Fusion mass bone quality after uninstrumented spinal fusion in older patients

Abstract

Older people are at increased risk of non-union after spinal fusion, but little is known about the factors determining the quality of the fusion mass in this patient group. The aim of this study was to investigate fusion mass bone quality after uninstrumented spinal fusion and to evaluate if it could be improved by additional direct current (DC) electrical stimulation. A multicenter RCT compared 40 and 100 lA DC stimulation with a control group of uninstrumented posterolateral fusion in patients older than 60 years. This report comprised 80 patients who underwent DEXA scanning at the 1 year follow-up. The study population consisted of 29 men with a mean age of 72 years (range 62-85) and 51 women with a mean age of 72 years (range 61-84). All patients underwent DEXA scanning of their fusion mass. Fusion rate was assessed at the 2 year follow-up using thin slice CT scanning. DC electrical stimulation did not improve fusion mass bone quality. Smokers had lower fusion mass BMD (0.447 g/cm 2 ) compared to non-smokers (0.517 g/cm 2 ) (P = 0.086). Women had lower fusion mass BMD (0.460 g/ cm 2 ) compared to men (0.552 g/cm 2 ) (P = 0.057). Using linear regression, fusion mass bone quality, measured as BMD, was significantly influenced by gender, age of the patient, bone density of the remaining part of the lumbar spine, amount of bone graft applied and smoking. Fusion rates in this cohort was 34% in the control group and 33 and 43% in the 40 and 100 lA groups, respectively (not significant). Patients classified as fused after 2 years had significant higher fusion mass BMD at 1 year (0.592 vs. 0.466 g/cm 2 , P = 0.0001). Fusion mass bone quality in older patients depends on several factors. Special attention should be given to women with manifest or borderline osteoporosis. Furthermore, bone graft materials with inductive potential might be considered for this patient population.

Patient-Rated Outcomes of Lumbar Fusion in Patients With Degenerative Disease of the Lumbar Spine

“…Despite numerous advances in surgical techniques and perioperative care, the outcome of spinal fusion might be expected to be poorer in the elderly due to their lower bone quality and increased susceptibility to complications. 5,6 To date, there are little data on the clinical outcome of spinal fusion in older patients, with most studies comprising only small study groups. 4,[7][8][9][10] Reports of the clinical outcome of geriatric patients (>80 years of age) who have undergone lumbar fusion are particularly rare.…”

The Relationship of SmokingOpioidAntidepressant Use and History of Spine Surgery

“…In spine surgery, it has been associated with a negative effect on fusion rates [1]. We studied the interaction of this habitual use with other possibly-addictive psychotropic substances that chronic back pain patients are frequently prescribed.…”

“…A large percentage of back pain patients subsequently develop depression or carry depression as a comorbid diagnosis from the beginning. In a recent paper, smoking was found to be an independent predictor of long-term continued opioid use in lumbar disk hernia and spinal stenosis patients (1). Pursuant to that, we studied the interaction of smoking with opioid and antidepressant use and the relationship with prior spine surgery and future spine surgery.…”

Guideline update for the performance of fusion procedures for degenerative disease of the lumbar spine. Part 17: Bone growth stimulators as an adjunct for lumbar fusion

“…The final study from this series demonstrated, through the use of dual energy x-ray absorptiometry (DEXA), that the application of DCS had no impact on the bone mineral density of the fusion mass. 4 These investigations suffer from the same limitations as the first study in this series. The blinded radiographic assessment of the CT imaging strengthens the observations and conclusions regarding the impact of DCS on fusion rate.…”

“…2,4 Of the original 107 patients randomized, 95 were available for fusion assessment at 1 year and 84 were available at 2 years. Thin-slice CT images and plain radiographs were used to assess fusion status.…”