Pullout strength of pedicle screws with cement augmentation in severe osteoporosis: A comparative study between cannulated screws with cement injection and solid screws with cement pre-filling

Table 3 Ultimate pullout strength of fully inserted conical and cylindrical pedicle screws with various screw insertion techniques. (Unit: Newton)

	Conical Screw			Cylindrical Screw
Specimen number	Solid Screw with PMMA prefilling	Cannulated Screw with PMMA injection	Solid Screw without PMMA augmentation	Solid Screw with PMMA prefilling	Cannulated Screw with PMMA injection	Solid Screw without PMMA augmentation
1	346	298	47	357	240	45
2	365	355	22	372	249	34
3	442	308	54	469	348	62
4	416	245	18	371	246	27
5	376	351	15	463	340	37
6	426	368	52	493	364	49
Ave.	396	321	35	421	298	42
SD	37	46	18	60	59	13

P-value:
p = 0.0129 (Solid Screw with PMMA prefilling vs. Cannulated Screw with PMMA injection, Conical Screw)
p = 0.005 (Solid Screw with PMMA prefilling vs. Cannulated Screw with PMMA injection, Cylindrical Screw)

ISSN: 1471-2474