研发一种适用于关节镜下治疗前交叉韧带止点骨折(TSAFs)的新型双瓣钢板内固定系统，并论证其可行性及实用性。

收集松山湖中心医院50例17~45岁TSAFs病例(排除膝骨折及骨代谢异常等)的CT数据，掌握骨折块大小及解剖分布特点；对8具新鲜成年人膝关节标本髁间窝及前叉韧带止点周围骨性空间测量，确定止点前方空间大小及特点。60例猪膝标本制作成TSAFs模型，简单随机抽样法分为4组，每组15例，分别予不同方式内固定：单股钢丝环扎固定(钢丝环扎组)，空心钉固定(空心钉组)，指钢板不可吸收Fiber Wire线固定(指钢板线组)；实验组为双瓣钢板固定(双瓣钢板组)。对各组进行抗拨伸力生物力学实验并进行对比分析，多组间采用方差检验，各组间采用SNK-q检验进行两两对比。通过临床应用双瓣钢板内固定系统对8例17~45岁TSAFs病人进行关节镜下手术，并排除有影响骨质疾病的患者。术前术后采用Lysholm膝关节功能评分及(国际膝关节文献委员会IKDC)2000膝关节功能评分评估效果，评分数据进行t检验。

确定TSAFs骨折块分布区域特点为O点(以外侧半月板前角游离缘与前叉韧带止点中线交点为"O"点)。前侧部分骨块大小约长(10±5)mm×宽(15±4)mm，内外侧旁开各6 mm的范围，能容纳一块不超过2 mm厚度的薄片类内固定物，在多角度活动下均不会撞击关节软骨面。在猪膝关节生物力学测定中，4组的一级抗拨伸力和最大抗拨伸力差异均有统计学意义(F＝38.091、15.885, both P<0.001 )；其中双瓣钢板组组一级抗拨伸力为(105±6)N、最大抗拨伸力为(346±21)N，较其他三组有优势，两两比较差异有统计学意义(P<0.05)，为临床应用提供生物力学证据。8例TSAFs病例骨折愈合时间(3.5±0.8)个月，Lysholm膝关节功能评分从术前(43±7)分提高到术后3个月的(89±6)分，且差异均有统计学意义(t＝－14.87，P<0.05)。IKDC 2000膝关节功能主观评分从术前的(55±6)分提高到术后3个月(92±5)分，术前术后评分比较差异均具有统计学意义(t＝－13.54，P<0.05)。5例骨愈合病例术后关节镜取出内固定，未见关节软骨有磨损表现。

双瓣钢板内固定系统是利用胫骨髁间窝骨性空间特点，可在关节镜下直接在关节内钢板固定TSAFs骨折块，简化了关节内操作步骤，具有操作简捷、固定可靠、疗效确切的优点，并不会增加对关节软骨的损伤，值得深入研究推广。

To develop a novel double-flap plate internal fixation system for arthroscopic treatment of tibial spine avulsion fractures (TSAFs), and to demonstrate its feasibility and practicability.

CT data of 50 TSAFs patients (those with knee fractures and abnormal bone metabolism diseases, etc. were exluded) in Songshan Lake Hospital were gathered to explore the size and anatomical distribution of fracture blocks. The bone space around the intercondylar fossa and anterior fork ligament insertion in eight fresh adult knee specimens was measured to determine the size and characteristics of the anterior insertion space. Sixty knee specimens of swines were selected and made into TSAFs model. Simple random sampling method was used to divide the samples into four groups, 15 samples in each group. The samples were treated with different internal fixation methods: single-strand wire loop fixation (the wire loop fixation group), hollow nail fixation (the hollow nail group), and finger steel plate fixation with non-absorbent Fiber Wire( the finger steel plate wire group). The experimental group were fixed with double plate (the double plate group). The biomechanical experiment of tensile force was conducted and comparative analysis was conducted by variance test among the groups, and SNK-q test was utilized for paired comparison. Arthroscopic surgery was conducted using double-flap plate internal fixation system on eight TSAFs patients aged from 17 to 45 years; osteogenic diseases were excluded. Lysholm knee function score and International Knee Documentation Committee (IKDC) 2000 subjective knee function score were used to evaluate effects before and after surgery, and t test was conducted for data comparisons.

The distribution area of TSAFs fracture fragments was characterized as O point (the " O" point was the intersection point between the free margin of the lateral meniscus anterior angle and the mid line of the anterior cruciate ligament insertion). The size of the anterior part of the bone fragments was about (10±5) mm× (15±4) mm, and the inner and lateral parts were six millimeters apart, which could accommodate a thin slice of internal fixation with a thickness of less than two millimeters, which would not impact the articular cartilaginous surface under multiple angle movements. Considering the biomechanical determination of swine knee joints, the differences in the first-order tensile force and maximum tensile force among the groups were statistically significant (F=38.091, 15.885, both P<0.001); the first-order tensile force and maximum tensile force of the double-flap steel plate group were (105±6) N and (346±21) N respectively, which were superior to those of the other three groups (all P<0.05), providing biomechanical evidence for clinical application. The fracture healing time of eight TSAFs patients was (3.5±0.8) months, and Lysholm knee functional score was increased from (43±7) before surgery to (89±6) three months after surgery, with statistically significant differences (t=-14.87, P<0.05). IKDC 2000 subjective score increased from preoperative (55±6) to (92±5) three months after surgery, and the difference was statistically significant (t=-13.54, P<0.05). The internal fixations were removed in five cases of bone union by arthroscope, and no articular cartilage abrasion was observed.

The double-flap plate internal fixation system utilizes the characteristics of the osseous space of the tibial intercondylar fossa, and can directly fix the TSAFs fracture block with intraventricular plate under arthroscope. It simplifies the intramuscular operation steps, and provides the advantages of simple operation, reliable fixation and exact efficacy. It does not increase the damage to articular cartilage, and is worthy of further study and promotion.