Accepted Manuscript Biomechanical and Anatomical Considerations in Lumbar Spinous Process FixationAn In Vitro Human Cadaveric Model Xiaolei Sun, MD Ashley A. Murgatroyd, BS Kenneth P. Mullinix, BA Bryan W. Cunningham, PhD Xinlong Ma, MD Paul C. McAfee, MD, MBA PII:
S1529-9430(14)00242-3
DOI:
10.1016/j.spinee.2014.03.002
Reference:
SPINEE 55804
To appear in:
The Spine Journal
Received Date: 28 June 2013 Revised Date:
21 January 2014
Accepted Date: 2 March 2014
Please cite this article as: Sun X, Murgatroyd AA, Mullinix KP, Cunningham BW, Ma X, McAfee PC, Biomechanical and Anatomical Considerations in Lumbar Spinous Process Fixation- An In Vitro Human Cadaveric Model -, The Spine Journal (2014), doi: 10.1016/j.spinee.2014.03.002. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT
Biomechanical and Anatomical Considerations in Lumbar Spinous Process Fixation
RI PT
- An In Vitro Human Cadaveric Model a,b
Xiaolei Sun, MD
a
SC
Ashley A. Murgatroyd, BS Kenneth P. Mullinix, BA
a
a,
M AN U
Bryan W. Cunningham, PhD * Xinlong Ma, MD
b
Paul C. McAfee, MD, MBA a
a
EP
TE D
Orthopaedic Spinal Research Institute, University of Maryland St. Joseph Medical Center, 7601 Osler Drive, Towson, MD 21204, USA b Department of Orthopaedic Surgery, Tianjin Hospital, 406 Jiefangnan Road, Tianjin, TJ 300211, China
AC C
Running Head: Biomechanical Considerations in Lumbar Spinous Process Fixation Research Funding: Funding was provided by Orthopaedic Associates Research Foundation, Inc., University of Maryland. Towson, Maryland.
* Corresponding author:
BW Cunningham Orthopaedic Spinal Research Institute, St. Joseph Medical Center, 7601 Osler Drive, Towson, MD 21204, Tel.: (410) 337-1274; Fax: (410) 427-2140. E-mail address: [email protected]
ACCEPTED MANUSCRIPT
Abstract
2
BACKGROUND CONTEXT: While multiple mechanisms of device attachment to the
3
spinous processes exist, there is a paucity of data regarding lumbar spinous process
4
morphology and peak failure loads.
5
PURPOSE: Using an in-vitro human cadaveric spine model, the primary objective of the
6
current study was to compare the peak load and mechanisms of lumbar spinous process
7
failure with variation in spinous process hole location and pullout direction. A secondary
8
objective was to provide an in-depth characterization of spinous process morphology.
9
STUDY DESIGN: Biomechanical and anatomical considerations in lumbar spinous
M AN U
SC
RI PT
1
process fixation using an in-vitro human cadaveric model.
11
METHODS: A total of 12 intact lumbar spines were utilized in the current investigation.
12
The vertebral segments (L1-L5) were randomly assigned to 1 of 5 treatment groups with
13
variation in spinous process hole placement and pullout direction: 1) Central hole
14
placement with superior pullout (n=10), 2) Central hole placement with inferior pullout
15
(n=10), 3) Inferior hole placement with inferior pullout (n=10), 4) Superior hole
16
placement with superior pullout (n=10) and 5) Intact spinous process with superior
17
pullout (n=14). A 4mm diameter pin was placed through the hole followed by pullout
18
testing using a material testing system (MTS). As well, the bone mineral density (BMD)
19
(g/cm3) was measured for each segment. Data were quantified in terms of anatomic
20
dimensions (mm), peak failure loads (Newtons) and fracture mechanisms, with linear
21
regression analysis would identify relationships between anatomic and biomechanical
22
data.
AC C
EP
TE D
10
2
ACCEPTED MANUSCRIPT
RESULTS: Based on anatomic comparisons, there were significant differences between
2
the anteroposterior and cephalocaudal dimensions of the L5 spinous process versus L1
3
through L4 (p0.05). However, a significant linear
6
correlation was observed between peak failure load and anteroposterior and
7
cephalocaudal dimensions (p
S1529-9430(14)00242-3
DOI:
10.1016/j.spinee.2014.03.002
Reference:
SPINEE 55804
To appear in:
The Spine Journal
Received Date: 28 June 2013 Revised Date:
21 January 2014
Accepted Date: 2 March 2014
Please cite this article as: Sun X, Murgatroyd AA, Mullinix KP, Cunningham BW, Ma X, McAfee PC, Biomechanical and Anatomical Considerations in Lumbar Spinous Process Fixation- An In Vitro Human Cadaveric Model -, The Spine Journal (2014), doi: 10.1016/j.spinee.2014.03.002. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT
Biomechanical and Anatomical Considerations in Lumbar Spinous Process Fixation
RI PT
- An In Vitro Human Cadaveric Model a,b
Xiaolei Sun, MD
a
SC
Ashley A. Murgatroyd, BS Kenneth P. Mullinix, BA
a
a,
M AN U
Bryan W. Cunningham, PhD * Xinlong Ma, MD
b
Paul C. McAfee, MD, MBA a
a
EP
TE D
Orthopaedic Spinal Research Institute, University of Maryland St. Joseph Medical Center, 7601 Osler Drive, Towson, MD 21204, USA b Department of Orthopaedic Surgery, Tianjin Hospital, 406 Jiefangnan Road, Tianjin, TJ 300211, China
AC C
Running Head: Biomechanical Considerations in Lumbar Spinous Process Fixation Research Funding: Funding was provided by Orthopaedic Associates Research Foundation, Inc., University of Maryland. Towson, Maryland.
* Corresponding author:
BW Cunningham Orthopaedic Spinal Research Institute, St. Joseph Medical Center, 7601 Osler Drive, Towson, MD 21204, Tel.: (410) 337-1274; Fax: (410) 427-2140. E-mail address: [email protected]
ACCEPTED MANUSCRIPT
Abstract
2
BACKGROUND CONTEXT: While multiple mechanisms of device attachment to the
3
spinous processes exist, there is a paucity of data regarding lumbar spinous process
4
morphology and peak failure loads.
5
PURPOSE: Using an in-vitro human cadaveric spine model, the primary objective of the
6
current study was to compare the peak load and mechanisms of lumbar spinous process
7
failure with variation in spinous process hole location and pullout direction. A secondary
8
objective was to provide an in-depth characterization of spinous process morphology.
9
STUDY DESIGN: Biomechanical and anatomical considerations in lumbar spinous
M AN U
SC
RI PT
1
process fixation using an in-vitro human cadaveric model.
11
METHODS: A total of 12 intact lumbar spines were utilized in the current investigation.
12
The vertebral segments (L1-L5) were randomly assigned to 1 of 5 treatment groups with
13
variation in spinous process hole placement and pullout direction: 1) Central hole
14
placement with superior pullout (n=10), 2) Central hole placement with inferior pullout
15
(n=10), 3) Inferior hole placement with inferior pullout (n=10), 4) Superior hole
16
placement with superior pullout (n=10) and 5) Intact spinous process with superior
17
pullout (n=14). A 4mm diameter pin was placed through the hole followed by pullout
18
testing using a material testing system (MTS). As well, the bone mineral density (BMD)
19
(g/cm3) was measured for each segment. Data were quantified in terms of anatomic
20
dimensions (mm), peak failure loads (Newtons) and fracture mechanisms, with linear
21
regression analysis would identify relationships between anatomic and biomechanical
22
data.
AC C
EP
TE D
10
2
ACCEPTED MANUSCRIPT
RESULTS: Based on anatomic comparisons, there were significant differences between
2
the anteroposterior and cephalocaudal dimensions of the L5 spinous process versus L1
3
through L4 (p0.05). However, a significant linear
6
correlation was observed between peak failure load and anteroposterior and
7
cephalocaudal dimensions (p
