Secondary Prevention of Low-Trauma Fractures: In Search of an Effective Solution

From the Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA.

Abstract

• Objective: To review and summarize the literature regarding current approaches to secondary prevention of low-trauma osteoporotic fractures.
• Methods: PubMed search and summary of existing literature related to complications and secondary prevention of osteoporotic fractures was performed.
• Results: Fragility fractures are associated with high rates of short and long term morbidities and carry a high risk of mortality and fracture recurrence. Several of the currently available anti-osteoporosis medications have been shown to decrease the risk of fracture recurrence in patients with prevalent osteoporotic fractures and some may even decrease mortality. However, only a minority of patients with fragility fractures are adequately evaluated and treated for osteoporosis. Fracture liaison services that ensure identification and risk stratification of patients with fragility fractures and proper evaluation and treatment of osteoporosis have proven effective at enhancing osteoporosis care in these patients, decreasing fracture recurrence and possibly even decreasing long-term mortality, while providing long-term cost savings. Unfortunately, however, this model of care has not been widely adopted and implemented.
• Conclusion: Fragility fractures represent a major health care problem for aging populations. Unfortunately, most patients with low-trauma fractures still receive suboptimal osteoporosis care.

Key words: osteoporosis; fracture; fragility; low-trauma; bone density.

Low-trauma fractures are fractures that occur from a trauma equivalent to a fall from standing height or less [1,2]. They can involve any skeletal site, but the most significant are vertebral, pelvic, wrist and hip fractures, which together represent close to 90% of all low-trauma fractures [3,4]. The overall burden of low-trauma fractures is quite high worldwide and is projected to increase over time [3–6]. In 2010, 3.5 million new low-trauma fractures were reported in the European Union [3]. In the United States, there were more than 2 million fractures in 2005, and it is estimated that more than 3 million fractures will occur in year 2025 [4].

Low-trauma fractures are generally indicative of compromised bone strength—especially when they involve the hip—and are thus often referred to as fragility fractures. While the traditional definition of osteoporosis is a bone mineral density (BMD) T-score of -2.5 or lower, low-trauma fractures of the hip are also diagnostic of osteoporosis, regardless of bone mineral density [2,7–9]. In addition, low-trauma fractures of the vertebrae, the proximal humerus, and the pelvis are considered diagnostic of osteoporosis when combined with T-scores between -1 and -2.5 [2,7]. Bone biopsies and high-resolution peripheral quantitative computed tomography (HR-pQCT) in patients with low-trauma fractures and normal BMD suggest microarchitectural alterations and abnormalities of collagen orientation and crosslinking within the bone matrix [10-12], leading to decreased bone strength.

This review will address the individual and societal costs of low-trauma fractures and issues related to secondary prevention of fractures, with specific emphasis on pharmacotherapy and fracture liaison services.

Impact of Low-Trauma Fractures

Acute and Long-Term Complications

Of all fragility fractures, hip fractures are the ones most likely to result in serious acute complications. The most common acute complications are delirium in up to 50% of patients and malnutrition in up to 60%, both of which predict slower and less complete recovery [13–16]. Other complications include urinary tract infections in up to 60% of patients in certain reports [17], thromboembolic disease with deep venous thrombosis in around 27% of patients and pulmonary embolism in up to 7% [16], and acute kidney injury in about 15% [18].

In addition, it is not uncommon for patients to suffer from significant long-term functional limitations following fragility fractures. While vertebral fractures do not frequently lead to hospitalization or institutionalization, they often lead to significant physical limitations and chronic pain [19,20] and to negative effects on self-esteem, mood, and body image [21,22]. However, the most remarkable functional decline and limitations are seen after hip fractures [23–25]. In a study of 2800 women and men with hip fracture, Beringer et al found that more than 30% were still institutionalized, and only 40% were able to walk outdoors independently 1 year later. Predictors of poor outcome included male sex, advanced age, cognitive impairment, and presence of comorbidities [23].

It is not surprising then that a fracture is often associated with an overall decline in the individual’s quality of life and this has been demonstrated in several studies [26–28]. In the largest study of this type, Tarride et al examined over 23,000 patients with fragility fractures and found a sharp decline in health-related quality of life (HRQOL) immediately after the fracture, which remained below baseline for up to 3 years [26]. The decline was worse in patients with hip and spine fractures compared to other fractures [27].