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 of Age.

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, that is, by their "decade of life" [ie, "under 30" (29 years and younger), "the 30s" (30-39 years), "the 40s" (40-49 years), and "the 50s" (50-59 years)].

Design: Multicenter retrospective comparative cohort series.

Setting: Twenty-six North American Level 1 Trauma Centers.

Patient Selection Criteria: Skeletally mature patients aged 18-59 years 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, 30-39 years, 40-49 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 women, and the mean Pauwels angle was 53.8 degrees. Complications and the need for major secondary surgeries increased with each increasing decade of life assessed: 36% of failure occurred in patients <30 years of age, 40% in their 30s, 48% in their 40s, and 57% in their 50s (P < 0.001). Rates of osteonecrosis increased with decades of life (under 30s and 30s vs. 40s vs. 50s 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 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 sixth decade experiencing osteonecrosis at the highest rate seen among patients in the decades studied. Interestingly, treatments provided to patients in their 50s were notably different than those provided to younger patient groups.

Level Of Evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.