Moholkar Kirti, Taylor David, O'Reagan Myra, Fenelon Gary
Department of Orthopaedics, St. Jame's Hospital, Dublin, Ireland.
J Bone Joint Surg Am. 2002 Oct;84(10):1782-7. doi: 10.2106/00004623-200210000-00007.
Anterior cruciate ligament reconstruction with use of bone-patellar tendon-bone graft is commonly performed to treat functional instability of the knee after injury of the anterior cruciate ligament. Patellar fracture is an underreported complication of this procedure, yet it may be a career-ending injury for a professional athlete. The purpose of this study was to design a new technique to procure the patellar bone plug when reconstructing the cruciate ligament with use of patellar tendon.
Fifty-eight knees were harvested from eighteen to twenty-four-month-old pigs. Bone plugs of four geometrical shapes were cored out of the patellae from forty knees (four plug shapes for each of ten knees). Ten knees had no graft removed. Fifty knees were tested for the effects of a single impact. Eight knees (two plug shapes for each of four knees) were tested for the effects of repeated impacts. Data were analyzed statistically with use of an ordinal logistic model. The probability of impact failure of the patella at different energy levels was calculated.
Impact energy has been shown to have a significant effect on the outcome (p < 0.001). When controlling for energy level, there was a significant difference between the sharp and round corners (p < 0.01). The ordinal logistic model was found to be very good for predicting the outcome of impact testing. The impact energy required to create a 1% probability of complete fracture was 7 J for a patella with a sharp-cornered plug defect, 17 J for a patella with a trapezoidal plug, 22 J for a patella with a sharp-cornered defect with a drill-hole at the corner, 40 J for a patella with a round-cornered defect, and about 49 J for a normal patella. Repeat impact testing substantially damaged the patellae with sharp-cornered defects, as they failed earlier at a lower energy and after a lower number of impacts than did the patellae with round-cornered defects.
We propose the use of the round-cornered patellar bone plug when bone-patellar tendon-bone graft is harvested for anterior cruciate ligament reconstruction, to further reduce the small likelihood of a patellar fracture occurring intraoperatively or in the early postoperative rehabilitation phase.
使用骨-髌腱-骨移植物进行前交叉韧带重建常用于治疗前交叉韧带损伤后膝关节的功能不稳。髌骨骨折是该手术一种报道较少的并发症，但对于职业运动员而言可能是终结职业生涯的损伤。本研究的目的是设计一种在使用髌腱重建交叉韧带时获取髌骨骨栓的新技术。
从18至24月龄的猪身上获取58个膝关节。从40个膝关节的髌骨中取出四种几何形状的骨栓（10个膝关节，每种骨栓形状4个）。10个膝关节未取出移植物。50个膝关节接受单次撞击的影响测试。8个膝关节（4个膝关节，每种骨栓形状2个）接受反复撞击的影响测试。使用有序逻辑模型对数据进行统计学分析。计算不同能量水平下髌骨撞击失败的概率。
已表明撞击能量对结果有显著影响（p < 0.001）。在控制能量水平时，尖角与圆角之间存在显著差异（p < 0.01）。发现有序逻辑模型对预测撞击测试结果非常有效。对于有尖角骨栓缺损的髌骨，造成完全骨折概率为1%所需的撞击能量为7焦耳；对于有梯形骨栓的髌骨为17焦耳；对于在角部有钻孔的尖角缺损的髌骨为22焦耳；对于有圆角缺损的髌骨为40焦耳；对于正常髌骨约为49焦耳。反复撞击测试使有尖角缺损的髌骨严重受损，因为它们比有圆角缺损的髌骨更早地在较低能量和较少撞击次数后就发生失败。
我们建议在获取骨-髌腱-骨移植物用于前交叉韧带重建时使用圆角髌骨骨栓，以进一步降低术中或术后早期康复阶段发生髌骨骨折的小概率事件。
