As a result of axial compression, traumatic vertebral burst fractures disrupt the anterior column, leading to segmental instability and cord compression. In situations with diminished anterior column support, pedicle screw fixation alone may lead to delayed kyphosis, nonunion, and hardware failure. Vertebroplasty and kyphoplasty (balloon-assisted vertebroplasty) have been used in an effort to provide anterior column support in traumatic burst fractures. Cited advantages are providing immediate stability, improving pain, and reducing hardware malfunction. When used in isolation or in combination with posterior instrumentation, these techniques theoretically allow for improved fracture reduction and maintenance of spinal alignment while avoiding the complications and morbidity of anterior approaches. Complications associated with cement use (leakage, systemic effects) are similar to those seen in the treatment of osteoporotic compression fractures; however, extreme caution must be used in fractures with a disrupted posterior wall.
Anton V. Zaryanov, Daniel K. Park, Jad G. Khalil, Kevin C. Baker and Jeffrey S. Fischgrund
Myles Luszczyk, Justin S. Smith, Jeffrey S. Fischgrund, Steven C. Ludwig, Rick C. Sasso, Christopher I. Shaffrey and Alexander R. Vaccaro
Although smoking has been shown to negatively affect fusion rates in patients undergoing multilevel fusions of the cervical and lumbar spine, the effect of smoking on fusion rates in patients undergoing single-level anterior cervical discectomy and fusion (ACDF) with allograft and plate fixation has yet to be thoroughly investigated. The objective of the present study was to address the effect of smoking on fusion rates in patients undergoing a 1-level ACDF with allograft and a locked anterior cervical plate.
This study is composed of patients from the control groups of 5 separate studies evaluating the use of an anterior cervical disc replacement to treat cervical radiculopathy. For each of the 5 studies the control group consisted of patients who underwent a 1-level ACDF with allograft and a locked cervical plate. The authors of the present study reviewed data obtained in a total of 573 patients; 156 patients were smokers and 417 were nonsmokers. A minimum follow-up period of 24 months was required for inclusion in this study. Fusion status was assessed by independent observers using lateral, neutral, and flexion/extension radiographs.
An overall fusion rate of 91.4% was achieved in all 573 patients. A solid fusion was shown in 382 patients (91.6%) who were nonsmokers. Among patients who were smokers, 142 (91.0%) had radiographic evidence of a solid fusion. A 2-tailed Fisher exact test revealed a p value of 0.867, indicating no difference in the union rates between smokers and nonsmokers.
The authors found no statistically significant difference in fusion status between smokers and nonsmokers who underwent a single-level ACDF with allograft and a locked anterior cervical plate. Although the authors do not promote tobacco use, it appears that the use of allograft with a locked cervical plate in single-level ACDF among smokers produces similar fusion rates as it does in their nonsmoking counterparts.
Yossi Smorgick, Kevin C. Baker, Harry Herkowitz, David Montgomery, Siddharth A. Badve, Casey Bachison, Steven Ericksen and Jeffrey S. Fischgrund
The purpose of this prospective cohort study was to identify risk factors for incidental durotomies in lumbar spine surgery. The authors hypothesized that the incidence of durotomy would be higher in cases involving multiple operations.
The authors prospectively evaluated 523 patients who underwent lumbar and thoracolumbar spine surgery. They compared data on patients in whom a dural tear occurred and those in whom a dural tear did not occur. Data from patients in whom a dural tear occurred were compared with data from patients who did not experience durotomy. The data included basic demographic information, intraoperative data, and clinical information from a medical record review.
One hundred thirty-one patients underwent discectomy and 392 patients underwent laminectomy. Among the 131 patients who underwent discectomy 6 patients had a dural tear. Among the 392 patients who underwent discectomy 49 patients had dural tear. Patients with incidental durotomy were older (mean 65 ± 13 vs 60 ± 14 years of age; p = 0.044, t-test), and had longer surgery (146 ± 59 vs 110 ± 54 minutes; p = 0.025, t-test), compared with the patients without dural tear. The incidence of dural tear was more common in patients with a history of previous spine surgery (p < 0.001).
In patients who underwent lumbar and thoracolumbar spine surgery for degenerative problems, previous surgery and older age were found to be predisposing factors for dural tear.
Chang Ju Hwang, Alexander R. Vaccaro, Joseph Hong, James P. Lawrence, Jeffrey S. Fischgrund, Moulay Hicham Alaoui-Ismaili and Dean Falb
The aim in this study was to detect and quantify antibody responses against recombinant human osteogenic protein 1 (OP-1) and to compare these responses to patient clinical outcomes and safety information.
A controlled, open-label, randomized, prospective, multicenter pivotal study was performed in which patients with single-level Grade I or II degenerative lumbar spondylolisthesis (Meyerding classification) and spinal stenosis underwent decompression and uninstrumented posterolateral spinal arthrodesis. Three hundred thirty-six patients were randomized in a 2:1 fashion to receive either OP-1 Putty or autogenous iliac crest bone graft. Patients were evaluated at regular postoperative intervals for radiographic results, clinical outcomes, and safety parameters for more than 36 months. Serum samples were collected over this period and evaluated for the presence of anti–OP-1 antibodies and neutralizing activity by using a battery of in vitro binding assays (including enzyme-linked immunosorbent assay [ELISA]) and cell-based bioassays, respectively.
Antibodies were predominantly seen in the OP-1–treated patients, although some responses were recorded preoperatively and in patients receiving autograft alone. Antibody production peaked in the 6-week to 3-month postoperative time frame and diminished thereafter. Neutralizing antibodies (Nabs) were detected at 1 time point at least in 25.6% of the patients treated with OP-1 Putty, but were not found in any patient following the 24-month postoperative time period. A single autograft patient (1.2%) also presented with OP-1 Nabs. An anti–OP-1 antibody status did not correlate with any measure of patient outcomes or adverse events.
Recombinant human OP-1 (bone morphogenetic protein 7), like many recombinant human proteins, induces an immune response following its use as a bone graft alternative. This response was transient and diminished over time, and there was no statistical evidence to suggest an association between Nab status and any of the efficacy or safety criteria that were examined.