Fraser Helyn G, Honeycutt M Wesley, Thompson Daniel, Suh Nina, Phen Huai Ming, Godfrey William S, Boissoneault Adam R, Maceroli Michael A
Emory University Department of Orthopaedic Surgery, USA.
San Antonio Military Medical Center Department of Orthopaedic Surgery, USA.
J Orthop. 2024 Jul 30;59:1-7. doi: 10.1016/j.jor.2024.07.007. eCollection 2025 Jan.
AIMS & OBJECTIVES: To establish whether a suprapectineal pelvic reconstruction plate and posterior column screw (P&S) construct or a single 6.5-mm cannulated posterior column screw (PCS) construct demonstrates greater mechanical stability for fixation of acetabulum fractures involving the posterior column (PC). We hypothesized that the PCS construct would result in less fracture site motion.
MATERIALS & METHODS: Twelve fourth-generation composite hemipelvi were utilized, 6 for each construct. The P&S construct consisted of a suprapectineal pelvic reconstruction plate with two 3.5-mm posterior column screws crossing the fracture site in lag-by-technique fashion and two screws anchoring the plate to the sciatic buttress. The PCS construct consisted of a single 6.5-mm partially threaded cannulated screw placed in an antegrade fashion. Both fixation models were cyclically loaded at 0.5 cycles/second at 400N and 800N, first in a sit-to-stand position that is expected during recovery, and subsequently in a squat-to-stand position to test overload conditions.
Under sit-to-stand loading, the PCS construct resulted in less motion at the fracture site than the P&S construct (0.06 ± 0.02 mm vs 0.1 ± 0.02 mm at 400N, p = 0.02; 0.13 ± 0.03 mm vs 0.19 ± 0.04 mm at 800N, p = 0.03). The PCS construct also demonstrated less fracture site motion under squat-to-stand loading (0.22 ± 0.13 mm vs 1.9 ± 0.5 mm at 400N, p = < 0.001; 1.48 ± 0.44 mm vs 4.77 ± 0.3 mm at 800N, p = < 0.001). At 800 N, half of the repairs failed during squat-to-stand loading (2 PCS, 4 P&S).
Fixation of the posterior column of the acetabulum with a 6.5-mm cannulated screw demonstrated comparable fracture motion upon loading compared to the plate and screw construct.
确定耻骨上骨盆重建钢板联合后柱螺钉（P&S）结构或单枚6.5mm空心后柱螺钉（PCS）结构在固定累及后柱（PC）的髋臼骨折时是否具有更高的机械稳定性。我们假设PCS结构会使骨折部位的活动度更小。
使用12个第四代复合半骨盆模型，每种结构6个。P&S结构由一块耻骨上骨盆重建钢板和两枚以拉力螺钉技术穿过骨折部位的3.5mm后柱螺钉以及两枚将钢板固定于坐骨支的螺钉组成。PCS结构由一枚以顺行方式置入的单枚6.5mm部分螺纹空心螺钉组成。两种固定模型均以400N和800N、0.5次/秒的频率进行循环加载，首先是在恢复过程中预期的从坐位到站立位的姿势，随后是从蹲位到站立位的姿势以测试过载情况。
在从坐位到站立位加载时，PCS结构在骨折部位产生的活动度小于P&S结构（400N时为0.06±0.02mm对0.1±0.02mm，p = 0.02；800N时为0.13±0.03mm对0.19±0.04mm，p = 0.03）。在从蹲位到站立位加载时，PCS结构在骨折部位的活动度也更小（400N时为0.22±0.13mm对1.9±0.5mm，p < 0.001；800N时为1.48±0.44mm对4.77±0.3mm，p < 0.001）。在800N时，一半的修复在从蹲位到站立位加载过程中失败（2个PCS结构，4个P&S结构）。
与钢板联合螺钉结构相比，使用6.5mm空心螺钉固定髋臼后柱在加载时骨折部位的活动度相当。
