Brown C H, Hecker A T, Hipp J A, Myers E R, Hayes W C
Department of Orthopaedic Surgery, Charles A. Dana Research Institute, Beth Israel Hospital, Boston, Massachusetts.
Am J Sports Med. 1993 Nov-Dec;21(6):880-6. doi: 10.1177/036354659302100622.
Twenty-seven paired human cadaveric knee specimens were used to determine the effect of surgical technique and various interference screw parameters on the pullout strength of patellar tendon femoral bone blocks. The study compared the fixation strength of endoscopically inserted and conventional "rear-entry" screws of different diameters and lengths. In all tests the most frequent mode of failure was bone block pullout from the interference screw. There was no significant difference in fixation strength between 9-mm diameter screws inserted through a conventional rear-entry technique and 7-mm diameter screws inserted through an endoscopic technique. There was no significant effect of screw length on fixation strength. The pullout force for 20-mm long screws increased on average 120% when 7-mm diameter screws were compared with 5.5-mm diameter screws. There was no significant effect of increased screw core diameter on fixation strength. There was a weak positive correlation (r2 = 0.45) between screw insertion torque and pullout force. Our measured mean pullout force for the 7-mm endoscopically inserted screws of 362 +/- 198 N represents 20.1% of the failure load of the normal young adult anterior cruciate ligament. Our data indicate that properly inserted 7-mm diameter endoscopic interference screws can provide fixation strengths of patellar tendon anterior cruciate ligament grafts equivalent to those of conventional 9-mm diameter rear-entry, outside-in screws.
使用27对人体尸体膝关节标本，以确定手术技术和各种干涉螺钉参数对髌腱股骨骨块拔出强度的影响。该研究比较了不同直径和长度的关节镜插入式螺钉与传统“后入路”螺钉的固定强度。在所有测试中，最常见的失效模式是骨块从干涉螺钉中拔出。通过传统后入路技术插入的9毫米直径螺钉与通过关节镜技术插入的7毫米直径螺钉在固定强度上没有显著差异。螺钉长度对固定强度没有显著影响。与5.5毫米直径螺钉相比，20毫米长的7毫米直径螺钉的拔出力平均增加了120%。螺钉芯直径增加对固定强度没有显著影响。螺钉插入扭矩与拔出力之间存在弱正相关（r2 = 0.45）。我们测量的通过关节镜插入的7毫米螺钉的平均拔出力为362 +/- 198 N，占正常年轻成人前交叉韧带失效负荷的20.1%。我们的数据表明，正确插入的7毫米直径关节镜干涉螺钉可为髌腱前交叉韧带移植物提供与传统9毫米直径后入路、由外向内螺钉相当的固定强度。
