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The Role of Posterior Longitudinal Ligament in Cervical Disc Replacement: An Ovine Cadaveric Biomechanical Analysis.

Yu CC, Hao DJ, Ma YL, Huang DG, Li HK, Feng H, Hou Q - Med. Sci. Monit. (2016)

Bottom Line: RESULTS The C3/C4 ROM in group 3 (CDR with PLL removed) increased significantly in flexion-extension and axial rotation compared with group 1 (intact spine).All the ROM observed in group 2 (CDR with PLL preserved) did not significantly differ from the ROM observed in group 1.Moreover, the ROM in CDR with PLL preservation did not significantly differ from the ROM observed in intact spines.

View Article: PubMed Central - PubMed

Affiliation: Department of Spine Surgery, Honghui Hospital, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, China (mainland).

ABSTRACT
BACKGROUND Cervical disc replacement (CDR) has been widely used to restore and maintain mobility and function of the treated and adjacent motion segments. Posterior longitudinal ligament (PLL) resection has been shown to be efficient in anterior cervical decompression and fusion. However, less is known about the biomechanical effect of PLL removal versus preservation in cervical disc arthroplasty. MATERIAL AND METHODS Three motion segments of 24 ovine cervical spines (C2-C5) were evaluated in a robotic spine system with axial compressive loads of 50 N. These cervical spines were divided in three groups according to the following conditions: (1) intact spine, (2) C3/C4 CDR with the Prestige LP prosthesis and PLL preservation, and (3) C3/C4 CDR with the Prestige LP prosthesis and PLL removal. The ranges of motion (ROMs) were recorded and analyzed in each group. RESULTS The C3/C4 ROM in group 3 (CDR with PLL removed) increased significantly in flexion-extension and axial rotation compared with group 1 (intact spine). Moreover, in flexion-extension, the mean total ROM was significantly larger in group 3 than in group 1. All the ROM observed in group 2 (CDR with PLL preserved) did not significantly differ from the ROM observed in group 1. CONCLUSIONS Compared with intact spines, CDR with PLL removal partly increased ROM. Moreover, the ROM in CDR with PLL preservation did not significantly differ from the ROM observed in intact spines. The PLL appears to contribute to the balance and stability of the cervical spine and should thus be preserved in cervical disc replacement provided that the posterior longitudinal ligament is not degenerative and the compression can be removed without PLL takedown.

No MeSH data available.


Related in: MedlinePlus

An intact spine specimen. Each rigid rod connected the motion capture markers to the vertebral bodies for detection by the optical tracking system.
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f2-medscimonit-22-1843: An intact spine specimen. Each rigid rod connected the motion capture markers to the vertebral bodies for detection by the optical tracking system.

Mentions: An optical tracking system (OptiTrack, NaturalPoint Inc., USA) was used to evaluate the ROM of the C2/C3, C3/C4, and C4/C5 segments. A rigid rod connected to a motion capture marker was inserted into each vertebral body of C2, C3, and C4 (Figure 2). Every motion capture marker was composed of three noncollinear optical balls to ensure it could be detected by the optical tracking system. A marker was placed on the socket to attach the C5 vertebra due to its immovability. The angular ROM value was directly measured by the optical tracking system.


The Role of Posterior Longitudinal Ligament in Cervical Disc Replacement: An Ovine Cadaveric Biomechanical Analysis.

Yu CC, Hao DJ, Ma YL, Huang DG, Li HK, Feng H, Hou Q - Med. Sci. Monit. (2016)

An intact spine specimen. Each rigid rod connected the motion capture markers to the vertebral bodies for detection by the optical tracking system.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4920594&req=5

f2-medscimonit-22-1843: An intact spine specimen. Each rigid rod connected the motion capture markers to the vertebral bodies for detection by the optical tracking system.
Mentions: An optical tracking system (OptiTrack, NaturalPoint Inc., USA) was used to evaluate the ROM of the C2/C3, C3/C4, and C4/C5 segments. A rigid rod connected to a motion capture marker was inserted into each vertebral body of C2, C3, and C4 (Figure 2). Every motion capture marker was composed of three noncollinear optical balls to ensure it could be detected by the optical tracking system. A marker was placed on the socket to attach the C5 vertebra due to its immovability. The angular ROM value was directly measured by the optical tracking system.

Bottom Line: RESULTS The C3/C4 ROM in group 3 (CDR with PLL removed) increased significantly in flexion-extension and axial rotation compared with group 1 (intact spine).All the ROM observed in group 2 (CDR with PLL preserved) did not significantly differ from the ROM observed in group 1.Moreover, the ROM in CDR with PLL preservation did not significantly differ from the ROM observed in intact spines.

View Article: PubMed Central - PubMed

Affiliation: Department of Spine Surgery, Honghui Hospital, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi, China (mainland).

ABSTRACT
BACKGROUND Cervical disc replacement (CDR) has been widely used to restore and maintain mobility and function of the treated and adjacent motion segments. Posterior longitudinal ligament (PLL) resection has been shown to be efficient in anterior cervical decompression and fusion. However, less is known about the biomechanical effect of PLL removal versus preservation in cervical disc arthroplasty. MATERIAL AND METHODS Three motion segments of 24 ovine cervical spines (C2-C5) were evaluated in a robotic spine system with axial compressive loads of 50 N. These cervical spines were divided in three groups according to the following conditions: (1) intact spine, (2) C3/C4 CDR with the Prestige LP prosthesis and PLL preservation, and (3) C3/C4 CDR with the Prestige LP prosthesis and PLL removal. The ranges of motion (ROMs) were recorded and analyzed in each group. RESULTS The C3/C4 ROM in group 3 (CDR with PLL removed) increased significantly in flexion-extension and axial rotation compared with group 1 (intact spine). Moreover, in flexion-extension, the mean total ROM was significantly larger in group 3 than in group 1. All the ROM observed in group 2 (CDR with PLL preserved) did not significantly differ from the ROM observed in group 1. CONCLUSIONS Compared with intact spines, CDR with PLL removal partly increased ROM. Moreover, the ROM in CDR with PLL preservation did not significantly differ from the ROM observed in intact spines. The PLL appears to contribute to the balance and stability of the cervical spine and should thus be preserved in cervical disc replacement provided that the posterior longitudinal ligament is not degenerative and the compression can be removed without PLL takedown.

No MeSH data available.


Related in: MedlinePlus