Response to the letter to the editor: Can intraoperative T1 tilt predict postoperative shoulder imbalance in patients with Lenke 2 adolescent idiopathic scoliosis?: a retrospective study in Japan

Article information

Asian Spine J. 2026;20(4):821-822

Publication date (electronic) : 2026 August 28

doi : https://doi.org/10.31616/asj.2026.0677.r2

Yuki Kinoshita¹, Yusuke Hori², Masaki Kawamura², Takashi Namikawa², Masatoshi Hoshino³, Akira Matsumura^,2

¹Department of Orthopaedic Surgery, Osaka Metropolitan University Graduate School of Medicine, Osaka, Japan

²Scoliosis Center, Osaka City General Hospital, Osaka, Japan

³Department of Orthopaedic Surgery, Osaka Saiseikai Nakatsu Hospital, Osaka, Japan

Corresponding author: Akira Matsumura Department of Orthopaedic Surgery, Osaka City General Hospital, Miyakojimahondouri, Miyakojimaku, Osaka city, Osaka, 543-0021, Japan Tel: +81-6-6929-1221, Fax: +81-6-6929-1084, E-mail: akiramattsu1969@gmail.com

Received 2026 August 10; Accepted 2026 August 12.

Dear Editor,

We sincerely thank the authors for their thoughtful comments regarding our study, “Can intraoperative T1 tilt predict postoperative shoulder imbalance in patients with Lenke 2 adolescent idiopathic scoliosis?: a retrospective study in Japan [1].” We appreciate the opportunity to clarify these important points.

First, regarding cohort overlap, there was partial overlap between the patient populations of our previous study and the present study. However, the purpose of the current study was different. Our previous study focused on postoperative changes in T1 tilt as a predictor of postoperative shoulder imbalance (PSI), whereas the present study specifically evaluated intraoperative T1 tilt as a potentially modifiable parameter during surgery. Thus, the present study was designed to extend our previous findings toward their practical intraoperative application.

Second, we agree that the subgroup analysis of the PSI group should be interpreted cautiously because it included only 12 patients. The correlation between intraoperative T1 tilt change and radiographic shoulder height (RSH) change in this subgroup should therefore be considered exploratory rather than definitive. This limitation was acknowledged in our manuscript.

Third, we agree that the difference between the prone anesthetized position and the postoperative standing position is an important consideration. Muscle tone, gravitational loading, and spinal flexibility may influence coronal alignment. Nevertheless, in our study, intraoperative changes in T1 tilt were significantly correlated with postoperative changes in T1 tilt (r=0.619, p<0.001), suggesting that intraoperative T1 tilt reflects, at least in part, postoperative standing alignment. Moreover, intraoperative T1 tilt changes were significantly correlated with changes in both RSH and clavicle angle. We therefore believe that intraoperative T1 tilt can serve as a useful practical indicator, although it should not be regarded as an exact surrogate for postoperative standing alignment.

We fully agree that further prospective studies with larger cohorts are required to establish clinically useful intraoperative thresholds and to validate the predictive value of T1 tilt.

We again thank the authors for their constructive comments, which provide an important perspective on the interpretation and clinical application of our findings.

Sincerely,

Akira Matsumura on behalf of the authors