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Selecting the SSV-1 as LIV in Scheuermann's Kyphosis

Selecting the Vertebra Above Sagittal Stable Vertebra as the Distal Fusion Level in Scheuermann's Kyphosis

Status
Completed
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT05953792
Enrollment
74
Registered
2023-07-20
Start date
2018-01-01
Completion date
2022-12-31
Last updated
2023-07-20

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Scheuermann's Kyphosis

Brief summary

The proper selection of the lowest instrumented vertebra (LIV) remains controversial in the surgical treatment of Scheuermann's disease and there is a paucity of studies investigating the clinical outcomes of fusion surgery when selecting the vertebra one level proximal to the sagittal stable vertebra (SSV-1) as LIV. The purpose of this study is to investigate whether SSV-1 could be a valid LIV for Scheuermann kyphosis (SK) patients with different curve patterns.

Detailed description

The proper selection of the lowest instrumented vertebra (LIV) remains controversial in the surgical treatment of Scheuermann's disease and there is a paucity of studies investigating the clinical outcomes of fusion surgery when selecting the vertebra one level proximal to the sagittal stable vertebra (SSV-1) as LIV. The purpose of this study is to investigate whether SSV-1 could be a valid LIV for Scheuermann kyphosis (SK) patients with different curve patterns. This was a prospective study on consecutive SK patients treated with posterior surgery between January 2018 and September 2020, in which the distal fusion level ended at SSV-1. The LIV was selected at SSV-1 only in patients with Risser \> 2 and with LIV translation less than 40mm. All of the patients had a minimum of 2-year follow-up. Patients were further grouped based on the sagittal curve pattern as thoracic kyphosis (TK) and thoracolumbar kyphosis (TLK). Radiographic parameters including global kyphosis (GK), lumbar lordosis (LL), sagittal vertical axis (SVA), LIV translation, pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS) were measured preoperatively, postoperatively and at the latest follow-up. The intraoperative and postoperative complications were recorded. The Scoliosis Research Society (SRS)-22 scores were performed to evaluate clinical outcomes.

Interventions

PROCEDURESelect the vertebra above sagittal stable vertebra as the distal fusion level

The surgeries were performed by the same surgical team. Multi-level Ponte osteotomies were performed across the apex of the kyphosis after complete exposure of the spine, with resection of supra- and inter-spinous ligaments, ligamentum flavum, and the whole facet joints. After placement of the pedicle screws at the expected fusion levels, pre-contoured rods were attached to the screws followed by segmental compression. During rod placement, two to three rounds of compression in the area with Ponte osteotomies were employed to enhance kyphosis correction. Satellite rods were routinely added to long rods and implanted with duet screws. The final tightening was performed, and the posterior fusion was completed with a mixture of local and allogeneic bone. Due attention was given to preserving the posterior ligamentous structures at the upper and lower junctional areas.

Sponsors

The Affiliated Nanjing Drum Tower Hospital of Nanjing University Medical School
Lead SponsorOTHER

Study design

Observational model
COHORT
Time perspective
PROSPECTIVE

Eligibility

Sex/Gender
ALL
Age
10 Years to 20 Years
Healthy volunteers
No

Inclusion criteria

* diagnosis of SK patients; * underwent one-stage posterior spinal fusion (PSF) with multi-level Ponte osteotomies; * selecting SSV-1 as LIV; * with a minimum follow-up of 2 years.

Exclusion criteria

* with previous spinal surgical history; * with any other spinal deformities; * without complete follow-up data.

Design outcomes

Primary

MeasureTime frameDescription
Global kyphosis (GK) in degrees24 monthsMeasured on anteroposterior and lateral radiographs and defined as the angle from upper to lower most tilted end vertebrae.
Lumbar lordosis (LL) in degrees24 monthsMeasured on anteroposterior and lateral radiographs and defined as the angle between the the superior end plate of L1 and S1
Sagittal vertical axis (SVA) in millimeters24 monthsMeasured on anteroposterior and lateral radiographs and defined as the horizontal distance between C7PL and the posterior superior corner of sacrum.

Secondary

MeasureTime frameDescription
Rates of distal junctional kyphosis24 monthsrecord the incidence of the distal junctional kyphosis at the last follow-up. Distal junctional kyphosis was defined as a distal junctional angle ≥10˚, or a distal junctional angle ≥ 10˚ than the preoperative measurement
Scoliosis Research Society (SRS)-22 questionnaire24 monthsThe Scoliosis Research Society (SRS)-22 questionnaire is adopted to assess the patient-reported outcomes. The overall score can range from 22 to 110 points, and higher scores reflect better health status.

Countries

China

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026