Proximal junctional kyphosis in adolescent idiopathic scoliosis following segmental posterior spinal instrumentation and fusion minimum 2 years follow-up

  Abstract   Background: To evaluate proximal junctional segment changes in Adolescent Idiopathic   Scoliosis(AIS) the posterior spinal fusion and also instrumentation also and   finding of probable risk factors, were all considered in this study.   Methods: We retrospectively reviewed radiographs of 121 consecutive patients   who underwent posterior spinal fusion for AIS from T3 or below, with a mean follow-   up of 32.8 months(range,24-83). All coronal and sagittal measurements including   the proximal junctional kyphosis (PJK)angle recorded on standing anteroposterior   and lateral radiographs preoperative, early postoperative and on follow-up radiographs.   The data were analyzed using the Spss 10.0 software. Dependent(paired)   samples student t-test was used for analysis between the groups   Results: There was PJK angle above normal for the same junctional segment preoperatively in 13 patients (10.7%) and the incidence of the PJK postoperatively was   7.4% (9 patients, 7 female and 2 male), all detected until 2 years postoperation.The   mean increase in the PJK angle from pre-operation until 6 weeks postoperation was   5.9° (range,0-13°)(P=0.02) and until 2 years post operation was 14.3° (range, 2-   16°)(p=0.000). The mean proximal junctional angle increased 1.6° until 2 years postoperation in non-PJK group(n=112).   Conclusion: The prevalence of Proximal Junctional Kyphosis was low and a   silent radiographic problem. In some cases is preventable with perfect pre-operative   planning. There is no specific demographic or radiographic variables or instrumentation   types associated with developing PJK .