Function, sarcopenia and osteoporosis 10 years after a femoral neck fracture in patients younger than 70 years

BACKGROUND AND PURPOSE: A femoral neck fracture (FNF) may have long-term effects on the patient's function, also in patients younger than 70 years. These long-term effects are not well described, since most studies have short follow-ups. The aim of this study was to investigate clinical outcome by performance-based functional tests, hand grip strength, and hip function in different subgroups. The secondary aim was to study surgical complications, bone mineral density (BMD) and occurrence of sarcopenia 10 years after a FNF. PATIENTS AND METHODS: A prospective multicenter study with a 10-year follow-up of patients aged 20-69 years with a FNF treated with internal fixation (IF). Five-times sit-to-stand test (5TSST), 4-m walking speed test, hand grip strength (HGS) and Harris Hip Score (HHS) were performed. A radiographic examination of the hip was performed and re-operations were registered. Bone mineral density (BMD) at the hip, spine and total body composition were assessed with dual energy x-ray absorptiometry (DXA). Present sarcopenia was determined by the combination of reduced functional performance and low fat-free mass index (FFMI). RESULTS: A total of 58 patients were included. 5TSTS was normal in 45% of the patients and old age was associated with poorer performance (p<0.001). 76% of the study population had a normal speed gait and likewise, old age (p = 0.005) and walking aids (p = 0.001) were associated with poor performance. HGS was normal in 82% of the men and 64% of the women. HHS showed that 85% had a good/excellent function. A major re-operation was performed in 34% of the patients with displaced FNF and in 20% of patients with non-displaced FNF. 74% displayed osteopenia and 12% osteoporosis. 17% of the men and 38% of the women had sarcopenia. INTERPRETATION: The majority of patients less than 70 years of age with a FNF treated with IF, had normal functional tests, muscle strength and a good hip function ten years post-operatively. However, one in ten had osteoporosis, and one third was sarcopenic which indicate the importance of encouraging regular muscle preserving resistance training after hip fracture.