Dynamic stabilization in addition to decompression for lumbar spinal stenosis with degenerative spondylolisthesis.
METHODS
Prospective clinical study.


OBJECTIVE
To test whether elastic stabilization with the Dynesys system (Zimmer Spine, Minneapolis, MN) provides enough stability to prevent further progression of spondylolisthesis as well as instability after decompression for spinal stenosis with degenerative spondylolisthesis.


BACKGROUND
In spinal stenosis with degenerative spondylolisthesis, decompression and fusion is widely recommended. However, patients have donor site pain. In 1994, a dynamic transpedicular system (Dynesys) was introduced to the market, stating that stabilization is possible without bone grafting.


METHODS
A total of 26 patients (mean age 71 years) with lumbar spinal stenosis and degenerative spondylolisthesis underwent interlaminar decompression and dynamic stabilization with the Dynesys system. Minimum follow-up was 2 years. Operative data, clinical outcome, and plain and flexion/extension radiographs were obtained and compared to preoperative and postoperative data.


RESULTS
Mean leg pain decreased significantly (P < 0.01), and mean walking distance improved significantly to more than 1000 m (P < 0.01). There were 5 patients (21%) who still had some claudication. A total of 21 patients (87.5%) would undergo the same procedure again. Radiographically, no significant progression of spondylolisthesis could be detected. The implant failure rate was 17%, and none of them were clinically symptomatic.


CONCLUSIONS
In elderly patients with spinal stenosis with degenerative spondylolisthesis, dynamic stabilization with the Dynesys system in addition to decompression leads to similar clinical results as seen in established protocols using decompression and fusion with pedicle screws. It maintains enough stability to prevent further progression of spondylolisthesis or instability. With the Dynesys system, no bone grafting is necessary, therefore, donor site morbidity can be avoided.
Center for Musculosceletal Surgery, Department of Orthopedic Surgery and Traumatology, Charité-Universitätsmedizin Berlin, Berlin, Germany.
Klaus John
KJ
Schnake
Stefan
S
Schaeren
Bernard
B
Jeanneret
D000368:Aged; D000369:Aged, 80 and over; D001863:Bone Screws; D019299:Decompression, Surgical / Q000379:methods*; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000601:surgery*; D007796:Laminectomy; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011859:Radiography; D013123:Spinal Fusion / Q000295:instrumentation* / Q000379:methods; D013130:Spinal Stenosis / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery*; D013168:Spondylolisthesis / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery*; D016896:Treatment Outcome; D021801:Zygapophyseal Joint / Q000601:surgery