Hip fractures in young adults are rare but represent an important cohort of patients, of which relatively limited data exists. The aim of this study was to evaluate this distinct subgroup of hip fractures from an epidemiological perspective and assess their subsequent outcomes.

Patients aged 18–50 were identified across an 8 year period from a total of 5326 hip fractures. 46 hip fractures met the inclusion criteria and a retrospective case series analysis was conducted.

25/46 (54%) of fractures were intracapsular and 21/46 (46%) were extracapsular. Only 15/46 (33%) of fractures were sustained from a high energy mechanism and 31/46 (67%) low energy. The low energy cohort was significantly more comorbid with a mean Elixhauser comorbidity score of 1.5 compared to the high energy cohort 0.3 (p<0.0005, unpaired t-test). Alcohol excess was the most prevalent comorbidity present in 24% of patients and was a positive predictor in complication (p=0.006, binary regression). Failure of fixation (non-union/avascular necrosis) in displaced intracapsular fractures sustained following low energy trauma managed by internal fixation 5/11 (45%) was markedly higher than the high energy cohort 0/6 (0%). 5 year mortality was 9% for all hip fractures, six times higher than an aged matched cohort of non-hip fractures (p=0.007, Wilcoxon test).

Representing only 0.86% of all hip fractures in the study period, hip fractures in young adults are rare. A clear sub-division of patients is observed between patients with a low and high energy mechanism, both in terms of level of comorbidity and surgical outcome.