Analysis of factors associated with intercostal neuralgia after osteoporotic thoracic spine fracture and construction of a prediction model

Abstract

Objective

This study aims to investigate the associated factors of intercostal neuralgia in patients with osteoporotic vertebral compression fractures (OVCF) of the thoracic spine and to develop a predictive model to assess the likelihood of patients developing intercostal neuralgia following thoracic vertebral fractures.

Methods

The retrospective study involved 518 patients with thoracic OVCF treated at our hospital, among whom those with and without intercostal neuralgia were matched at a 1:1 ratio.Relevant basic clinical data and imaging parameters of the patients were recorded, t-test was used for continuous variables and chi-square test for categorical variables to determine the factors associated with intercostal neuralgia. Subsequently, the above associated variables were screened using univariate and multivariate logistic regression models to obtain associated factors. Finally, a prediction model for osteoporotic thoracic spine fracture was developed and validated.

Results

This study included a total of 104 patients based on the presence or absence of intercostal neuralgia.The results of multifactorial logistic regression analysis showed that injured vertebral intervertebral foraminal area (P = 0.0008, regression coefficient estimate 0.0490, 95% confidence interval 0.0219–0.0798, OR = 1.0503), injured vertebral intervertebral foraminal volume (P = 0.0001, regression coefficient value − 0.0028, 95% confidence interval − 0.0044 to -0.0015, OR = 0.9972), and nerve root area (P = 0.0038, regression coefficient estimate=-0.0876, 95% confidence interval − 0.1506 to -0.0309, OR = 0.9161) were independent associated factors.The fatty degeneration ratio have a positive promotional effect on the probability of developing intercostal pain.The area under the ROC curve (AUC) of the prediction model was 0.851, which indicated that the line graph model had a certain degree of predictive validity.

Conclusion

Thoracic osteoporotic fractures are a common geriatric disease, and changes in the morphological parameters of the intervertebral foramina, such as a reduction in the area and volume of the injured vertebral intervertebral foramina, as well as fatty degeneration of the thoracic back muscles, suggest an increased probability of developing intercostal neuralgia.

Introduction

OVCF, a common complication of osteoporosis, refers to the compression fractures or deformations of the vertebral bodies that occur due to reduced bone density and fragility caused by osteoporosis, especially under the influence of external forces [1]. These fractures are more prevalent in the elderly, particularly in postmenopausal women. OVCF can lead to symptoms such as back pain, reduced height, and kyphosis, and in severe cases, may even affect neurological function [2, 3]. OVCF is a common cause of pain and disability, with a significant proportion of fractures occurring in the thoracic spine, and the incidence of OVCF is showing a trend of increasing year by year [4, 5]. In addition to severe back pain at the level of the fractured vertebrae, patients also suffer from intercostal neuralgia symptoms such as chest or upper abdominal pain, which reduces the quality of life. Intercostal neuralgia is characterized by neuropathic pain along the distribution of the affected intercostal nerves, encompassing the ribcage, chest, or abdomen. The pain is typically intense, sharp, lancinating, or burning, and may be accompanied by paresthesia such as numbness and tingling [6, 7]. It can be intermittent or constant, often manifesting as a band-like pain encircling the chest and back or following a thoracic dermatomal pattern. This condition can lead to prolonged pain that may persist even after the underlying disease process has resolved.

In the context of osteoporotic vertebral compression fractures (OVCF), intercostal neuralgia is associated with potential nerve compression or injury following the fracture. Patients with OVCF may experience chest or upper abdominal pain, which not only exacerbates their suffering but also diminishes their quality of life. The etiology of intercostal neuralgia can be multifactorial, including nerve entrapment, traumatic or iatrogenic neuromas, ongoing nerve irritation, or herpes zoster [8, 9]. Consequently, for patients with OVCF, it is essential to address not only the treatment of the fracture itself but also the potential development of intercostal neuralgia, employing appropriate therapeutic measures to alleviate pain and enhance the patient’s quality of life.The location of intercostal neuralgia is determined by the nerves that innervate it, and the affected segments of OVCF may correlate with the location of intercostal neuralgia [10]. The ventral rami of spinal nerves T1 through T11 form the intercostal nerves that enter the intercostal spaces. The ventral ramus of T12 forms the subcostal nerve, which is located inferior to the 12th rib. The dorsal rami of T1 through T12 pass posteriorly to supply sensation to the skin, muscles, and bones of the back [11, 12]. In clinical practice, we have observed that patients may still experience symptoms of intercostal neuralgia even when CT or MRI imaging studies show no significant nerve compression or spinal canal encroachment.However, the relationship between intercostal neuralgia and morphological changes in fractures is still unclear. Some researchers believe that changes in the intervertebral foramina leading to nerve compression within the foramina, reduction in vertebral height, local kyphosis deformity of the vertebrae, and instability of the facet joints may be the causes of intercostal neuralgia [13].

Percutaneous vertebroplasty (PVP) is widely used for the treatment of osteoporotic vertebral compression fractures. This procedure can quickly alleviate thoracic and back pain, significantly improving the quality of life for patients. However, there are still some issues. These include complications such as the reduction in vertebral height, cement leakage, and subsequent fractures in adjacent vertebrae [14, 15]. In addition, PVP surgery does not ideally restore the space of the intervertebral foramina or eliminate the compression of the nerve roots by soft tissue within the foramina, leading to relatively poor alleviation of intercostal neuralgia. Studies have shown that sarcopenia is an independent associated factors for secondary osteoporotic vertebral fractures in elderly patients after PVP surgery [16]. The degenerative changes in the paravertebral muscles may be closely related to the stability and function of the spine. Studies have shown that paravertebral muscles play an important role in maintaining the normal biomechanical function of the spine. When paravertebral muscles degenerate, it may lead to a decrease in spinal stability, thereby triggering or exacerbating nerve-related symptoms, including intercostal neuralgia [17]. This study suggests that the degeneration of paravertebral muscles and changes in vertebral morphology may be the causes of intercostal neuralgia.

This study retrospectively compared the data of 52 patients with intercostal neuralgia following OVCF and 52 patients without post-fracture intercostal neuralgia. Starting from preoperative clinical and radiological information, the study assessed the correlation between the occurrence of intercostal neuralgia and the morphological characteristics of the intervertebral foramina, as well as the relevance to the muscles of the thoracic and back regions. It also identified the factors associated with intercostal neuralgia and constructed a predictive model based on these associated factors. Furthermore, the study validated the effectiveness of this risk prediction model.

Methods

This study was approved by the ethics committee of China-Japan Union Hospital of Jilin University (No.2024110706) and was therefore performed in accordance with ethical standards. All patients provided their informed consent prior to inclusion in the study.The study retrospectively analyzed 518 patients with osteoporotic thoracic vertebral fractures who visited from September 2021 to September 2023 (patients with intercostal neuralgia often exhibit diffuse pain that radiates from the back along the intercostal nerves to the anterior chest and upper abdomen when lying down or changing positions. Patients coming to the hospital were divided into two groups: Group A with intercostal neuralgia and Group B without intercostal neuralgia.

Due to the limited incidence of Neuralgia following OVCF, we adopted a 1:1 matched case-control design. The case group included patients who developed Neuralgia after OVCF, while the control group included patients without intercostal neuralgia after OVCF. To ensure comparability between the two groups, we conducted propensity score matching based on the following general clinical characteristics: age (within 5 years), gender (male or female), bone mineral density (BMD) (within 1 standard deviation), analgesic use (yes or no), and history of trauma (yes or no). First, we determined the number of Neuralgia cases, and then matched them with the same number of non-Neuralgia cases based on the aforementioned variables.

Inclusion and exclusion criteria

Inclusion Criteria:

• 1. Meet the diagnostic criteria for a single-segment OVCF and osteoporosis (bone mineral density T-score < -2.5).

• 2. Diagnosed with thoracic vertebral compression fracture by imaging examinations such as X-ray, CT, and MRI.

• 3. Meet the diagnostic criteria for intercostal neuralgia: it may occur bilaterally or unilaterally, with pain sensations described as stabbing, cutting, burning, or band-like, varying in intensity and frequency, often exacerbated in paroxysms.

• 4. Patients exhibit clinical manifestations of OVCF, with thoracic and back pain that worsens upon movement.

Exclusion Criteria:

• 1. Fractures caused by pathological reasons, such as primary or secondary tumors, vertebral infections, etc.

• 2. Concurrent rib fractures.

• 3. Presence of multi-segment vertebral injuries.

• 4. Existence of spinal cord injury or significant nerve compression.

Inclusion factors

Clinical basic information includes: gender, age, history of trauma, use of analgesics, vertebral fracture segment, fracture type (wedge, biconcave, and flat), bone mineral density (BMD), duration of fracture pain, presence of rest pain in supine position, preoperative VAS score, and preoperative ODI index.

Patient-related imaging parameters include: anterior vertebral height (AVH, cm), posterior vertebral height (PVH, cm), local kyphosis angle, intervertebral foramen height (mm), intervertebral foramen width (mm), intervertebral foramen depth (mm), minimum cross-sectional area of the intervertebral foramen (for the upper, Injured, and lower intervertebral foramina, refers to the intervertebral foraminal area obtained through CT scanning measurements), reduction rate of the minimum area of the intervertebral foramen (%), volume of the intervertebral foramen (for the upper, Injured, and lower intervertebral foramina, refers to the volume obtained through intervertebral foramen reconstruction and measurement from CT data), reduction rate of the volume of the intervertebral foramen (%), cross-sectional area of the nerve root in the intervertebral foramen (mm², refers to the smallest nerve root area measured through sagittal MRI), ratio of nerve root area to intervertebral foramen area (%), muscle area of the thoracic and back region on MR imaging (cm²), fatty degeneration area (cm²), fatty degeneration ratio (%), and whether the edema signal exceeds 50%. Figure 1 shows the distribution of involved vertebrae in Groups A (Neuralgia) and B (Non-neuralgia). Table 1 shows the basic data of the two groups of patients.

Fig. 1

Distribution of Injured Vertebrae in Groups A and B

Table 1 Basic Data of patients in Groups A (Neuralgia) and B (Non-neuralgia)

Measurement method

Firstly, Preoperative VAS is a simple yet effective tool for measuring the severity of a patient’s symptoms before surgery, especially in assessing pain and functional limitations. The VAS typically consists of a straight line with the two ends representing the extreme states of symptoms, such as “no pain” to “the most severe pain.” Patients make a mark on this line based on the severity of their perceived symptoms, thereby quantifying their symptom experience. The VAS score is usually determined by measuring the distance from one end of the line to the patient’s marked point, which can be converted into a numerical rating, typically ranging from 0 to 10, where 0 indicates no symptoms and 10 indicates the most severe symptoms [18].

Thoracic spine CT data were extracted from our hospital’s radiological database and saved in DICOM file format. Subsequently, the DICOM format data were input into the thoracic spine parameter measurement software RadiAnt DICOM Viewer (Medixant, Poland), where the CT images in the sagittal and axial planes were opened, the midline sagittal CT image was locked, and the height of the vertebral body (anterior edge, posterior edge), wedge change, and local kyphosis angle were measured. Since the intervertebral foramen data before the injury cannot be restored, a computational method is used to simulate the pre-injury intervertebral foramen parameters. If the area of the intervertebral foramina above and below the injured vertebra are denoted as A and C, respectively, and the area of the injured vertebra’s intervertebral foramen is denoted as B, then the area of the intervertebral foramen before the injury is represented as (A + C) / 2, and the reduction rate of the intervertebral foramen area is calculated as [1–2B / (A + C)] × 100% [13, 19,20,21] (Fig. 2). The MR data were imported into the measurement software, where the MR images in the sagittal and axial planes were opened, the intervertebral foramen in the sagittal MR image was locked, and the cross-sectional area of the nerve root (Neural root area, NA) and the area of the intervertebral foramen were measured, thereby calculating the ratio of the nerve root area to the intervertebral foramen area to deduce the degree of nerve root compression within the intervertebral foramen [22, 23] (Fig. 3).

Fig. 2

Sagittal images (A) The green lines represent the height and width of the intervertebral foramen, (B) represents the width of the intervertebral foramen, (C) and (D) are measurements of the local kyphosis angle at the midline of the vertebral body

Fig. 3

Images for measuring the nerve root area and the ratio of nerve root area to intervertebral foramen area

Subsequently, the DICOM format data were input into the three-dimensional reconstruction software Mimics Medical 20.0 (Materialise, Belgium). The imported imaging data were pre-processed as needed, including adjusting image contrast and removing noise to capture the details. Taking the 12th thoracic vertebra as an example, the Mimics segmentation tool was used to create a mask that matches the threshold of the intervertebral foramen, which would be used to extract the intervertebral foramen area from the raw data, and after determining the appropriate threshold, a mask was generated. Then, using the region growing tool within the obtained spinal selection hot zone, the “modeling” command was executed to generate a spinal model. The centerline was extracted from the segmented model of the intervertebral foramen, and the minimum cross-sectional area was located along the minimum normal plane of the centerline of the vertebral foramen (Fig. 4).

Fig. 4

Workflow diagram of intervertebral foramen reconstruction and measurement from CT data using Mimics software

As shown in Fig. 5, after determining the minimum cross-sectional area, the built-in volume and area measurement functions of the Mimics software are used to measure the model that needs to be inspected. The processed model is optimized by smoothing curves, adjusting dimensions, and increasing resolution [24, 25].

Fig. 5

Legend for the measurement of the minimum area and minimum volume of the intervertebral foramen

Muscle imaging analysis of the thoracic and back area is performed as follows. Referring to the measurement method of Wen et al. [23], The DICOM format data are input into the muscle parameter measurement software ImageJ (National Institutes of Health, Bethesda, USA). After the data is imported into ImageJ, T2-weighted images parallel to the lower edge of the fractured vertebra are selected for analysis. The cross-sectional area (CSA) of the paraspinal muscles and the subcutaneous fat (SCF) area on both sides are selected and the grayscale histograms of the two areas are measured. The functional CSA refers to the fat-free paraspinal muscles, and the functional CSA is calculated by the pixels within the muscle tissue block (Fig. 6A). After exporting the grayscale histogram data, the overlapping area OA data is calculated, and the grayscale distribution line charts of CSA, SCF, and the overlapping area OA are plotted (Fig. 6B). The overlapping area (OA) between the grayscale ranges of CSA and SCF is generated, indicating the amount of fat degeneration within the CSA. The Fat Degeneration Ratio (FDR) is represented by the number of pixels in the overlapping area divided by the total number of pixels in the CSA, and the ratio result reflects the severity of fatty degeneration (Fig. 6C). The degree of fat degeneration in the paraspinal muscles is categorized as mild (FDR < 10%), moderate (10-50%), and severe (> 50%) [26], The lumbar muscle mass (LMM) is calculated by multiplying the cross-sectional area (CSA) by (1 - FDR). To avoid measurement errors, the aforementioned measurement indicators are measured separately by two physicians in our department, and the average value is taken. If the measurement results of the two physicians differ by more than 1 mm, the measurement is redone [23].

Fig. 6

(A) manually outlines the cross-sectional area (CSA) of the paraspinal muscles, subcutaneous fat (SCF), and vertebral body (VB). (B) Grayscale distribution line chart of the cross-sectional area (CSA), subcutaneous fat (SCF), and the overlapping area (OA). (C) Specific situations of VB、CSA、SCF、OA

Data analysis methods

Statistical analysis was performed using SPSS 25.0. Initially, the differences in relevant variables between Group A and Group B patients were compared. For continuous variables, t-tests were used, and categorical variables were analyzed using chi-square tests to preliminarily identify associated factors that significantly affect the presence or absence of intercostal neuralgia in patients. Subsequently, univariate Logistic regression was used to further screen for relevant risk variables. Based on the results of the univariate t-tests and the univariate regression model, the appropriate associated factors were reasonably included to establish a Logistic regression model. A Nomogram (line chart) was then drawn based on the results of the Logistic regression model to predict the probability of intercostal neuralgia in patients. Finally, the predictive effectiveness of this probability prediction Nomogram was verified using calibration curves and ROC curves. A P-value less than 0.05 was considered to indicate statistical significance.

Results

Among the 104 patients with thoracic vertebral fractures, all cases were diagnosed with thoracic vertebral fractures combined with osteoporosis after preoperative X-ray, CT, MRI, and bone density examination. There were 52 patients in the intercostal pain group and 52 patients in the non-intercostal pain group. There were 45 male patients and 59 female patients. The patients’ ages ranged from 51 to 85 years old, with an average age of 68 years old. There were 50 cases of osteoporotic fractures without obvious causes (50/104, 48%) and 54 cases of fractures due to trauma (54/104, 52%). The most patients were distributed in the T12 segment, with 17 patients with and without intercostal pain, respectively; the T6 segment had the second most patients, with 8 patients without intercostal pain and 11 patients with intercostal pain. The distribution of patients in segments T11, T10, and T8 was relatively even. The distribution of patients without intercostal neuralgia in segment T7 was significantly higher than that of patients with intercostal neuralgia in segment T7. The clinical baseline of the patients is shown in Table 2. By using t-tests or chi-square tests between variables, variables that have a significant difference in affecting the occurrence of intercostal pain were identified, including ODI index, VAS score, supine resting pain, spinal canal invasion, minimum cross-sectional area of the intervertebral foramen, volume of the intervertebral foramen, reduction rate of the volume of the intervertebral foramen, cross-sectional area of the nerve root, area of the intervertebral foramen, ratio of nerve root to foramen area, amount of fat degeneration, and the fatty degeneration ratio. The above variables were included in the subsequent predictive model for variable selection.

Table 2 Results of Univariate Analysis for groups a (Neuralgia) and B (Non-neuralgia) patients

Risk factor selection based on univariate logistic regression model

Preoperative ODI index (P-value = 0.0009), minimum cross-sectional area of the intervertebral foramen, reduction rate of the volume of the intervertebral foramen (P-value < 0.0001), cross-sectional area of the nerve root (P-value = 0.0070), area of the intervertebral foramen (P-value = 0.0033), ratio of nerve root to foramen area (P-value < 0.0001), amount of fat degeneration (OA) (P-value = 0.0171), fat degeneration ratio (P-value = 0.0099), and spinal canal invasion (P-value = 0.0077) have a significant impact on the occurrence of intercostal neuralgia.

The regression coefficients for preoperative ODI index (regression coefficient = -0.7937), minimum cross-sectional area of the intervertebral foramen (regression coefficient = -0.0341), reduction rate of the volume of the intervertebral foramen (regression coefficient = -4.0052), ratio of nerve root to foramen area (regression coefficient = -0.6516), amount of fat degeneration OA (regression coefficient = -0.0031), and fat degeneration ratio (regression coefficient = -0.0522) are all negative. This indicates that, all other conditions being equal, the higher the values of the above indicators in patients, the less likely they are to develop intercostal pain.

The regression coefficient estimates for the volume of the intervertebral foramen at the injured vertebra (regression coefficient = 0.0018), cross-sectional area of the nerve root (regression coefficient = 0.0624), area of the intervertebral foramen (regression coefficient = 0.0262), and spinal canal invasion (regression coefficient = 1.1073) are all positive. This indicates that, all other conditions being equal, the higher the values of the above indicators in patients, the greater the probability of developing intercostal pain.

Subsequently, the univariate Logistic regression model was further used to screen for related factors. Finally, the area of the intervertebral foramen at the injured vertebra (centre), volume of the intervertebral foramen at the injured vertebra (centre A), area of the nerve root (nerve root), amount of fat degeneration (OA), and fat degeneration ratio (fat percentage) were selected as five factors for estimation in the multivariate Logistic regression model. A nomogram model was established to predict the occurrence of intercostal pain.The results of the multifactorial logistic analysis are shown in Table 3.

Table 3 Estimation of the logistic regression model

Construction and validity analysis of the nomogram for intercostal neuralgia after OVCF

After establishing the logistic regression model for the variables of the area of the injured vertebral intervertebral foramen (centre), volume of the injured vertebral intervertebral foramen (centre_A), nerve root area (nerve_root), amount of fat degeneration (OA), and fat degeneration ratio (fat_percentage), and validating the predictive effectiveness of the model with a residual plot, this study constructed a predictive Nomogram for the probability of patients developing intercostal neuralgia after OVCF based on the aforementioned associated factors. The results can be seen in Fig. 7. Add the scores corresponding to the red dashed lines in the figure to obtain the predicted total score Total score of 1.57 for this patient. At this time, the predicted probability of the patient developing intercostal neuralgia is 0.531, which indicates that there is a 53.1% chance of the patient developing intercostal neuralgia.

Fig. 7

Predictive Nomogram for Intercostal Neuralgia Following OVCF

In Fig. 8(A), the black dashed line represents the ideal predictive situation, the grey dashed line represents the calibration error curve, and the red curve represents the predictive situation of the model after the Bootstrap resampling. The fact that the red curve is very close to the ideal situation indicates that the nomogram model constructed in this study has a certain degree of calibration. Figure 8(B) is the ROC curve for the validation of the predictive effectiveness of the nomogram model, with an AUC value of 0.851 under the ROC curve, indicating that the model has good predictive performance for the outcome of whether intercostal neuralgia occurs.

Fig. 8

(A) Calibration Curve of the Nomogram Model (B) ROC Curve of the Nomogram Model

Discussion

Osteoporotic vertebral compression fractures and the resulting intercostal neuralgia are common diseases. This study screened for potential associated factors associated with intercostal neuralgia following osteoporotic thoracic vertebral fractures. The analysis found that a reduction in the area of the injured vertebral foramen and an increase in the proportion of fatty degeneration of the thoracic and back muscles are associated factors for the occurrence of intercostal pain in patients with thoracic osteoporotic vertebral compression fractures (OVCF). This provides a corresponding supplement to previous research results.Retrospective data may not accurately reflect the pre-injury state because they are collected after the injury has occurred. This could lead to estimates of the pre-injury foraminal parameters being influenced by post-injury changes. In this study, we used a computational approach to estimate the relevant parameters of the foramen before injury, which might be difficult to achieve in prospective studies and is particularly useful for situations that require a rapid understanding of the pre-injury state. The estimation method may not provide the same level of precision as direct measurement. Injury may lead to changes in the vertebral bone structure, which could affect the accuracy of the estimation.

Choi et al. [27] conducted a retrospective observational study involving 35 patients who received surgical treatment for thoracic OVCF, and found that the incidence of postoperative intercostal pain was 28.6%. Tang et al. [28]and others conducted a retrospective observational study including 188 patients with osteoporotic fractures, and the study showed a slightly lower incidence of intercostal pain at 20.20%. Chen et al. [13] and colleagues, in a study involving 205 patients with thoracic OVCF, found that 39 cases (19.02%) had intercostal pain. The most common segment for intercostal pain after thoracic OVCF in this study was T12 (32.7%), while the study by Chen Runsen and others suggested that the most common location for fracture segments was in the middle thoracic vertebrae. Although both studies consider that the fracture segment is not an independent risk factor for intercostal pain after thoracic OVCF, further analysis and verification are needed to confirm this conclusion.

Wei et al. [29] reported on 6 patients who developed intercostal pain after thoracic OVCF and observed the narrowing of the intervertebral foramina in the corresponding nerve pathway area through CT scans. This finding suggests that the occurrence of intercostal pain in patients may be related to the compression of the intercostal nerve due to the narrowing of the intervertebral foramina. The study by Wei et al. [13] provides important clues for our further understanding of the pathological mechanisms of intercostal pain after thoracic OVCF. The research results of Chen et al. found a certain correlation between the reduction rate of the intervertebral foramen area and the incidence of intercostal pain. Specifically, the greater the reduction rate of the intervertebral foramen area, the higher the possibility of patients developing intercostal pain. In this study, there was a significant difference in the area of the injured vertebral intervertebral foramina between the rib pain group and the non-rib pain group (p < 0.01), and the area of the injured vertebral intervertebral foramina was an independent risk factor for intercostal pain after thoracic OVCF. The reduction in the area of the injured vertebral intervertebral foramina may increase the incidence of intercostal pain after the fracture. However, some patients with negative imaging findings in the study had intercostal neuralgia, indicating that the influencing factors of intercostal neuralgia are non-uniform and multi-dimensional. The possible mechanism of intercostal neuralgia is the change in the mechanical properties of the vertebral body, which then mechanically stimulates the intercostal nerve to cause pain, the sympathetic nerve pathway inducing distant pain, and the accumulation of inflammatory mediators, with the reduction in vertebral body height leading to the narrowing of the intervertebral foramina and stimulating the intercostal nerve to produce intercostal neuralgia.

Muscle fat infiltration is an important indicator for measuring muscle quality and functional status, which can occur without a change in the total volume of the muscle. This study included indicators related to the chest and back muscles, aiming to explore the impact of muscle quality and the degree of fat infiltration on intercostal pain after thoracic OVCF. Shira et al. [16] demonstrated that sarcopenia is an independent risk factor for secondary osteoporotic vertebral fractures after percutaneous vertebroplasty (PVP). Ikchan et al. [22] considered that paraspinal muscle fat infiltration is a predictive factor for progressive vertebral collapse, and the reduction in the cross-sectional area (CSA) of paraspinal muscles is closely related to an increase in lower back pain [30, 31]. The relative paraspinal muscle CSA significantly affects the fracture healing in patients with OVCF [32]. This study found a clear correlation between the degree of fat infiltration in paraspinal muscles and rib pain in thoracic OVCF, and it is an independent risk factor for rib pain after thoracic OVCF.

Currently, the treatment for osteoporotic vertebral compression fractures mainly includes two approaches: conservative treatment and surgical treatment. Conservative treatment typically involves rest, analgesics, muscle strength training, and rehabilitation therapy, which can to some extent alleviate the patient’s symptoms. Conservative treatment, including pharmacological management and physical therapy, has been proven to be effective in alleviating the symptoms of intercostal neuralgia. Particularly, physical therapies such as local heat application, massage, infrared radiation, and microwave diathermy can promote blood circulation and reduce inflammatory responses, thereby relieving pain. By enhancing the strength and function of the paraspinal muscles, not only can the symptoms of intercostal neuralgia be mitigated, but also the overall quality and speed of the patient’s recovery can be improved [33, 34].However, conservative treatment requires the patient to have prolonged bed rest, which may lead to a series of complications such as pressure sores, deep vein thrombosis of the lower limbs, and spinal kyphosis deformity. Prolonged bed rest can cause muscle atrophy, a decline in cardiopulmonary function, increase the risk of infection, and adversely affect the function of various bodily systems. At the same time, the occurrence of pressure sores is also a common problem encountered by patients with long-term bed rest, which severely affects the quality of life and the rehabilitation process of the patient. In addition, deep vein thrombosis of the lower limbs is a common complication that can lead to thrombotic embolism and cause serious consequences. Spinal kyphosis deformity can affect the patient’s posture and spinal stability, thereby reducing the quality of life [35].

For the surgical treatment of osteoporotic vertebral compression fractures, minimally invasive surgery and open surgery are two common approaches. In minimally invasive surgery, percutaneous vertebroplasty (PVP) and balloon kyphoplasty are two common procedures. These minimally invasive surgeries not only effectively alleviate the patient’s back pain and other symptoms but also have the advantages of minimal trauma, simple operation, and rapid recovery. Percutaneous vertebroplasty stabilizes the vertebral structure and reduces the patient’s pain by guiding bone cement or other suitable filling materials into the vertebral body through a small skin incision. This minimally invasive surgery reduces surgical trauma and postoperative recovery time, helping to shorten the patient’s hospital stay and rehabilitation cycle. Balloon kyphoplasty, on the other hand, expands the vertebral space with a balloon expander, then injects filling material to restore the height of the vertebral body and relieve nerve compression, thereby improving the patient’s symptoms and function.However, extensive use of percutaneous kyphoplasty (PKP) can lead to risks and complications, such as cement leakage [19, 36], epidural hematoma [37], and delayed infection or refracture [38]. Studies have shown that PKP reconstructs the stability of the fractured vertebra, reducing the micromotion at the fracture site, thereby alleviating irritation to the nerve roots. Secondly, the cytotoxic effect of polymethyl methacrylate (PMMA) monomers can cause necrosis of peripheral nerve endings [39], thereby reducing intercostal neuralgia. PKP is beneficial for restoring the height of the vertebral body and improving kyphosis, expanding the intervertebral foramina, thereby reducing irritation to the intercostal nerves [40], which is consistent with the results of this study that the reduction in the area of the injured vertebral intervertebral foramina is an independent risk factor for rib pain after thoracic OVCF. Percutaneous vertebroplasty (PVP) is an interventional treatment method that stabilizes the fractured vertebral body by injecting bone cement material into the vertebral body to alleviate pain and restore the height of the vertebral body. Some patients with intercostal neuralgia who undergo PVP surgery experience good relief from chest and back pain and intercostal neuralgia symptoms, but for some patients with intercostal neuralgia, the therapeutic effect is poor, and they still need to take oral painkillers to alleviate pain after surgery, which poses challenges for clinical treatment.

For patients with OVCF, percutaneous vertebroplasty (PVP) surgery has already shown good therapeutic effects, but for patients with neurological dysfunction, the effect is minimal, and the improvement of intercostal neuralgia is poor. Currently, there is still controversy over the surgical treatment methods for patients with neurological dysfunction, and the surgical approaches mainly include anterior approach, posterior approach, and combined anterior and posterior approach. Anterior decompression and fusion with internal fixation can achieve thorough decompression through subtotal vertebrectomy and can reconstruct the stability of the anterior and middle columns, but the incidence of complications is high, and the probability of iatrogenic injury to thoracic and abdominal organs increases. More and more scholars are using posterior fusion and internal fixation, and there are still different views on whether decompression is needed in posterior fusion and internal fixation and whether bone graft fusion is used to improve vertebral stability. Pedicle screw correction of post-fracture kyphosis deformity has certain advantages and the technology is mature. Previous studies have shown that there is no statistically significant difference in neurological recovery and pain scores between anterior and posterior surgeries, and the potential for neurological recovery in patients with osteoporotic vertebral fractures is independent of the surgical method. However, there is no consensus on open decompression surgery for intercostal neuralgia after OVCF. According to the results of this study, there is a significant correlation between the minimum cross-sectional area of the intervertebral foramen, the area of the nerve root in the intervertebral foramen, and intercostal neuralgia after OVCF. Therefore, patients with intercostal neuralgia after thoracic vertebral fracture may improve the effect of intercostal neuralgia by resecting the articular process and expanding the volume of the nerve root foramen, which needs further verification.

Conclusion

Thoracic osteoporotic fractures are a common geriatric disease, and changes in the morphological parameters of the intervertebral foramina, such as a reduction in the area and volume of the injured vertebral intervertebral foramina, as well as fatty degeneration of the thoracic back muscles, suggest an increased likelihood of developing intercostal neuralgia. Therefore, it is essential to be vigilant about the possibility of intercostal pain. To clarify the diagnosis of the area of the injured vertebral intervertebral foramina and the proportion of muscle fat infiltration, imaging and clinical evaluations are necessary. We should take into account all relevant factors of intercostal pain, develop a personalized treatment plan, and ensure that patients are well-informed and engaged in their condition management.