Objective The tendon-bone heal ing is the key point to ensure the success of the anterior cruciate l igament (ACL) reconstruction. To observe the histological change in the tendon-bone heal ing after ACL reconstruction by different concentrations of platelet-rich plasma (PRP) combined with deproteinized bone (DPB) of calf as bone tunnel infill ing and to investigate the active effect of the complex on tendon-bone heal ing and to define the optimal concentration of PRP. Methods Eight mL blood was drawn from central artery of New Zealand rabbit ears; PRP was prepared by Landesbergmethod, and l iquid supernatant was used as thinner to prepare different concentrations of PRP (30%, 60%, and 100%). Fresh osteoepiphysis spongy bone was harvested from lower end of femur of newborn calf to prepare DPB by way of 30% H2O2 and ether alternating soaking for 24 hours continuous 6 times. DPB was soaked in different concentrations of PRP and mixed with activator to prepare the PRP/DPB complex. A total of 54 New Zealand white rabbits, aging 8-12 months, weighing (2.5 ± 0.4) kg, were divided randomly into 3 groups: group A (30%PRP/DPB complex, n=18), group B (60%PRP/DPB complex, n=18), and group C (100%PRP/DPB complex, n=18). The legs of the rabbits were randomly divided into experimental side and the control side; ACL was reconstructed by semitendinosus and PRP/DPB complex in bone tunnel in the experimental side, and only by semitendinosus in the control side. The general conditions of the rabbits were observed postoperatively and HE staining was used to observe the tendon-bone heal ing, then I-IV levels of semi-quantitative analysis of the tendon-bone heal ing were evaluated according to Demirag standard at 3, 6, and 12 weeks. Results General observation: Synovial fluid sl ightly increased in the specimens and no bony tissue was found in inner of femoral tunnel at 3 weeks; there was no synovial fluid in all the specimens and scar tissue was discovered in inner of femoral tunnel at 6 weeks; and there was no synovial fluid and the tendons became tighter with fibrous tissue at 12 weeks. Histological observation: New granulation tissue formed in the tendon-bone interface of group A experimental sides at 3 weeks; there was various widths of Sharpey type textile fiber in the tendon-bone interface at 6 weeks; Sharpey type textile fiber arranged regularly, which formed an irregular and blur “tidal l ine” at 12 weeks. Group B experimental sides were better than any other group at 3, 6, and 12 weeks; chondrocyte-l ike arranged regularly in the tendonboneinterface at 3 weeks; the number of chondrocyte-l ike per unit area was more than that of the other groups at 6 weeks;and chondrocyte-l ike prol iferated and matured in the tendon-bone interface, Sharpey type textile fiber became tighter andordered. Group C experimental sides were similar to both sides of group A at 3 weeks, however, the prol iferation of relatively mature dense connective tissue was worse than that of other groups at 6 and 12 weeks. According to Demirag grading, there were significant differences in tendon-bone heal ing between the experimental sides and the control sides of group B at 3 and 6 weeks, and between group B experimental sides and group C experimental sides at 12 weeks (P lt; 0.05). Conclusion The mixture of PRP/PRP has good biocompatibil ity and bone induction, so it can enhance tendon-bone heal ing after ACL reconstruction when the concentration of PRP is 60%.
ObjectiveTo investigate the effects of different concentrations of osteoprotegerin (OPG) combined with deproteinized bone (DPB) on the bone tunnel after the anterior cruciate ligament (ACL) reconstruction. MethodsThe femoral epiphyseal side was harvested from newborn calf, and allogenic DPB were prepared by hydrogen peroxide-chloroform/methanol method. Then, DPB were immersed in 3 concentrations levels of OPG (30, 60, 100 μg/mL) and 3 concentration ratios (30%, 60%, 100%) of the gel complex were prepared. Sixty healthy New Zealand white rabbits, male or female, weighing (2.7±0.4) kg, were divided randomly into 4 groups (n=15):control group (group A), 30% (group B), 60% (group C), and 100% (group D) OPG/DPB gel complex. The ACL reconstruction models were established by autologous Achilles tendon. Different ratios of OPG/DPB gel complex were implanted in the femoral and tibial bone tunnel of groups B, C, and D, but group A was not treated. The pathology observation (including the percentage of the femoral bone tunnel enlargement) and histological observation were performed and the biomechanical properties were measured at 4, 8, and 12 weeks after operation. ResultsOne rabbit died of infection in groups A and D, 2 rabbits in groups B and C respectively, and were added. General pathology observation showed that the internal orifices of the femoral and tibia tunnels were covered by a little of scar tissue at 4 weeks in all groups. At 8 weeks, white chondroid tissues were observed around the internal orifices of the femoral and tibia tunnels, especially in groups C and D. At 12 weeks, the internal orifices of the femoral and tibia tunnels enlarged in groups A, B, and C, but it was completely closed in group D. At each time point, the rates of the femoral bone tunnel enlargement in groups B, C, and D were significantly lower than that in group A, and group D was significantly lower than groups B and C (P<0.05); group C was significantly lower than group B at 8 weeks, but no significant difference was found at 4 and 12 weeks (P<0.05). Hisological observation showed that fresh fibrous connective tissue was observed in 4 groups at 4 weeks; there was various arrangements of Sharpey fiber in all groups at 8 weeks and the atypical 4-layer structure of bone was seen in group D; at 12 weeks, Sharpey fiber arranged regularly in all groups, with typical 4-layer structure of bone in groups B, C, and D, and an irregular "tidal line" formed, especially in group D. Biomechanics measurement showed that the maximum tensile load in group D was significantly higher than that in groups A and B at 4 weeks (P<0.05), but no significant difference was shown among groups A, B, and C, and between groups C and D (P>0.05); at 8 weeks, it was significantly higher in groups C and group D than group A, and in group D than group B (P<0.05), but there was no significant difference between groups A, C and group B (P>0.05); at 12 weeks, it was significantly higher in groups C and D than groups A and B, and in group D than group C (P<0.05), but difference was not significant between groups A and B (P>0.05). ConclusionDifferent concentrations ratios of OPG/DPB gel complexes have different effects on the bone tunnel after ACL reconstruction. 100% OPG/DPB gel complex has significant effects to prevent the enlargement of bone tunnel and to enhance tendon bone healing.
ObjectiveTo compare the strength difference between the interfacial screw and the interfacial screw combined with bone tunnel crossing technology to fix the tibial end of ligament during anterior cruciate ligament (ACL) reconstruction through the biomechanical test.MethodsTwenty fresh frozen pig tibia were randomly divided into two groups (n=10) to prepare ACL reconstruction models. The graft tendons in the experimental group were fixed with interfacial screw combined with bone tunnel crossing technology, and the graft tendons in the control group were fixed with interfacial screw. The two groups of specimens were fixed in the high-frequency dynamic mechanics test system M-3000, and the length change (displacement), ultimate load, and stiffness of graft tendons were measured through the reciprocating test and load-failure test.ResultsThe results of reciprocating test showed that the displacement of the experimental group was (3.06±0.58) mm, and that of the control group was (2.82±0.46) mm, and there was no significant difference between the two groups (t=0.641, P=0.529). The load-failure test results showed that the stiffness of the experimental group and the control group were (95.39±13.63) and (91.38±14.28) N/mm, respectively, with no significant difference (t=1.021, P=0.321). The ultimate load of the experimental group was (743.15±173.96) N, which was significantly higher than that of the control group (574.70±74.43) N (t=2.648, P=0.016).ConclusionIn ACL reconstruction, the fixation strength of tibial end with interface screw combined with bone tunnel crossing technology is obviously better than that of interface screw alone.
Fourteen patients with anterior cruciate ligament (ACL) injuries were treated with carbon fiber—superficial fascia complex and were followed up with an average of 25 months. The overall results in our series were excellent or good. The patients had stable knees and few had some subjective complaints. The influence on the knee function after injury of ACL was discussed.
目的:对同侧胫腓骨骨折、髋关节骨折后脱位合并膝后交叉韧带损伤的创伤机制及诊断进行分析探讨。方法:对2007年1月至2008年6月收治的7例同侧胫腓骨骨折、髋关节骨折后脱位合并膝后交叉韧带损伤患者的临床资料、诊治经过和随访结果进行总结分析。结果: 胫腓骨开放性骨折3例(42.9%),闭合性骨折4例(57.1%);髋关节均有后脱位,其中伴有髋部骨折5例(71.4%)。膝后交叉韧带实质部断裂4例(57.1%),胫骨止点撕脱骨折3例(42.9%)。7例患者获平均14.7个月(12～18个月)随访。Lysholm膝关节功能评分术后6月95.8±3.71,术后12月97.6±2.7。结论:明确同侧胫腓骨骨折、髋关节骨折后脱位合并膝后交叉韧带损伤的创伤机制,全面、准确、系统的问诊查体和完善的辅助检查是早期确诊、提高疗效的关键。
ObjectiveTo summarize the research progress of killer turn in posterior cruciate ligament (PCL) reconstruction.MethodsThe literature related to the killer turn in PCL reconstruction in recent years was searched and summarized.ResultsThe recent studies show that the killer turn is considered to be the most critical cause of graft relaxation after PCL reconstruction. In clinic, this effect can be reduced by changing the fixation mode of bone tunnel, changing the orientation of bone tunnel, squeezing screw fixation, retaining the remnant, and grinding the bone at the exit of bone tunnel. But there is still a lack of long-term follow-up.ConclusionThere are still a lot of controversies on the improved strategies of the killer turn. More detailed basic researches focusing on biomechanics to further explore the mechanism of the reconstructed graft abrasion are needed.
Objective To investigate whether anterior cruciate l igament (ACL) reconstruction with the remnants and the remaining bundle preservation is beneficial for the revascularization of the graft or not. Methods Animal models of the ACL reconstruction in 18 healthy New Zealand White rabbits (2-3 months old) were made using about 2.5 cm long extensordigitorum longus tendon and randomly divided into three groups (n=6): remnants debridement group (group A), remnantspreservation group (group B) and remaining bundle preservation group (group C). The histological examination was made after 2, 4 and 8 weeks of operation. The intravascular injection of ink was used to observe the revascularization of the graft. The specimens were stained with HE method to observe the histological changes of the graft. Results All the animals were in good condition and had good knee functions in the observation period. There was no new vessel in groups A and B at 2 and 4 weeks postoperatively. And new vessels were observed in the synovium of the graft in group C. The areas of the vessels in group C were (505 ± 27) pixels at 2 weeks and (624 ± 23) pixels at 4 weeks. At 8 weeks postoperatively new vessels were observed in all the three groups. The new vessel areas of groups A, B and C were (674 ± 65), (836 ± 76) and (1 219 ± 146) pixels, respectively. The vessel areas of group C were significantly bigger than those of groups A and B (P lt; 0.05). The vessel area of group B was significantly bigger than that of group A (P lt; 0.05). The fibroblast amount in group B was significantly more than that in group A at 2 and 4 weeks postoperatively (P lt; 0.05). But there was no significant difference between them at 8 weeks postoperatively (P gt; 0.05). The fibroblast amount of group C was significantly more than that of group A (P lt; 0.05) at each observation time postoperatively. At 2 and 4 weeks postoperatively, the fibroblast amount of group C was significantly more than that of group B (P lt; 0.05), but there was no significant difference between them at 8 weeks postoperatively (P gt; 0.05). Conclusion ACL reconstruction with remnants and remaining bundle preservation is beneficial for the early revascularization and fibroblasts growing of the graft. So the course of necrosis, regeneration and remodel ing of the graft is shortened.
OBJECTIVE To measure the isometric point of the attachment site in femur during the reconstruction of posterior cruciate ligament (PCL). METHODS Seven fresh knee specimens from cadavers were adopted in this experiment. The anterior, posterior, proximal, distal and central points of the PCL’s femoral attachment site were respectively anchored to the middle of the PCL’s tibial attachment site by the trial isometer wires. The length changes of the intra-articular part of the wires were recorded while the knee was flexed from 0 degree to 120 degrees by a continuous passive motion(CPM) machine. RESULTS The maximal length changes in every points were compared. It showed that the length change in anterior point was the biggest, the distal point was less than that of anterior point, and the proximal point was the least. There was significant difference between proximal and posterior points, but no significant difference between proximal and central points, neither between central and posterior points. All of the maximal length changes of proximal, central and posterior points were not greater than 2 mm. CONCLUSION The femoral tunnel for the PCL reconstruction should be located at the proximal point, which is the middle point of upper edge of femoral attachment site. The selected point for femoral tunnel also may be moved slightly in the direction to central or posterior points according to the needs of operation.