Joshua Yang1, Lindsay M Andras1, Alexander M Broom1, Nicholas R Gonsalves1, Kody K Barrett1, Andrew G Georgiadis2, John M Flynn2, Vernon T Tolo1, David L Skaggs3. 1. Children's Orthopaedic Center, Children's Hospital Los Angeles, 4650 Sunset Blvd, MS#69, Los Angeles, CA 90027, USA. 2. Children's Hospital of Philadelphia, 34th St and Civic Center Blvd, Philadelphia, PA 19104, USA. 3. Children's Orthopaedic Center, Children's Hospital Los Angeles, 4650 Sunset Blvd, MS#69, Los Angeles, CA 90027, USA. Electronic address: dskaggs@chla.usc.edu.
Abstract
STUDY DESIGN: Multicenter retrospective review. OBJECTIVE: To assess the effectiveness of using the stable sagittal vertebra (SSV) for selecting the lowest instrumented vertebrae (LIV) to prevent distal junctional kyphosis (DJK) in selective thoracic fusions. SUMMARY OF BACKGROUND DATA: Cho et al. reported that including the SSV in a fusion decreased the rate of DJK in thoracic hyperkyphosis. METHODS: A retrospective review was performed of patients from two pediatric hospitals with adolescent idiopathic scoliosis who underwent selective posterior thoracic fusion with the LIV at L2 or above from 2000 to 2012. Patients with less than 2 years' follow-up were excluded. The primary outcome measure was DJK, defined radiographically as ≥10° between the superior end plate of the LIV and the inferior end plate of the vertebra below on a standing lateral radiograph. We investigated the SSV, which was defined as the vertebral level at which 50% of the vertebral body was in front of the posterior sacral vertical line (PSVL) on a standing lateral radiograph. This particular definition was referred to as SSV. RESULTS: A total of 113 patients met the inclusion criteria. Mean age was 14.4 years. Mean Cobb angle was 58°. The overall rate of DJK was 7% (8/113). When the LIV was superior to SSV, the rate of DJK was 17% (8/46) versus 0% (0/67) when the LIV was at or inferior to SSV (p=.01). The rates of DJK for patients with the LIV one, two, and three levels above SSV were 17% (4/24), 7% (1/14), and 43% (3/7), respectively. There was no significant association between preoperative or postoperative maximum kyphosis, thoracic kyphosis, thoracolumbar kyphosis, pelvic incidence, sagittal balance or coronal balance, and development of DJK. CONCLUSION: Although LIV selection is complex, choosing the LIV at or below the SSV is a simple rule that minimizes the risk of DJK. LEVEL OF EVIDENCE: Level IV.
STUDY DESIGN: Multicenter retrospective review. OBJECTIVE: To assess the effectiveness of using the stable sagittal vertebra (SSV) for selecting the lowest instrumented vertebrae (LIV) to prevent distal junctional kyphosis (DJK) in selective thoracic fusions. SUMMARY OF BACKGROUND DATA: Cho et al. reported that including the SSV in a fusion decreased the rate of DJK in thoracic hyperkyphosis. METHODS: A retrospective review was performed of patients from two pediatric hospitals with adolescent idiopathic scoliosis who underwent selective posterior thoracic fusion with the LIV at L2 or above from 2000 to 2012. Patients with less than 2 years' follow-up were excluded. The primary outcome measure was DJK, defined radiographically as ≥10° between the superior end plate of the LIV and the inferior end plate of the vertebra below on a standing lateral radiograph. We investigated the SSV, which was defined as the vertebral level at which 50% of the vertebral body was in front of the posterior sacral vertical line (PSVL) on a standing lateral radiograph. This particular definition was referred to as SSV. RESULTS: A total of 113 patients met the inclusion criteria. Mean age was 14.4 years. Mean Cobb angle was 58°. The overall rate of DJK was 7% (8/113). When the LIV was superior to SSV, the rate of DJK was 17% (8/46) versus 0% (0/67) when the LIV was at or inferior to SSV (p=.01). The rates of DJK for patients with the LIV one, two, and three levels above SSV were 17% (4/24), 7% (1/14), and 43% (3/7), respectively. There was no significant association between preoperative or postoperative maximum kyphosis, thoracic kyphosis, thoracolumbar kyphosis, pelvic incidence, sagittal balance or coronal balance, and development of DJK. CONCLUSION: Although LIV selection is complex, choosing the LIV at or below the SSV is a simple rule that minimizes the risk of DJK. LEVEL OF EVIDENCE: Level IV.
Authors: Lorena V Floccari; Alvin W Su; Amy L McIntosh; Karl Rathjen; William J Shaughnessy; A Noelle Larson Journal: J Pediatr Orthop Date: 2019-04 Impact factor: 2.324
Authors: Peter Gust Passias; Haddy Alas; Katherine E Pierce; Matthew Galetta; Oscar Krol; Lara Passfall; Nicholas Kummer; Sara Naessig; Waleed Ahmad; Bassel G Diebo; Renaud Lafage; Virginie Lafage Journal: J Craniovertebr Junction Spine Date: 2021-09-08