When the cartilaginous discs that separate the lower spinal vertebrae are damaged, disc replacement is sometimes the treatment of choice. Dr. Brian Freeman, a surgeon with the Centre for Spinal Studies and Surgery at Queen’s Medical Center in Nottingham, U.K., states that artificial disc replacements using polyethylene prostheses gained favor in Europe in the late 1980s, and currently many different types of artificial disc are undergoing research and development. As with any surgical procedure, the risks should be assessed before undergoing disc replacement.
Prosthetic Displacement
Complications of lumbar disc replacement sometimes arise due to slippage of the prosthesis. During a systematic review of lumbar disc replacement research, Freeman noted references to disc displacement in a number of studies, including anterior subluxation, or a forward shift in the disc’s position, or subsidence, where the artificial disc sinks into the body of the vertebra above or below it. Further complications can ensue from repeat surgeries needed to correct the displacement of the disc.
Retrograde Ejaculation
A number of cases of retrograde ejaculation have been reported as complications of lumbar disc replacement. Retrograde ejaculation occurs when the sphincter that closes the bladder fails to contract during ejaculation. As a result, sperm that would normally be expelled through the urethra instead backs up into the urinary bladder. The result is an orgasm without ejaculation. The condition is not life threatening, but does negatively impact male fertility. Dr. André van Ooij, of the Department of Orthopaedic Surgery, University Hospital Maastricht, reports several cases of loss of libido and/or erection weakness in conjunction with lumbar disc replacement.
Disc Degeneration at Adjacent Levels
When two vertebral segments have undergone spinal fusion surgery, it is common that the adjacent vertebra become less stable, leading to disc degeneration at those levels. This phenomena has also been reported in cases of lumbar disc replacement, according to Freeman. Disc replacement is typically only performed on single discs. Further studies are needed to evaluate the effectiveness of, and the complications related to, multiple disc replacements.
Facet Joint Arthrosis
Van Ooij reports that lumbar disc replacement can cause facet joint arthrosis, a condition wherein the cartilage between the joints at the rear of the spinal column erodes. The purpose of the cartilage is to facilitate the smooth frictionless gliding of the vertebral segments where they press against each other. Facet joint arthrosis can cause bone spurs and lead to arthritis, with back pain and nerve compression.
References
- "European Spine Journal"; Total Disc Replacement in the Lumbar Spine; Brian J.C. Freeman, corresponding author and James Davenport; August 2006
- "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; February 2005
