The effect of intraosseous graft length on tendon-bone healing in anterior cruciate ligament reconstruction using flexor tendon

The current study was performed to understand the relationship between graft length placed within the bone tunnel and intraosseous graft healing in anterior cruciate ligament (ACL) reconstruction. Twenty-four adult beagle dogs were divided into two groups of 12 animals each. In each animal, ACL reconstruction using a 4-mm diameter autogenous flexor tendon graft was done in the left knee. In groups I and II, the graft having a length of 15 and 5 mm, respectively, was placed within the tibial tunnel. The proximal end of the graft was placed through the over-the-top route in all animals. In each group, five animals were sacrificed immediately after surgery, and the remaining seven were sacrificed at 6 weeks postoperatively. Biomechanical and histologic evaluations were performed. In pull out testing, the ultimate failure load and the linear stiffness of the graft-tibia complex harvested at 6 weeks were significantly greater than those harvested at the time-zero period. There were no significant differences in those parameters between groups I and II at 6 weeks. In each group, the perpendicular collagen fibers connecting the tendon to the bone tunnel wall were observed only in the narrow area located close to the intra-articular tunnel outlet. In conclusion, excessively long placement of the flexor graft within the bone tunnel does not result in an additional increase of anchoring strength and stiffness of the graft in ACL reconstruction.     

Effect of hyaluronan on the healing of partially ruptured anterior cruciate ligament of rabbits

The midportion of the anterior cruciate ligament (ACL) of rabbits was partially transected, and the effect of hyaluronan (HA) on its healing was determined. A 1% solution of HA (HA group) or physiological phosphate-buffered saline (control group) was administered intraarticularly, at 0.1 ml/kg body weight, once a week from 1 week after the operation. Two, 4, and 6 weeks after the initiation of HA administration, the ACLs were examined grossly, histologically and immunohistochemically. At 2 weeks, the lacerated portions were completely covered with scar-like tissue in both groups. These tissue areas were smaller in the HA group than in the control group. Histologically in the HA group, the regularity of collagen fibers (indicating the maturity of regenerated collagen fibers) had increased compared to findings in the control group, and the number of fibroblastic cells decreased gradually at a significantly faster rate. The number of inflammatory cells and blood vessels decreased gradually in both groups, with these values being lower in the HA group at each time point but not significantly so. Immunohistochemical examination of the repaired tissue revealed strong staining with anti-chondroitin sulfate proteoglycan antibody in the HA group 2 weeks after the first HA administration. The staining gradually became reduced, with the rate of reduction being faster in the HA group than in the control group. The stimulation of chondroitin sulfate proteoglycan production and the faster reduction of it in the HA group suggests that HA facilitated tissue repair and inhibited the formation of scar tissue.     

Periarticular heterotopic ossification: A complication of arthroscopic anterior cruciate ligament reconstruction using a two-incision technique

Extra-articular heterotopic bone formation was recognized as a postoperative complication of arthroscopic anterior cruciate ligament reconstructions in four knees around the femoral drill hole. Although laxity of the reconstructed anterior cruciate ligament was not observed in these patients, local pain, swelling, and deformity at the site of heterotopic ossification required surgical intervention. The ectopic bone can be successfully excised with restoration of function. The incidence rate of this complication is less than 1%.     

The use of frame fixation in the management of open distal extensor mechanism avulsion fracture in a dislocated knee

An avulsion fracture of the tibial tubercle is a common injury in traffic accident. If the fracture is closed, then a comparatively good prognosis can be expected through reinforcement of the bone via osteosynthesis and the use of artificial ligaments. In this case, an open wound was observed in the tibial tubercle, and the wound was so polluted that the healing process was significantly delayed. It was therefore difficult to provide simultaneous surgical treatment and so three operations were required to perform the reconstruction of the extensor mechanism. The reconstruction of extensor mechanism and the frame fixation between the patella and tibia was performed. Six months after the injury, the patient was able to walk without aid, had a range of movement from 5°to 130°, and did not show any indications of ADL disorder. Using this method of frame fixation between the patella and tibia proved to be an effective technique for the reconstruction of the open knee extension mechanism injury.     

关节镜下可吸收空心界面螺钉固定、四股腘绳肌腱重建前交叉韧带

目的探讨关节镜下可吸收空心界面螺钉固定、四股自体腘绳肌肌腱重建前交叉韧带(anterior cruciate ligament,ACL)的方法及疗效. 方法关节镜下以四股自体腘绳肌肌腱作为ACL替代物,应用(96L-4D)SR-PLA聚丙交酯生物可降解界面螺钉进行移植物固定, 对42例ACL损伤行ACL重建术. 结果 42例术后随访3～22个月,平均11.4月,膝关节活动度均在正常范围.术后Lachman 试验:37例≤1 ,4例2 ,1 例3 .轴移试验:42 例均为阴性.术后Lysholm 评分(89.7 ±9.6)分较术前(49.4±9.1)分显著提高(t=2.12,P=0.038).术后Tegner 活动评分(5.3±1.1)分较术前(2.3±0.7)分显著提高(t=4.13,P=0.008).术后1年MRI示29例可吸收空心界面螺钉部分被吸收;27例重建的韧带位置良好、形态正常;2例韧带在股骨的止点偏前;3例胫骨止点偏前,有轻度顶撞击现象. 结论四股腘绳肌腱是ACL重建的理想替代材料,可吸收空心界面螺钉是ACL重建的理想内固定材料.     

Anterior Cruciate Ligament Reconstruction: State of the Art

Abstract The rupture of the Anterior cruciate ligament (ACL) belongs to the most common ligament injuries of the human knee joint. ACL rupture results in an increased anterior translation and internal rotation of the tibia. Untreated knee instability causes a disintegration of the roll and sliding movement and a high incidence of secondary meniscus and chondral damages with consecutive or advanced arthritic changes. For deciding on a conservative or operative therapy, it is necessary to develop a high-risk profile. Elderly, inactive patients without instability symptoms can be treated conservatively; younger, active people and complex ligament injuries should receive an ACL replacement. The goal is to eliminate instability by maintaining the physiological kinematics of the knee. Anterior cruciate ligament may be reconstructed arthroscopically assisted by autologous tendons. Predominantly, hamstring- and bone-patellar-tendon grafts are used. No significant differences in knee laxity, clinically and functionally, were observed between both grafts. Various reconstruction techniques, single- or double-bundle techniques, were described. Successful replacement depends on a correct tunnel placement and reconstruction of the physiological band tension, a sufficient mechanical stability of fixation, an impingement-free range of motion and an adequate rehabilitation. A high degree of patient satisfaction in clinical and functional outcome could be evaluated.     

Hybrid Anterior Cruciate Ligament Reconstruction: Introduction of a New Technique for Anatomic Anterior Cruciate Ligament Reconstruction

Recently, anatomic or double-bundle reconstruction of the anterior cruciate ligament (ACL) has been presented in an effort to more accurately restore the native anatomy. These techniques create 2 tunnels in both the femur and tibia to reproduce the bundles of the ACL. However, the increased number of tunnels, particularly on the femoral side, has raised some concerns among authors and surgeons. We describe a technique to reconstruct the 2 distinct bundles of the ACL by using a single femoral tunnel and 2 tibial tunnels, the “hybrid” ACL reconstruction. The femoral tunnel is drilled through an anteromedial arthroscopy portal, which allows placement in a more anatomic position. Fixation in the femur is achieved with a novel device that separates a soft-tissue graft into 2 independently functioning bundles. Once fixed in the femur, the anteromedial and posterolateral bundles of the graft are passed through respective tunnels at the anatomic footprint on the tibia. These bundles are independently tensioned, which creates a reconconstruction that is similar to the native ACL. The technique presented provides surgeons with an alternative to other double-bundle techniques involving 4 tunnels.