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.     

近节指骨段屈肌腱鞘不同范围损伤对肌腱功能的影响

目的 探索手指屈肌腱在近节指骨段不同范围损伤时对屈指肌腱功能的影响。方法 采用12只成人尸体手指。实验分为:第一阶段屈指肌腱完整,以后四个阶段依次沿近节指骨掌侧小线闭开小央1/4、1/2、3/4及全长。在掌指关节被动屈80°和掌指关节屈80°同时近侧指关节屈100°时,测量指浅屈肌腱(FDS)和指深屈肌腱(FDP)的滑动距离。根据肌腱力臂和滑动距离的关系,得出屈指肌腱在掌指关节处和近侧指间关节及肌腱在近节指骨段的弓弦畸形程度。结果 腱鞘中央1/4切开时,指屈肌腱的滑动距离、力臂均无显著变化;1/2切开后,单纯屈曲掌指关节时的FDS腱和掌指、近节指间关节屈曲时的FDS、HDP腱的滑动距离和力臂较腱鞘完整时显苫增大(P<0.05);切开3/4长度后,FDS、FDP腱滑动距离均有统计学意义变化,FDS、FDP腱力臂平均增加8～9％;全切开腱鞘,FDS、FDP腱滑动距离变化正统计学上有高度显著性(P<0.01),两腱力臂分别增加16％和15％。随腱鞘切开范围增大,FDS、FDP在近节指骨段的弓弦畸形程度也越来越大。结论 从肌腱的生物力学变化可见,近节指骨段腱鞘的小范围损伤如中间1/4以内损伤时,对肌腱功能影响小,可以不予修复;若损伤超过1/2长度,尤其对腱鞘全长损伤,应予以修复以恢复肌腱功能。     

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.     

Posterior Acromioclavicular Dislocation with Clavicular Fracture and Trapezius Entrapment

AbstractBackground: Posterior acromioclavicular dislocation is rare. Dislocation associated with fracture of the clavicle and simultaneous entrapment of the lateral end of the clavicle by trapezius muscle has not been reported. Posterior dislocation occurs frequently owing to forceful move of the scapula anteriorly and superiorly or from direct force applied to the lateral end of the clavicle and this may be associated with clavicular fracture. In acute dislocations, open reduction, internal joint stabilization and soft tissues reconstruction have been recommended.Case Study: Acute posterior dislocation occurred in a 32-year-old man. The lateral end of the clavicle was displaced posteriorly and inferiorly, and firmly entrapped in trapezius muscle. The clavicular fracture was undisplaced. The coracoclavicular ligaments were stretched but intact. Open reduction was secured with two smooth Kirschner wires. The disrupted soft tissues were repaired. The clavicular fracture was not explored. Shoulder movement started at 6 weeks. Wires were removed. 10 years later he had pain-free, unrestricted shoulder movement, and the radiographs showed wellreduced, essentially normal acromioclavicular joint.Conclusion: Open reduction, internal joint stabilization and soft tissue reconstruction will result in return and long lasting unrestricted pain-free function of the shoulder.     

骨髓间质干细胞体外预构组织工程化肌腱的实验研究

目的探讨骨髓间质干细胞与胶原-聚羟基乙酸的细胞相容性,为构建组织工程化肌腱寻求理想方法.方法以贴壁法分离、培养骨髓间质干细胞,并检测CD44.在实验组中将骨髓间质干细胞置入含胶原-聚羟基乙酸的DMEM培基中培养:在对照组中将骨髓间质干细胞置入DMEM培基中培养.通过MTT方法比较两组的细胞活性和生长情况,并对实验组进行超微观察.以骨髓间质干细胞为种子细胞,以胶原-聚羟基乙酸为支架在体外预构组织工程化肌腱.结果以贴壁法原代培养骨髓间质干细胞,11天细胞即汇合成片,检测CD44示阳性.骨髓间质干细胞接种于胶原-聚羟基乙酸中混合培养后14天生长良好,始终保持89%以上的细胞活力,与对照组比较无显著差别;实验组细胞数未发生明显改变,而对照组从第4天开始即发生增殖.透射电镜示实验组细胞培养14天后仍保持旺盛的分泌功能.体外预构的组织工程化肌腱具有良好的形态,细胞伸展成梭形,沿聚羟基乙酸缝线大致平行排列.结论骨髓间质干细胞与胶原-聚羟基乙酸的细胞相容性好.以骨髓间质干细胞为种子细胞,以胶原-聚羟基乙酸为支架可在体外初步预构组织工程化肌腱.     

Microarray analysis of healing rat Achilles tendon: evidence for glutamate signaling mechanisms and embryonic gene expression in healing tendon tissue.

Tendon healing is a complex process consisting of a large number of intricate pathways roughly divided into the phases of inflammation, proliferation, and remodeling. Although these processes have been extensively studied at a variety of levels in recent years, there is still much that remains unknown. This study used microarray analyses to investigate the process at a genetic level in healing rat Achilles tendon at 1, 7, and 21 days postinjury, roughly representing the inflammation, proliferation, and remodeling phases. An interesting temporal expression profile was demonstrated, identifying both known and novel genes and pathways involved in the progression of tendon healing. Both inflammatory response and pro-proliferative genes were shown to be significantly upregulated from 24 h postinjury through to 21 days. Day 7 showed the largest increase in genetic activity, particularly with the expression of collagens and other extracellular matrix genes. Interestingly, there was also evidence of central nervous system-like glutamate-based signaling machinery present in tendon cells, as has recently been shown in bone. This type of signaling mechanism has not previously been shown to exist in tendon. Another novel finding from these analyses is that there appears to be several genes upregulated during healing which have exclusively or primarily been characterized as key modulators of proliferation and patterning during embryonic development. This may suggest that similar pathways are employed in wound healing as in the tightly regulated progression of growth and development in the embryo. These results could be of use in designing novel gene-based therapies to increase the efficacy and efficiency of tendon healing.