BackgroundThe incidence and number of fragility hip fractures are gradually increasing, resulting in a wide consumption of medical resources. Various factors affecting functional recovery in patients with fragility hip fractures are known, and comorbid diseases are one of them. The purpose of this study is to determine the effect of comorbidities on functional outcomes in patients surgically treated for fragility hip fractures, thereby contributing to the efficient distribution of medical resources.MethodsThis was a retrospective cohort study performed in the three tertiary rehabilitation facilities. A total of 211 patients (50 men and 161 women; average age 81.6 ± 6.7 years) who had undergone surgery for fragility hip fractures were followed up from immediately after transfer to the Department of Rehabilitation Medicine to 6 months postoperatively. Comorbidities referred to a summary of the following conditions: hypertension, diabetes mellitus, chronic liver disease, dementia, cerebrovascular accident, and osteoporosis. Functional outcomes included Koval’s grade, Functional Ambulatory Category (FAC), Functional Independence Measure (FIM)-locomotion, Modified Rivermead Mobility Index, Berg Balance Scale (BBS), 4-Meter Walking speed Test (4MWT), the Korean version of the Mini-Mental State Examination(K-MMSE), Geriatric Depression Scale (GDS), EuroQol Five-Dimension (EQ-5D) questionnaire, the Korean version of the Modified Barthel Index (K-MBI), the Korean version of the Instrumental Activities of Daily Living (K-IADL), and Korean version of Fatigue, Resistance, Ambulation, Illnesses, and Loss of weight scale (K-FRAIL). For all tests, each patient was assessed immediately after transfer and 6 months post-surgery.ResultsMultivariate linear regression analyses adjusted for age, sex, the initial variable of the functional outcomes, and comorbidities revealed that dementia had a significant negative impact on Koval’s grade and K-FRAIL 6 months postoperatively. Diabetes mellitus had a significant negative impact on the FAC, GDS, EQ-5D, K-IADL, and K-FRAIL 6 months postoperatively. Patients with osteoporosis showed a significant negative outcome of FIM-locomotion 6 months postoperatively. A cerebrovascular accident revealed a significant negative impact on the BBS 6 months postoperatively. In addition, hypertension led to significantly less favorable outcomes of the K-FRAIL 6 months postoperatively.ConclusionsThis study confirmed that comorbidities, particularly dementia and diabetes mellitus, significantly influence functional outcomes 6 months after fragility hip fracture surgeries.