact; collagen type Ⅱ immunohisto-chemistry staining showed that the cultured cells were chondrocytes. After tendon transplantation, the content of glycosaminoglycan in group A was significantly higher than that in group B (P<0.05). At 6 weeks after operation, HE staining showed that the nuclear in tendon tissue of group A was significantly more than that of group B (t=20.043, P=0.000). Masson staining showed that the number of nuclei in tendon tissue of group A was significantly increased, the muscle fibers and collagen fibers were interlaced, the tissue structure was more compact, and the tendon tissue was mainly blue stained; while the number of nuclei in group B was less, mainly collagen fibers of the original graft.ConclusionThe allogeneic tendon inactivated by chemical extraction can be used to reconstruct the defect of anterior labrum of shoulder joint in rabbits, and the combination of allogeneic chondrocytes can promote the healing of tendon transplantation.
ObjectiveTo compare the effectiveness of coracoclavicular ligament reconstruction between by using autologous plantaris tendon graft combined with hook plate fixation and allogeneic tendon graft combined with hook plate fixation for treating acromiocavicular joint dislocation. MethodsThirty-three patients with acromioclavicular joint dislocation who accorded with the inclusion criteria between January 2013 and June 2014 were assigned into 2 groups. The patients were treated with autologous plantaris tendon graft combined with hook plate fixation in group A (n=17), and with allogeneic tendon graft combined with hook plate fixation in group B (n=16). Thirteen-one patients was followed up more than 12 months (15 in group A and 16 in group B). There was no significant difference in gender, age, cause of injury, sides, time between injury and surgery, and type of dislocation (P>0.05). The assessments included operation time, hospitalization time, hospitalization expenses, shoulder range of motion, gap of acromioclavicular, Constant-Murley scores, and visual analogue scale (VAS) for pain. ResultsThe operation time of group A was significantly longer than that of group B, and the hospitalization expense was significantly lower than that of group B (P<0.05). There was no significant difference in hospitalization time (t=1.046, P=0.316). The incisions healed by first intention, and hook plate was removed after 3 months. The mean follow-up time was 21.3 months (range, 19-34 months) in group A and was 23.7 months (range, 18-37 months) in group B. X-ray examination showed no osteolysis. There was no significant difference in gap of acromiocavicular between 2 groups at preoperation, 1 week after operation, and last follow-up (P>0.05). No redislocation of acromioclavicular joint and rejection reaction occurred during follow-up. At last follow-up, there was no significant difference in shoulder range of motion, Constant-Murley score, and VAS score between 2 groups (P>0.05). ConclusionCoracoclavicular ligament reconstruction by autologous plantaris tendon or allogeneic tendon graft combined with hook plate fixation for the treatment of acromioclavicular joint dislocation can achieve good effectiveness. The appropriate treatment should be chosen according to the patient's economic situation.
Objective To observe the long-term effectiveness of tendon allograft to repair tendon defect. Methods Between October 1996 and September 1999, 24 patients with tendon defect were treated with tendon allograft which was cultured with deoxyguanosine and preserved at low-temperature or ultra-deep-low-temperature. There were 19 males and 5 females, aged from 12 to 46 years with an average of 25.9 years. These patients included 7 cases of total extensor tendon defect of 2nd-5th fingers, 7 cases of index finger extensor tendon defect, 3 cases of deep flexor tendon defect of 2nd- 5th fingers, 1 case of ring finger deep flexor tendon defect, 3 cases of long extensor tendon defect of 2nd-5th toes, 2 cases of long extensor hallucis tendon defect, and 1 case of shoulder adduction missing. The sizes of tendon defect ranged from 5 to 15 cm. The mean time from injury to operation was 1.3 months (range, 2 hours to 3 months). Results Incisions healed by first intention. No deep infection, infectious diseases, and obvious immune rejection occurred. All patients were followed up from 10 to 12 years with an average of 10.8 years. When compared with contralateral sides, at 10 years of follow-up, 1 patient lost 6-10° flexion function; after 10.6 years, flexion tendon releasing was performed; allografted tendon had normal color and elasticity with decreased diameter and with mild and moderate adherence; and after releasing, function was improved. According to Hand Surgery Association assessment standard, the results were excellent in 12 cases, good in 6, and poor in 6; the excellent and good rate was 75%. Conclusion Tendon allograft which is cultured with deoxyguanosine and preserved at low-temperature or ultra-deep-low-temperature is safe to use in cl inical, which has good long-term effectiveness in treating tendon defect.
ObjectiveTo systematically review the efficacy of hamstring tendon autograft versus hamstring tendon allograft in anterior cruciate ligament reconstruction by arthroscopy. MethodsDatabases including PubMed, EMbase, The Cochrane Library (Issue 2, 2015), CNKI, VIP, WanFang Data were electronically searched to collect randomized controlled trials (RCTs) about hamstring tendon autograft versus hamstring tendon allograft in anterior cruciate ligament reconstruction by arthroscopy from inception to February 2015. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Then, meta-analysis was performed using RevMan 5.2 software. ResultsA total of 6 RCTs involving 535 knees were included. The results of meta-analysis showed that:(1) Postoperative physical outcomes:There were no significant differences between the hamstring tendon autograft group and the hamstring tendon allograft group in positive rate of Lachman test (RR=1.25, 95%CI 0.92 to 1.71, P=0.15) and positive rate of Pivot shift test (RR=1.04, 95%CI 0.93 to 1.17, P=0.47) at 1 year postoperatively. (2) Postoperative functional recovery outcomes:There were no significant differences between both groups in KT-1000/2000 measurement (MD=-0.79, 95%CI -1.78 to 1.20, P=0.12), abnormal rate of IKDC scores (RR=1.03, 95%CI 0.90 to 1.1, P=0.42) and Lysholm scores (MD=0.23, 95%CI -1.86 to 2.33, P=0.83) at 1 year postoperatively. ConclusionHamstring tendon autograft and hamstring tendon allograft have similar efficacy in anterior cruciate ligament reconstruction by arthroscopy. Due to limited quality and quantity of the included studies, more large-scale and high quality studies are needed to verify the above conclusion.
Objective To investigate the method and short-term effectiveness of arthroscopic reconstruction of anterior cruciate l igament (ACL) using RetroButton-allogeneic tendon-interference screw. Methods Between June 2009 and October 2009, 23 patients with ACL rupture were treated by arthroscopic reconstruction with RetroButton-allogeneic tendon-interference screw. There were 15 males and 8 females with an average age of 32.5 years (range, 19-46 years), including 17 left knees and 6 right knees. The injury causes were sport trauma (13 cases), traffic accident (8 cases), and fall ing injury(2 cases). There were 7 acute cases (lt; 6 weeks) and 16 chronic cases (gt; 6 weeks). Among the cases, 11 cases compl icated by medial meniscus injury, 6 by lateral meniscus injury, 3 by the both injuries, and 5 by articular cartilage injury. All cases had no injuries of posterior cruciate l igament, medial or lateral collateral l igament, or posterolateral structure. The time from injury to operation ranged from 3 weeks to 32 months. Lysholm and International Knee Documentation Committee (IKDC) scores were used for subjective evaluation, while Lachman test and KT-1000 measurement for objective evaluation. Results All wounds healed by first intention. The symptoms of unstable knee were improved obviously. No high fever, infection, or immunologic rejection were observed. Refractoriness synovitis and joint effusion occurred in 1 case after operation, and was improved after articular cavity flushing for 7 times within 3 weeks. All cases were followed up 10-17 months (mean, 14.7 months). There were significant differences in Lysholm score, IKDC score, Lachman test, and KT-1000 measurement between pre-operation and last follow-up (P lt; 0.05). Conclusion Arthroscopic reconstruction of ACL with RetroButton-allogeneic tendon-interferencescrew is simple and safe, and its short-term effectiveness is satisfactory.
Objective To compare the recovery of proprioception between autograft and allograft for anterior cruciate l igament (ACL) reconstruction. Methods Between January 2008 and January 2010, 40 patients underwent ACL reconstruction with autologous tendon (autograft group, n=20) and allogeneic tendon (allograft group, n=20). No significant difference was found in gender, age, disease duration, and function scores between 2 groups (P gt; 0.05). All the patients underwent the ACL reconstruction with single-bundle technique. The knee range of motion (ROM), International Knee Documentation Committee (IKDC) score, and Lysholm score were measured after operation. The proprioception was assessedby the joint position sense (JPS) at 3 and 12 months postoperatively. The normal knee was used as control. Results Thepatients of 2 groups achieved heal ing of incision by first intention without compl ication of infection or haemarthrosis. Allpatients were followed up 12-18 months (mean, 13.5 months). There were significant differences in knee ROM, IKDC score, and Lysholm score between preoperation and 12 months postoperatively in 2 groups (P lt; 0.05). There was no significant difference in JPS 30°, JPS 60°, and JPS 90° between affected knees and normal knees in autograft group at 3 months postoperatively (P gt; 0.05). No significant difference was found in JPS 30° between affected knees and normal knees in allograft group at 3 months postoperatively (P gt; 0.05); but significant differences were found in JPS 60° and JPS 90° between affected knees and normal knees in allograft group at 3 months postoperatively (P lt; 0.05). There was no significant difference in JPS 30°, JPS 60°, and JPS 90° between affected knees and normal knees in 2 groups at 12 months postoperatively (P gt; 0.05). Significant differences were also found in JPS 60° and JPS 90° between affected knees of 2 groups (P lt; 0.05) at 3 months postoperatively, whereas no significant difference was found in JPS 30° between affected knees of 2 groups (P gt; 0.05). No significant difference was found in JPS 30°, JPS 60°, and JPS 90° between affected knees of 2 groups at 12 months postoperatively (P gt; 0.05). Conclusion Autologous andACL reconstruction is better than allogeneic ACL reconstruction in the recovery of proprioception at early time after surgery.