Osteoporosis is a complex disease characterized by loss of bone mass, resulting in increased bone fragility and destruction of bone outcomes. Older adults with osteoporosis often inadvertently develop OVCF. Sometimes it just happens after a sneeze. With the ascent of the ageing population, OVCF, which are mainly caused by osteoporosis, have become one of the most major health problems14. OVCF have been shown to adversely affect patients' quality of life, physical function, and mental health. These effects are related to the severity of the spinal fracture and the resulting deformity and pain18. Traditional treatment of OVCF consists of conservative management including bed rest, analgesia and braces, and physical therapy after symptom relief. However, due to long-term bed rest, patients are more likely to be accompanied by bone demineralization and disease progression19, and lead to a series of complications, such as lower extremity deep vein thrombosis, pulmonary infection and urinary tract infection. It is generally believed that bone cement and bone cement combined with balloon expansion surgery, as the two most common minimally invasive surgical methods for the treatment of severe symptomatic OVCF, can effectively restore the compressed vertebral body and relieve pain20. The main difference is that bone cement combined with balloon is a new type of operation. During the operation, balloon reduction is placed into the injured vertebra and then bone cement is poured into the injured vertebra, which is more helpful to restore the height of the injured vertebra and enhance its stability21. However, there are different conclusions about the advantages and disadvantages of the two surgical methods in the treatment of OVCF.
Our research focuses on OVOCF, a special type of OVCF. The majority of OVCF patients mainly showed the loss of anterior vertebral height and the increase of kyphotic angle on X-ray lateral films, while OVOCF patients showed the serious loss of vertebral height and the increase of vertebral scoliosis angle on X-ray lateral films. Both bone cement and bone cement combined with balloon have achieved significant clinical efficacy in the treatment of OCVF induced spinal pain, and their main roles are to restore vertebral height and strength, correct kyphosis, and rebuild spinal stability22,23. In the past, when they were used to treat OVCF, only the sagittal height of vertebral body was restored, and kyphosis was corrected24. For spinal fractures with vertebral oblique compression fracture, not enough attention is often paid. If the vertebral compression scoliosis angle is not corrected, scoliosis deformity is highly likely to occur, resulting in uneven longitudinal pressure distribution of adjacent vertebrae, and even fracture of adjacent vertebrae. Therefore, which surgical method has better clinical effect for OOVCF is worthy of further discussion. In the present study, our results indicated that both functional and radiographic outcomes get significant improvement after bone cement and bone cement combined with balloon surgery. However, functional and radiographic outcomes obtained better improvement under bone cement combined with balloon expansion surgery when compared with bone cement surgery alone. Compared with bone cement surgery, the height of the short side of the vertebral body after bone cement combined with balloon expansion surgery was significantly recovered, and the height of the long side was almost the same to a large extent. The postoperative height difference between the two sides of the vertebral body is small, so that the vertebral body is almost balanced at the bilateral height. Therefore, the scoliosis angle after bone cement combined with balloon expansion surgery is also significantly smaller than that after bone cement alone. Many researchers believed that the most significant feature of bone cement combined with balloon expansion surgery lies in the placement of balloon reduction into the injured vertebra during the operation, followed by the perfusion of bone cement. The endplate is raised by percutaneous insertion of an expandable high-pressure bone pile into the fractured vertebra by creating a cement-filled cavity inside the vertebra to help restore and stabilize the height of the vertebra, which improves the problem that bone cement alone cannot improve the structural parameters of the vertebral body, and is more helpful to restore the height of the injured vertebra and enhance the stability of the vertebral body25–27. We believe that during the bone cement combined with balloon expansion operation for OVOCF patients, the height of the vertebral body on the heavily compressed side was effectively supported by placing a balloon in the vertebral body, so that the height of the bilateral vertebral body was as consistent as possible. when the height difference between the two vertebral bodies is large, the longitudinal pressure distribution of the vertebral body is uneven, and the scoliosis angle cannot be corrected, which will lead to scoliosis deformity in the long run. This also explains why patients after bone cement combined with balloon expansion surgery have lower VAS and ODI scores than patients in the treatment of bone cement alone one year after surgery, and fewer postoperative scoliosis complications in patients in the treatment of bone cement combined with balloon expansion surgery. At the same time, we also found that the complications of bone cement leakage after bone cement combined with balloon expansion surgery were significantly less than those of bone cement surgery alone. This is also consistent with the current research results of most scholars. It is generally believed that bone cement combined with balloon expansion surgery has a lower leakage rate than bone cement surgery alone28.
Although our study found that bone cement surgery also has the advantages of short operation time, short fluoroscopy time, and recovery of vertebral height to a certain extent. However, we took the long-term recovery of vertebral height after surgery to reduce the occurrence of scoliosis and bone cement leakage into account. We believe that bone cement combined with balloon expansion surgery has better clinical outcomes. This surgery can be performed by unilateral and bilateral puncture methods. Many studies have shown that unilateral and bilateral bone cement combined with balloon expansion surgery can restore vertebral height and improve patients' pain, thus achieving good clinical benefits29,30. However, for OVOCF patients with vertebral compression scoliosis angle greater than 11°, it is required that the lateral angle can be corrected after bone cement combined with balloon expansion surgery, otherwise the spinal force line imbalance will lead to further aggravation of scoliosis, resulting in intractable pain. Then we should be more cautious in the choice of puncture methods. Some scholars believe that the use of unilateral pedicle approach will cause insufficient diffusion of bone cement in the vertebral body, resulting in unilateral load bearing of the vertebral body and spinal instability. Moreover, under constant load, it is easy to inject bone cement into the contralateral lateral buckling, resulting in compression deformation of the vertebral body31. Bilateral pedicle approach can make both sides of the injured vertebrae be reduced by balloon compression at the same time, avoiding the problem of unbalanced lateral stress caused by uneven diffusion of bone cement. We believe that bilateral pedicle approach can elevate both sides of the injured endplate by expanding the balloon, to restore the height of the vertebral body. In the unilateral pedicle approach, the short side with heavy compression was selected for puncture, and the balloon could also effectively raise the injured endplate and restore the height of the vertebral body.
Of course, there are some limitations to our study. The sample size of patients involved in our study was still too small, and we only conducted a simple retrospective study, not a prospective study. At the same time, the follow-up time of patients is relatively short, and the study of unilateral and bilateral bone cement combined with balloon dilation surgery relies more on clinical experience, and there is no systematic retrospective study and analysis of unilateral and bilateral puncture methods. This aspect should be further studied in the following research.