The intervertebral disc is a major load bearing component of the spine. The mechanical loading of the disc is one of the main causes of its degeneration . For chronic patients, the treatment regimen may range from conservative approach to surgical procedures, including fusion with and without instrumentation. The fusion has proven successful in reducing the segmental motion. However, a majority of patients after a fusion procedure may still experience pain. The procedure may also lead to adjacent level degeneration, pseudarthrosis and donor site pain. These shortcomings have led the researchers to develop alternative approaches such as the total disc arthroplasty which is expected to preserve motion and relieve pain . Thus, it is essential to evaluate the clinical outcomes in terms of an artificial disc’s ability to provide normal kinematics following total disc replacements.
The wide clinical experience in the area of lower extremity joint replacements suggests that the long-term success of any total arthroplasty system is a function of three primary factors: implant design parameters (geometry, material, kinetics, ROM in all 6 degrees of freedom), patient related parameters (weight, kinematics, age) and surgeon related factors such as surgical procedures. One expects that similar parameters would influence the long-term success of the cervical disc replacement. (1)
For more than 50 years, anterior cervical discectomy and fusion (ACDF) has been the workhorse procedure for cervical degenerative pathology. The procedure has yielded successful results clinically in multiple large series. Advances in allograft and cage techniques as well as the use of anterior plating systems have diminished complications in ACDF. However, concerns about adjacent segment degeneration (ASD) have lowered some enthusiasm for the procedure. (1)
Cervical disc arthroplasty has the potential to maintain anatomical disc space height, normal segmental lordosis, and physiological motion patterns after surgery. These characteristics may reduce or delay the onset of degenerative disc disease at adjacent cervical spinal motion segments after anterior cervical decompression surgery. (2)
Cervical disc replacement has been developed as a motion-preserving alternative to fusion, with the hope that retained motion at the operative level may reduce adjacent segment disease. Cervical disc replacement has become an acceptable
alternative to anterior cervical fusion for the surgical treatment of cervical spine spondylosis resulting in radiculopathy or myelopathy following anterior discectomy and decompression.
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