OBJECT: The authors compared the biomechanical stability of two multilevel cervical constructs involving the placement of equal size anterior cervical plates (ACPs) after decompressive surgery: the first is placed after three-level corpectomy with strut graft and the second after two-level corpectomy and aggressive discectomy with strut graft. In addition, both constructs were evaluated with and without the application of a screw attaching the ACP to the strut graft to determine whether the additional screw enhanced stability in any mode of loading. METHODS: Nondestructive repeated-measures in vitro flexibility tests were performed in human cadaveric cervical spines. Nonconstraining pure moments of up to 1.5 Nm were applied while recording three-dimensional angular motion stereophotogrammetrically at each level from C4-5 to C7-T1. Nine specimens underwent the three-level corpectomy/strut graft procedure and eight specimens the two-level corpectomy/discectomy strut graft procedure. Failures during testing eliminated two of the former specimens and three of the latter specimens from analysis. The construct applied after the two-level procedure allowed a significantly smaller normalized neutral zone during flexion-extension than the three-level construct (p = 0.04). Normalized elastic zone and range of motion were consistently smaller in the two- than in the three-level construct, but the differences were not significant. Addition of a screw to the strut graft significantly reduced motion in the three-level procedure-treated specimens during flexion and lateral bending but had no effect on two-level corpectomy-treated specimens. CONCLUSIONS: The construct associated with the two-level corpectomy/discectomy provided better immediate postoperative stability than that associated with the three-level corpectomy. The addition of a screw to the strut graft conferred stability on the three-level construct but not the two-level construct.
OBJECT: The authors compared the biomechanical stability of two multilevel cervical constructs involving the placement of equal size anterior cervical plates (ACPs) after decompressive surgery: the first is placed after three-level corpectomy with strut graft and the second after two-level corpectomy and aggressive discectomy with strut graft. In addition, both constructs were evaluated with and without the application of a screw attaching the ACP to the strut graft to determine whether the additional screw enhanced stability in any mode of loading. METHODS: Nondestructive repeated-measures in vitro flexibility tests were performed in human cadaveric cervical spines. Nonconstraining pure moments of up to 1.5 Nm were applied while recording three-dimensional angular motion stereophotogrammetrically at each level from C4-5 to C7-T1. Nine specimens underwent the three-level corpectomy/strut graft procedure and eight specimens the two-level corpectomy/discectomy strut graft procedure. Failures during testing eliminated two of the former specimens and three of the latter specimens from analysis. The construct applied after the two-level procedure allowed a significantly smaller normalized neutral zone during flexion-extension than the three-level construct (p = 0.04). Normalized elastic zone and range of motion were consistently smaller in the two- than in the three-level construct, but the differences were not significant. Addition of a screw to the strut graft significantly reduced motion in the three-level procedure-treated specimens during flexion and lateral bending but had no effect on two-level corpectomy-treated specimens. CONCLUSIONS: The construct associated with the two-level corpectomy/discectomy provided better immediate postoperative stability than that associated with the three-level corpectomy. The addition of a screw to the strut graft conferred stability on the three-level construct but not the two-level construct.
Authors: Heiko Koller; Rene Schmidt; Michael Mayer; Wolfgang Hitzl; Juliane Zenner; Stefan Midderhoff; Stefan Middendorf; Nicolaus Graf; Nicolaus Gräf; H Resch; Hans-Joachim Wilke; Hans-Joachim Willke Journal: Eur Spine J Date: 2010-06-30 Impact factor: 3.134
Authors: Murat Yilmaz; Kasim Zafer Yüksel; Seungwon Baek; Anna G U S Newcomb; Sedat Dalbayrak; Volker K H Sonntag; Neil R Crawford Journal: Clin Spine Surg Date: 2017-04 Impact factor: 1.876
Authors: Sebastian Hartmann; Claudius Thomé; Alexander Keiler; Helga Fritsch; Aldemar Andres Hegewald; Werner Schmölz Journal: Eur Spine J Date: 2015-08-02 Impact factor: 3.134
Authors: Heiko Koller; Axel Hempfing; Luis Ferraris; Oliver Maier; Wolfgang Hitzl; Peter Metz-Stavenhagen Journal: Eur Spine J Date: 2007-06-29 Impact factor: 3.134