Treatment of osteoporotic vertebral compression fractures

Abstract

In Chapter I, an outline of this thesis is given. In Chapter 2 we prospectively determined the natural course of pain in patients with conservatively treated acute osteoporotic vertebral compression fractures (VCF). In addition, we assessed the type of conservative therapy that these patients received. The natural fracture healing, in terms of pain relief, of an acute, osteoporotic VCF mainly took place within the first 6 months. In view of the high percentage (31%) of patients with chronic pain due to an acute VCF with conservative therapy only, minimal invasive techniques should be considered. In the Netherlands, conservative treatment mainly consists of pain medication and physiotherapy and is prescribed by the general practitioner. In Chapter 3 rationale, objectives and design of the VERTOS II study are described. VERTOS II is an open-label randomized controlled trial comparing percutaneous vertebroplasty (PV) with optimal conservative pain management. In Chapter 4 the main outcomes of the VERTOS II study are analyzed en discussed. Our results show that in patients with acute osteoporotic VCFs who have persistent severe pain, PV done at a mean 5.6 weeks after onset of symptoms resulted in quicker and greater pain relief than conservative treatment did. Pain relief was sustained throughout a year of follow-up. After PV, patients used a lower class of drugs than did those receiving conservative treatment, or no drugs at all. With conservative treatment, pain relief was slower and less than with PV, and pain treatment required tended to increase during the first month. Some patients (24%) in the control group developed chronic back pain, possibly because of non-healing of the fracture. For both quality of life and function, improvement with time was significantly greater and quicker after PV than with conservative treatment. Incremental costs of PV roughly equaled procedural costs. The cost of one pain-free day gained was €20. The trial-based incremental cost-effectiveness ratio for PV, as compared with conservative treatment, was €22,685 per quality adjusted life year gained. The resulting incremental cost-effectiveness suggests that PV seemed warranted for the patients with VCFs treated at a mean 5.6 weeks after start of symptoms. In Chapter 5 we found that the incidence of new VCFs in patients with an acute osteoporotic VCF was not different after PV compared with conservative therapy in the first year of follow-up. The only risk factor for the occurrence of new VCFs was the number of VCFs at baseline indicating the severity of osteoporosis. PV contributed to preservation of stature by decreasing the incidence and severity of further height loss in treated vertebral bodies. In Chapter 6 we assessed the incidence of pulmonary cement embolism by performing native chest CT during follow-up in a large proportion of patients from the VERTOS II trial. Small and clinically silent pulmonary cement embolism occurred in a quarter of patients treated with PV. Cement leakage into the azygos vein was the only risk factor. With time, these small cement emboli remained inert on follow-up CT, without inflammatory pulmonary response. Standard post-procedural CT or chest radiographs are not necessary. In Chapter 7 we assessed the incidence, anatomical location, and clinical impact of perivertebral cement leakage on short- and long-term in a large patient cohort. Cement leakage after PV outside the vertebral body was frequently detected on CT. Most leakages are into adjacent disks or segmental veins and all patients were asymptomatic. Cement leakage occurred more frequently with higher injected volumes. Late cement migration during follow-up did not occur. Standard post-procedural CT of the treated vertebral body in PV is not necessary. In Chapter 8 pain management during PV is evaluated. In a substantial proportion of patients, local anaesthesia was not sufficient for pain reduction during PV. The severity of pain experienced by the patient is usually not appreciated correctly by the operator. In Chapter 9 the results of the VERTOS II study are interpreted and the clinical implications are discussed.