Foley Kevin T, Woodard Eric J, Slotkin Jonathan R, Mayotte Cassandra K, Baldwin Abigail C, Brown Michael C, Hess Brian J
1Department of Neurosurgery, University of Tennessee Health Science Center and Semmes Murphey Neurologic and Spine Institute, Memphis, Tennessee.
2Department of Neurosurgery, New England Baptist Hospital, Boston, Massachusetts.
J Neurosurg. 2020 Feb 7;134(2):621-629. doi: 10.3171/2019.11.JNS192806. Print 2021 Feb 1.
The authors' goal in this study was to investigate the use of a novel, bioresorbable, osteoconductive, wet-field mineral-organic bone adhesive composed of tetracalcium phosphate and phosphoserine (TTCP-PS) for cranial bone flap fixation and compare it with conventional low-profile titanium plates and self-drilling screws.
An ovine craniotomy surgical model was used to evaluate the safety and efficacy of TTCP-PS over 2 years. Bilateral cranial defects were created in 41 sheep and were replaced in their original position. The gaps (kerfs) were completely filled with TTCP-PS (T1 group), half-filled with TTCP-PS (T2 group), or left empty and the flaps fixated by plates and screws as a control (C group). At 12 weeks, 1 year, and 2 years following surgery, the extent of bone healing, local tissue effects, and remodeling of the TTCP-PS were analyzed using macroscopic observations and histopathological and histomorphometric analyses. Flap fixation strength was evaluated by biomechanical testing at 12 weeks and 1 year postoperatively.
No adverse local tissue effects were observed in any group. At 12 weeks, the bone flap fixation strengths in test group 1 (1689 ± 574 N) and test group 2 (1611 ± 501 N) were both statistically greater (p = 0.01) than that in the control group (663 ± 385 N). From 12 weeks to 1 year, the bone flap fixation strengths increased significantly (p < 0.05) for all groups. At 1 year, the flap fixation strength in test group 1 (3240 ± 423 N) and test group 2 (3212 ± 662 N) were both statistically greater (p = 0.04 and p = 0.02, respectively) than that in the control group (2418 ± 1463 N); however, there was no statistically significant difference in the strengths when comparing the test groups at both timepoints. Test group 1 had the best overall performance based on histomorphometric evaluation and biomechanical testing. At 2 years postoperatively, the kerfs filled with TTCP-PS had histological evidence of osteoconduction and replacement of TTCP-PS by bone with nearly complete osteointegration.
TTCP-PS was demonstrated to be safe and effective for cranial flap fixation in an ovine model. In this study, the bioresorbable, osteoconductive bone adhesive appeared to have multiple advantages over standard plate-and-screw bone flap fixation, including biomechanical superiority, more complete and faster bony healing across the flap kerfs without fibrosis, and the minimization of bone flap and/or hardware migration and loosening. These properties of TTCP-PS may improve human cranial bone flap fixation and cranioplasty.
本研究作者的目标是研究一种新型的、可生物吸收的、骨传导性的、湿场矿物有机骨粘合剂（由磷酸四钙和磷酸丝氨酸组成，即TTCP-PS）用于颅骨瓣固定，并将其与传统的低轮廓钛板和自攻螺钉进行比较。
采用绵羊开颅手术模型评估TTCP-PS在2年时间内的安全性和有效性。在41只绵羊身上制造双侧颅骨缺损，并将其复位到原始位置。缺损间隙（切口）完全用TTCP-PS填充（T1组），一半用TTCP-PS填充（T2组），或者留空并用钢板和螺钉固定颅骨瓣作为对照（C组）。在术后12周、1年和2年，通过宏观观察、组织病理学和组织形态计量学分析，分析骨愈合程度、局部组织效应以及TTCP-PS的重塑情况。在术后12周和1年通过生物力学测试评估颅骨瓣固定强度。
所有组均未观察到不良局部组织效应。在12周时，试验组1（1689±574 N）和试验组2（1611±501 N）的颅骨瓣固定强度在统计学上均显著高于对照组（663±385 N）（p = 0.01）。从12周到1年，所有组的颅骨瓣固定强度均显著增加（p < 0.05）。在1年时，试验组1（3240±423 N）和试验组2（3212±662 N）的颅骨瓣固定强度在统计学上均高于对照组（2418±1463 N）（分别为p = 0.04和p = 0.02）；然而，在两个时间点比较试验组时，强度没有统计学上的显著差异。基于组织形态计量学评估和生物力学测试，试验组1的总体性能最佳。术后2年，用TTCP-PS填充的切口有骨传导的组织学证据，且TTCP-PS被骨替代，骨整合接近完全。
在绵羊模型中，TTCP-PS被证明用于颅骨瓣固定是安全有效的。在本研究中，这种可生物吸收的、骨传导性骨粘合剂相对于标准的钢板和螺钉颅骨瓣固定似乎具有多种优势，包括生物力学优势、跨颅骨瓣切口更完全且更快的骨愈合且无纤维化，以及使颅骨瓣和/或硬件移位和松动最小化。TTCP-PS的这些特性可能会改善人类颅骨瓣固定和颅骨成形术。
