Introduction
The incidence of vertebral compression fracture is estimated at 800,000 per year in the United States, and they often result in hospitalization. Osteoporotic compression fractures affect 30% to 50% of people older than 50 years. Additionally, the vertebral column is a common site for painful bone metastases and multiple myeloma, which results in vertebral fractures on presentation in up to 70% of patients. , Diagnosis and treatment of compression fractures is important, as these injuries can lead to chronic back pain, pulmonary dysfunction, recurrent falls, severe compromise of activities of daily life, reduced quality of life, and greater health care utilization. , , These fractures are also a chief factor of morbidity in cancer patients. Furthermore, vertebral fractures are an underappreciated cause of morbidity and mortality among the elderly.
Treatment for vertebral compression fractures begins with medical management with bracing, oral pain medications, and rest. If conservative therapy fails after 3 weeks (and preferably before 6 weeks), the patient should be referred to be evaluated for interventional therapy (i.e., vertebral augmentation). ,
Vertebroplasty was first performed to treat an aggressive cervical hemangioma; other indications surfaced in the literature of the late 1980s. A variation in the technique referred to as “kyphoplasty” was described in 2001 by Garfin and Lieberman in which balloons were used in an attempt to restore vertebral height prior to introduction of cement. , As surgical treatments evolve, further techniques and technologies continue to be introduced to this familiar procedure, such as the recent method of vertebral augmentation with osteotome.
Vertebral augmentation with osteotome
A cadaveric study using a prototype curved osteotome for vertebral augmentation was published in 2002. Clinical studies were further described in the late 2000s. , While Zhong and colleagues report clinical application with a curved osteotome for vertebral augmentation since 2013, the curved osteotome differs in methodology from vertebroplasty in that there is more significant cavity creation prior to cement administration. It also differs from balloon kyphoplasty in that the pre-cement maneuver allows greater control of the shape, size, and direction of the cavity created for the cement.
The advantage of cavity creation addresses the issue of cement leakage. Nontarget cement leakage is the most common complication of vertebral augmentation procedures, which can result in pulmonary embolism or nerve damange. In vertebroplasty, higher pressures build as cement is injected to the fractured vertebrae. Kyphoplasty offers a lower-pressure alternative by creating a cavity with the balloon first. Vertebral augmentation with osteotome offers a more refined approach to cavity creation prior to cement injection. A curved or maneuverable osteotome can be guided to selected portions of the vertebrae. This preserves cancellous bone that otherwise would have been destroyed by a balloon kyphoplasty. Advantages of a vertebral augmentation osteotome include amenability to the unipedicular approach, directional control of the osteotome, a side hole for cement delivery that prevents inadvertent administration of cement to soft tissues upon withdrawal of the cannula, and preservation of the native cancellous bone matrix , , ( Figs. 6.1 and 6.2 ).
The benefits of using an osteotome have also been reported in the literature. In one head-to-head study, unilateral curved osteotome utilization was compared with more traditional bilateral vertebroplasty and was found to have significantly lower operation time, lower number of fluoroscopic images taken, and lower cement leakage rate. Importantly, both techniques demonstrated similar improvement in pain and disability indices at 1 year after the procedure. Vertebral augmentation with osteotome, like kyphoplasty, achieves reductions in kyphotic deformity. , , However, there are still a limited amount of comparisons between balloon kyphoplasty and osteotome vertebral augmentation for kyphotic deformity.
Cancellous bone preservation is an area of interest for the future of vertebral augmentation procedures. Specifically, there has been interest in incorporating calcium and other related biological substances into cements that would eventually merge into native bone. Unfortunately, this cannot be done with typical balloon-based systems due to the absence of Haversian canal systems. Cements and other technologies amenable to osteotomes leave this field ripe for innovation. Operator-controlled curving of the osteotome and radiofrequency technology for more controlled cement hardening are two such examples. , Significant interdigitation of the cement injection is noted using these technologies ( Fig. 6.3 ).
