Long-term outcomes following closed reduction and internal fixation of femoral neck fractures with cannulated screws in patients under 65 years

Background: The long-term studies for femoral neck fractures (FNFs) in young patients treated with closed reduction and internal fixation (CRIF) are limited. This study aimed to evaluate the long-term outcomes of a group of young patients (<65 years) with FNFs treated with CRIF at our department during the last decade. We estimated treatment failure rates and identified risk factors for poor outcomes. Methods: This retrospective cohort study included patients under 65 with a unilateral FNF treated with CRIF using partially threaded cannulated screws (CSs) between 2011 and 2021. During the latest follow-up visit, we recorded the patients' complications, re-admissions, reoperations, functional outcomes, and quality of life scores. Results: We included 52 patients with a mean age of 53.04 years and a mean follow-up of 5.3 (range: 1.3-11) years. No non-union was recorded. Nine patients (17.3 %) underwent total hip arthroplasty (THA) due to femoral head avascular necrosis (AVN) at an average of 1.68 years following the index operation (THA group). The mean age (p =0.96), trauma type (p =0.290), sex prevalence (p =0.989), Garden classification (p =0.187), CSs number (p =0.751), and comorbidities (p =0.516) were comparable between THA and non-THA groups. Time from trauma to index surgery was significantly shorter for the THA than the non-THA group (p =0.03). Conclusions: During a mid-to-long follow-up, 17.3 % of patients under 65 years who were treated with CRIF and CSs for FNFs developed AVN. Age, trauma type, comorbidities, time from trauma to treatment, and the number of screws did not affect the outcomes.