Search Results

You are looking at 1 - 10 of 14 items for :

  • "graft settling" x
Clear All
Restricted access

Richard L. Saunders, Philip M. Bernini, Thomas G. Shirrefks Jr. and Alexander G. Reeves

very slowly. The shortest period reported for the uniting of fibula with vertebra is 6 months; 41 the time for complete incorporation of the fibula graft is more likely closer to 1 year. In the patient with osteoporosis, the fibula probably should not be used, unless protected with a halo vest. The dense character of fibula used in the osteoporotic spine creates the phenomenon of “pistoning” ( Fig. 5 ), which risks fracturing off the front of the vertebral body as the fibula graft settles through its mortices. Fig. 5. Studies of a recently performed

Restricted access

Nevan G. Baldwin, Gregg P. Hartman, Martin W. Weiser and Edward C. Benzel

tend to be user friendly; there is evidence that in certain clinical settings they are biomechanically advantageous; 1, 8, 9 and they may reduce the incidence of certain other cervical fusion complications, such as graft migration or collapse. The biomechanical forces encountered by a cervical plate, however, increase postoperatively. As healing progresses, graft settling occurs, resulting in increased force application to the plate. Until solid bone fusion occurs, any movement of the neck will cause force application to the plate and its points of attachment

Restricted access

% is considered within tolerable limits. We are essentially in complete agreement with the statements made by Dr. Segal regarding measures to avoid plate breakage. His statement about overdistending the disc space with a graft that is oversized is particularly insightful. The use of a large graft may distend the interspace and cause increased ligamentous tension across the graft with a resulting increase in graft settling. This increased graft settling might certainly result in a larger portion of the spinal load being transferred to the implant. Dr. Segal also

Restricted access

graft that is oversized is particularly insightful. The use of a large graft may distend the interspace and cause increased ligamentous tension across the graft with a resulting increase in graft settling. This increased graft settling might certainly result in a larger portion of the spinal load being transferred to the implant. Dr. Segal also mentions the need to avoid bending the plate, and again we are in complete agreement with these statements. In Dr. Harrington's letter, he correctly points out that the screw heads were not properly locked into the plate. He

Restricted access

Tobias R. Pitzen, Dieter Matthis, Dragos D. Barbier and Wolf-Ingo Steudel

consequence, any type of external orthosis worn by the patient who has undergone surgery in which no additional plating had been implanted, should prevent flexion. The same device, however, will not necessarily be effective in preventing graft settling following an anterior cervical plating procedure. Limitations of the Model The manner in which our FE model was validated has already been described and used previously for other cervical spine FE models. 4, 20 Although several biomechanical parameters such as stiffness, axis of rotation, compression strength, and

Restricted access

Alexander R. Vaccaro, John A. Carrino, Benjamin H. Venger, Todd Albert, Peter M. Kelleher, Alan Hilibrand and Kush Singh

copolymer 70/30-PLLDA, which is degraded and resorbed through the process of bulk hydrolysis and is ultimately metabolized into carbon dioxide and water. This polymer has a substantial history of use in medical implants and has been assessed in various animal models for its biocompatibility with bone, brain tissue, and dura. 15, 24, 26, 36, 45 A noninstrumented single-level ACDF is typically successful. Many surgeons elect to apply anterior instrumentation to prevent graft settling and expulsion and to reduce motion across the grafted segment. The presence of an

Restricted access

Bikash Bose

the unicortical systems. In the DOC ventral cervical stabilization system (DePuy AcroMed, Inc., Raynham, MA) dynamization is used to provide load sharing between the graft and the system while controlling lordotic graft settling during the fusion process. In this prospective series the use of this dynamized system is evaluated. Clinical Material and Methods Patient Population A total of 37 patients (19 women and 18 men) underwent ACDF involving placement of the DOC system. Their mean age was 46.2 years (range 32.8–69.1 years), and all were enrolled in this

Restricted access

Steven Casha and Michael G. Fehlings

.15 ± 0.33 * inferior endplate-plate distance (mm) −0.43 ± 0.42 −0.18 ± 0.32 −0.31 ± 0.58 −0.63 ± 0.36 −0.36 ± 0.60 * Significant (p < 0.05; paired t-test) compared with immediate postoperative measurement. Fig. 4. Lateral radiographs obtained at initial postoperative period (left) and at 3 months (right) , demonstrating graft settling and dramatic change in both rostral and caudal screw—plate angles. Semiconstrained load-sharing cervical plates The incidence of hardware failure was 8.2% (16 of 195 cases

Restricted access

Lisa A. Ferrara, Illya Gordon, Madeline Coquillette, Ryan Milks, Aaron J. Fleischman, Shuvo Roy, Vijay K. Goel and Edward C. Benzel

–endplate interfaces at C3–4 and the load along the ventral cervical plate. Ventral and dorsal motion was measured across the C3–4 motion segment using a Coolpix 4.0-megapixel digital camera (Nikon, Inc.) with a resolution of 320 × 240 pixels at a sampling rate of 14 Hz and a MaxTRAQ v1.41 software image analysis system (Innovision Systems, Inc.). This technique was employed to quantify graft settling or subsidence. Descriptive statistics were used to gather the means and standard deviations of the acquired data for all of the treatment conditions. An analysis of variance with a

Restricted access

Sumit Thakar, M.Ch., Aditya Vedantam and Vedantam Rajshekhar

segmental angle had no relationship with functional outcome in terms of improvement in Nurick grade (by ≥ 1); we had reached a similar conclusion in our previous study on changes in cervical spine curvature following CC. 26 The degree of change in graft height likewise had no correlation with functional outcome. Hughes et al. 15 also noted that pain outcomes did not have any correlation with either graft settling or kyphotic change at the fused segment. However, we must caution that these functional outcomes were determined after a relatively short follow-up period and