Q & A With the Expert on: Osteoporosis

Minimizing the Risk of Another Hip Fracture in a Patient with Osteoporosis

Q: A 90-year-old female sustained a hip fracture as a result of a fall. She is now admitted to the nursing home after undergoing hip fracture surgery. What does a nursing home practitioner need to do to minimize her risk of suffering another hip fracture?

A: This is a frequently encountered situation in skilled nursing facilities. This 90-year-old patient is at increased risk of suffering another hip fracture, and efforts should be taken to minimize this risk.¹ These efforts should not only focus on increasing her bone mineral density (BMD), but should also involve interventions to prevent falls and protect the hip.²

The occurrence of a hip fracture as a result of a fall in this patient indicates that she has osteoporosis. Ideally, this patient should undergo DEXA (dual-energy x-ray absorptiometry) scanning to assess her BMD to establish the diagnosis of osteoporosis and to obtain a baseline BMD reading for future follow-up. Obtaining DEXA assessments in the nursing home setting, however, is often not possible for logistical reasons. For practical reasons, the diagnosis of osteoporosis in nursing home residents is often based on clinical grounds (eg, history of hip fracture in this patient).

In order to prevent further bone deterioration, individuals with osteoporosis should receive adequate amounts of calcium and vitamin D, exercise regularly, stop smoking, and limit alcohol intake. Current recommendation for calcium intake in this patient is 1500 mg of elemental calcium a day if she is not receiving estrogen replacement therapy and 1200 mg of elemental calcium a day if she is receiving estrogen replacement therapy.³ A typical nursing home diet provides only about 800 mg of elemental calcium a day.⁴ In addition, most institutionalized older adults, including this patient, are in a low-vitamin-D status secondary to inadequate diet, decreased sun exposure, and an age-related decline in the production of the active form of vitamin D, 1,25(OH)2 D. This, combined with strong published evidence that calcium and vitamin D supplementation protect against hip fractures in institutionalized eldlery,⁵ indicates that this patient should receive calcium and vitamin D supplementation. There is also evidence that vitamin D supplementation decreases the incidence of falls in older adults.⁶ This is probably attributed to neuromuscular function in older adults at risk of falling.⁷

There are currently three oral bisphosphonates approved by the FDA for the treatment of postmenopausal osteoporosis: alendronate, risedronate, and ibandronate. Alendronate is available in a 10-mg daily dose and a 70-mg weekly dose. Risedronate is available in a 5-mg daily dose and a 35-mg weekly dose. Both of the daily doses of alendronate and risedronate have been shown to prevent vertebral and nonvertebral fractures, including hip fractures in postmenopausal women with osteoporosis.^8-10 The efficacy of the weekly doses of both drugs on hip fractures in this patient population was not tested but was believed to have the same protective effect as the daily doses. Ibandronate is available in a 2.5-mg daily dose and a 150-mg monthly dose. Ibandronate has been shown to have a protective effect against vertebral fractures in postmenopausal women with osteoporosis.¹¹ The effect of ibandronate on hip fractures in postmenopausal women has not yet been tested. However, considering its demonstrated potency on BMD, ibandronate is thought to have a protective effect against hip fractures similar to that of risedronate and alendronate.¹¹

Teriparatide or PTH (1-34) is another potent drug available for the treatment of osteoporosis that has been shown to have protective effects against both vertebral and nonvertebral fractures in postmenopausal women with osteoporosis.¹² Teriparatide, however, needs to be injected subcutaneously daily and should not be given for more than 2 years, as its long-term safety has not yet been determined. A recent study showed that concurrent use of teriparatide and a bisphosphonate (alendronate) is not synergistic and could reduce the anabolic effect of teriparatide.¹³ Teriparatide should be reserved for patients with very low BMD and administered only for a short period.

Estrogen is another drug that has been shown to be effective in preventing hip fractures in postmenopausal women. The Women’s Health Initiative randomized, controlled trial demonstrated a significant protective effect of estrogen against hip fracture (estimated hazard ratio of 0.66).¹⁴ However, data from the trial indicated that the use of conjugated equine estrogen was not associated with a net benefit in women considered at high risk of fractures when considering the effects of hormone therapy on other important disease outcomes.¹⁵ The side effects attributed to estrogen use in this trial (notably the increased risk of coronary heart disease, stroke, and breast cancer) were likely influenced by the formulation of estrogen used (conjugated equine estrogen), which is unnatural to the human body. Estradiol is the primary estrogen produced by the human ovaries and is currently available in the form of skin parches, tablets, and creams. The risk versus benefits of estradiol is yet to be determined.

Other medications shown to prevent bone deterioration in postmenopausal women include calcitonin and the selective estrogen receptor modulator raloxifene. These two drugs have been shown to decrease the incidence of spine fractures, but not hip fractures.^16,17

In conclusion, this patient needs to have BMD assessment by DEXA scanning, if possible. However, the inability to obtain BMD assessment should not delay starting pharmacotherapy. She needs to receive calcium and vitamin D supplementation as well as be prescribed a bisphosphonate. A short course of teriparatide may be indicated if the patient has very low BMD ( < -3 SD), cannot tolerate bisphosphonate therapy, or if she failed bisphosphonate therapy as demonstrated by continuing worsening of BMD or sustaining an osteoporotic fracture while taking a bisphosphonate. In addition to pharmacotherapy, an interdisciplinary effort that involves facility staff education, environmental modification, exercise programs designed to improve strength and balance, supplying aids, reviewing drug regimens (to minimize the use of psychotropics and eliminate polypharmacy), having post-fall problem-solving conferences, and providing hip protectors should be implemented in this patient, as these interventions combined have been shown to decrease the risk of falling and hip fractures.^18,19