Would an anatomically shaped lumbar interbody cage provide better stability? An in vitro cadaveric biomechanical evaluation.
Τίτλος | Would an anatomically shaped lumbar interbody cage provide better stability? An in vitro cadaveric biomechanical evaluation. |
Publication Type | Journal Article |
Year of Publication | 2012 |
Authors | Tsitsopoulos, P. P., Serhan H., Voronov L. I., Carandang G., Havey R. M., Ghanayem A. J., & Patwardhan A. G. |
Journal | J Spinal Disord Tech |
Volume | 25 |
Issue | 8 |
Pagination | E240-4 |
Date Published | 2012 Dec |
ISSN | 1539-2465 |
Λέξεις κλειδιά | Aged, Biomechanical Phenomena, Cadaver, Carbon, Equipment Design, Humans, In Vitro Techniques, Internal Fixators, Lumbar Vertebrae, Middle Aged, Range of Motion, Articular, Spinal Fusion, Zygapophyseal Joint |
Abstract | STUDY DESIGN: A biomechanical cadaveric study of lumbar spine segments.OBJECTIVE: To compare the immediate stability provided by parallel-shaped and anatomically shaped carbon fiber interbody fusion I/F cages in posterior lumbar interbody fusion (PLIF) and transforaminal lumbar interbody fusion (TLIF) constructs with posterior pedicle screw instrumentation.SUMMARY OF BACKGROUND DATA: Few biomechanical data are available on the anatomically shaped cages in PLIF and TLIF constructs.METHODS: Twenty human lumbar segments were tested in flexion-extension (FE) (8 N m flexion, 6 N m extension), lateral bending (LB) (± 6 N m), and torsional loading (± 5 N m). Each segment was tested in the intact state and after insertion of interbody cages in one of 3 constructs: PLIF with 2 parallel-shaped or anatomically shaped cages and TLIF with 1 anatomically shaped cage. All cages received supplementary pedicle screw fixation. The range-of-motion (ROM) values after cage insertion and posterior fixation were compared with the intact specimen values using analysis of variance and multiple comparisons with Bonferroni correction.RESULTS: All constructs significantly reduced segmental motion relative to intact (P < 0.001). The motion reductions in FE, LB, and axial rotation were 85 ± 15%, 83 ± 18%, and 67 ± 6.8% for the PLIF construct using parallel cages, 79 ± 5.5%, 87 ± 10%, and 66 ± 20% for PLIF using anatomically shaped cages, and 90 ± 6.8%, 87 ± 12%, and 77 ± 22% for TLIF with an anatomically shaped cage. In FE and LB, the reductions in the ROM caused between the 3 constructs were equivalent (P > 0.05). In axial rotation, the TLIF cage provided significantly greater limitation in the ROM compared with the parallel-shaped PLIF cage (P = 0.01).CONCLUSIONS: The parallel-shaped and anatomically shaped I/F cages provided similar stability in a PLIF construct. The greater stability of the TLIF construct was likely due to a more anterior placement of the TLIF cage and preservation of the contralateral facet joint. |
DOI | 10.1097/BSD.0b013e31824c820c |
Alternate Journal | J Spinal Disord Tech |
PubMed ID | 22362111 |