Clinical Report: Prognostic Nutritional Index and Functional Status in Hip and Distal Femur Fractures

Overview

This study evaluated the relative predictive value of the Prognostic Nutritional Index (PNI) and functional status on postoperative outcomes in geriatric patients with hip and distal femur fractures. Functional status was found to be a more critical predictor of 30-day mortality and prolonged length of stay than PNI. The analysis included over 81,000 patients aged 65 and older from the ACS-NSQIP database.

Background

Hip fractures (HFs) and distal femur fractures (DFFs) are common fragility fractures in the elderly, associated with high morbidity, mortality, and healthcare costs. Nutritional status, assessed by the Prognostic Nutritional Index (PNI), and functional capacity are important factors influencing surgical outcomes. While PNI has been validated in elective orthopedic surgeries, its predictive value in acute trauma settings remains uncertain due to inflammatory responses. Functional status is also a known predictor of postoperative outcomes, but its comparative importance relative to PNI in fragility fractures has been underexplored.

Data Highlights

Key Findings

• Functional status was a stronger predictor of 30-day mortality and prolonged length of stay than PNI in geriatric patients with hip and distal femur fractures.
• Patients classified as totally or partially dependent had significantly worse postoperative outcomes compared to independent patients.
• PNI, calculated from serum albumin and total lymphocyte count, showed limited predictive utility in the acute trauma setting due to inflammatory influences.
• Approximately 29.4% of the cohort were male and 78.2% identified as White, with a median age of 81 years.
• Prolonged length of stay was defined as greater than 7 days, with the mean length of stay being 6.5 days.
• Multivariable logistic regression models included interaction terms between PNI and functional status to assess combined effects on outcomes.

Clinical Implications

Assessment of functional status should be prioritized over PNI when evaluating preoperative risk in elderly patients with hip and distal femur fractures. While nutritional status remains important, reliance on PNI alone may be insufficient due to confounding inflammatory responses in acute trauma. Incorporating functional capacity into risk stratification can better inform perioperative management and discharge planning.

Conclusion

Functional status is a more critical predictor than Prognostic Nutritional Index for postoperative mortality and length of stay in geriatric fragility fracture patients. Comprehensive preoperative evaluation should emphasize functional capacity to optimize outcomes.

References

1. ACS-NSQIP Database 2005-2021 -- Patient Data on Hip and Distal Femur Fractures
2. PNI Calculation Reference -- (10×serum albumin) + (0.005×total lymphocyte count)
3. Previous Studies on Mortality and Functional Status in Fragility Fractures