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.
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.
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.
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 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.
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.
ObjectiveTo systematically review the effects of autograft versus allograft tendon for posterior cruciate ligament single-bundle reconstruction. MethodsDatabases including PubMed, The Cochrane Library (Issue 3, 2015), EMbase, CBM, CNKI, VIP and WanFang Data were searched from inception to August 2015, to collect randomized controlled trials, clinical controlled trials and cohort studies of autograft tendon versus allograft tendon for posterior cruciate ligament single-bundle reconstruction. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Meta-analysis was performed using RevMan 5.3 software. ResultsA total of 7 cohort studies involving 376 patients who had undergone the arthroscopic transtibial single-bundle PCL reconstruction were included. The results of meta-analysis indicated that no significant differences were found between the autograft group and the allograft group in Lysholm score (MD=-0.54, 95%CI -2.36 to 1.27, P=0.56), Tegner score (MD=-0.04, 95%CI -0.88 to 0.80, P=0.93), IKDC objective score (OR=1.31, 95%CI 0.68 to 2.53, P=0.41) and posterior translation side-to-side difference (SMD=-0.15, 95%CI -0.37 to 0.07, P=0.18). However, patients in the allograft group had a longer duration of fever when compared with the autograft group patients (MD=-3.55, 95%CI-5.61 to -1.49, P=0.0007). ConclusionCurrent evidence shows that autograft tendon and allograft tendon tibial have similar effects in PCL single-bundle reconstruction, though there is a longer duration of fever in patients with allograft. Due to limited quality and quantity of the included studies, more high quality studies are needed to verify the above conclusion.