Radiographic progression of vertebral fractures in patients with multiple myeloma

Background Context Nearly 70% of patients with multiple myeloma (MM) experience vertebral fracture. As a consequence, these patients suffer significantly poorer quality of life. However, no studies have characterized the natural progression of these fractures. Purpose The purpose of this study was to characterize the progression of MM-associated vertebral fractures. Study Design/Setting A consecutive retrospective chart review at a single tertiary-care center was carried out. Patient Sample Patients with MM and pathologic vertebral fracture with at least one follow-up between January 2007 and December 2013 were included. Radiographic measurements were recorded until last follow-up (LFU) or until surgical intervention or patient death. Patients with a history of vertebral fracture not associated with MM were excluded. Outcome Measures The primary outcome measure was change in height of the fractured vertebrae. Fractures were characterized by Genant grade and morphology. Methods At baseline and each follow-up, anterior, middle, and posterior vertebral body heights were measured from midline sagittal T1-weighted magnetic resonance imaging. Student t tests and Fisher exact tests were performed to identify variables associated with fracture progression. Results Among 33 patients, 67 fractures were followed. Sixty-four percent of patients were female, with a mean age of 66. Baseline mean anterior, middle, and posterior vertebral body height losses were 30%, 36%, and 15%, respectively. Forty-three percent of fractures were Genant grade 3, and 57% were biconcave. Mean time to LFU was 40 months. At LFU, mean anterior, middle, and posterior vertebral body height losses increased to 47% (p<.01), 49% (p<.01), and 28% (p<.01), respectively. More fractures became Genant grade 3 (75%, p<.01) and wedge (54%, p=.03). On average, patients lost 0.83% in vertebral body height per month, with initial Genant grade 1 fractures progressing most rapidly (1.69%/month, p<.01). Patients treated with bisphosphonates suffered less additional height loss compared with untreated patients (14% vs. 24%, p=.07). Conclusions We observed significant fracture progression despite high utilization of bisphosphonates. Patients lost nearly 1% of additional vertebral body height per month, with the least severe presenting fractures progressing most rapidly, highlighting the necessity for early referral to spine specialists and evidence-based guidelines for surveillance and treatment in the myeloma population.