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.
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 study the effectiveness of anterior cruciate l igament (ACL) reconstruction using autologous periosteum wrapping tendon allograft by comparing with using simple tendon allograft. Methods Between March 2008 and November 2008, 68 patients with ACL injury were treated, who were in accordance with the inclusion criteria. They were divided into 2 groups randomly according to different treatment methods: ACL was reconstructed with autologous periosteum wrapping tendon allograft in 31 patients (test group) and with simple tendon allograft (control group) in 37 patients. There was no significant difference in gender, age, disease duration, the cause of injury, and functional score preoperatively between 2 groups (P gt; 0.05). Anatomic single-bundle ACL reconstruction was performed in 2 groups. Results Little exudation at tibial tunnel incision was found in 1 case respectively in both groups at 2 weeks after operation and was cured by dressing change and antibiotics. The other incisions healed by first intention. The patients were followed up 24-29 months (mean, 26 months) in the test group and 24-32 months (mean, 27 months) in the control group. CT showed bone tunnel enlargement in both groups at 2 years after operation, but the rate of the tunnel enlargement was less inthe test group (5/31, 16.1%) than in the control group (14/37, 37.8%), showing significant difference (χ2=3.948, P=0.047). At 2 years after operation, the results of Lachman test and pivot shift test were negative in 23 cases (74.2%) and 25 cases (80.6%) of the test group, and in 26 cases (70.3%) and 30 cases (81.1%) of the control group, respectively. KT-1000 examination showed the displacement of the test group [(1.74 ± 0.88) mm] was less than that of the control group [(2.36 ± 0.83) mm], showing significant difference (t= —2.979, P=0.004). There was no significant difference in Lysholm score, Hospital for Special Surgery (HSS) score, Tegner score, and International Knee Documentation Committee (IKDC) score between 2 groups at 2 years after operation (P gt; 0.05). Conclusion Compared with simple tendon allograft, ACL reconstruction with autologous periosteum wrapping tendon allograft can improve tendon-bone heal ing, and decrease the rate of bone tunnel enlargement, so it has good short-term outcome.
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.
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 explore the effects of cryopreservation on the cell survival rate, cell viability, early apoptosis, migration ability, and tendon-related marker expression of tendon-derived stem cells (TDSCs) in rat patellar tendons.MethodsThe patellar tendon tissues were harvested from 12 4-month-old male Sprague Dawley rats; 12 patellar tendon tissues from 6 rats were cryopreserved (the experimental group), and the other 12 patellar tendon tissues were not treated (the control group). The patellar tendons were digested with 0.3% type I collagenase to obtain nucleated cells. The survival rate of nucleated cells was detected by trypan blue exclusion assay, and colony-forming ability by crystal violet staining. TDSCs were isolated and cultured to passage 3 (P3). The cell viability of TDSCs was detected by Alamar Blue method, the early apoptosis by Annexin V-FITC/PI assay, the cell migration ability by Transwell method, and the mRNA expressions of tendon-related markers [collagen type I (Col1α1), scleraxis (Scx), and tenomodulin (Tnmd)] by real-time quantitative PCR.ResultsThe survival rate of nucleated cells was 91.00%±3.63% in the control group, and was 61.65%±4.76% in the experimental group, showing significant difference (t=12.010, P=0.000). The formation of the primary nucleated cell clones was observed in 2 groups. At 12 days, the number of colonies forming of the experimental group [(8.41±0.33)/1 000 nucleated cells] was significantly lower than that of the control group [(15.19±0.47)/1 000 nucleated cells] (t=28.910, P=0.000). The percentage of TDSCs in the active nucleated cells in the experimental group (1.37%±0.09%) was significantly lower than that in the control group (1.67%±0.10%) (t=5.508, P=0.003). The growth trend of TDSCs (P3) in the 2 groups was consistent within 14 days. There was no significant difference in absorbance (A) value between 2 groups at each time point (P>0.05). The early apoptotic rate of TDSCs was 1.67%±0.06% in the experimental group and was 1.63%±0.06% in the control group, showing no significant difference (t=0.707, P=0.519). Under microscope, TDSCs adhered to the lower chamber of the Transwell chamber; the number of cells was 445.00±9.70 in the experimental group and was 451.50±12.66 in the control group, showing no significant difference (t=0.998, P=0.342). The relative mRNA expressions of Col1α1, Scx, and Tnmd were 3.498±0.065, 0.062±0.002, and (4.211±0.211)×10–5 in the experimental group and were 3.499±0.113, 0.062±0.001, and (4.341±0.274)×10–5 in the con-trol group, showing no significant difference (t=0.013, P=0.991; t=0.042, P=0.969; t=0.653, P=0.549).ConclusionThe survival rate of nucleated cells in cryopreserved rat tendon tissues is lower, but a large number of active TDSCs, and its cell viability, early apoptosis rate, migration ability in vitro, and cell tenogenic differentiation ability are remained.
ObjectiveTo investigate effectiveness of allogeneic tendon of " W” type knit in repair of traumatic anterior dislocation of sternoclavicular joint.MethodsBetween June 2013 and June 2017, 12 patients with traumatic anterior dislocation of sternoclavicular joint after poor conservative treatment were treated with allogeneic tendon of " W” type knit. Of them, 10 were males and 2 were females, aged from 25 to 58 years (mean, 42 years). All injuries were caused by traffic accidents. The time from injury to operation was 4-12 weeks (median, 6 weeks). All of them were closed injuries. The patients had no fracture around the shoulder, or blood vessels, nerves, and other adjacent limb joint injuries. The operation time, intraoperative blood loss, incision healing, and complications were recorded. The sternoclavicular joint was observed by X-ray film and CT at 1 year after operation. Visual analogue scale (VAS) score, University of California Los Angeles (UCLA) score, Rockwood score, modified Hospital for Special Surgery (HSS) score, and Constant-Murley score were used to evaluate the function of shoulder joint after operation.ResultsThe operation time was 60-80 minutes (mean, 70 minutes). The intraoperative blood loss was 50-100 mL (mean, 60 mL). Primary healing of incision was obtained in all patients without complications. All the patients were followed up 12-24 months (mean, 18 months). At 1 year after operation, X-ray film and CT examination showed that the position of sternoclavicular joint was satisfactory. At 1 year after operation, the Rockwood score was 12-14 (mean, 13). The UCLA score was 28-34 (mean, 31). The VAS score was significant lower than that before operation (P<0.05), and the Constant-Murley score and modified HSS score were significantly higher than those before operation (P<0.05).ConclusionThe repair of traumatic anterior dislocationr of sternoclavicula joint with allogeneic tendon of " W” type knit can effectively reconstruct the stability of the joint, retain the physiological fretting, and obtain satisfactory results.
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.