Nadim Joukhadar1, Ozren Kubat2, John Heflin3, Mohamad S Yasin4, Anna McClung5, Tara Flynn6, Megan Sheppard7, David Skaggs8, Ron El-Hawary9. 1. Dalhousie University, 6299 South St, Halifax NS B3H 4R2, Canada. 2. University of Zagreb, School of Medicine, Šalata ul. 2, 10000, Zagreb, Croatia. 3. Primary Children's Hospital, 100 Mario Capecchi Dr, Salt Lake City, UT 84113, USA. 4. Izaak Walton Killam (IWK) Health Centre, 5980 University Ave, Halifax, NS B3K 6R8, Canada. 5. Growing Spine Study Group. 6. Children's Spine Study Group. 7. Universite de Sherbrooke, 2500, boul. de l'Université, Sherbrooke, Québec J1K 2R1, Canada. 8. Children's Hospital of Los Angeles, 4650 Sunset Blvd, Los Angeles, CA 90027, USA. 9. Izaak Walton Killam (IWK) Health Centre, 5980 University Ave, Halifax, NS B3K 6R8, Canada. Electronic address: ron.el-hawary@iwk.nshealth.ca.
Abstract
BACKGROUND: Proximal junctional kyphosis (PJK) is a reported complication of distraction-based growth-friendly surgery for early-onset scoliosis (EOS). A potential consequence of PJK is revision surgery with superior extension of the upper instrument vertebrae (UIV). The purpose of this study was to determine the risk of radiographic and clinically significant PJK during growth-friendly surgery. METHODS: This is a retrospective review of children treated with distraction-based growth-friendly surgeries from two EOS registries with minimum two-year follow-up. PJK is defined as clinically significant in this study if surgery with superior extension of the UIV was performed. RESULTS: Of 419 total patients, there was a 20% risk of developing clinically significant PJK (24% rib vs. 15% spine-based anchors, p = .03). These patients had a mean preoperative age of 5.6 years (5.2-year rib vs. 6.0-year spine, p < .001), scoliosis of 73° (69° rib vs. 77° spine, p < .001), and kyphosis of 51° (47° rib vs. 56° spine, p < .01). Regression analysis demonstrated that these differences in age, scoliosis, and kyphosis between anchor type did not account for a significant proportion of the measured variance. CONCLUSIONS: There was a 20% risk of developing clinically significant PJK, with a slightly higher risk for patients treated with rib-based proximal anchors (24%) than for those patients treated with spine-based proximal anchors (15%). LEVEL OF EVIDENCE: Level III.
BACKGROUND: Proximal junctional kyphosis (PJK) is a reported complication of distraction-based growth-friendly surgery for early-onset scoliosis (EOS). A potential consequence of PJK is revision surgery with superior extension of the upper instrument vertebrae (UIV). The purpose of this study was to determine the risk of radiographic and clinically significant PJK during growth-friendly surgery. METHODS: This is a retrospective review of children treated with distraction-based growth-friendly surgeries from two EOS registries with minimum two-year follow-up. PJK is defined as clinically significant in this study if surgery with superior extension of the UIV was performed. RESULTS: Of 419 total patients, there was a 20% risk of developing clinically significant PJK (24% rib vs. 15% spine-based anchors, p = .03). These patients had a mean preoperative age of 5.6 years (5.2-year rib vs. 6.0-year spine, p < .001), scoliosis of 73° (69° rib vs. 77° spine, p < .001), and kyphosis of 51° (47° rib vs. 56° spine, p < .01). Regression analysis demonstrated that these differences in age, scoliosis, and kyphosis between anchor type did not account for a significant proportion of the measured variance. CONCLUSIONS: There was a 20% risk of developing clinically significant PJK, with a slightly higher risk for patients treated with rib-based proximal anchors (24%) than for those patients treated with spine-based proximal anchors (15%). LEVEL OF EVIDENCE: Level III.