Trabecular metal collars in endoprosthetic replacements: do they osseointegrate?

Area of Science:

• Orthopaedic Oncology
• Biomaterials Engineering
• Surgical Reconstruction

Background:

• Limb salvage surgery (LSS) is the standard treatment for primary bone malignancy, aiming to preserve the limb.
• Endoprosthetic replacements (EPRs) are utilized in LSS to reconstruct bone defects and avoid amputation.
• Trabecular metal (TM) collars are designed to promote osseointegration (OI) of EPRs into the host bone.

Purpose of the Study:

• To evaluate the occurrence and extent of osseointegration (OI) in trabecular metal (TM) collars used in endoprosthetic replacements (EPRs) for bone tumors.
• To assess the long-term efficacy of TM collars in facilitating bone ingrowth within EPRs for limb salvage surgery.

Main Methods:

• Radiographic analysis of 81 patients who underwent EPR with TM collars for bone tumors.
• Independent review of radiographs at 3, 12 months, and last follow-up using a modified Stanford Radiological Assessment System.
• Assessment of osseointegration and radiolucency at the bone:collar junction.

Main Results:

• Osseointegration (OI) of the TM collar was observed in approximately 65% of patients.
• The rate of OI remained consistent across 3-month, 12-month, and long-term follow-up periods.
• While radiolucency at the bone:collar junction occurred in some cases, progression was minimal in the long term.

Conclusions:

• Osseointegration (OI) is achieved in a significant proportion (approximately 65%) of trabecular metal collars used in endoprosthetic replacements for bone tumors.
• The degree of OI is stable over time, suggesting the effectiveness of TM collars in promoting bone ingrowth.
• TM collars demonstrate a favorable safety profile regarding radiolucency progression at the bone-collar junction in limb salvage surgery.