Proximal junction kyphosis after posterior spinal fusion for early-onset scoliosis.

STUDY DESIGN

Retrospective study.

OBJECTIVE

The aim of this study was to assess the presence of proximal junctional kyphosis (PJK) in our population of children with early-onset scoliosis (EOS) and to identify the predisposing factors for the development of PJK in the postoperative period after posterior spinal fusion (PSF). Few studies have been conducted to evaluate the incidence of proximal junction kyphosis (PJK) in children after early-onset scoliosis (EOS) after posterior spinal fusion (PSF).

MATERIALS AND METHODS

Overall, 114 pediatric patients aged < 10 years who underwent surgery for scoliosis or kyphoscoliosis at a single center between 2013 and 2015 were evaluated. Forty-five patients submitted to PSF of five or more levels met the inclusion criteria. The sample included 12 female and 10 male patients. Mean age at surgery was 7 years and 8 months.

RESULTS

PJK was observed in 22 patients (48.9%). Overall, the mean proximal junctional angle at 12 and 36 months was 17.1° and 22°, respectively. The uppermost instrumented vertebra (UIV) with the highest PJK rate was T6-T7. The lowest instrumented vertebra (LIV) with the highest PJK rate was L2. Etiology was idiopathic in 4, neuromuscular in 11, congenital in 14, and syndromic in 16. According to underlying disorder, prevalence of PJK was 78% in those with a congenital, 50% in those with a syndromic, 12% in those with idiopathic, and 9% in those with a neuromuscular EOS. Surgical revision rate was 4% (one patient). Mean postoperative follow-up was of 3 years and 4 months (range 3-4 years and 1 month).

CONCLUSION

Congenital and syndromic etiology, but not age at PJK onset or sex of the patient, significantly affected the incidence rate of PJK. The UIV with the highest PJK rate was T6-T7 and the LIV with the highest PJK rate was L2. The patients had a low surgical revision rate.

LEVEL OF EVIDENCE

Level IV.