Functional outcome of femoral peri prosthetic fracture and revision hip arthroplasty: a matched-pair study from the New Zealand Registry.

Background And Purpose: The number of periprosthetic fractures following total hip arthroplasty (THA) is increasing. There is, however, limited data on the functional outcome following these injuries. We analyzed functional outcome for revision THA following periprosthetic fracture, and compared this to the outcome of elective revision THA performed for aseptic loosening.

Methods: 232 patients undergoing revision THA for femoral fracture were identified from the New Zealand National Registry. Functional outcome was measured using the Oxford 12 hip score (OHS). A reference group of 232 patients undergoing elective revision THA was selected and matched for age and sex.

Results: Outcome was worse following revision THA for periprosthetic fracture than in reference patients (mean OHS: 29 vs. 24, p = 0.006). A higher 6-month mortality rate was seen in periprosthetic fracture patients (7.3% vs. 0.9%, p < 0.001), along with a higher likelihood of re-revision (7.3% vs. 2.6%, p = 0.06).

Interpretation: This large comparative series of periprosthetic fractures following THA shows that patients with periprosthetic fracture have poorer functional outcome and higher death rates than patients undergoing revision THA for aseptic loosening.