The lumbar region of the spine extends below the ribcage and down to the pelvis. It consists of five vertebral segments, separated by cartilaginous shock absorbers known as intervertebral discs. Discs are subject to wear and tear over the course of a lifetime, and they are vulnerable to injuries due to trauma. When a disc is damaged, the surgical option exists of replacing it with an artificial prosthesis. As with any surgical procedure, the potential for complications exists following disc replacement in the lumbar spine.
Vascular Embolism
The formation of blood clots in the deep veins of the legs is a common complication of surgery. These clots are significant not simply for the leg swelling and discomfort they can cause, but also for their ability to break free, or embolize, and travel to the lungs, where they can cause fatal complications.
In a study of complications following disc replacement using the SB Charité lumbar disc prosthesis, Ilona M. Punt, of the Department of Orthopaedic Surgery at the University Hospital Maastricht in the Netherlands, reported the occurrence of deep venous thrombosis in a patient following surgical correction of a lesions found in the leg veins.
Nerve Injury
The proximity of the discs to the spinal cord makes the neurological system vulnerable to injury during disc replacement. Punt explains that surgical disc replacement was thought to have placed excessive tension on the lumbosacral nerves, which are those that exit the lower spine, in several patients surveyed. This led to severe leg pain and muscle weakness.
Prosthetic Displacement
Placement and sizing of the prosthesis appear to pose problems in many cases of complications after disc replacement. Sometimes the discs subside, meaning they sink into the body of the vertebrae below. This is most often due to the use of a prosthetic disc that is too small. Slippage of the prosthesis has been observed to occur when it is not securely fixed during surgery, according to Dr. André van Ooij, of Maastricht's University Hospital.
Adjacent Disc Degeneration
Though some doctors may hope to halt the progression of degenerative disc disease through prosthetic replacement, Brian J.C. Freeman of the Centre for Spinal Studies and Surgery at University Hospital Queen's Medical Centre in Nottingham in the U.K., concluded that the effectiveness of prosthetic replacement in preventing the degeneration of adjacent discs is unproven.
The occurrence of degeneration of the discs above or below the prosthesis may, in fact, be a possible consequence of disc replacement surgery. This may be the result of a degenerative tendency that may have continued regardless of whether surgery had occurred, or it could also be a consequence of stress placed on those discs due to incorrect anatomical functioning of the disc replacement.
References
- "Journal of Spinal Disorders & Techniques"; Complications of Artificial Disc Replacement: A Report of 27 Patients With the SB Charité Disc; André van Ooij et al.; August 2003
- "European Spine Journal"; Total Disc Replacement in the Lumbar Spine: A Systematic Review of the Literature; Brian J.C. Freeman and James Davenport; August 2006
- "European Spine Journal"; Complications and Reoperations of the SB Charité Lumbar Disc Prosthesis: Experience in 75 Patients; Ilona M. Punt et al.; January 2008
