Biomechanical evaluation of an expandable lumbar interbody spacer.
World Neurosurg. 2018 Mar 13;:
Authors: Soriano-Baron H, Newcomb AGUS, Malhotra D, Palma AE, Martinez-Del-Campo E, Crawford NR, Theodore N, Kelly BP, Kaibara T
OBJECTIVE: Lately developed expandable interbody spacers are broadly accepted in spinal surgical procedure; nonetheless, the ensuing biomechanical results of their use haven’t but been absolutely studied. We analyzed the biomechanical results of an expandable polyetheretherketone interbody spacer inserted by way of a bilateral posterior method with and with out completely different modalities of posterior augmentation.
METHODS: Biomechanical nondestructive flexibility testing was carried out in 7 human cadaveric lumbar (L2-L5) specimens adopted by axial compressive loading. Every specimen was examined underneath 6 circumstances: (1) intact, (2) bilateral L3-L4 cortical screw/rod (CSR) alone, (three) WaveD alone, (four) WaveD+CSR, (5) WaveD+bilateral L3-L4 pedicle screw/rod (PSR), and (6) WaveD+CSR/PSR, the place CSR/PSR was a hybrid assemble comprising bilateral cortical-level L3 and pedicle-level L4 screws interconnected by rods.
RESULTS: The vary of movement (ROM) with the interbody spacer alone decreased considerably in comparison with intact throughout flexion-extension (p=zero.02) however not throughout lateral bending or axial rotation (p?zero.19). The addition of CSR or PSR to the interbody spacer alone situation considerably decreased the ROM in comparison with interbody spacer alone (p?zero.002), and WaveD+CSR, WaveD+PSR, and WaveD+CSR/PSR (hybrid) (p?zero.29) didn’t differ. The axial compressive stiffness (resistance to alter in foraminal peak throughout compressive loading) with interbody spacer alone didn’t differ from intact (p=zero.96), whereas WaveD+posterior instrumentation considerably elevated compressive stiffness in comparison with intact and interbody spacer alone (p?zero.001).
CONCLUSIONS: The WaveD alone considerably lowered ROM throughout flexion-extension whereas sustaining the axial compressive stiffness. CSR, PSR, and CSR/PSR hybrid constructs had been all efficient in augmenting the expandable interbody spacer system and enhancing its stability.
PMID: 29548956 [PubMed – as supplied by publisher]