Several types of pedicular screw systems have been utilized to augment lumbar spine fusion. All systems are made of stainless steel, which interferes with imaging techniques, especially MRI and CT scans. In search of a solution for this problem, we decided to study the use of titanium systems in the lumbar spine. Because there were no titanium pedicle screw systems available on the market, we decided to use the titanium Alta system currently used for femur fractures. This report details our experience in using this device for lumbar spine fusion. From 1990 to 1992, 25 patients underwent thoracic and lumbar fusion with Alta titanium screws and plates. Spinal fusion was performed for a variety of conditions, including metastatic tumor, fracture, spondylolisthesis, pseudoarthrosis, and postdecompressive instability. All but two patients obtained solid fusion clinically and radiographically and considerable improvement in back pain. There was loosening of the implant in both patients. Both patients had osteoporosis. One of these two patients developed pseudoarthrosis, which required further surgery. The other patient with a metastatic tumor of the spine remained asymptomatic without change in the spine alignment despite progression of the tumor. There were no broken screws encountered during follow-up. Two patients sustained subsequent fracture of the vertebra above the fusion. One of the patients also developed a fracture below the fusion. Fusion with titanium implants allowed postoperative evaluation and subsequent periodic examination of the spinal canal with high-quality MR images as well as significant reduction of artifacts on CT scan.(ABSTRACT TRUNCATED AT 250 WORDS)