MSCT guidance bolsters orthopedic intervention

Multislice CT allows accurate measurement, guidance, and assessment of several minimally invasive interventional procedures to fix pelvic, spinal, and other musculoskeletal lesions, according to studies from France and Germany presented at the RSNA meeting Monday.

Dr. Nicolas Amoretti, an interventional radiologist at the Centre Hospitalier Universitaire in Nice, released two studies on percutaneous CT-guided repair of disrupted or fractured sacroiliac and spinal joints.

The first study provided a prospective review of data collected from November 2001 to May 2005 on 86 patients with post-traumatic sacroiliac disruption as a result of traffic injuries, falls, and suicide attempts. Patient selection included several types of sacroiliac disruption and excluded highly displaced, unstable pelvic fractures and severe pelvic joint injuries.

Researchers found the procedure to be a safe and viable alternative to open surgery. CT-guided repair could also be performed in coordination with surgery for complex injuries, Amoretti said.

Researchers reported no major intra- or postprocedural complications. All patients achieved a satisfactory sacroiliac stabilization, and fewer than 20% experienced residual pain. The percutaneous procedure can be performed with devices routinely used by interventional radiologists and orthopedic surgeons. It requires about two hours for completion, has a lower morbidity rate than open surgery or bed rest, and allows most patients to stand after 48 hours, Amoretti said.

In the second study, Amoretti and colleagues reviewed preliminary results from the first 30 patients undergoing CT-guided percutaneous spinal arthrodesis - transfacetar screw placement - using a posterior approach. A radiological-surgical team performed the procedure at the CT table and under fluoroscopic control. They used axial CT images to gauge the depth and angulation needed for accurate screw placement.

Twenty-seven patients have shown clinical improvement, no lumbar pain, and stabilization of the immobilized lumbar segment three months after intervention. Only one major complication has been reported to date. The procedure takes about the same time to perform as the sacroiliac repair. It requires a two-day hospital stay and periodic follow-up, and the patient must wear a corset for two months.

In a separate study, Dr. Martin G. Mack, an interventional radiologist at the J. W. Goethe University in Frankfurt, presented data on 40 patients who underwent CT-guided transpedicle screw placement for unstable thoracic spine fractures.

The investigators achieved 100% technical success by correctly placing all 340 guide wires needed for intervention and 337 screws. The procedure takes about two to three hours and is safer and more accurate than standard orthopedic stabilization procedures, Mack said.

None of these procedures are risk-free, however. More studies should eventually confirm their feasibility and cost-effectiveness, the researchers said.