Modular Revision of a Failed Patient-Specific 3D-Printed Scapulo-Humeral Endoprosthesis in a Dog with Proximal...

Area of Science:

• Veterinary Orthopedics
• Surgical Oncology
• Biomaterials Engineering

Background:

• Canine appendicular osteosarcoma (OSA) often necessitates limb amputation, which can be challenging in dogs with concurrent osteoarthrosis (OA).
• Limb-sparing surgery with patient-specific implants (PSIs) offers an alternative, but data on proximal humeral reconstruction durability and revision is limited.

Purpose of the Study:

• To describe the feasibility and outcomes of using 3D-printed PSIs for limb-sparing surgery in a dog with proximal humeral OSA and concurrent OA.
• To evaluate implant durability, functional recovery, and potential salvage strategies following implant failure.

Main Methods:

• A 9-year-old dog with proximal humeral OSA and severe hip OA underwent limb-sparing surgery using 3D-printed patient-specific guides and endoprostheses.
• Postoperative assessment included functional recovery monitoring, implant integrity evaluation, and histopathological analysis.
• Revision surgery was performed using a novel modular 3D-printed endoprosthesis after initial implant failure.

Main Results:

• Initial surgery resulted in favorable functional recovery with weight-bearing for 8 months.
• Implant failure occurred at 9 months due to fracture at the distal humeral fixation.
• Revision surgery restored limb function for an additional 6 months; the dog was euthanized due to metastatic disease.
• Post-mortem assessment revealed osseointegration with no local recurrence or infection.

Conclusions:

• 3D-printed PSI-based limb-sparing reconstruction is a feasible option for proximal humeral OSA in dogs, particularly when amputation is contraindicated.
• Mechanical fatigue represents a significant limitation for PSIs in this region.
• Modular revision strategies utilizing additive manufacturing show promise for salvage after implant failure.