Spinal Fractures

Table 1 lists the 35 administrative data case definitions that were selected for investigation. These were selected based on a review of published studies [3 (link),12 (link),30 (link)], recommendations from clinical co-investigators with expertise in fracture ascertainment in administrative databases (WDL, SM), and the authors’ previous experience ascertaining other chronic diseases, include osteoporosis, in administrative data [31 (link)-33 (link)]. The case definitions were differentiated by: (a) source of data, (b) number of records with the relevant diagnosis code(s), (c) type of diagnosis in hospital data, (d) presence of service codes in physician billing claims, and (e) duration of the fracture-free period. With the exception of one hip fracture case definition, all site-specific definitions used the same ICD-9-CM and ICD-10-CA diagnosis code(s). For hip fracture, we considered ICD-9-CM 820 (fracture of neck of the femur) and 821 (fracture and other unspecified parts of the femur) because some hip fractures may be assigned a less precise diagnosis code [34 (link)]. Case definitions were based on hospital data only (hip) or hospital and physician claims data, in keeping with previous research [3 (link),15 (link)]. For the latter, case definitions requiring one or at least two records with the specified diagnosis code(s) were considered. Service codes capture radiologic and magnetic resonance imaging services for incident clinical vertebral fracture, immobilization or fixation services for wrist fracture, and surgical repair and fixation procedures for hip fracture. Service codes have also been used in previous studies to improve fracture ascertainment [35 (link)]. Fracture-free periods of zero, six or twelve months were considered, using the site-specific fracture index date to establish the end-point of the fracture-free period.
To illustrate the interpretation of the case definitions, H1 identifies hip fractures using hospital records with ICD-9-CM 820 or 821 (ICD-10-CA S72.0, S72.1, or S72.2) as the most responsible (i.e., primary) diagnosis; it does not use physician service codes nor does it require a fracture-free period. In contrast, case definition H13 identifies hip fractures from hospital records with ICD-9-CM 820 (ICD-10-CA S72.0, S72.1, or S72.2) in any diagnosis field. A physician service code was present within the hospitalization period and a 12-month fracture-free period was adopted. For wrist fracture, case definition W1 identifies fractures using hospital or physician billing records with ICD-9-CM 813 (ICD-10-CA S52) in any diagnosis field. This case definition requires a physician service code to accompany the diagnosis code and does not adopt a fracture-free period.
The fracture index date was the date of the first diagnosis or service code for a fracture event. Pathologic fractures were included because they represent a small proportion of all fractures and their exclusion can lead to underestimation of the fracture burden due to osteoporosis [36 (link)]. For each case definition, the number of incident fractures was generated for the Manitoba population 50years of age and older for fiscal years 1997/98 to 2006/07. Age, which was defined using the fracture index date, was obtained from health insurance registration files. For hip fracture, counts of incident fractures were generated both including and excluding residents of long-term care (i.e., nursing home) facilities [37 (link)]; the CaMos data excludes residents of these facilities and this may affect comparability of estimates. Residence in a facility was determined from nursing home files containing admission and separation dates.

The mRNA expression profile microarray data were obtained from the GEO dataset: GSE7158 series included 12 OP (low bone density) samples and 14 NC (high bone density) samples; GSE56814 series included 31 pre-treatment samples (15 OP and 16 NC) and 43 prognostic samples, and GSE56815 series included 40 pre-treatment samples (20 OP and 20 NC) and 40 post-treatment samples. For GSE56814 and GSE56815, sample data before treatment were used for difference analysis. As this study involves only a bioinformatics analysis of the GEO data set, no ethical approval was required. The inclusion criteria included age >18 years, osteoporosis fractures grades 1–4 according to OF classification, pathological fractures: osteoporotic fractures, fracture of at least 1 vertebral body, fractures of thoracic or lumbar vertebral body. The exclusion criteria included pathological neoplastic fractures, osteoporosis fractures (OF) grade 5 according to OF classification and AO type B and C fractures.

Following the institutional review board approval for the study (number: 119/2019; Muğla Sıtkı Koçman University Ethical Committee), a retrospective cohort analysis was performed using the medical records of patients. For the current study, patient consent is not required. All procedures executed involving human participants were in accordance with the ethical standards of the institutional ethical committee and with the 1964 Helsinki declaration.
A total of 146 patients who applied to the neurosurgery outpatient clinic with a recent abdominal CT (max three months) because of a lower back pain complaint were included in the study. Patients with a previous history of surgery or a vertebral fracture were excluded. After excluded patients, a total of 146 patients were included in the study, of whom 90 were female (61.6%) and 56 were male (38.4%). The mean age of the patients was 51.42±13.91 (20-82) years.
Lumbar vertebra CT scans of all patients were reviewed retrospectively. CT images at the level from L3-L4 intervertebral disc were analyzed for body composition of fat tissue and muscle mass volume through the dedicated CT software (Syngo.via, SOMATOM Definition Flash: Siemens Healthcare, Forchheim, Germany). The L3-L4 level was selected in sagittal reformat CT images with the software (Figure 1).
The density range of -200, -40 HU was selected for the fat density measurement in the cross-section with the "region grooving" application in the angled axial images obtained parallel to the disc plane at this level. First, the fat volume in the whole section was measured (visceral and subcutaneous). Then, only the visceral adipose tissue volume was calculated by drawing borders to exclude subcutaneous adipose tissue (Figure 2). The subcutaneous fat tissue volume was obtained by subtracting the visceral fat tissue volume from the total fat volume (Figure 3).
With the same application, muscle density was selected and paravertebral muscle tissue volume was calculated (bilateral musculus psoas major, musculus quadratus lumborum, musculus iliocostalis, musculus longissimus, musculus multifidus volumes). A Spearman correlation model was used to analyze visceral adiposity, subcutaneous fat, and muscle mass.
In CT images, each intervertebral disc space was evaluated in terms of the presence of osteophytes, loss of disc height, sclerosis in the end plates, and spinal stenosis (spinal canal narrowing under 15 mm AP diameter) to investigate the presence of degeneration. Each level was scored according to the presence of findings, with 1 point for the presence of osteophytes, loss of disc height, sclerosis in the end plates, and spinal stenosis. The total score at all levels (L1-S1) was calculated for each patient.
Statistical analyses were performed using IBM SPSS version 20.0 software (IBM Corp., Armonk, NY). The conformity of the data to normal distribution was assessed using the Shapiro-Wilk test. Normally distributed variables were presented as mean±standard deviation and those not showing normal distribution as median (minimum-maximum) values. Categorical variables were presented as numbers (n) and percentages (%). The Spearman's rank correlation coefficient test was used to determine the correlation between the measured parameters in various vertebral pathologies. Continuous variables were compared using the Mann-Whitney U test. The receiver operating characteristic (ROC) analysis was used to detect the area under the curve (AUC) and define the cutoff values with their sensitivities and specificities of the measurements. An alpha value of p<0.05 was accepted as statistically significant.

For this review, only pretreatment imaging studies were collected and analyzed. Lateral-view radiographs of the cervical spine were used to measure the C2/3 anterior translation and angulation according to the method described by Li et al. and Watanabe et al. (Fig. 1) [10 (link), 15 (link)]. The axial-plane CT scans, sagittal- and coronal-plane reconstructions, and three-dimensional reconstructions were used to look for the posterior vertebral wall (PVW) fracture of C2, which was defined as fracture lines propagating through the posterior wall of the vertebral body of C2 on one or two sides (Fig. 2) [7 (link), 9 (link)]. Magnetic resonance imaging (MRI) images acquired in some patients were used to determine if there were spinal cord signal changes, and if so, identify the location and range of the signal changes.Fig. 1

A schematic diagram showing that anterior translation of C2-3 is measured as the distance between lines drawn parallel to the posterior margins of the C3 and C2 bodies at the level of the disc space (a), and angulation of C2-3 is measured as the angle formed by lines drawn along the inferior endplate of the C2–C3 vertebrae (b)

Fig. 2

A schematic diagram showing the presence of the posterior vertebral wall (PVW) fracture of C2 on the right side (A) or two sides (B)

Since a significant anterior translation of C2/3 (≥ 3.5 mm) and/or angulation of C2/3 (≥ 11°) were accepted as radiographic evidence for segmental instability, we divided the translation of C2/3 into 50% (≥ 1.8 mm) and 100% (≥ 3.5 mm) of significant translation to help establish the threshold of parameters for neurological deficit, and we also divided the angulation of C2/3 into 50% (≥ 5.5°) and 100% (≥ 11°) of significant angulation [13 (link)]. Then, PVW fractures combined with a different degree of translation of C2/3, as causative factors of neurological deficit, and the presence of PVW fractures and ≥ 1.8 mm and 3.5 mm of C2/3 translation were recorded as PVW fractures combined with 50% and 100% of significant translation, respectively. Similarly, PVW fractures combined with a different degree of C2/3 angulation, as causative factors of neurological deficit, and the presence of PVW fracture and ≥ 5.5° and 11° of C2/3 angulation were recorded as PVW fractures combined with 50% and 100% of significant angulation, respectively.