With the increase in life expectancy, the incidence of osteoporotic fractures has also increased, with vertebral fracture the most common type of osteoporotic fracture. Osteoporotic vertebral fractures (OVFs) are conventionally treated conservatively; however, complicated cases requiring surgery are challenging to address. OVFs are significant injuries that result in a functional loss in activities of daily living (ADLs), subsequent fracture (fourfold increase), pulmonary-related complications (threefold increase), and increased mortality (15% increase) [1-3]. The presence of an OVF is also a strong predictor of morbidity, including back pain, spinal deformity (such as kyphosis, kyphoscoliosis, and loss of vertebral height), and a reduced quality of life (QOL) [4]. The only published clinical practice guidelines were developed by the American Academy of Orthopedic Surgeons, and of the 11 recommendations, only one has strong evidence (one has moderate evidence) backing it; nine recommendations are weak or inconclusive [5]. In 2017, an overview of the clinical guidelines for OVF noted that the diagnostic and therapeutic recommendations were generally inconsistent. The best management guidelines for OVF are limited in quantity and quality, and there are few level I studies available for review. Greater efforts therefore need to made to improve the quality of the guidelines [6-10]. The aim of this review is to provide an up-to-date overview of the current evidence on the management of OVF. Considering the incidence of OVF, this review focused on the OVF of the thoracic and lumbar spine. (Cervical OVFs were not included.)

Acute pain from a new OVF usually resolves within 6–12 weeks [11]. Conservative treatment for acute OVF is considered the primary treatment option and focuses on pain relief through short-term bed rest, analgesics, antiosteoporotic drugs, exercise (physiotherapy), and braces (spinal orthosis). Especially in medically underserved areas and low to middle-income settings, conservative treatment is particularly useful and should be actively performed [12,13]. Although there are no definitive conclusions in the conservative management of these fractures, this option has remained an effective initial treatment strategy.

Studies on vertebral augmentation (VA), including vertebroplasty and kyphoplasty, have been widely reported.More than 4,000 articles have been published on vertebroplasty alone, and 14 randomized control trials have been published examining the role of VA. However, there is still debate and controversy regarding the effectiveness of VA compared with conservative treatment, specifically for patients with osteoporosis. Although drawing definite conclusions is difficult, VA is generally considered to show an effect in reducing pain during acute periods.

Several studies have suggested the advantages of VA in the early stages of its introduction. VA can be performed under local anesthesia, mechanical stabilization is possible by injecting cement, and pain-related nerve endings can be damaged by the thermal reaction of polymethyl methacrylate (PMMA) cement, resulting in an analgesic effect [32]. Several studies have shown that alleviation of local kyphosis and pain through VA might have greatly contributed to the improvement in sagittal imbalance in osteoporotic vertebral compression fractures (OVCFs) [33]. American spine intervention societies have presented positioning statements emphasizing the advantages of VA and have highlighted the numerous adverse effects of bed rest (e.g., decreased muscle strength, increased pressure sores, deep vein thrombosis, and gastrointestinal and genitourinary complications) [34]. Several studies have addressed osteoporotic burst fractures (OBF), with one reporting satisfactory results with VA in patients with OBF and poor general condition but with no neurologic deficit [35]. Short-segment fixation with cement augmentation (a hybrid technique) has also been reported as an alternative option for OBF [36]. However, given that these studies were conducted with limited surgical indications, routine VA performed without a close examination for unstable OVF might result in serious complications. VA should be applied after sufficiently assessing the patient’s general condition and radiological status. Several papers have suggested VA as a treatment option for patients with an intravertebral cleft or vertebral osteonecrosis due to nonunion; however, other articles have reported a high failure rate (Fig. 1) [37], due to the fact that vertebral instability is a determinant factor for inducing pain and perhaps the predominant factor for a delayed neurologic deficit in patients with OVF and an intravertebral cleft. These findings indicate that treatment for instability is important [38]. Despite several studies suggesting the advantages of VA, the critical reason for the lack of acceptance of the evidence is the significant heterogeneity among these trials, resulting in difficulty in translating the results to routine clinical practice.

Although low complication rates have generally been reported for VA, the potentially serious nature of these complications needs to be addressed. The calculated critical complication rate was approximately 2% for kyphoplasty versus 3.9% for vertebroplasty [39]. Five trials (821 cases of vertebroplasty) with moderate‐quality evidence noted the risk of serious adverse effects including osteomyelitis, cord compression, thecal sac injury, pulmonary artery embolism, and respiratory failure. Cement extravasation is a representative serious complication, which in a retrospective review of 473 VA cases, showed high rates of local leakage (almost asymptomatic, with 87.5% for vertebroplasty and 49.2% for kyphoplasty) [40]. Two meta-analyses calculated the symptomatic leakage rate of kyphoplasty at 0%–0.3% compared with 1.6%–3.0% for vertebroplasty [41]. To reduce the risk of cement leakage, several measures have been recommended: (1) meticulous evaluation of preoperative images, (2) a total injected cement volume less than or equal to the void created by the balloon, (3) careful injection of a small volume of cement (0.2–0.5 mL), (4) frequent assessment by fluoroscopy, (5) high-viscosity cement in a doughy state, and (6) a typical injection time of 3–4 minutes after cement mixing [35].

Another concern are re-fractures at the index level of VA or subsequent fractures at the adjacent level [42]. The following factors have been suggested as related to index level re-fracture: preoperative intravertebral cleft and severe kyphosis, thoracolumbar OVF, solid lump cement distribution pattern, and higher vertebral height restoration [43]. Adjacent-segment fracture (ASF) is a frequently observed complication, with a risk of 2%–23% in kyphoplasty and up to 52% in vertebroplasty, and most cases of ASF occur within 2 months after VA [44]. In contrast, the rate of recurrent or subsequent fractures ranges from 12% to 20% after conservative treatment [44]. The possible reasons for the increased rate of ASF include increased stiffness of the cemented vertebra, which can induce biomechanical change, resulting in 35-fold harder and 12-fold stiffer cementing than in control groups. Decreased spinal motion and load failure can cause 19% bone loss in the adjacent level than when adjacent to a nonaugmented vertebra. Unusual loading distribution can increase adjacent level pressure (13%–18%) [45]. Until recently, there has been a lack of information regarding the effects of VA on subsequent ASF. A number of authors have suggested that restoring sagittal balance and physiologic loading by VA could reduce the ASF and that the major cause of ASF was underlying osteoporosis and abnormal mechanical load due to spinal deformity [46]. While still controversial, it is reasonable to assume that the effects of VA on subsequent fracture risk are unclear. To overcome ASFs, prophylactic vertebroplasty of the adjacent level has been attempted, based on the results of several studies that suggested building a gradient in mechanical properties through cement injection for adjacent levels [47,48]; however, the preventive effects of this approach have not been fully verified.

After the publication of randomized studies in 2009 showing no superiority of VA over a sham procedure [7,8], several studies disputing the beneficial effects of VA have been reported. Debate and widespread concern have also been raised regarding the design and execution of these studies [49]. In 2018, the ASBMR Task Force Report stated that because the role of VA in both acute and chronic fractures has been controversial, the routine use of VA is not supported by current evidence. When VA is offered, patients should be fully informed about the evidence [31].

When summarizing the results of the studies to date, the effects of VA are inconclusive. VA should only be applied to selected patients who do not respond to conservative treatment and it needs to be carefully performed to achieve initial pain management while considering potentially serious complications. Until better evidence becomes available, the potential benefits of VA remain unproven, and VA should not be routinely offered to patients with OVF.

Although most OVFs heal well, approximately 15%–35% of patients can develop persistent pain, poor chest function, deformity, and neurological deficit requiring surgery [50].

Based on the current literature, there is still an obvious lack of standard management strategies for OVFs. To improve the quality of the guidelines, greater efforts are needed through multimodal approaches including conservative treatment, surgery, osteoporosis treatment, and drugs that promote fracture healing.