Regeneration of periodontal ligament and cementum by BMP-applied tissue engineering

Previously, we demonstrated that the inductive properties of bone morphogenetic protein (BMP) highly depend on the nature of the carrier material used for implantation. In this paper, we show that administration of BMP incorporated in a fibrous collagen membrane can help to regenerate periodontal ligament and cementum both in cat canines and in monkey molars. The partially purified bovine BMP was combined with one or two layers of a fibrous collagen membrane. Although the single layer approach showed partial regeneration of periodontal defects, it also quite often led to ankylosis. The double layer technique in artificially prepared class III furcation defects in monkey molars gave favorable results. After 12 wk, not only the alveolar process but also the periodontal ligament and cementum had regenerated along the entire treated dentin surface. Collagen fibers were arranged more or less perpendicular to the surface of the new cementum. Ankylosis was not seen. It is concluded that the double-layer approach is superior to the single-layer technique in regenerating cementum.     

An ultrastructural study on anterior cruciate ligament reconstruction using autogenous patellar tendon grafts in dogs

An ultrastructural study was undertaken concerning morphological changes within the autografted patellar tendon (PT) after being transplanted to the anterior cruciate ligament (ACL) in mongrel dogs. After 4 weeks, the arrangements of both large and small collagen fibrils in the PT graft became disordered, and the number of inflammatory cells increased. However, the same PT grafts revealed postsurgical signs of newly-produced collagen fibrils around activated fibroblasts at 12 to 24 weeks. At 52 weeks after the transplantation, small collagen fibrils increased in both number and density, showing a remarkable morphological similarity to the collagen fibrils of normal ACL. These data indicate that the characteristics of the PT graft eventually resemble those of a normal ACL. This paper was presented in part at the Combined Meeting of the Orthopedic Research Societies of the USA, Japan and Canada in Banff, Alberta, Canada, October, 1991.     

关节镜下四股半腱肌腱与股薄肌腱重建前交叉韧带

目的　探讨关节镜下应用四股半腱肌腱与股薄肌腱重建前交叉韧带的方法及疗效。方法　对 2 3例前十字韧带 (ACL )损伤患者行关节镜下四股半腱肌腱与股薄肌腱 ACL重建术 ,均取自同侧 ,将两股肌腱分别对折组成 4股 ,编织后预牵张 ,等长点部位钻胫骨骨道、股骨骨道 ,将肌腱拉入骨道 ,分别在屈膝 90°和伸膝位分别将两肌腱收紧 ,两端可吸收扣栓固定。合并损伤同期处理。结果　术后随访 3月～ 4年 ,平均 2 6月。术后 4周关节活动均达正常范围 ,术后抽屉试验除 4例 I度外 ,余 19例均阴性 ;L ysholm评分 ,术后 72～ 10 0分 ,平均 89分 ,较术前 5 4分明显提高 ;Tegner运动评级术后 4～ 8级 ,平均 6级 ,较术前平均 3级有所提高。结论　关节镜下四股半腱肌腱与股薄肌腱重建前交叉韧带 ,可吸收扣栓固定 ,是治疗 ACL断裂的较好方法。     

高压氧下大鼠脑组织中氧化氮合酶阳性细胞的表达(论著)

目的：探讨高压氧（HBO）对视觉中枢的影响。方法：SD大鼠12只，随机分为3组：分别为常压对照组（NP组），高压空气对照组（HBA组），和HBO实验组（HBO组）。HBA组和HBO组动物分别给予0．25MPa高压空气和纯氧，升压20分钟，在0．25MPa下稳压4小时，然后经20分钟减至常压。动物出舱后立即灌注取脑，利用NADPH-黄递酶（NADPH-diaphorase）组织化学方法，观察氧化氮合酶（NOS）阳性细胞见脑组织外侧膝状体（LGN）、视皮层及大脑顶叶皮层的表达。结果：NOS阳性细胞存在于大鼠LGN、视皮层及大脑项叶皮层中。在0．25MPaHBO作用下，视皮层、大脑顶叶皮层中NOS阳性细胞明显增加（P＜0．05），而LGN与对照组相比无显著性差异（P＞0．05）。结论：HBO对视觉中枢的毒性作用与视皮层NOS阳性细胞增加密切相关。     

关节镜下可吸收交叉钉固定腘绳肌腱重建前十字韧带

目的介绍在关节镜下腘绳肌腱移植重建前十字韧带并利用可吸收交叉钉固定的方法，探讨其临床效果。方法2005年3月至2006年3月，共治疗31例前十字韧带断裂患者。男18例，女13例；年龄19-51岁，平均34岁。致伤原因：交通伤15例，日常生活及运动损伤16例。病程为5d～36个月。合并半月板损伤12例，合并内侧副韧带Ⅰ、Ⅱ度损伤6例，Ⅲ度损伤3例，均为新鲜损伤。合并后十字韧带断裂6例。术后随访12-24个月，平均16．8个月，观察此固定方法的可靠性和疗效。以Lyscholm评分和KT-2000评价手术前后膝关节功能及稳定性。结果26例患者获得随访，所有患者均无伸膝受限，膝关节屈曲活动度均〉120°。屈膝90°时前抽屉试验均阴性；Lachman试验强阳性1例，阳性4例，阴性21例；膝关节功能Lyscholm评分为（94．6±4．2）分。KT-2000检查结果：25例双膝差距为0-4．0mm，平均2．4mm，1例患者关节不稳定，双膝差距5．5mm。结论可吸收交叉钉固定可为关节镜下腘绳肌腱移植重建前十字韧带提供早期的初始稳定性和后期的生物稳定性，是一种可靠的固定方法。     

后纵韧带钩辅助下颈椎后纵韧带骨化物切除减压术

目的探讨后纵韧带钩辅助下颈椎后纵韧带骨化物前路切除的适应证、方法及其临床效果。方法患者19例，男14例，女5例；年龄51-71岁，平均59岁。术前影像学检查结果示后纵韧带骨化物局限型6例，分节型13例；椎管狭窄率32％-75％，平均54％。术前神经功能JOA评分4-14分，平均9．6分。行颈前路常规手术入路，椎体开槽切骨达椎体后壁，范围超过后纵韧带骨化灶。利用后纵韧带钩插入后纵韧带下，钩起后纵韧带及骨化物，在后纵韧带与硬膜间形成一间隙，直视下用超薄型枪状咬骨钳切除后纵韧带及骨化物，而后植骨固定，恢复颈椎稳定性。结果随访6-36个月，平均16个月。术后JOA评分8～16分，平均12．8分，恢复率42％＇-92％，其中疗效优9例，良7例，可3例，优良率84．2％。4例患者术后并发脑脊液漏，保守治疗后均获得痊愈。术后CT和MR检查显示骨化后纵韧带切除完全，脊髓和硬膜囊形态恢复良好。结论后纵韧带钩可提高颈椎前路手术切除后纵韧带骨化物的安全性和有效性，适用于局限型和分节型、切除范围在两个椎节之间的颈椎后纵韧带骨化症患者。     

Does a tensioning device pinned to the tibia improve knee anterior–posterior load‐displacement compared to manual tensioning of the graft following anterior cruciate ligament reconstruction? A cadaveric study of two tibial fixation devices

Devices that are pinned to the tibia to tension an anterior cruciate ligament (ACL) graft produce joint reaction loads that in turn can affect the maintenance of graft initial tension after tibial fixation and hence knee anterior-posterior (AP) load-displacement. However, the effect of these devices on AP load-displacement is unknown. Our objectives were to determine whether tensioning by device versus tensioning by hand causes differences in AP load-displacement and intraarticular graft tension for two commonly used tibial fixation devices: a bioresorbable interference screw and a WasherLoc. AP load-displacement and intraarticular graft tension were measured in 20 cadaveric knees using a custom arthrometer. An initial tension of 110 N was applied to a double-looped tendon graft with the knee at extension using a tensioning device pinned to the tibia and a simulated method of tensioning by hand. After inserting the tibial fixation device, the 134 N anterior limit (i.e., anterior position of the tibia with respect to the femur with a 134 N anterior force applied to the tibia) and 0 N posterior limit (i.e., AP position of the tibia relative to the femur with a 0 N force applied to the tibia) were measured with the knee in 25 degrees flexion. Intraarticular graft tension was measured at extension. These limits and intraarticular graft tension were also measured after cyclically loading the knee 300 times. Compared to a simulated method of tensioning by hand, tensioning with a device pinned to the tibia did not decrease the 134 N anterior limit and did not cause posterior tibial translation. However, intraarticular graft tension was maintained better with a tensioning device pinned to the tibia for the Washerloc, but not the interference screw. For two commonly used tibial fixation devices, a tensioning device pinned to the tibia does not improve AP load-displacement at 25 degrees flexion over tensioning by hand when the graft is tensioned at full extension, but does improve the maintenance of intraarticular graft tension for the Washerloc.     

交叉韧带重建手术中可吸收挤压螺钉的应用

目的探讨交叉韧带重建术中可吸收挤压螺钉的使用方法和疗效。方法总结53例交叉韧带重建病例使用可吸收挤压螺钉的情况，在术中、术后并发症、术后康复、膝关节功能状况等方面进行回顾性分析。结果三例出现韧带切割现象。两例股骨侧螺钉拧入后导引针无法拔出。一例挤压螺钉断裂。术后Lysholm评分平均92.4±4．1。结论交叉韧带重建术中使用可吸收挤压螺钉固定的方法固定牢固，术后恢复快，利于早期康复。     

Plain radiographic findings in anterior cruciate ligament injury and repair

Although magnetic resonance imaging is the most accurate imaging method of evaluating the anterior cruciate ligament, several plain radiographic signs suggestive of anterior cruciate ligament injury have been described. Plain radiographs also play an important role in evaluating anterior cruciate ligament reconstruction.