Surgical delay as a risk factor for wound infection after a hip fracture

Analysis of significant risk factors for mortality and for medical and orthopaedic complications.

Observational study of a prospective consecutive cohort of 697 patients diagnosed of hip fracture from December 2012 to December 2014. Average age was 85±9years and 520 were female (75%). Intracapsular fractures (308, 44%) were treated non-operatively, (19 patients), with cannulated screws (58) or with hip arthroplasty (228 bipolar, 3 total hip atrhoplasty). Extracapsular fractures (389, 56%) were reduced and fixed with 375 trochanteric nails and 14 sliding-hip-screw-plates. Patients were controlled clinically and radiographically in outpatient clinic after 1, 3, 6 and 12months. Bivariate analysis (Pearson, Mann-Whitney, Wilcoxon) was applied to study statistically significant relations, and Odds Ratio were calculated.

Surgical delay reached 2.1±2.2days, 1.7±1.9 in medically stable patients. Main reason for delay was anticoagulant/anti-platelet therapy. Immediate weight-bearing was begun for 72% of patients. Average time in-hospital was 12±8days and 63% returned to previous environment. Lost-to-follow-up reached 4% after 1month and 8% after 6months. After 1year, 6% of previously-walking patients were unable to walk. Mortality reached 4% while in-hospital and 14% after 1year, with older age as only significant risk factor (p=0.004), OR=1.9. Wound infection developed in 2.3% of the series, and surgical delay longer than 24hours was a significant risk factor (p=0.023), with an OR=3.48 (1.1-10.8). Fixation failed in 7.9% of cannulated screws and 1.9% of trochanteric nails (1.1% cut-out, 0.8% nail fracture), while 2.7% of arthroplasty patients suffered a prosthesis dislocation and 1.3% a periprosthetic fracture. Pyelonephritis appeared in 6.7%, pneumonia in 6.3% and cardiac failure in 2.2% of patients; significant risk factors were previous comorbidity for pneumonia (p=0.007) (OR=2.7) and cardiac failure (p=0.007) (OR=9.7), as well as older age (p=0.006) (OR=2.2) for pneumonia.

Surgical delay longer than 24hours has been an important risk factor for wound infection, a finding not previously described in literature. Older age is a significant risk factor for mortality and pneumonia, and previous comorbidity for cardiac failure and pneumonia.