The effect of spinopelvic parameters on the development of proximal junctional kyphosis in early onset scoliosis

Abstract

Pre- and postoperative spinopelvic anatomy can influence results of distraction treatment in early onset scoliosis. I hypothesize patients with abnormal spinopelvic alignment have increased risk of proximal junctional kyphosis (PJK) during distraction treatment. Patients were treated between April 1997 and August 2014. A subsegment of patients were evaluated for quality of life. 135 patients were treated at an average age of 5.3 ± 2.83 years (range, 0.97-12.18), with minimum 2-year follow-up (average, 4.5 ± 2.6 years). 96 of 135 were included in the radiographic PJK study. 89 rib- and 46 spine-based distraction implants were used.Radiographic PJK developed in 38%, and clinical PJK in 18% of patients. Only pre-operative TK >50º increased risk for radiographic PJK (RR: 1.667, P=0.04). Pre-operative spinopelvic parameters did not increase risk for clinical PJK. Regarding quality of life, pelvic incidence –lumbar lordosis (PI-LL) mismatch > ±20o increased risk for poor outcomes through multiple domains while pelvic tilt (PT) >30°, implant type or fusion to pelvis had no effect. Preoperative TK >50º and spine-based distraction construct increased risk of radiographic PJK, and postoperative PI-LL >20º and PT ≥30º increased risk for clinical PJK. Preoperative PI >60° was shown to increase pain.Pre- i postoperativna spinopelvina anatomija utječu na rezultate liječenja djece s ranopojavnom skoliozom. Hipoteza predmnijeva da bolesnici s abnormalnom spinopelvinom anatomijom imaju veći rizik od nastanka kifoze proksimalnog spoja (KPS) u tijeku liječenja rastućim instrumentacijama. Ova studija obuhvatila je bolesnike liječene od travnja 1997. do kolovoza 2014. Kod dijela bolesnika evaluirana je i kvaliteta života. 135 bolesnika liječeno je u prosječnoj dobi od 5,3 ± 2,83 godina (raspon, 0,97-12,18) s minimalnim praćenjem od 2 godine (prosjek, 4,5 ± 2,6 godina). 96 bolesnika uključeno je u ispitivanje radiografske kifoze. Ukupno je upotrijebljeno 89 kralježničnih i 46 rebrenih instrumentacija. Radiografska KPS pronađena je u 38% (36/96), dok je ona klinički značajna otkrivena u 18% (24/135) bolesnika. Preoperativna torakalna kifoza (TK) >50° povećala je rizik za radiografsku KPS (RR: 1.667, P=0.04), dok preoperativni spinopelvini parametri nisu utjecali na razvoj klinički značajne kifoze. Utjecaj navedenih anatomskih varijanti na kvalitetu života bio je slijedeći: razlika incidence zdjelice i lordoze (eng. pelvic incidence lumbar lordosis mismatch (PI-LL)) >20° uzrokuje loš rezultat u multiplim domenama, nagib zdjelice (eng. pelvic tilt (PT)) >30°. Preoperativna TK >50° i kralježnične instrumentacije povećavaju rizik pojave radiografske kifoze, a postoperativni PI-LL >20° i PT ≥30º povećavaju rizik od klinički značajne kifoze. Preoperativna PI >60° uzrokuje bolove