Clinical evaluation of a new kyphoplasty technique with directed cement flow.

STUDY DESIGN Prospective, single-center 2-year study. OBJECTIVE The long-term clinical performance of a new cement-directing kyphoplasty system was evaluated for treatment of painful osteoporotic compression fractures. SUMMARY OF BACKGROUND DATA Cement leakage is a common clinical complication of vertebroplasty and kyphoplasty procedures. Balloon kyphoplasty restricts cement flow and reduces leakage by injection of high-viscosity cement into a compacted bone cavity. Biomechanical reinforcement of surrounding bone is limited, leaving the vertebral body vulnerable to continued collapse. METHODS The patient population consisted of 20 patients at least 50 years of age with up to 3 painful osteoporotic vertebral compression fractures between T4-L5. The cement-directing kyphoplasty system procedure was performed unipedicularly using a curved drill and reamer to create a central cavity. The cement-directing implant was positioned inside the cavity and cement was injected through it. A total of 37 levels were treated. Pain relief was assessed using a verbal pain scale. The Roland-Morris Questionnaire was used to evaluate disability. Cement leakage was determined from radiographs (anterior/posterior and lateral) obtained within 24 hours of the procedure. RESULTS : Significant pain relief was achieved immediately after the procedure, as shown by a decrease in the mean pain scores from 8.20 (±1.40) measured preoperatively to 2.85 (±2.13) measured postoperatively. Pain relief was sustained throughout the 2-year follow-up period. Mean Roland-Morris Questionnaire scores improved from 21.8 (±3.5) measured preoperatively to 11.6 (±5.6) measured 6 weeks postoperatively. The investigators reported 1 moderate cortical leak (2.7%) and an independent reviewer identified 8 additional minor segmental vein and cortical leaks (24.3%). None of the leaks was symptomatic. CONCLUSIONS Directed cement flow allows cement to fill the anterior vertebral body, stabilizing fractures and supporting biomechanical loading. Control of cement flow may help minimize the risk of posterior leakage into the basivertebral vein or spinal canal.