Clinical guide

Complications in veterinary orthopedics: how to recognize, prevent and resolve them

By Prof. Antonio Gorios Filho, MSc, and Prof. Diogo Borges · SOMAVET – Bone Reconstruction Center

Summary: the most common complications after orthopedic surgery in dogs and cats are implant failure, delayed union and nonunion, infection and osteomyelitis, and residual deformity. Resolution depends on identifying the cause (mechanical, biological or infectious) before reoperating. In many revision cases, the Ilizarov circular fixator allows stabilization, infection control and alignment correction at the same time.

Why complications happen

Almost every orthopedic complication combines three origins: mechanical (insufficient stability for that patient and fracture), biological (poor blood supply, tissue loss, age, comorbidities) and infectious. Treating only the consequence, replacing the implant without understanding the cause, often leads to recurrence.

Plate, screw or pin failure

Loosening, breakage or migration of implants indicates that the load on the fracture exceeded what the construct could withstand, or that healing did not progress in the expected time. Before reoperating, assess alignment, bone quality, signs of infection and the reason for instability.

Delayed union and nonunion

When a fracture does not heal, the decision starts with classification: nonunion with good biology (which mainly needs stability) or with poor biology (which also needs biological stimulation, such as bone grafting). The circular fixator allows controlled compression or distraction at the site and early weight bearing.

Infection and osteomyelitis

Implant-associated infection is among the hardest complications, because bacteria are protected in biofilm on the metal. It usually requires removing contaminated implants, debridement, culture sampling and maintaining stability with fixation away from the infected site. Reconstruction of the bone defect comes later, once infection is controlled.

TPLO complications

Reported complications after TPLO include surgical site infection, implant failure, tibial tuberosity fracture, late meniscal injury and alignment changes. Cases with persistent infection or fixation failure usually require a planned revision strategy, not just implant replacement.

Residual deformity and shortening

Malunion or shortening compromises limb function and overloads adjacent joints. Planning identifies the center of the deformity and defines whether correction will be acute or gradual, through distraction osteogenesis.

Planning revision surgery

• Define the cause: mechanical, biological, infectious or combined.
• Obtain complete imaging and, when possible, CT with 3D planning.
• Take cultures when infection is suspected.
• Choose stabilization based on the remaining bone and soft tissue, not on the previous implant.
• Plan aftercare: adjustments, radiographic controls and owner involvement.

Referral and second opinion

Complex cases benefit from discussion among colleagues. Equipe Somavet (Brazil) accepts referrals from veterinarians and keeps the referring colleague involved. Pet owners can also request a second opinion through the clinical care page.

FAQ

Informational content for veterinarians. Management depends on the assessment of each patient.