Oral Presentation 1st Asia Pacific Herbert Fleisch Workshop 2025

Histomorphometric markers of bone matrix and lacunocanalicular network alterations distinguish septic from aseptic osteolysis in revision arthroplasty. (#5)

Dzenita Muratovic 1 , Dongqing Yang 1 , Ryan D Quarrington 1 2 , Renjy Nelson 2 , Boopalan Ramasamy 1 3 , Bogdan Solomon 1 3 , Gerald Atkins 1
  1. Centre for Orthopaedic & Trauma Research, The University of Adelaide, Adelaide, South Australia, Australia
  2. The University of Adelaide, Adelaide, SA, Australia
  3. Orthopaedic and Trauma Service, The Royal Adelaide Hospital and the Central Adelaide Local Health Network, ADELAIDE, SA, Australia

Objective: Timely and accurate differentiation between septic osteolysis or prosthetic joint infection (PJI) and aseptic osteolysis (AO) remains a major clinical challenge in revision joint replacement surgery. To address this gap, we developed and validated novel histological methods targeting specific alterations in bone matrix integrity and the osteocyte lacunocanalicular network (LCN).

Design: Bone biopsies were collected from patients undergoing revision arthroplasty and classified postoperatively as PJI (n=13) or AO (n=13) based on clinical and microbiological criteria. Control bone (n=6) was obtained from patients undergoing primary joint replacement. Specimens were histologically processed and stained to evaluate bone matrix degradation and osteocyte LCN morphometric parameters, which can effectively distinguish between pathological groups.

Results: Quantitative analysis revealed significantly increased bone matrix degradation in PJI compared to control (p = .001) and AO (p < .001). PJI samples exhibited a higher lacunar area fraction (vs control: p = .03; vs AO: p = .01), increased lacunar circularity (vs control: p = .001; vs AO: p < .001), and greater lacunar width (vs control: p = .02). PJI bone also displayed marked disruption of the canalicular network, including reduced canalicular length (p < .001), width (p < .001), density (vs AO: p < .001), and area fraction (vs control: p = .006). Receiver Operating Characteristic (ROC) analysis demonstrated strong discriminative performance for several parameters in identifying PJI, with the highest AUROC values observed for bone matrix degradation (AUROC 0.93), lacunar circularity (AUROC 0.94), and canalicular width (AUROC 0.93).

Conclusions: These findings highlight distinctive histomorphological signatures of PJI bone, characterised by severe matrix degradation and profound LCN disruption. These features clearly distinguish PJI from aseptic failure and control bone. Furthermore, these histological biomarkers provide promising additional tools to support intraoperative and pathological diagnosis of PJI.