CORRELATIONS BETWEEN SCREW HOLE PREPARATION, TORQUE OF INSERTION, AND PULLOUT STRENGTH FOR SPINAL SCREWS

被引:130
作者
DAFTARI, TK [1 ]
HORTON, WC [1 ]
HUTTON, WC [1 ]
机构
[1] EMORY UNIV,DEPT ORTHOPAED,DECATUR,GA
来源
JOURNAL OF SPINAL DISORDERS | 1994年 / 7卷 / 02期
关键词
SCREWS; TORQUE; CORTEX; PULLOUT STRENGTH;
D O I
10.1097/00002517-199407020-00007
中图分类号
R74 [神经病学与精神病学];
学科分类号
摘要
The bone-screw interface is critical in the use of spinal instrumentation. The purpose of these experiments described here was twofold. First, to determine whether a correlation existed between torque generated during screw insertion and the pullout strength. Second, to determine how differing surgical methods of screw hole preparation influenced torque of insertion and screw pullout strength. A series of experiments were carried out in which screws were inserted into synthetic bone (experiment 1) and into calf vertebrae (experiment 2). The method of screw hole preparation (i.e., diameter of entrance hole and pilot hole) was varied while the resulting torque of insertion and the pullout strength of the screw was measured in each case. A torque screwdriver was used to measure the torque of insertion of the screws. Screw pullout strength was measured using a materials testing machine. Two important results emerged from these experiments. First, a higher torque of insertion correlated with a higher screw pullout force. This correlation may be useful intraoperatively in evaluating fixation. Second, torque of insertion and pullout force were more influenced by cortex over-drill diameter than pilot hole diameter. These experiments show the importance of the dorsal cortex in pedicle screw fixation.
引用
收藏
页码:139 / 145
页数:7
相关论文
共 13 条
[1]  
Ansell R.H., Scales J.T., A study of some factors which affect the strength of screws and their insertion and holding power in bone, J Biomech, 1, pp. 279-302, (1968)
[2]  
Asher M.A., Strippgen W.E., Anthropometric studies of the human sacrum relating to dorsal transsacral implant designs, Clin Orthop, 203, pp. 58-62, (1986)
[3]  
Decoster T.A., Heetderks D.B., Downey D.J., Ferries J.S., Jones W., Optimizing bone screw pullout force, J Orthop Trauma, 4, pp. 169-174, (1990)
[4]  
Hughes A.N., Jordan B.A., The mechanical properties of surgical bone screws and some aspects of insertions practice, Injury, 4, pp. 25-38, (1972)
[5]  
Koranyi E., Bowman C.E., Knecht C.D., Janssen M., Holding power of orthopaedic screws in bone, Clin Orthop, 72, pp. 283-286, (1970)
[6]  
Krag M.H., Beynnon B.D., Pope M.H., Decoster T.A., Depth of insertion of transpedicular screws into human vertebrae: Effect upon screw-vertebra interface strength, J Spinal Disord, 1, pp. 284-294, (1989)
[7]  
Moran J.M., Berg W.S., Berry J.L., Geiger J.M., Steffee A.D., Transpedicular screw fixation, J Orthop Res, 7, pp. 107-114, (1989)
[8]  
Nunamaker D.M., Perren S.M., Force measurements in screw fixation, J Biomech, 9, pp. 669-675, (1976)
[9]  
Schatzker J., Sanderson R., Mumaghan J.P., The holding power of orthopaedic screws in vivo, Clin Orthop, 108, pp. 115-126, (1975)
[10]  
Swiontkowski M.F., Harrington R.M., Keller T.S., Vanpatten P.K., Torsion and bending analysis of internal fixation techniques for femoral neck fractures: The role of implant design and bone density, J Orthop Res, 5, pp. 433-444, (1987)