Combination of retrospective and prospective study.

Methods: This study prospectively examined nine T-OPLL patients who underwent posterior thoracic decompression with kyphosis correction and instrumented fusion at Hamamatsu University School of Medicine between 2017 and 2019. All underwent preoperative selective angiography to detect and evaluate the Adamkiewicz artery and ASA. Intraoperative neuromonitoring and Doppler ultrasonography were performed to analyze neurological complications and spinal cord blood flow. Results: All nine patients showed ASA stenosis in the area of T-OPLL. In all patients, the Adamkiewicz artery was located between T7 and L2 and the area of ASA stenosis corresponded to the level of T-OPLL and greatest spinal cord compression; intraoperative Doppler ultrasonography confirmed the ASA defect at the same spinal level. The number of spinal levels from the Adamkiewicz artery to the most compressive OPLL lesion was greater in the two patients who developed postoperative neurological deficit compared to those who did not (5.5 vs. 2.3, p=0.014). Conclusions This is the first study to report detection of ASA stenosis in patients with T-OPLL. Maintaining spinal cord blood flow is important in these patients to avoid neurological deterioration.

Methods: We retrospectively reviewed the medical records of 404 patients who underwent corrective fusion surgery for ASD with a minimum 2-year follow-up. We studied cases of reoperation for postoperative rod fractures and investigated surgical procedure, intraoperative findings, clinical course, and rod refracture following revision surgery. Results: Rod fracture was observed in 88 patients (21.8%). Fifty-three patients (average age, 68.3 years; average blood loss, 502.2 mL [% estimated blood volume=16.4%]; and operation time, 203.3 minutes) who suffered from a rod fracture at an average of 28.3 months after the primary operation underwent reoperation. Surgical invasiveness had no significant differences in total or partial rod replacement; however, the procedures with and without an anterior bone graft significantly differed. The replaced rod refractured at an average of 35.3 months after the revision surgery of five patients. The rod also refractured at a level outside multiple rods in two patients and with traumatic episodes in three patients. Three patients had bone grafts in the anterior column. Conclusions Revision surgery involving a multirod with a posterior-only approach for a rod fracture that occurred after ASD was performed successfully. Bone grafting in the anterior column is unnecessary for patients without massive bone defects.

Combination of retrospective and prospective study.

Methods: As part of a 2016 health screening, 320 female volunteers underwent whole-spine radiographs. Age-matched healthy women were grouped according to the number of vaginal deliveries (0, 1–2, or ≥3). Demographic variables and spinopelvic parameters were compared among the three groups. Results: Of the 320 volunteers, 213 were enrolled (mean age, 71.1±7.2 years). The mean number of vaginal deliveries was 2.2. The average pelvic incidence (PI) was 55.6°±11.1° and was significantly higher in the 90 women with three or more vaginal deliveries than in the other two groups (p<0.001). The average sacral slope was 33.4°±11.1° and was significantly higher in the women with three or more vaginal deliveries than in the 18 who did not deliver vaginally (p<0.001). The 105 women with one or two vaginal deliveries had significantly higher PIs and sacral slopes than did those who did not deliver vaginally (p<0.001). Conclusions This is the first study documenting an association between vaginal delivery and pelvic parameters. Bony birth canal realignment during vaginal delivery can affect postnatal PI. Our study helps in understanding the PI changes over a woman’s life span.

Methods: Radiological parameters were extracted from the whole lateral radiographs. Patients were divided into two groups: the ASD group (segmental kyphosis of ≥10º, and/or a ≥50% loss of disc height, and/or ≥3 mm of anteroposterior translation) and the non-ASD group. Results: All 112 included patients underwent PLIF for lumbar degenerative diseases. The minimum follow-up period was 2 years, with an average follow-up time of 63.6 months. Fifty-two patients (46.4%) were classified into the ASD group and of these, 13 required reoperation due to failure of conservative treatment. Patients with ASD exhibited significantly more caudal and posterior inflection vertebrae (IV), while the lumbar apical vertebra was significantly more caudal immediately after surgery. The IV position was identified as a significant risk factor for ASD, and the ASD incidence was significantly higher in the group where IV ≤5 (L1 vertebral body) than in the group where IV ≥5.5 (T12–L1 disc) (69.0% vs. 38.6%). Conclusions The IV position is a significant risk factor for ASD development. Although it is difficult to control intraoperative IV levels, we note a high risk of ASD in patients with IV lower than T12–L1.

Methods: This retrospective study includes 295 corrective surgery patients with ASD. Subjects were divided into two groups after propensity age matching analysis: cranial malalignment (McGS <−8 or >13) and normal cranial alignment (−8≤ McGS ≤13). Lumbar lordosis (LL), pelvic tilt (PT), TK, cervical lordosis (CL), and sagittal vertical axis (SVA) were evaluated between the two groups. Results: SVA (95–56 mm) and PT (34°–25°) decreased and LL (19°–41°) increased 2 years after surgery (p <0.05), but McGS (−1.1° to −0.5°) and CL (21°–19°) did not change. Conversely, in the group with cranial malalignment, SVA (120–64 mm), PT (35°–26°), and LL (12°–41°) showed similar results to the normal cranial parameter group 2 years after surgery, but in contrast, McGS (−13° to −2°) and CL (24°–18°) improved significantly. Conclusions Severe ASD adversely affects to maintain horizontal gaze but can be improved by spinal corrective surgery.

Methods: Radiological parameters were extracted from the whole lateral radiographs. Patients were divided into two groups: the ASD group (segmental kyphosis of ≥10º, and/or a ≥50% loss of disc height, and/or ≥3 mm of anteroposterior translation) and the non-ASD group. Results: All 112 included patients underwent PLIF for lumbar degenerative diseases. The minimum follow-up period was 2 years, with an average follow-up time of 63.6 months. Fifty-two patients (46.4%) were classified into the ASD group and of these, 13 required reoperation due to failure of conservative treatment. Patients with ASD exhibited significantly more caudal and posterior inflection vertebrae (IV), while the lumbar apical vertebra was significantly more caudal immediately after surgery. The IV position was identified as a significant risk factor for ASD, and the ASD incidence was significantly higher in the group where IV ≤5 (L1 vertebral body) than in the group where IV ≥5.5 (T12–L1 disc) (69.0% vs. 38.6%). Conclusions The IV position is a significant risk factor for ASD development. Although it is difficult to control intraoperative IV levels, we note a high risk of ASD in patients with IV lower than T12–L1.

Methods: Radiological parameters were extracted from the whole lateral radiographs. Patients were divided into two groups: the ASD group (segmental kyphosis of ≥10º, and/or a ≥50% loss of disc height, and/or ≥3 mm of anteroposterior translation) and the non-ASD group. Results: All 112 included patients underwent PLIF for lumbar degenerative diseases. The minimum follow-up period was 2 years, with an average follow-up time of 63.6 months. Fifty-two patients (46.4%) were classified into the ASD group and of these, 13 required reoperation due to failure of conservative treatment. Patients with ASD exhibited significantly more caudal and posterior inflection vertebrae (IV), while the lumbar apical vertebra was significantly more caudal immediately after surgery. The IV position was identified as a significant risk factor for ASD, and the ASD incidence was significantly higher in the group where IV ≤5 (L1 vertebral body) than in the group where IV ≥5.5 (T12–L1 disc) (69.0% vs. 38.6%). Conclusions The IV position is a significant risk factor for ASD development. Although it is difficult to control intraoperative IV levels, we note a high risk of ASD in patients with IV lower than T12–L1.

Methods: Radiological parameters were extracted from the whole lateral radiographs. Patients were divided into two groups: the ASD group (segmental kyphosis of ≥10º, and/or a ≥50% loss of disc height, and/or ≥3 mm of anteroposterior translation) and the non-ASD group. Results: All 112 included patients underwent PLIF for lumbar degenerative diseases. The minimum follow-up period was 2 years, with an average follow-up time of 63.6 months. Fifty-two patients (46.4%) were classified into the ASD group and of these, 13 required reoperation due to failure of conservative treatment. Patients with ASD exhibited significantly more caudal and posterior inflection vertebrae (IV), while the lumbar apical vertebra was significantly more caudal immediately after surgery. The IV position was identified as a significant risk factor for ASD, and the ASD incidence was significantly higher in the group where IV ≤5 (L1 vertebral body) than in the group where IV ≥5.5 (T12–L1 disc) (69.0% vs. 38.6%). Conclusions The IV position is a significant risk factor for ASD development. Although it is difficult to control intraoperative IV levels, we note a high risk of ASD in patients with IV lower than T12–L1.