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Surgical Treatment of Lenke 1 Main Thoracic Idiopathic Scoliosis: Results of a Prospective, Multicenter Study

Newton, Peter O. MD*; Marks, Michelle C. PT, MA*; Bastrom, Tracey P. MA*; Betz, Randal MD; Clements, David MD; Lonner, Baron MD§; Crawford, Alvin MD; Shufflebarger, Harry MD; O'Brien, Michael MD; Yaszay, Burt MD*Harms Study Group

doi: 10.1097/BRS.0b013e31826c6df4

Study Design. Prospective, consecutive, nonrandomized, multicenter study.

Objective. The purpose of this study was to compare the outcomes of idiopathic scoliosis treatment for Lenke 1 curves with 3 treatment approaches.

Summary of Background Data. Surgical treatment options for Lenke 1 or primary main thoracic curve pattern in adolescent idiopathic scoliosis include thoracoscopic anterior spinal fusion, open anterior spinal fusion, and posterior spinal fusion (PSF) and instrumentation procedures.

Methods. This was a prospective, consecutive, nonrandomized, multicenter study of surgical correction in adolescent idiopathic scoliosis. Patients with Lenke type 1 curve patterns from 7 sites were enrolled in this minimum 2-year follow-up study. Changes in pre- to postoperative radiographs, pulmonary function tests, Scoliosis Research Society questionnaire scores, and trunk rotation measures were compared.

Results. A total of 149 patients (age: 14.5 ± 2 yr) were included (91% follow-up at 2 yr). The 3 groups were similar preoperatively in thoracic and lumbar curve size. There were 55 patients with thoracoscopic anterior spinal fusion, 17 patients with open anterior spinal fusion, and 64 patients with PSF. The fusion included on average 3 to 4 more levels in PSF than the 2 anterior approaches (P ≤ 0.001). Surgical time tended to be greater in the anterior groups by approximately 2 to 3 hours; however, blood loss was greatest with PSF. At 2 years, all 3 approaches showed similar improvements in the thoracic Cobb angle, coronal balance, the lumbar Cobb angle, Scoliosis Research Society questionnaire scores, and trunk rotation measures. The PSF approach resulted in overall reduction in kyphosis compared with the anterior approaches. Postoperative hyperkyphosis was an issue only in the 2 anterior groups. Major complication rates were similar.

Conclusion. All 3 approaches resulted in similarly satisfactory outcomes for the majority of patients with specific advantages to each technique. The patients with PSF had more levels fused, yet with the shortest operative time. The thoracoscopic anterior spinal fusion group had the smallest incisions and the lowest requirement for transfusion. The open anterior spinal fusion group had a modest loss of pulmonary function without any clear advantages compared with the other 2 groups.

Level of Evidence: 2

This prospective outcomes study suggests that Lenke type 1 (main thoracic) curves can be effectively managed surgically with an open anterior, thoracoscopic anterior, or a posterior instrumented fusion. Each option, however, has specific advantages and challenges that the surgeon must acknowledge when treating a specific patient.

*Department of Orthopedic Surgery, Rady Children's Hospital and Health Center, San Diego, CA;

Department of Orthopedic Surgery, Shriners Hospital, Philadelphia, PA;

Cooper Bone & Joint Institute, Camden, NJ;

§Department of Orthopaedic Surgery, New York University Hospital for Joint Diseases, New York, NY;

Department of Orthopaedic Surgery, Cincinnati Children's Hospital Medical Center, Cincinnati, OH;

Department of Orthopedics, Miami Children's Hospital, Miami, FL; and

**Baylor Scoliosis Center, Plano, TX.

Address correspondence and reprint requests to Peter O. Newton, MD, 3030 Children's Way, Ste 410, San Diego, CA 92123; E-mail:

Acknowledgment date: April 19, 2012. First revision date: June 19, 2012. Acceptance date: July 28, 2012.

The device(s)/drug(s) is/are FDA-approved or approved by corresponding national agency for this indication.

A research grant to setting Scoliosis Straight FKA Harms Study Group was received from DePuy Synthes Spine Inc. to support this work.

One or more of the author(s) has/have received or will receive benefits for personal or professional use from a commercial party related directly or indirectly to the subject of this manuscript: e.g., honoraria, gifts, consultancies, royalties, stocks, stock options, decision making position.

© 2013 Lippincott Williams & Wilkins, Inc.