Operative management of periprosthetic patella fractures: A case series.

BACKGROUND

Periprosthetic patella fractures (PPPFs) following total knee arthroplasty (TKA) are rare but challenging complications associated with poor outcomes and high failure rates. Optimal surgical fixation strategies remain unclear, particularly in the setting of compromised bone stock and extensor mechanism disruption.

QUESTIONS/PURPOSES: We aimed to (1) evaluate clinical and radiographic outcomes following operative fixation of PPPFs, (2) compare results across fixation methods, and (3) assess functional recovery using extension lag, ambulation status, and PROMIS Physical Function scores.

METHODS

We retrospectively reviewed 15 patients who underwent open reduction and internal fixation (ORIF) for PPPFs between 2018 and 2025, with ≥3 months of follow-up. Data collected included patient demographics, fixation technique, fracture pattern, component status, and time to surgery. Outcomes assessed were radiographic and clinical union, complications, reoperations, extension lag, ambulatory status, and change in PROMIS Physical Function scores. Fixation methods included plate and screws (n= 6), tension band wiring (n= 5), and cerclage techniques (n= 4).

RESULTS

Clinical union was achieved in 13 of 15 patients (87 %), and radiographic union in 10 of 15 (67 %). Reoperation occurred in 6 patients (40 %), most commonly for hardware irritation. Patients treated with plate fixation had the highest rate of radiographic union (4 of 6) and no reoperations. Mean change in PROMIS Physical Function score was +4.2 for plate fixation, -3.6 for cerclage, and +0.2 for tension band wiring. Notably, four patients developed significant extensor lag (≥20°).

LEVEL OF EVIDENCE: Level IV, therapeutic case series.