Device for intervertebral assisted motion: technique and initial results

The DIAM is a polyester-encased silicone interspinous dynamic stabilization device that can unload the anterior column and reestablish the functional integrity of the posterior column.

The DIAM was implanted in 104 patients between May 1, 2001 and October 30, 2001. A retrospective evaluation was performed based on chart review and patient questionnaire at a median follow-up interval of 18.1 months. There were no implant migrations, infections, or neurological injuries. Of the 20 patients who suffered adverse events, 13 underwent second lumbar spinal operations 0 to 19 months after the initial surgery (in seven the event occurred in a location other than the lumbar spine). The pain level as recorded by the physician showed improvement in 88.5%, no change in 9.6%, aggravation in 0%, and was indeterminate in 1.9%. The questionnaire revealed that at 18 months postoperatively, analgesic usage was decreased in 63.1%, increased in 12.3%, and unchanged in 24.6% of patients, and activities of daily living were improved in 46.2%, decreased in 30.8%, and unchanged in 23.1%. Specific outcomes measures for sitting, standing, physical activity, and psychosocial functioning revealed similar results.

The DIAM implant appears to be a useful and effective alternative in the surgical management of a wide range of lumbar disorders. Patient complications are few and satisfaction is high.