Ethical statements
This study was approved by the Institutional Review Board of our Institution and performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its later amendments. Informed consent was obtained from all patients.
Patients
Although there is no consensus on the concept of old age, the World Health Organization (WHO) defines elderly as 60–74 years of age and extremely elderly as 75–89 years of age.7 Based on this definition, we retrospectively reviewed the medical records of 52 extremely elderly patients aged >75 years who underwent surgeries for DVC from 2017 to 2019 in a single institution. The inclusion criteria were as follows: aged ≥ 75 years; vertebral height loss of ≥ 50%; magnetic resonance imaging (MRI) showing the morphology of DVC, such as vertebra plana or concave vertebra, with or without intravertebral cleft; and clinically unilateral, bilateral, and/or neurogenic intermittent claudication. Patients who had segmental kyphotic changes, intravertebral instability,2 had undergone lumbar decompressive laminectomy and/or arthrodesis, or had been diagnosed with an old compression fracture at/below L3, pyogenic spondylitis, inflammatory spondylitis, spinal tumor, or systemic infection were excluded from the study.
Among these patients, we enrolled 18 (6 men and 12 women) patients whose vertebral (L3 and below) level was affected and had DVC-related LSR. Based on the electronic medical records, comorbidities included hypertension (n=9), type 2 diabetes (n=8), ischemic heart disease (n=4), Cushing’s syndrome (n=2), and Alzheimer’s disease (n=2). The initial neurologic status according to the American Spinal Injury Association (ASIA) impairment scale was at grade C in 3 patients and grade D in 15 patients (Table 1).
Radiological Assessment
All patients were diagnosed with DVC using MRI. MR images were evaluated for changes in bone marrow signal intensity that would be consistent with persistence of bone remodeling at the levels of the vertebral compression fractures, either as simple bone marrow edema with low signal intensity on T1-weighted images, high signal intensity on T2-weighted images, and normal signal intensity on contrast-enhanced T1-weighted images, or as an intravertebral cleft with well-demarcated linear or ellipsoid areas with signal intensity prolongation on T2-weighted images when fluid-filled, or signal intensity void when gas-filled.8 Based on these evaluations, each DVC was classified into one of three types of vertebral collapse. In type 1 (wedge-type collapse), the ratio of the anterior height of the vertebral body to its posterior height is < 60%. A type 2 collapse (flat-type fracture) encompasses vertebra plana-like fracture with uniform compression. Type 3 (concave collapse or H-shaped fracture) comprises anterior spur formation or sclerotic change.2 Spinal stenosis was also evaluated and anatomically classified as either central, lateral recess, foraminal, or extraforaminal.
Surgeries
Although all 18 patients initially received conservative treatment, neurologic symptoms subsequently developed, and vertebral collapse progressed gradually. In 14 patients, BEPLD was performed simultaneously with VP under epidural anesthesia. In the remaining 4, BEPLD was performed when the neurologic symptoms persisted even after a percutaneous VP was performed. In both cases, BEPLD was performed in the manner described by Kim et al.9-11 There are two surgical methods of BEPLD, namely, biportal endoscopic unilateral laminectomy bilateral decompression (BE-ULBD) and biportal endoscopic unilateral foraminal decompression (BE-UFD). The surgical method used was determined on the basis of the patient’s symptoms and lesions observed on MRI scan. VP was performed with a polymethyl methacrylate (PMMA) cement filling through the pedicle of the fractured vertebra. All procedures were performed using a uniform technique (Figure 1). To avoid bias, two independent assessors, not involved in the surgery, evaluated the postoperative outcomes.
Clinical outcomes
The operation time, amount of surgical drainage, and volume of the injected PMMA cement were recorded. The dominant dermatome of LSR was assessed and stratified by the morphological features of OVC. All patients completed a visual analog scale (VAS) as an assessment of their pain and a modified Japanese Orthopedic Association (mJOA) scale as an assessment of their neurologic status (Table 2). VAS score and postoperative complications were follow-up for 12 months (6 weeks and 3, 6, and 12 months postoperatively; mean, 13.4 months; range, 12 to 20 months). Furthermore, the recovery rate (RR) was calculated as follows:
Based on the RR values, the surgical results were classified as good (50%–100%), fair (25%–49%), unchanged (0%–24%), or deteriorated (< 0%).12, 13
Statistical analysis
All values are expressed as mean ± SD. Differences between groups were examined for statistical significance using Student’s t-test. A probability value less than 0.05 was considered to represent a significant difference. All statistical analyses were conducted using the SPSS software version 20.0 (IBM Corporation, Armonk, NY, USA).