The 24 to 48 Hour Window for Hip Fracture Surgery
Older adults with a hip fracture face roughly 1 in 4 odds of dying within a year, and every day spent waiting in bed for the OR adds exposure to pressure sores, pneumonia and death.
Key terminology
- Femoral neck fracture
- Break through the narrow bridge between the femoral head and the shaft, inside the hip capsule - a displaced one can cut off blood supply to the head
- Intertrochanteric fracture
- Break between the greater and lesser trochanters, outside the hip capsule - blood supply is rich, so it is usually fixed with a nail or screw rather than replaced
- Propensity-matched
- Each early-surgery patient paired with a later-surgery patient of similar age, health and injury - an observational study's attempt to compare like with like
- Post hoc
- An analysis chosen after the trial data were in rather than planned at the start - a signal worth testing in a new trial, never proof on its own
- AAOS
- The US professional society for orthopedic surgeons - publishes the clinical practice guidelines most US surgeons follow
- NICE
- National Institute for Health and Care Excellence, the UK body that writes national treatment guidelines for the NHS
Takeaways
- Hip fracture in an older adult carries about 1 in 4 odds of death within a year. A Finnish population cohort of patients 65 years and older found 27.3% 1-year postoperative mortality, an all-cause mortality rate 3-fold higher than the general population, and men faring worse than women (HR 1.55) (Panula et al, BMC Musculoskelet Disord 2011;12:105, PMID 21599967).
- Observational meta-analyses tie early surgery to fewer deaths and fewer pressure sores. Moja et al pooled 35 studies and 191,873 patients (cutoff mostly 24-48 h), giving an odds ratio of 0.74 for death (0.67-0.81) and 0.48 for pressure sores, and Simunovic et al's adjusted analysis of 4208 patients found relative risk 0.81 for death and 0.59 for in-hospital pneumonia (Moja et al, PLoS One 2012;7:e46175, PMID 23056256; Simunovic et al, CMAJ 2010;182:1609-1616, PMID 20837683).
- Population data put the inflection point at 24 h. In an Ontario cohort of 42,230 patients across 72 hospitals, every measured complication rose once the wait passed 24 h, with propensity-matched 30-day mortality of 6.5% versus 5.8% (absolute difference 0.79%) and death or medical complication in 12.2% versus 10.1% (Pincus et al, JAMA 2017;318:1994-2003, PMID 29183076).
- Whether 24 h or 48 h is the cutoff remains unsettled. Klestil et al pooled 28 prospective studies totaling 31,242 patients and found that surgery within 48 h lowered 12-month mortality (RR 0.80, 0.66-0.97), while surgery within versus after 24 h did not reach significance (RR 0.82, 0.67-1.01) (Klestil et al, Sci Rep 2018;8:13933, PMID 30224765).
- The only large RCT found no benefit from surgery within 6 h. HIP ATTACK randomized 2970 patients across 69 hospitals in 17 countries to a median time to surgery of 6 h (accelerated) versus 24 h (standard, IQR 10-42), with 90-day mortality 9% versus 10% (HR 0.91, 0.72-1.14) and major complications 22% in both arms, though this compares very fast against fast, not waits past 48 h (HIP ATTACK Investigators et al, Lancet 2020;395:698-708, PMID 32050090).
- A post hoc HIP ATTACK analysis suggests patients with myocardial injury may gain the most from speed. Among patients with a measured troponin, 23% had it elevated on arrival, and in this subgroup mortality was 10% with accelerated surgery versus 23% with standard care (HR 0.43, 0.24-0.77), though the authors state this finding is hypothesis generating only and needs confirmation (Borges et al, J Bone Joint Surg Am 2024;106:2303-2312, PMID 39052767).
- AAOS and NICE set different clocks. AAOS 2021 strongly recommends surgery within 24-48 h of admission (allowing for hospital resources), while NICE CG124 calls for surgery on the day of, or the day after, admission, and directs correctable comorbidities such as anemia, anticoagulation, volume depletion and electrolyte abnormalities to be treated immediately so surgery is not delayed (O'Connor and Switzer, J Am Acad Orthop Surg 2022;30:e1291-e1296, PMID 36200817; NICE CG124 guideline 2011).
- Most delays are due to the system, and those delays still cost lives. In a Nottingham cohort of 5414 patients 60 years and older, 38.5% waited more than 36 h (27.5% OR capacity versus 11.0% medical unfitness), and a purely logistical delay was associated with a 1-year mortality HR of 1.20 (1.06-1.36); an Australian series found OR availability caused 60% of delays beyond 48 h (Busby et al, Bone Joint J 2026;108-B:1021-1028, PMID 42538006; Sarkies et al, Bone Jt Open 2025;6:876-885, PMID 40759410).