Summary: Surgical treatment of adult scoliosis patients undergoing long instrumented fusion showed a PJK incidence of 20%. Fusion to sacrum and posterior spinal fusion were identified as risk factors. The incidence of PJK can be minimized by normalization of post operative global sagittal alignment. However, no significant difference was found in SRS outcome scores and ODI for PJK and non PJK patients, with a low revision rate of 12.5% (4/32 pts).
Introduction: To assess the prevalence, clinical outcomes and risk factors of proximal junctional kyphosis (PJK) in adult idiopathic scoliosis (AIS) patients undergoing long instrumented spinal fusion (>5 vertebrae).
Methods: A retrospective review of the chart and x‐ray of 157consecutive patients with adult scoliosis patients treated with long instrumented spinal fusion. PJK was defined by a proximal junctional angle greater than 10° and at least 10° greater than the corresponding preoperative measurement. Radiographic measurements included sagittal plumb line (SVA), thoracic kyphosis (TK), lumbar lordosis (LL) and Pelvic incidence (PI) on preoperative, immediate post op and at follow‐up. Bone mineral density (BMD), Body mass index (BMI), age, sex, instrumentation type, surgery type and fusion to sacrum were reviewed. Postoperative SRS outcome scores and Oswestry Disability Index (ODI) were also evaluated. Means were compared with student's t test and chi‐square test. P value of <0.05 with confidence Interval 95% was considered significant.
Results: The average age was 46.9 yrs (22‐81 yrs) and the avg. f/u was 4.3 yrs (2‐12 yrs). PJK occurred in 32 pts (20° ). The SRS outcome scores and ODI did not demonstrate significant differences between PJK group and non PJK‐ group, 4 pts had additional surgeries performed for local pain. Fusion to sacrum and posterior fusion were significant risk for PJK (P=0.03, P<0.01). BMD, BMI, age, sex and instrumentation type indicated no difference. 84° of PJK group was associated with TK+LL+PI>45 degree or pre ope ‐ post ope SVA >50mm vs 6.4° of non PJK group (P<0.01, P<0.01).
Conclusion: Despite the occurrence of PJK in 20° of adult scoliosis patients undergoing long fusion, no significant difference was found in SRS outcome scores and ODI in PJK and non PJK patients. Fusion to sacrum and posterior fusion were identified as risk factors. PJK can be minimized by post operative normalization of global sagittal alignment.