The Ponte procedure: posterior only treatment of Scheuermann's kyphosis using segmental posterior shortening and pedicle screw instrumentation.

Study Design: Case series.

Objective: To examine a consecutive series of surgically treated Scheuermann kyphosis that had a posterior only procedure with segmental pedicle screw fixation and segmental Ponte osteotomies.

Summary Of Background Data: The gold standard for surgical treatment of Scheuermann kyphosis (a rigid kyphosis associated with wedged vertebral bodies occurring in late childhood or adolescence) has been combined anterior and posterior approach surgery. Alberto Ponte has advocated a posterior-only procedure with posterior column shortening via segmental osteotomies, but his procedure has not been widely accepted owing to concerns that without anterior column support there would be a risk of correction loss and/or instrumentation failure. With the advent of improved spinal instrumentation and fixation with thoracic pedicle screws, the Ponte procedure may offer an advantage over anterior/posterior reconstruction.

Methods: The study prospectively enrolled 17 consecutive patients with Scheuermann kyphosis who were treated with the Ponte procedure by the senior surgeon at one institution. Standardized radiographic analysis was performed and included full-length coronal and sagittal radiographs preoperatively, postoperatively, and at final follow-up. Analysis also included the correction obtained through the most severe, wedged segments of the deformity by the osteotomies.

Results: Seventeen patients had the Ponte procedure satisfactorily performed. No patient needed an anterior approach to achieve sufficient correction or fusion. There were no reoperations for nonunion or instrumentation failure. Correction of the instrumented levels was 61% and of worst Cobb was mean 49%. The apex of the deformity was measured over the most deformed 3 to 7 wedged segments. The average correction across the apex was 9.3 degrees per osteotomy (range 5.9 to 15). No patient lost more than 4 degrees of correction through their instrumented and fused levels. There were no neurologic complications. There was one late infection with a solid fusion treated with instrumentation removal and intravenous antibiotics.

Conclusions: Using thoracic pedicle screw instrumentation as the primary anchor, the Ponte procedure was successfully performed in 17 consecutive patients for Scheuermann kyphosis with no exclusions for the size or rigidity of the kyphosis. Results were as good as anterior/posterior historical controls with excellent correction and minimal loss of correction at final follow-up. This procedure avoids the morbidity and extended operative time attributed to the anterior approach.

Level Of Evidence: Therapeutic study, level IV [case series (no, or historical, control group)].