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

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.

Study Overview

• Status: Completed
• Conditions: Scheuermann's Kyphosis
• Intervention / Treatment: Procedure: Select the vertebra above sagittal stable vertebra as the distal fusion level

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.

• Study Type: Observational
• Enrollment (Actual): 74

Contacts and Locations

Study Locations

• China
  • Jiang Su
    • Nanjing, Jiang Su, China, 210000
      • Drum Tower Hospital of Nanjing University Medical School

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Probability Sample

Study Population

A total of 36 SK patients (including 23 with TK and 13 patients with TLK) were included in this study, among which 29 were male, and 7 were female.

Description

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.

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
thoracic kyphosis; patients with their kyphotic apex located at T10 or above	Procedure: Select 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.
thoracolumbar kyphosis; patients with their kyphotic apex located below T10	Procedure: Select 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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Global kyphosis (GK) in degrees	Measured on anteroposterior and lateral radiographs and defined as the angle from upper to lower most tilted end vertebrae.	24 months
Lumbar lordosis (LL) in degrees	Measured on anteroposterior and lateral radiographs and defined as the angle between the the superior end plate of L1 and S1	24 months
Sagittal vertical axis (SVA) in millimeters	Measured on anteroposterior and lateral radiographs and defined as the horizontal distance between C7PL and the posterior superior corner of sacrum.	24 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Rates of distal junctional kyphosis	record 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	24 months
Scoliosis Research Society (SRS)-22 questionnaire	The 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.	24 months

Collaborators and Investigators

• Sponsor: The Affiliated Nanjing Drum Tower Hospital of Nanjing University Medical School

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2018
• Primary Completion (Actual): September 30, 2022
• Study Completion (Actual): December 31, 2022

Study Registration Dates

• First Submitted: July 2, 2023
• First Submitted That Met QC Criteria: July 18, 2023
• First Posted (Actual): July 20, 2023

Study Record Updates

• Last Update Posted (Actual): July 20, 2023
• Last Update Submitted That Met QC Criteria: July 18, 2023
• Last Verified: July 1, 2023

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Spinal Diseases; Bone Diseases; Spinal Curvatures; Osteochondrosis; Kyphosis; Scheuermann Disease; Spinal Osteochondrosis
• Other Study ID Numbers: 2021-LCYJ-DBZ-05

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No