Exploratory analysis of predictors of revision surgery for proximal junctional kyphosis or additional postoperative vertebral fracture following adult spinal deformity surgery in elderly patients: a retrospective cohort study

Abstract

BackgroundProximal junctional kyphosis (PJK) following adult spinal deformity (ASD) surgery in elderly patients is markedly influenced by osteoporosis causing additional vertebral fracture and loosening of pedicle screws (PS). This study aimed to investigate the association between mean bone density represented in Hounsfield units (HU) on spinal computed tomography (CT) and revision surgery for PJK or postoperative additional vertebral fracture following ASD surgery in elderly patients.MethodsThe subjects were 54 ASD patients aged 65 years or older who were treated with correction and fusion surgery of four or more levels and could be followed for 2 years or longer. Bone density was measured before surgery using lumbar dual-energy X-ray absorptiometry (DXA) and spinal CT in all patients. The patients were divided into group A (n = 14) in which revision surgery was required for PJK or additional vertebral fracture and group B (n = 40) in which revision surgery was not required. We retrospectively investigated incidences of PJK, additional vertebral fracture, and PS loosening, perioperative parameters, radiographic parameters before and after surgery, and osteoporosis treatment administration rate.ResultsNo significant difference was noted in young adult mean (YAM) on DXA between groups A and B, respectively (P = 0.62), but the mean bone densities represented in HU of the T8 (P = 0.002) and T9 (P = 0.01) vertebral bodies on spinal CT were significantly lower in group A, whereas those of the L4 (P = 0.002) and L5 (P = 0.01) vertebral bodies were significantly higher in group A. The incidence of PJK was not significantly different (P = 0.07), but the incidence of additional vertebral fracture was significantly higher in group A (P < 0.001). The incidences of uppermost PS loosening within 3 months after surgery were 71% and 40% in groups A and B, respectively (P = 0.04).ConclusionsIn elderly patients who required revision surgery, the mean bone densities of vertebral bodies at T8 and T9 were significantly lower. The mean bone density represented in HU on spinal CT may be useful for risk assessment of and countermeasures against revision surgery after ASD surgery in elderly patients.

Association of osteopenia and osteoporosis with higher rates of pseudarthrosis and revision surgery in adult patients undergoing single-level lumbar fusion

“…Patients with osteoporosis or osteopenia undergoing lumbar fusions are at an elevated risk for a number of postoperative complications that may require revision surgeryincluding pedicle screw loosening, nonunion, proximal junctional kyphosis, and adjacent segment fractures. 5,[8][9][10][11] The primary aim of this study was to investigate the effects of osteopenia or osteoporosis on the development of pseudarthrosis and need for revision surgery following single-level lumbar spinal fusion. The secondary aim was to compare these same outcome measures, stratifying by the preoperative use of disease-modifying drugs (e.g., teriparatide, bisphosphonates, and denosumab) that prevent bone loss.…”

“…6,7 Patients with osteoporosis or osteopenia undergoing lumbar fusions have an elevated risk of postoperative complications that may require revision surgery-including pedicle screw loosening, nonunion, proximal junctional kyphosis, and adjacent segment fractures. 5,[8][9][10][11] However, there is a paucity of high-quality population-level analysis documenting the prevalence of osteoporosis and osteopenia in patients with degenerative disorders of the spine requiring spinal fusion, and hence the absolute risk of pseudarthrosis and revision surgery remains unclear.…”

A Review and Clinical Perspective of the Impact of Osteoporosis on the Spine

“…52 Uei et al found that low bone density was significantly associated with increased rates of revision surgery for PJK and postoperative vertebral fractures. 53 O'Leary et al similarly found that decreased bone density was a risk factor for fractures at the most proximal end of long pedicle screw constructs. 54 The most proximal end of a fusion construct is not the only area at risk in patients with low bone density.…”

Opportunistic Computed Tomography and Spine Surgery: A Narrative Review

“…Similar to Meredith et al, 77 Uei et al 3 retrospectively reviewed 54 adult spinal deformity patients who had undergone posterior spinal fusion of at least 4 levels. DXA and spine CT were performed within 3 months of surgery.…”