title: Correlation of cervical endplate strength with CT measured subchondral bone density.
abstract: Cervical interbody device subsidence can result in screw breakage, plate dislodgement, and/or kyphosis. Preoperative bone density measurement may be helpful in predicting the complications associated with anterior cervical surgery. This is especially important when a motion preserving device is implanted given the detrimental effect of subsidence on the postoperative segmental motion following disc replacement. To evaluate the structural properties of the cervical endplate and examine the correlation with CT measured trabecular bone density. Eight fresh human cadaver cervical spines (C2-T1) were CT scanned and the average trabecular bone densities of the vertebral bodies (C3-C7) were measured. Each endplate surface was biomechanically tested for regional yield load and stiffness using an indentation test method. Overall average density of the cervical vertebral body trabecular bone was 270 +/- 74 mg/cm3. There was no significant difference between levels. The yield load and stiffness from the indentation test of the endplate averaged 139 +/- 99 N and 156 +/- 52 N/mm across all cervical levels, endplate surfaces, and regional locations. The posterior aspect of the endplate had significantly higher yield load and stiffness in comparison to the anterior aspect and the lateral aspect had significantly higher yield load in comparison to the midline aspect. There was a significant correlation between the average yield load and stiffness of the cervical endplate and the trabecular bone density on regression analysis. Although there are significant regional variations in the endplate structural properties, the average of the endplate yield loads and stiffnesses correlated with the trabecular bone density. Given the morbidity associated with subsidence of interbody devices, a reliable and predictive method of measuring endplate strength in the cervical spine is required. Bone density measures may be used preoperatively to assist in the prediction of the strength of the vertebral endplate. A threshold density measure has yet to be established where the probability of endplate fracture outweighs the benefit of anterior cervical procedure.
authors: Department of Orthopedics, SUNY Upstate Medical Center, 550 Harrison Street, Syracuse, NY, 13202, USA.
authors: Nathaniel R
authors: NR
authors: Ordway
authors: Yen-Mou
authors: YM
authors: Lu
authors: Xingkai
authors: X
authors: Zhang
authors: Chin-Chang
authors: CC
authors: Cheng
authors: Huang
authors: H
authors: Fang
authors: Amir H
authors: AH
authors: Fayyazi
mesh_terms: D000368:Aged; D001696:Biomechanical Phenomena; D015519:Bone Density / Q000502:physiology*; D001860:Bone Plates / Q000009:adverse effects / Q000592:standards; D001863:Bone Screws / Q000009:adverse effects / Q000592:standards; D002102:Cadaver; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*; D017586:Diskectomy / Q000009:adverse effects; D005260:Female; D006801:Humans; D008297:Male; D011183:Postoperative Complications / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D011300:Preoperative Care / Q000379:methods*; D019736:Prostheses and Implants / Q000009:adverse effects / Q000592:standards; D016059:Range of Motion, Articular / Q000502:physiology; D013123:Spinal Fusion / Q000009:adverse effects; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016474:Weight-Bearing / Q000502:physiology
references: Spine (Phila Pa 1976). 1999 Feb 15;24(4):334-8
references: 10065516
references: Spine (Phila Pa 1976). 2004 Nov 1;29(21):2389-94
references: 15507800
references: Spine (Phila Pa 1976). 2005 Sep 1;30(17):E492-8
references: 16135971
references: Skeletal Radiol. 1988;17(4):264-9
references: 3212488
references: Osteoporos Int. 1998;8(5):460-7
references: 9850355
references: J Spinal Disord. 1998 Oct;11(5):410-5
references: 9811102
references: Spine (Phila Pa 1976). 1998 Apr 15;23(8):886-92
references: 9580955
references: Eur Spine J. 1997;6(6):385-9
references: 9455665
references: J Neurosurg. 1997 Jun;86(6):990-7
references: 9171178
references: Spine (Phila Pa 1976). 1996 May 1;21(9):1032-6
references: 8724086
references: AJR Am J Roentgenol. 1996 Jul;167(1):133-40
references: 8659357
references: Spine (Phila Pa 1976). 1994 Mar 15;19(6):660-3
references: 8009330
references: Bone. 1999 Dec;25(6):713-24
references: 10593417
references: Spine (Phila Pa 1976). 2000 May 1;25(9):1077-84
references: 10788851
references: Calcif Tissue Int. 2001 Feb;68(2):74-82
references: 11310350
references: Spine (Phila Pa 1976). 2001 Apr 15;26(8):889-96
references: 11317111
references: Spine (Phila Pa 1976). 2001 Apr 15;26(8):951-6
references: 11317120
references: Spine (Phila Pa 1976). 2001 Apr 15;26(8):957-63
references: 11317121
references: J Orthop Res. 2002 Sep;20(5):1115-20
references: 12382980
references: Spine (Phila Pa 1976). 2003 Jan 15;28(2):140-2
references: 12544930
references: Spine (Phila Pa 1976). 2003 Apr 15;28(8):771-7
references: 12698119
references: Di Yi Jun Yi Da Xue Xue Bao. 2003 May;23(5):402-8
references: 12754113
references: Spine (Phila Pa 1976). 2003 Oct 1;28(19):2204-8
references: 14520032
references: J Biomech. 2003 Dec;36(12):1875-81
references: 14614941
references: Spine (Phila Pa 1976). 2003 Dec 15;28(24):2648-50; discussion 2651
references: 14673362
references: Zhonghua Wai Ke Za Zhi. 2004 Nov 7;42(21):1330-2
references: 15634437
references: J Bone Joint Surg Br. 1969 Aug;51(3):540-50
references: 5820800
references: J Clin Endocrinol Metab. 1987 Feb;64(2):209-14
references: 3491831
references: Spine (Phila Pa 1976). 1989 Jun;14(6):606-10
references: 2749376
references: Spine (Phila Pa 1976). 1989 Sep;14(9):1012-9
references: 2781407
references: Invest Radiol. 1990 Jan;25(1):19-23
references: 2298545
references: Eur J Radiol. 1991 Jul-Aug;13(1):6-10
references: 1832380
references: Spine (Phila Pa 1976). 1992 Oct;17(10 Suppl):S427-30
references: 1440038
references: Spine (Phila Pa 1976). 1993 Jun 15;18(8):1011-5
references: 8367768
references: J Bone Joint Surg Am. 1993 Sep;75(9):1298-307
references: 8408151