| 1. The incidence and variation in tunnel enlargement after anterior cruciate ligament reconstruction.Objective:The purpose of this study was to determined the incidence, variation and location in tunnel enlargement after anterior cruciate ligament reconstruction.Methods : ACL reconstructions using hamstring tendons were performed in 58 patients (58 knees) in our study. MR scans were taken in a consistent manner at 1,3,6,12 and 24 months after surgery to measure tibial and femoral tunnel expansion. The diameter was measured perpendicular to the axis of the tunnel at proximal, middle, and distal . The diameter of bone tunnel at 1 months as reference width. under. The significant enlargement of bone tunnel was defined as more than 2 mm expansion. Viewing the occurrence ,location and change with bone tunnel enlargement . The diameter of unenlarged group was compared with enlarged group at 1,3,6,12 and 24 months after surgery .In enlarged group , the comparison of diameter on difference months was performed. Statistical analysis was performed using the t test for comparison of the diameter between enlarged and unenlarged group, analysis of variance was used for comparisons of diameter on difference months in enlarged group.Result:Bone tunnel enlargement was observed in 17 patients(29.3%),in 9 femoral tunnel(s15.5%)and in 12 tibial tunnel(s20.7%).Tunnel enlargement occurred at 3,6 and 12 months after surgery. The comparison of the diameter between enlarged and unenlarged group(formal and tibial tunnel) was no significant difference in 1,3 months(formal tunnel: t=0.12,P>0.05 ; t=0.30,P>0.05; tibial tunnel: t= 0.04,P>0.05; t= 0.52,P>0.05). The diameter of enlarged group was larger than unenlarged group in 6,12 and 24 months(formal tunnel: t= 4.01,P<0.01;t= 5.02, P<0.01; t= 5.13,P<0.01; tibial tunnel: t= 4.32,P<0.01; t= 5.51,P<0.01; t= 5.73,P<0.01).In enlarge group, there was no significant difference in the diameter of the bone tunnels between 1 and 3 months postoperatively(formal tunnel : q=0.22,P>0.05; tibial tunnel: q=0.33,P>0.05),but In 6,12 and 24 months postoperatively it was larger than 1 ,3 months postoperatively(formal tunnel : q= 2.11,p<0.01, q=2.55,p<0.01, q=2.77, p<0.01; tibial tunnel: q=2.33,p<0.05, q= 2.66, p<0.01, q=2.91, p<0.01)). There was no significant difference between6,12 and 24 months postoperatively(P>0.05).8 Femoral enlargements occurred at the distal side of the bone tunnel,and 1 at the proximal side of the bone tunnel. 9 tibial tunnel enlargements occurred at the proximal side of the bone tunnel, and 1 at the distal side of the bone tunnel.Conclusion:Tunnel expansion mainly ocuured during 3 to 6 months after surgery,and between 12 and 24 months postoperatively it remained basically unchanged. Femoral and tibial tunnel enlargements mainly occurred at the intra-articular side of the bone tunnel.2. Relationship between bone tunnel enlargement after anterior cruciate ligament reconstructions and clinical outcomeObjective: The purpose of this study was to observe the feature of tunnel enlargement after anterior cruciate ligament reconstructions and to investigate the influencing factors and the relationship between bone tunnel enlargement and clinical outcome.Methods: There were 103 patients who accepted anterior cruciate ligament reconstructions with autogenous hamstring tendons for follow-up . Magnetic resonance imaging (MRI) offers the possibility of visualizing the bone tunnels at time from 12 to 18 months after surgery. The width was measured for tibial and femoral tunnel and compared to diameter at 1 month.The tunnel size was graded to 4 level depend the increased width. Level 0 (<2mm), level 1 (2~4mm), level 2 (4~6mm), level 3 (>6mm).The femoral tunnel angle (α)and tibial tunnel angle (β) were meaured.The evalaution clinical outcome using the Lysholm score and anteroposterior stability using the KT-1000 arthrometer measurement. Statistical analysis was performed using the rank sum test for comparison of degree of femoral tunnel angle (α)and tibial tunnel angle (β), Lysholm score and KT data in deferent groups.Results:Bone tunnel enlargement was observed in27 patients (26.2%): among them ,16 cases in femoral tunnels(11 grade 1, 5 grade 2 ), and 19 cases in tibial tunnels (12 grade 1, 7 grade 2),and 8 cases in both side tunnels.There was no statistical significant difference in the lysholm scores(94±4.2) among the above different grades(formal side: H=0.273; tibial side :H=0.641 P>0.05),and the KT-1000 arthrometer measurements (1.9±1.2mm )in grade 2 was more than grade 1and grade 0(formal side: grade 2 and 1 H=34.3, grade 2 and 0 H=43.0; tibial side: grade 2 and 1 H=34.3, grade 2 and 0 H=340.8 P<0.05), and the angleα(86.5°±3.2°)in grade 2 was less than grade 0 and grade 1(grade 2 and 1 H=38.6, grade 2 and 0 H=40.6;P<0.05).In tibial tunnels, there was no statistical significant difference in angleβ(64.5°±1.4°)among these different grades(H=0.8,P>0.05).Conclusion:Bone tunnel enlargement occurred after anterior cruciate ligament reconstructions with autogenous hamstring tendons. The evident tunnel enlargement can affect anteroposterior stability of knee.Femoral tunnel angle concerned with tunnel enlargment.3. Use of periosteum, cancellous bone and BMP-2to enhance tendon healing in a bone tunnel: empirical studyObjective:This study examines the hypothesis that useing periosteum, cancellous bone and BMP-2 can enhance tendon healing in a bone tunnelMethods:60 male New Zealand White rabbits were used as an animal model for ACL reconstruction with semitendinosus tendon . The portion of the semitendinosus tendon to be placed in the bone tunnel was and then was treated with one of the five methods as described: Group A, no other treatment ;Group B, periosteal graft was wrapped around the tendon with the cambium layer facing toward the bone; Group C, cancellous bone particle was packed to the bone tendon interface. Group D, collagen sponge was packed to the bone tendon interface. Group E, rhBMP-2 was added to bone tendon interface. the contralateral (control) limb. The healed tendon-bone attachment was evaluated at serial times at 2, 4 and 8 weeks using histologic examination with hematoxylin and eosin and biomechanical testing. Statistical analysis was performed using the rank sum test for comparison of biomechanical testing in deferent groups at 2, 4 weeks.Result:Four weeks after the surgery, in group A, there was abundant alignment collagen fibers around tendon, and slight cartilage cell can see. Group B showed a tight interdigitation between the tendon graft and the newly formed bone with abundant collagen fibers. Group C showed a newly formed trabecular bone with a well-organized structure.Group D revealed progressive re-establishment of collagen-fiber continuity between the bone and the tendon. A layer of cellular, fibrous tissue was noted between the tendon and the bone.Group E showed collagen fibers interconnecting the newly formed bone and the tendon. Biomechanical testing result at 2 weeks, there was statistical significant among these five groups(group A:3.04±0.950 N; group B, 5.25±0.955 N; group C, 6.805±1.133 N; group D, 2.95±0.862 N; group E, 5.09±1.260 N). The strength of group A is lower than the group B, C and E(H=12.36,13.95,11.82; P<0.05); The strength of group C is greater than the group B and E(H=11.02,10.95; P<0.05); The strength of group E is greater than the group D(H=12.93; P<0.05).Conclusion:This study demonstrated that periosteal graft , cancellous bone graft and bone morphogenetic protein-2 can all accelerate the healing process and enhance pull-out strength when a tendon graft is transplanted into a bone tunnel.4. Anterior cruciate ligament reconstruction using periosteum wrapped autologous hamstring tendons: clinical researchObjective: we have developed a surgical technique using a periosteal flap wrapped autologous hamstring tendons in ACL reconstruction and to examine the short term outcome.Methods:110 patients were included: the experimental group of 52 patients had Anterior cruciate ligament reconstruction using periosteum wrapped autologous hamstring tendons. The control group of 58 patients had Anterior cruciate ligament reconstruction using autologous hamstring tendons. 110 patients were followed-up after average of 19(12–25) months.The evaluation of patients included a clinical assessment using the IKDC score, the Tegner score, the modified HSS score, KT 1000 arthrometer measurements and a radiographic assessment using anteroposterior and lateral radiographs.The incidence of femoral and tibial bone tunnel enlargement was assessed 12 months after surgery.Result:Clinical results in experimental guoupe (periosteum-wrapped grafts) are dependent on the wrapping up of Periosteum, bone tunnel,Graft Fixation,and Postoperative Rehabilitation .The good or excellent results have been reported in approximately 90% of cases 52. whereas 44patients had normal or nearly normal knee function, according to IKDC criteria. Follow-up KT 1000 tests showed an average maximal manual side-to-side difference of 1.7±1.1 mm. shows the KT 1000 results as well as the results of Lachman's knee ligament test and pivot-shift testing.The evaluation of the level of activity using the Tegner score revealed that 40 patients regained their preinjury activity level. 44 patients showed full knee extension and 42 patients showed full knee flexion at follow-up.The average HSS score are no significant difference between experimental group (90.6±0.57points) and control group (89.9±0.82points ) (t=0.714,p > 0.05). The KT 1000 measurements(133N) was larger in control group (2.3±1.0 mm) than in experimental group (1.7±1.1 mm). There was significant difference in laxity between the two groups(t=6.427,p < 0.05). At 12 months on average, tunnel walls were always visible, and widening was constant in both groups. The average enlargement decreased in experimental group (17.3% ) than control group (34.5% ) on femoral tunnel(χ2=4.17,p <0.05) , and enlargement decreased in experimental group (19.2% ) than control group (36.2%) on tibial tunnel(χ2=3.90,p <0.05) .Conclusion:The surgical technique using a periosteal flap wrapped autologous hamstring tendons in ACL reconstruction has exact outcome. This technique can enhance stability of knee, and prevent bone tunnel enlargement. |
PDF Full Text Request