Osteoporotic fractures and injurious accidental falls are associated with increased morbidity and mortality in older adults [1–4]. Proximal femoral fractures (PFF) are among the most common causes for acute admission to orthopaedic wards with a 30% mortality rate 12-months post surgery . Moreover, less than 50% of patients return to pre-fracture levels of mobility and independence, with older adults who survive a hip fracture being three times more likely to be functionally dependent, 50% requiring long-term assistance with routine functional activities and up to 25% requiring full-time residential care [5–7].
Malnutrition in the elderly is commonly overlooked in a clinical setting [8, 9]. There is an extremely high prevalence (up to 63%) of pre-existing malnutrition amongst PFF patients on acute admission to hospital [9, 10]. Malnutrition in this setting has consistently been demonstrated to lead to adverse patient outcomes through increasing the risk of postoperative complications , limiting participation in rehabilitation and delaying optimal recovery of ambulatory status and independence [12, 13]. Moreover, there is a marked decline in nutritional status in these patients throughout the acute admission, commencing within one week of admission and continuing for six to twelve weeks post surgery [14, 15].
Conventional nutritional management of PFF patients involves the provision of high energy, high protein diets, however the evidence for this approach is largely unconvincing. A systematic review of the literature highlighted that most nutrition support provided for PFF patients is based on the provision of a standard volume of high caloric oral supplement rather than individualised dietary requirements . One of the primary limitations of a standard approach is the failure to be patient orientated and tailor dietary therapy to each individual's energy and protein deficits associated with pre-existing malnutrition and inadequate dietary intakes post PFF surgery .
Weight loss in older adults, particularly loss of lean muscle, is highly predictive of increased morbidity and mortality [17–19]. Furthermore, rapid deconditioning of muscle may be responsible for secondary hospital readmissions, repeat injurious falls and loss of independence in older adults [20, 21]. Cachexia, characterized by disproportionate muscle wasting, associated with systemic inflammation and elevated plasma cytokines , is a plausible explanation for the inability of conventional nutrition support programs to generate an anabolic response in PFF patients. It is critical, therefore, that caloric and protein supplementation is supported with other aggressive treatment strategies in the treatment of cachexia [22, 23].
As a biomarker of cachexia, the magnitude of the inflammatory response post PFF surgery, and interventions to reduce this response, has not been adequately investigated. The normal physiological response to a major insult, such as the trauma of PFF and the subsequent surgical repair, is characterized by the activation of the hypothalamic pituitary adrenal axis and sympathetic nervous system with simultaneous activation of the immune system and systemic inflammation . Persistent inflammation among patients recovering from PFF is recognized as a major contributing factor to poor patient outcomes post surgery . Specifically, the combination of stress hormones and pro-inflammatory cytokines promotes catabolism and malnutrition, and impairs normal gastrointestinal functioning such that macronutrient utilization may be compromised . Moreover, inflammation in this population group is predictive of a decrease in physical functioning, the onset of disability and mortality [27–30].
Due to their anti-inflammatory properties and potential to suppress the metabolic consequences of PFF, fish oils are a relatively simple and promising therapeutic strategy for the treatment of cachexia in this population group. Provision of adequate fish oil in conjunction with adequate energy and protein could theoretically improve outcomes for PFF patients. Fish oils, more specifically eicosapentaenoic (EPA) and docosahexanoic (DHA) acids, have been extensively studied for their anti-inflammatory properties in inflammatory conditions including rheumatoid arthritis  and cardiovascular disease . However, the novel therapeutic benefit of fish oils in patients with end-stage disease is also attracting wider attention with research suggesting that fish oils may ameliorate cachexia in patients with advanced cancer . One proposed mechanism of the anti-inflammatory action of fish oils is impairment of the release of acute phase proteins and pro-inflammatory cytokines, in particular C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor-∝ (TNF-∝) and interleukin-1 (IL-1) .
The aim of the present randomised controlled trial (RCT) is to implement a 12 week, individualised nutrition program complemented with an anti-inflammatory dose of fish oil (20 ml/day containing 3.6 g EPA and 2.4 g DHA), commencing 7 days post PFF surgery that will result in clinically important and statistically significant improvements in terms of quality of life, appetite, body composition and physical function. Comparisons will be drawn with a control group receiving 10% of the active fish oil dose.