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.