Proximal junctional kyphosis after posterior hemivertebra resection and instrumented fusion in young children with congenital scoliosis / 中华外科杂志

ABSTRACT

Objective@#To investigate the risk factors of proximal junctional kyphosis(PJK) in young children who underwent posterior hemivertebra resection and instrumented fusion.@*Methods@#This study reviewed the charts and radiographs of 136 consecutive young children with congenital scoliosis who underwent posterior hemivertebra resection and instrumented fusion in Department of Orthopaedics, Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School from January 2009 to June 2014, including 75 males and 61 females, with an average age of (5.0±1.7)years(3-10 years). Proximal junctional angle(PJA), spino-pelvic parameters and segmental kyphosis (SK) were recorded pre- and post-operation and at last follow-up.The changes of PJA and radiographic features of proximal junction were also observed.χ2 test and t-test were used to analyzed enumeration data and measurement data, respectively.@*Results@#The average follow-up period was (32.8±10.3)months (ranging from 24 to 73 months) by June 2016. Among these patients, PJK occurred in 19 cases. Fifteen patients developed PJK during the first 3 months after surgery.The most common type of PJK was ligamentous failure.Compared with the non-PJK group (22.2%, 37.6%, 13.7%), the PJK group showed higher rate of preoperative TK>40°(9/19), fusion levels >4 (13/19) and greater SK change > 30°(9/19)(χ2=7.259, 6.375, 12.368; all P<0.05), while there were no difference between the two groups in terms of preoperative PJA, lumbar lordosis, SVA and upper instrument vertebra location(all P>0.05). The average PJA increased from 7.5°±2.9° to 21.3°±4.3° at 3 months after surgery to 20.6°±3.7° at the final follow-up visit in the PJK group.At the time of the final follow-up visit, ten patients received brace treatment, with no significant progression of PJA.@*Conclusions@#PJK might mainly occurs within 3 months postoperatively.Its prognostic factors include preoperative hyperkyphosis, over correction of kyphosis and ligamentous failure.