Retrospective cohort of 679 adult spinal deformity patients fused to the pelvis. It asks whether PJK relates to overcorrection measured against validated age-adjusted alignment goals rather than absolute SRS-Schwab targets. Patients were stratified into young, middle-aged, and elderly groups and compared at 1 year.
The clinical rule: plan deformity correction against age-specific alignment targets, not a single absolute PI-LL goal for every patient. Elderly spines physiologically sit with a higher SVA and more relaxed lordosis. Forcing a 70-year-old to a young adult's flat alignment is overcorrection, and the unfused thoracic spine answers with reciprocal kyphosis.
That is the mechanism behind the 50% PJK rate over age 65. The patients corrected closest to neutral PI-LL were the ones who failed proximally. Note the caveat: the offset-to-PJK correlations were weak (r around 0.3), so overcorrection is a modifiable contributor, not the sole cause. PJK remains multifactorial with bone quality, soft tissue, and age effects.
This paper operationalizes age-adjusted planning and pairs naturally with the GAP score as a way to individualize realignment and reduce junctional failure.
Retrospective cohort of 679 adult spinal deformity patients fused to the pelvis. It asks whether PJK relates to overcorrection measured against validated age-adjusted alignment goals rather than absolute SRS-Schwab targets. Patients were stratified into young, middle-aged, and elderly groups and compared at 1 year.
The clinical rule: plan deformity correction against age-specific alignment targets, not a single absolute PI-LL goal for every patient. Elderly spines physiologically sit with a higher SVA and more relaxed lordosis. Forcing a 70-year-old to a young adult's flat alignment is overcorrection, and the unfused thoracic spine answers with reciprocal kyphosis.
That is the mechanism behind the 50% PJK rate over age 65. The patients corrected closest to neutral PI-LL were the ones who failed proximally. Note the caveat: the offset-to-PJK correlations were weak (r around 0.3), so overcorrection is a modifiable contributor, not the sole cause. PJK remains multifactorial with bone quality, soft tissue, and age effects.
This paper operationalizes age-adjusted planning and pairs naturally with the GAP score as a way to individualize realignment and reduce junctional failure.