Treatment Considerations for Vertebroplasty in Men

Methods

The charts and radiographic studies of 29 consecutive male patients who underwent percutaneous vertebroplasty between February 1999 and November 2000 were retrospectively reviewed. Five patients were omitted from the study because of inadequate medical records. Documentation from outside hospitals was included when available. Records were studied to determine the mechanism of fracture and onset of pain and significant past medical and surgical history, including secondary causes of osteoporosis and malignancy. All radiographic studies (conventional radiographs and CT and MR images) were reviewed.

Results

The average age at presentation was 72 years, ranging from 53 to 97 years. Only three patients were less than 60 years of age. Vertebral levels treated ranged from T6 to L5, with one treatment at C2.

Bone densitometry data were available for six patients. Five of these patients had T scores greater than 2.5 SDs below the mean for peak bone mass at all measured locations.

Five patients (21%) had an obvious traumatic event preceding the onset of severe pain. Most patients had an acute onset of back pain at the level of the fracture without a clear precipitating event or following activities such as sneezing, coughing, opening windows, or bending at the waist. In one case, a compression fracture occurred while the patient was admitted for treatment of acute kidney transplant rejection.

Five patients (21%) had no clear predisposition for vertebral fractures at presentation and were considered to have idiopathic or primary osteoporosis. Two of these patients (8%) had previously unknown metastatic disease to the spine, diagnosed by core biopsy taken at the time of vertebroplasty (nonsecretory multiple myeloma and plasma cell dyscrasia).

Thirteen patients (54%) had secondary causes of osteoporosis. Ten of these patients (42%) were receiving chronic steroids. Three patients (13%) were hypogonadal (primary endocrine failure, prolactinoma, and orchiectomy). One patient had secondary osteoporosis due to AIDS and antiretroviral drug therapy. Seven (29%) patients had a history of cigarette use.

Three patients (13%) had biopsy-proved metastatic disease to the spine. These include the two undiagnosed malignancies described above and a nonsmall cell adenocarcinoma from an unknown primary. Biopsy was taken at the time of vertebroplasty by using a biopsy gun introduced through the vertebroplasty canula. One patient presented with a pathologic fracture of an aneurismal bone cyst of the C2 vertebral body diagnosed by MR imaging.

Discussion

The epidemiology of osteoporosis in men is limited. According to a European-based population study, the prevalence of vertebral body deformity, a surrogate measure for vertebral body fracture, is greater in men than women below the age of 60 years. With further aging this is reversed, presumably because the incidence of osteoporosis increases more rapidly in women than in men (12, 13). The prevalence of osteoporosis in men in the United States has been estimated at between 3% and 7% (14, 15), and male osteoporosis accounts for up to 20% of all cases of osteoporosis (14). This prevalence, however, is increasing. Longer life spans and the aging of the population are bringing both greater numbers and greater percentages of the male population into the osteoporotic range.

The advanced age of men referred for vertebroplasty in this study is consistent with the increase incidence of both osteoporosis and malignancy with age. Smoking is also known to be associated with osteoporosis (16) and is reflected in the high incidence of patients with a smoking history (seven of 24 patients). Decreased bone attenuation is also expected in a male population with vertebral compression fractures (6). This was evident in all six cases, where densitometry data were available. These findings suggest that bone densitometry measurements with subsequent treatment if indicated would be beneficial for men referred for vertebroplasty.

Ten patients were receiving chronic steroids, six of them because of cigarette-induced lung disease. The side effect of osteopenia with glucocorticoid therapy has been clearly established. Its mechanism of action is complex, resulting in both increased bone resorption and inhibition of formation (17–19), which contribute to rapid bone loss (19).

Hypogonadism was present in three of the 13 men with secondary osteoporosis. Hypogonadism is known to frequently occur among those with vertebral body compression fractures (20, 21). Androgens are needed in young males to achieve peak bone mass, but the role of androgens in the elderly to maintain adequate mass is less clear. Androgens in the elderly may be needed as a substrate for the formation of estradiol, which correlates more closely with bone mineral attenuation in some studies (22).

Conclusion

Most men treated with vertebroplasty in our study had significant risk factors for osteoporosis or a history of metastatic disease or trauma. Two patients, however, had compression fractures that were wrongly attributed to idiopathic osteoporosis. Though most series indicate that 50% of cases of male osteoporosis may indeed be idiopathic (23), these patients were discovered, by core biopsy taken at the time of vertebroplasty, to have multiple myeloma and plasma cell dyscrasia. The discovery of two patients (8%) with previously occult malignancies suggests that core biopsy of male patients undergoing vertebroplasty is indicated in cases of presumed idiopathic osteoporosis.