Treatment Failure After Repair of Displaced Femoral Neck Fractures in Patients compared by “Decade of Life”: An Analysis of 565 Cases in Adults Less than 60 Years Old

OBJECTIVES: To study the results of displaced femoral neck fractures (FNFs) in adults less than 60 years of age by comparing patients, injury, treatment, and the characteristics of treatment failure specifically according to patients’ age at injury, i.e. by their “decade of life” (i.e. “under 30” [29 years and younger], “the 30’s” [30 to 39 years], “the 40’s” [40 to 49 years], and “the 50’s” [50 to 59 years]). METHODS: Design: Multicenter retrospective comparative cohort series Setting: 26 North American Level 1 Trauma Centers. Patient Selection Criteria: Skeletally mature patients aged 18 to 59 with operative repair of displaced FNFs. Outcome Measures and Comparisons: Main outcome measures were treatment failures (fixation failure and/or nonunion, osteonecrosis, malunion, and the need for subsequent major reconstructive surgery (arthroplasty or proximal femoral osteotomy). These were compared across decades of adult life through middle age (<30 years old, 30 to 39 years, 40 to 49 years, and 50-59 years). RESULTS: Overall, treatment failure was observed in 264 of 565 (47%) of all hips. The mean age was 42.2 years, 35.8% of patients were female, and the mean Pauwels’ angle was 53.8°. Complications and the need for major secondary surgeries increased with each increasing decade of life assessed: 36% failure occurred in 36% of patients ages <30 years, 40% in the 30’s, 48 in the 40’s, and 57% in the 50’s, respectively; p <0.001). Rates of osteonecrosis increased with decades of life (under 30’s and 30’s vs. 40’s vs. 50’s developed osteonecrosis in 10%, 10%, 20%, and 27% of hips, p <0.001), while fixation failure and/or nonunion only increased by decade of life to a level of trend (p =0.06). Reparative methods varied widely between decade-long age groups, including reduction type (open vs. closed, p<0.001), reduction quality (p=0.030), and construct type (cannulated screws (CS) vs. fixed angle devices,p=0.024), while some variables evaluated did not change with age group. CONCLUSIONS: Displaced FNFs in young and middle-aged adults are a challenging clinical problem with a high rate of treatment failure. Major complications and the need for complex reconstructive surgery increased greatly by decade of life with the patients in their 6th decade experiencing osteonecrosis at the highest rate seen among patients in the decades studied. Interestingly, treatments provided to patients in their 50’s were notably different than those provided to younger patient groups. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.