Tetsuhiko Mimura1, Jun Takahashi2, Shota Ikegami1, Shugo Kuraishi1, Masayuki Shimizu1, Toshimasa Futatsugi1, Masashi Uehara1, Hiroki Oba1, Michihiko Koseki3, Hiroyuki Kato1. 1. Department of Orthopaedic Surgery, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano, 390-8621, Japan. 2. Department of Orthopaedic Surgery, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano, 390-8621, Japan. Electronic address: jtaka@shinshu-u.ac.jp. 3. Faculty of Textile Science and Technology, Shinshu University, 3-15-1 Tokida, Ueda, Nagano, 386-8567, Japan.
Abstract
BACKGROUND: It is generally recognized that the main thoracic curve Cobb angle threshold for surgical correction is approximately 50 degrees in patients with adolescent idiopathic scoliosis (AIS). Although AIS with a Cobb angle of <50 degrees is sometimes treated surgically to improve cosmesis, the precise outcomes are unclear. This study analyzed the postoperative results for AIS with a main thoracic curve of 50 degrees. METHODS: Thirty-nine consecutive patients with Lenke type 1-2 curves underwent posterior spinal fusion for AIS. These subjects were divided into the <50 degrees of main thoracic curve group (n = 14) and the ≥50 degrees group (n = 25). Clinical and radiographic data were compared. RESULTS: The mean Cobb angle of the main thoracic curve before and at 2 years after surgery for the <50 degrees and ≥50 degrees groups was 44.5 and 60.3 degrees (p < 0.001) and 14.0 and 19.5 degrees (p = 0.016), respectively. Preoperatively, both groups had comparable Scoliosis Research Society-22 (SRS-22) scores (all p > 0.05). Patients with a Cobb angle of <50 degrees displayed significantly milder postoperative pain (4.7 vs. 4.3, p = 0.031), with no remarkable differences in other SRS-22 domain scores. These patients also had a significantly shorter operative time (194 vs. 235 min, p = 0.021) and fused level (9.2 vs. 10.8 vertebrae, p = 0.006) along with similar correction rate (68.1 vs. 65.8%, p = 0.622) and blood loss volume (932 vs. 1009 ml, p = 0.715). CONCLUSIONS: Surgical correction of AIS with <50 degrees of main thoracic curve may less invasively achieve results that are comparable with those for AIS with 50 degrees or more, including improvements in self-image.
BACKGROUND: It is generally recognized that the main thoracic curve Cobb angle threshold for surgical correction is approximately 50 degrees in patients with adolescent idiopathic scoliosis (AIS). Although AIS with a Cobb angle of <50 degrees is sometimes treated surgically to improve cosmesis, the precise outcomes are unclear. This study analyzed the postoperative results for AIS with a main thoracic curve of 50 degrees. METHODS: Thirty-nine consecutive patients with Lenke type 1-2 curves underwent posterior spinal fusion for AIS. These subjects were divided into the <50 degrees of main thoracic curve group (n = 14) and the ≥50 degrees group (n = 25). Clinical and radiographic data were compared. RESULTS: The mean Cobb angle of the main thoracic curve before and at 2 years after surgery for the <50 degrees and ≥50 degrees groups was 44.5 and 60.3 degrees (p < 0.001) and 14.0 and 19.5 degrees (p = 0.016), respectively. Preoperatively, both groups had comparable Scoliosis Research Society-22 (SRS-22) scores (all p > 0.05). Patients with a Cobb angle of <50 degrees displayed significantly milder postoperative pain (4.7 vs. 4.3, p = 0.031), with no remarkable differences in other SRS-22 domain scores. These patients also had a significantly shorter operative time (194 vs. 235 min, p = 0.021) and fused level (9.2 vs. 10.8 vertebrae, p = 0.006) along with similar correction rate (68.1 vs. 65.8%, p = 0.622) and blood loss volume (932 vs. 1009 ml, p = 0.715). CONCLUSIONS: Surgical correction of AIS with <50 degrees of main thoracic curve may less invasively achieve results that are comparable with those for AIS with 50 degrees or more, including improvements in self-image.