Internal fixation or hip replacement for undisplaced femoral neck fractures? Pre-fracture health differences reflect survival and functional outcome

What is the Fate of Undisplaced Femoral Neck Fractures Treated With Cannulated Screws?

BACKGROUND

We aimed to report implant survival in Garden type I and II femoral neck fractures treated with cannulated screws in elderly patients.

METHODS

We retrospectively studied 232 consecutive unilateral Garden I and II patients (232 fractures) treated with cannulated screws. Mean age was 81 years (range, 65 to 100), and a body mass index of 25 (range, 15.8 to 38.3). No between-group differences were found in demographic variables and/or baseline measurements (P > .05). Mean follow-up was 36 months (range, 1 to 171). Two observers measured baseline radiographic variables with good-to-excellent interobserver reliability. The posterior tilt angle, measured on a cross-table lateral x-ray, was used to classify the cohort into <20° (n = 183) and ≥20° (n = 49). The cumulative incidence with competing risk analysis was used to predict association between posterior tilt and subsequent conversion to arthroplasty. Patient survival was calculated with the Kaplan-Meier estimate.

RESULTS

Implant survival was 86.3% (95% confidence interval (CI) 80 to 90) at 12 months and 77.3% (95% CI 64 to 86) at 70 months. The 12-month cumulative incidence failure was 12.6% (95% CI 8 to 17). After controlling for confounders, posterior tilt ≥20° had higher risk of subsequent arthroplasty when compared to posterior tilt <20° (38.8 [95% CI 25 to 52] versus 5% [95% CI 2.8 to 9], subhazard ratio 8.3, 95% CI 3.8 to 18), without any other radiologic or demographic factor being associated with failure. Patient survival was 88.2% (95% CI 83 to 91.7) at 12 months, 79.5% (95% CI 73 to 84) at 24 months, and 57% (95% CI 48 to 65) at 70 months.

CONCLUSION

Cannulated screws were a reliable treatment for Garden I and II fractures, except when there was posterior tilt ≥20°, where arthroplasty should be considered.

Conversion to Arthroplasty After Internal Fixation of Nondisplaced Femoral Neck Fractures: Results from a Swedish Register Cohort of 5,428 Individuals 60 Years of Age or Older

BACKGROUND

Although most nondisplaced or minimally displaced femoral neck fractures are routinely treated with internal fixation, high rates of secondary surgical procedures are common, especially in the elderly population. Primary arthroplasty in elderly patients has been proposed as an alternative treatment to reduce the need for a secondary surgical procedure. The objective of this study was to describe the rate of conversion to arthroplasty within 5 years after internal fixation of nondisplaced femoral neck fractures in patients ≥60 years of age.

METHODS

In this observational cohort study of prospectively collected data from the Swedish Fracture Register (SFR) between 2012 and 2018, cross-matched with the Swedish Arthroplasty Register (SAR), 5,428 nondisplaced femoral neck fractures in patients ≥60 years of age were included. Competing risk analysis was used to estimate conversion rates to arthroplasty and mortality in various age groups at 1, 2, and 5 years.

RESULTS

The cumulative incidence function (CIF) for conversion to arthroplasty was 6.3% at 1 year, 8.1% at 2 years, and 10.1% at 5 years. The conversion rates within 2 years were 6.5% in 60 to 69-year-olds, 9.6% in 70 to 79-year-olds, and 7.8% in ≥80-year-olds. Women had a higher risk of conversion; the hazard ratio (HR) was 1.49 (95% confidence interval [CI], 1.19 to 1.87). The cumulative mortality was 21.3% (95% CI, 20.3% to 22.5%) at 1 year, 31.3% (95% CI, 30.0% to 32.6%) at 2 years, and 54.9% (95% CI, 53.1% to 56.7%) at 5 years. Mortality was higher in men at all time points, and the adjusted 1-year HR was 1.79 (95% CI, 1.61 to 2.00).

CONCLUSIONS

One in 10 patients ≥60 years of age treated with internal fixation for a nondisplaced femoral neck fracture underwent conversion to arthroplasty within 5 years, and more than one-half of the conversions occurred within the first year. The risk of conversion was highest in women and in patients 70 to 79 years of age. These data warrant further studies in this frail patient group to identify subgroups of patients who would benefit from primary arthroplasty for nondisplaced femoral neck fractures.

LEVEL OF EVIDENCE

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