PAIN IN THE BACK
A 75-year-old woman presents to her general practitioner (GP) complaining of severe back pain. This developed suddenly a week previously after carrying a heavy suitcase at the airport. The pain is persistent and in her lower back. She has had increasing problems with back pain over the past 10 years, and her family have commented on how stooped
her posture has become. Her height has reduced by 10 cm over this period. Her past medical history is notable for severe chronic asthma. She takes courses of oral corticosteroids, and use steroid inhalers on a regular basis. She fell 2 years ago and sustained a Colles’ fracture to her left wrist. She developed the menopause at age 42 years. She smokes 30
cigarettes a day, and drinks four bottles of wine a week.
She has a thoracic kyphosis. She is tender over the L4 vertebra. She has a moon-face,abdominal striae and a number of bruises on her arms and thighs. She is not anaemic, and examination is otherwise unremarkable.
• What is the likely diagnosis?
• How would you manage this patient?
This woman has vertebral collapse due to osteoporosis. The symptoms of osteoporosis are deformity, localized pain and fracture. The loss of height is typical, and is usually noted more by others than the patient. The back pain is due to collapse of the vertebrae.
This can occur spontaneously or in association with a recognized stress such as carrying a heavy load. Examination confirms loss of trunk height, thoracic kyphosis and proximity of the ribs to the iliac crest.
The differential diagnoses of osteoporosis!
• Multiple myeloma
• Metastatic carcinoma, particularly from the prostate, breast, bronchus, thyroid and kidney
• Steroid therapy or Cushing’s syndrome
This patient has several risk factors for osteoporosis. Firstly she is aged 75 years, and ageing is associated with bone loss. Secondly she has been postmenopausal for over 30 years.
Premenopausal ovarian production of oestrogens help to preserve bone mass. Thirdly she has been on oral and inhaled corticosteroids for her asthma for years. Finally, excess alcohol intake may also be a factor. Her red cells are macrocytic, which is consistent with heavy alcohol intake. Alcohol can lead to an increased incidence of falls and fractures. She has
no clinical evidence of thyrotoxicosis or hypopituitarism which can cause osteoporosis.
This woman should have blood tests to exclude myeloma, cancer and metabolic bone disease. Patients with myeloma are anaemic with a raised ESR and a monoclonal paraprotein on serum protein electrophoresis. In contrast to metabolic bone diseases biochemical measurements (serum calcium, alkaline phosphatase and parathormone (PTH)) in osteoporosis
are normal. She should have plain X-rays of her spine. Collapse of the vertebral body will manifest as irregular anterior wedging affecting some vertebrae and not others (L1 and L4).
A dual-energy X-ray absorptiometry (DEXA) scan can be performed to assess the severity of the osteoporosis, but treatment is indicated anyway with a fracture at this age.
She should have her dose of corticosteroids reduced to the minimum required to control her asthmatic symptoms, using the inhaled routes as far as possible. She should be started on calcium and vitamin D supplements and a bisphosphonate to try to reduce her bone loss.
Oestrogen-based hormone replacement therapy is only used for symptoms associated with the menopause because of the increased incidence of thromboembolism and endometrial carcinoma. Newer treatments for osteoporosis include strontium and parathyroid hormone.
• Osteoporosis is common in the elderly.
• Bone loss is more rapid in women than in men.
• DEXA scan is the method of choice of screening for osteoporosis.
• There are increasingly effective treatments available for the treatment of osteoporosis.