Complication avoidance in 116 dynamic-plated single-level anterior corpectomy and fusion

Are External Cervical Orthoses Necessary after Anterior Cervical Discectomy and Fusion: A Review of the Literature

Introduction & Background: The use of external cervical orthosis (ECO) after anterior cervical discectomy and fusion (ACDF) varies from physician to physician due to an absence of clear guidelines. Our purpose is to evaluate and present evidence answering the question, “Does ECO after ACDF improve fusion rates?” through a literature review of current evidence for and against ECO after ACDF. 

Review: A PubMed database search was conducted using specific ECO and ACDF related keywords. Our search yielded a total of 1,267 abstracts and seven relevant articles. In summary, one study provided low quality of evidence results supporting the conclusion that external bracing is not associated with improved fusion rates after ACDF.  The remaining six studies provide very low quality of evidence results; two studies concluded that external bracing after cervical procedures is not associated with improved fusion rates, one study concluded that external bracing after cervical procedures is associated with improved fusion rates, and the remaining three studies lacked sufficient evidence to draw an association between external bracing after ACDF and improved fusion rates.

Conclusion: We recommend against the routine use of ECO after ACDF due to a lack of improved fusion rates associated with external bracing after surgery.

Recurrence of cervical myelopathy secondary to a strut graft fracture 20 years after anterior decompression and fusion: a case report

This study reports on a 70-year-old man with recurrent cervical myelopathy 20 years after anterior decompression and fusion of C4-7 using a free vascularised strut graft. The recurrent myelopathy was secondary to a kyphotic deformity of a fractured graft and residual ossification of the posterior longitudinal ligament with stenosis at C3/4. Intraoperative spinal cord-evoked potentials indicated that spinal cord traction secondary to progressive kyphosis of the cervical spine after the graft fracture was the cause. The patient underwent laminoplasty at C3 and laminectomy at C4 to decompress the stenosis at C3/4 as well as posterior cervical spinal fusion at C3-7 with pedicle screws and a lateral mass screw and a bone graft to prevent further progression of the kyphosis. At postoperative 18 months, the patient's Japanese Orthopaedic Association score had improved to 14 from 8, and he could walk without support.

Systematic review of the effect of dynamic fixation systems compared with rigid fixation in the anterior cervical spine

PURPOSE

Anterior cervical fixation is a procedure widely employed in medical practice, with different fixation systems in use. This study aimed to perform a systematic review of the literature comparing the use of rigid and dynamic cervical plates regarding the fusion rate and complications.

METHODS

A search was conducted in PubMed, Lilacs, and Cochrane databases and selecting comparative studies on the use of rigid and dynamic cervical plates. Prospective randomized studies were selected to describe the final results regarding the clinical and radiological outcomes; comparative observational studies were also cited. Complications of using the dynamic cervical plate were also evaluated.

RESULTS

Seven comparative studies were included in the review. Five of these were prospective and randomized studies that did not report significant differences in the clinical outcome. One study reported a faster fusion rate when dynamic cervical plate was used, and another study showed a higher fusion rate when a dynamic cervical plate was applied on multiple levels. Four studies investigated the complications of using a dynamic plate and reported that changes in the cervical curvature angle and material failure were the most frequent complications.

CONCLUSIONS

There were no clinical differences between the two types of cervical fixation systems. A difference in the fusion rates could not be found at any follow-up time or in any of the studies. There was a loss of lordotic correction in the dynamic systems and a higher rate of complications in patients with a loss of lordotic correction.

Iliac crest autograft versus alternative constructs for anterior cervical spine surgery: Pros, cons, and costs

Background:

Grafting choices available for performing anterior cervical diskectomy/fusion (ACDF) procedures have become a major concern for spinal surgeons, and their institutions. The “gold standard”, iliac crest autograft, may still be the best and least expensive grafting option; it deserves to be reassessed along with the pros, cons, and costs for alternative grafts/spacers.

Methods:

Although single or multilevel ACDF have utilized iliac crest autograft for decades, the implant industry now offers multiple alternative grafting and spacer devices; (allografts, cages, polyether-etherketone (PEEK) amongst others). While most studies have focused on fusion rates and clinical outcomes following ACDF, few have analyzed the “value-added” of these various constructs (e.g. safety/efficacy, risks/complications, costs).

Results:

The majority of studies document 95%-100% fusion rates when iliac crest autograft is utilized to perform single level ACDF (X-ray or CT confirmed at 6-12 postoperative months). Although many allograft studies similarly quote 90%-100% fusion rates (X-ray alone confirmed at 6-12 postoperative months), a recent “post hoc analysis of data from a prospective multicenter trial” (Riew KD et. al., CSRS Abstract Dec. 2011; unpublished) revealed a much higher delayed fusion rate using allografts at one year 55.7%, 2 years 87%, and four years 92%.

Conclusion:

Iliac crest autograft utilized for single or multilevel ACDF is associated with the highest fusion, lowest complication rates, and significantly lower costs compared with allograft, cages, PEEK, or other grafts. As spinal surgeons and institutions become more cost conscious, we will have to account for the “value added” of these increasingly expensive graft constructs.

New surgical technique to secure the bone strut during anterior cervical corpectomy and fusion: kusabi fixation technique--technical note

Fixation using an anterior cervical plate is frequently used in anterior cervical discectomy or corpectomy and fusion procedures because of the higher fusion rate than without instrumentation. The surgical outcomes with the anterior plate technique are acceptable, but various hardware-related complications have been reported. The authors describe a new surgical technique, called the kusabi fixation technique, for securing the bone strut during anterior cervical corpectomy using cylindrical cages. Following corpectomy, the trimmed bone strut was placed into the space drilled-out. Two small holes of 5-6-mm diameter and 5-mm depth were drilled out at the interface of two bones at the top and bottom of the bone strut in a diagonal orientation. Two cylindrical cages filled with autologous bone tips were tapped into the interface. Eight patients with myelopathy were treated by this method. All procedures were uneventfully performed as a single level surgery (two vertebral bodies and one disk level). Solid bone union was obtained in all patients at 6 months after the operation. Apparent alignment change in the cervical spine was observed in only one patient, who developed asymptomatic kyphosis. No instrumentation failure or significant complications related to the surgery occurred. Precise biomechanical aspects and long-term radiographic analysis compared with the plate fixation technique should be established, but this new method provides another way to secure the bone strut in anterior cervical corpectomy and fusion.