Biomechanical Analysis of 2 Versus 4 Rods Across the Cervicothoracic Junction in a Human Cadaveric Model.

Autor:	Pivazyan G; Department of Neurosurgery, MedStar Georgetown University Hospital, Washington , District of Columbia , USA.; Department of Orthopaedic Surgery, Musculoskeletal Research Center, MedStar Union Memorial Hospital, Baltimore , Maryland , USA., Winters CG; Georgetown University School of Medicine, Washington , District of Columbia , USA., Brooks DM; Department of Orthopaedic Surgery, Musculoskeletal Research Center, MedStar Union Memorial Hospital, Baltimore , Maryland , USA.; Department of Orthopaedic Surgery, MedStar Union Memorial Hospital, Baltimore , Maryland , USA., Sandhu FA; Department of Neurosurgery, MedStar Georgetown University Hospital, Washington , District of Columbia , USA., Cunningham BW; Department of Orthopaedic Surgery, Musculoskeletal Research Center, MedStar Union Memorial Hospital, Baltimore , Maryland , USA.; Department of Orthopaedic Surgery, MedStar Union Memorial Hospital, Baltimore , Maryland , USA.
Jazyk:	angličtina
Zdroj:	Neurosurgery [Neurosurgery] 2024 Jan 01; Vol. 94 (1), pp. 217-225. Date of Electronic Publication: 2023 Sep 14.
DOI:	10.1227/neu.0000000000002686
Abstrakt:	Background and Objectives: Posterior reconstruction of the cervicothoracic junction poses significant biomechanical challenges secondary to transition from the mobile cervical to rigid thoracic spines and change in alignment from lordosis to kyphosis. After destabilization, the objectives of the current investigation were to compare the rod strain and multidirectional flexibility properties of the cervicothoracic junction using a 4-rod vs traditional 2-rod reconstructions. Methods: Ten human cadaveric cervicothoracic specimens underwent multidirectional flexibility testing including flexion-extension, lateral bending, and axial rotation. After intact analysis, specimens were destabilized from C4 to T3 and instrumented from C3 to T4. The following reconstructions were tested: (1) 3.5-mm titanium (Ti) 2-rod, (2) 3.5-mm Ti 4-rod, (3) 4.0-mm cobalt chrome (CoCr) 2-rod, (4) 4.0-mm CoCr 4-rod, and (5) Ti 3.5- to 5.5-mm tapered rod reconstructions. The operative level range of motion and rod strain of the primary and accessory rods were quantified. Results: The addition of accessory rods to a traditional 2-rod construct improved the biomechanical stability of the reconstructions in all three loading modalities for Ti ( P < .05). The accessory CoCr rods improved stability in flexion-extension and axial rotation ( P < .05). The addition of accessory rods in Ti or CoCr reconstructions did not significantly reduce rod strain ( P < .05). CoCr 2 and 4 rods exhibited less strain than both Ti 2 and 4 rods. Conclusion: Supplemental accessory rods affixed to traditional 2-rod constructs significantly improved stability of Ti alloys and CoCr alloy materials. The 4.0-mm CoCr rods provided greater stability than 3.5-mm Ti rods in flexion-extension, lateral bending, and axial rotation. While rod strain was not significantly reduced by the addition of accessory rods, it was reduced in CoCr rod treatment groups compared with the Ti rods. (Copyright © Congress of Neurological Surgeons 2023. All rights reserved.)
Databáze:	MEDLINE
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