Myeloma and osteoporosis

A 60-year-old gentleman was referred by his orthopedic surgeon for medical management of multiple vertebral fractures sustained over a period of five years. The patient was a stoic and had not sought medical attention between the first fracture and the most recent one that had occurred a few months before.

The orthopedist ordered an MRI and a DXA study. The MRI revealed six fractured vertebrae between T4 and L4, some of which were clearly old and two that were more recent. One of these only involved the inferior endplate. A comment was made about marrow edema in one of the vertebrae that was not fractured. The spine T-score was –4.2 and the proximal femur T-score –2.8.

Initially the patient denied any systemic symptoms, early childhood fractures or family history of osteoporosis with or without fractures. A review of systems did not suggest any gastrointestinal or hormonal diseases.

The only relevant medication was warfarin which had been prescribed following a mini-stroke two years earlier.

As I kept inquiring about possible reasons for so many fractures and such a low bone density the patient reported that he was prone to drop attacks that he had attributed to “pinched nerves” resulting from the fractures. I patiently explained that osteoporosis-related vertebral fractures are “implosion” fractures, not “explosion” fractures as one might sustain following severe trauma so that we need to investigate the cause of the drop attacks.

He had never discussed this with his primary care physician because the patient “knew” they were from pinched nerves. I felt obliged to let his physician know about this and he confirmed that this was indeed news to him. He also reported that he now had the result of the protein electrophoresis that revealed a monoclonal spike and suppression of other globulins. The patient had a follow-up visit scheduled for the next week and was to be referred to a hematologist.

Myeloma is often associated with vertebral collapse because of local deposits. It is also often associated with diffuse loss of bone mass, indistinguishable from osteoporosis on DXA or plane X-ray unless local lesions are present. Treatment for the myeloma and for the accelerated bone loss can be given concurrently.

Serum protein electrophoresis is not part of my routine search for secondary causes of osteoporosis but this patient represents one circumstance where it is indeed indicated. Very few patients, even the very old, have a T-score < –4.0 unless there is a secondary cause for accelerated bone loss. A complete blood count is part of my routine work-up, but serum protein electrophoresis is considered if there is any otherwise unexplained hematologic abnormality or the serum proteins are elevated.