fractured bone dowel

  : Diagnosed with herniniated C5/6 cervical disc 12.97. Surgery performed 05.98 anterior discectomey and keel bone fusion. Approximately 3-4 weeks after surgey my body told me that something was wrong. My neurosurgeon would not listen and I did not see him until schedualled post-operative appointment 7 weeks after surgery. Upon examination and regular cervical x-ray, neurosurgeon advised that bone dowel had cracked/fractured/extruded. He could not explain why this happened, and to date I still do not have answers. Had second surgery 09.98; removed extruded bone dowel, replaced and stabilized with metal plate. Was told pre-surgerically that bone dowel would be removed and replaced with exactly the same material. When woke up from surgery, relized that bone graft was taken from hip, which is fine with me if rate of success is greater.
  : My question is why did this bone dowel crack/fracture/extrude (all terms used by my neurosurgeon). How common is this?
Could you point me in the direction of studies?
  : My inquiry is twoforld,and I apologize for the length of my inquiry. Is there any research that would support a claim that a herniated cervical disc can be the result of a Cummulative Trauma Disorder/Repetive Strain Injury, as a result of years of intensive work at VDU's. One such work site being ergonomically deficient. It seems to me that the incereased pressure on the neck and hence cervical discs as a result of work at a VDU is not such a strange proposition. I am convinced that this is how my injury occured, but am having a difficult time proving this. Any help would be great.
  : Thank you
  : Kathi
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Dear Kathi,
Occasionally a cervical bone plug will fracture after a fusion procedure.  Often the bone does not extrude in the anterior or posterior direction and may be simply observed and allowed to fuse on its own.  When the bone fragments and pushes out to a significant degree, it should be fixed as there is a risk of injury to the spinal cord, the esophagus or both.  Also, a patient's own bone is the best graft and carries the highest fusion rate of possible bone grafts.
Whether your job contributed significantly to your present problems is difficult to say.  Cervical disc disease occurs in the general population, both patients who have added stressors to the region and those who have not.  It would be likely, that there was some contribution of cervical stress to the condition.  Definitively stating that A + B = C would be difficult given the above information.
Good luck.