Sarcopenia at the upper instrumented vertebra is more significantly associated with proximal junctional kyphosis after long fusion for adult spinal deformity surgery than osteopenia

Sarcopenia in Lumbar and Cervical Spine Surgery

“…37 Interestingly, a separate study of 29 patients undergoing T9 or T10 to pelvic fusions for failed prior fusions due to degenerative ASD demonstrated that only fatty degeneration of the paraspinal muscles was significant predictors of PJK, whereas paraspinal CSA was similar between those who did and did not develop ASD. 38 It is worth noting that unlike previous studies these cases were all revisions and with patient samples this low, conflicting results should not be unexpected.…”

“…With regard to this population, decreased psoas CSA at the L4 vertebral level was found to be independently predictive of risk for PJK and PJF in a separate study, with authors claiming that each 1-cm 2 decrease in psoas CSA reflected a 2.8-degree increase in PJK and a 1.1% increase in risk for developing PJF 37. Interestingly, a separate study of 29 patients undergoing T9 or T10 to pelvic fusions for failed prior fusions due to degenerative ASD demonstrated that only fatty degeneration of the paraspinal muscles was significant predictors of PJK, whereas paraspinal CSA was similar between those who did and did not develop ASD 38. It is worth noting that unlike previous studies these cases were all revisions and with patient samples this low, conflicting results should not be unexpected.…”