Atsushi Okawa, Hirotoshi Yoshida, Hirotaka Haro and Kenichi Shinomiya
Report of 2 cases
Hirotaka Haro, Toru Domoto, Shingo Maekawa, Tadahiro Horiuchi, Hiromichi Komori and Yoshiki Hamada
✓The authors describe 2 cases of thoracic disc herniation, resulting in acute myelopathy without bladder dysfunction or progressive muscular weakness; the herniated disc apparently resorbed without surgical intervention. Thoracic disc herniations are less frequent than cervical or lumbar disc herniations and are usually associated with severe neurological deficits. In these 2 cases, the herniated discs exhibited marked decreases in size, corresponding to a favorable clinical outcome within a few months after the initiation of conservative treatment with prostaglandin E1 and/or steroids in conjunction with physical therapy. The authors conclude that thoracic herniated discs are capable of undergoing natural resorption and that conservative treatment could be indicated, even in the presence of moderate myelopathy, when the myelopathy is not accompanied by bladder dysfunction or progressive muscular weakness.
Upper instrumented vertebra to the right of the lowest instrumented vertebra as a predictor of an increase in the main thoracic curve after selective posterior fusion for the thoracolumbar/lumbar curve in Lenke type 5C adolescent idiopathic scoliosis: multicenter study on the relationship between fusion area and surgical outcome
Hiroki Oba, Jun Takahashi, Sho Kobayashi, Tetsuro Ohba, Shota Ikegami, Shugo Kuraishi, Masashi Uehara, Takashi Takizawa, Ryo Munakata, Terue Hatakenaka, Michihiko Koseki, Shigeto Ebata, Hirotaka Haro, Yukihiro Matsuyama and Hiroyuki Kato
Unfused main thoracic (MT) curvatures occasionally increase after selective thoracolumbar/lumbar (TL/L) fusion. This study sought to identify the predictors of an unacceptable increase in MT curve (UIMT) after selective posterior fusion (SPF) of the TL/L curve in patients with Lenke type 5C adolescent idiopathic scoliosis (AIS).
Forty-eight consecutive patients (44 females and 4 males, mean age 15.7 ± 2.5 years, range 13–24 years) with Lenke type 5C AIS who underwent SPF of the TL/L curve were analyzed. The novel “Shinshu line” (S-line) was defined as a line connecting the centers of the concave-side pedicles of the upper instrumented vertebra (UIV) and lowest instrumented vertebra (LIV) on preoperative radiographs. The authors established an S-line tilt to the right as S-line positive (S-line+, i.e., the UIV being to the right of the LIV) and compared S-line+ and S-line− groups for thoracic apical vertebral translation (T-AVT) and MT Cobb angle preoperatively, early postoperatively, and at final follow-up. The predictors for T-AVT > 20 mm at final follow-up were evaluated as well. T-AVT > 20 mm was defined as a UIMT.
Among the 48 consecutively treated patients, 26 were S-line+ and 22 were S-line−. At preoperative, early postoperative, and final follow-up a minimum of 2 years later, the mean T-AVT was 12.8 mm (range −9.3 to 32.8 mm), 19.6 mm (range −13.0 to 41.0 mm), and 22.8 mm (range −1.9 to 68.7 mm) in the S-line+ group, and 10.8 mm (range −5.1 to 27.3 mm), 16.2 mm (range −11.7 to 42.1 mm), and 11.0 mm (range −6.3 to 26.9 mm) in the S-line− group, respectively. T-AVT in S-line+ patients was significantly larger than that in S-line− patients at the final follow-up. Multivariate analysis revealed S-line+ (odds ratio [OR] 23.8, p = 0.003) and preoperative MT Cobb angle (OR 7.9, p = 0.001) to be predictors of a UIMT.
S-line+ was defined as the UIV being to the right of the LIV. T-AVT in the S-line+ group was significantly larger than in the S-line− group at the final follow-up. S-line+ status and larger preoperative MT Cobb angle were independent predictors of a UIMT after SPF for the TL/L curve in patients with Lenke type 5C AIS. Surgeons should consider changing the UIV and/or LIV in patients exhibiting S-line+ during preoperative planning to avoid a possible increase in MT curve and revision surgery.