Osteosarcoma incidence in dogs following a tibial plateau levelling osteotomy

Question In dogs, does undergoing a tibial plateau levelling osteotomy (TPLO) compared to not undergoing a TPLO affect the future risk of developing osteosarcoma? Clinical bottom line Category of research: Risk. Number and type of study designs reviewed: One experimental study, designed as a matched case control. Strength of evidence: Weak. Outcomes reported: Only one study is appropriately designed to investigate a TPLO and associated osteosarcoma risk. This study found a 40-fold increased risk in dogs with a history of TPLO, compared to dogs that had not undergone a TPLO (OR, 40.65; 95% CI, 4.04 to 409.06; P = 0.002). Conclusion: There is weak yet preliminary indication to suggest a TPLO increases a dog’s risk of developing osteosarcoma later in life. However, with such a wide confidence interval, the true effect remains unclear. Additional matched case-control studies are needed to strengthen knowledge of this correlation, however until this time osteosarcoma should be considered as a differential diagnosis in post-TPLO dogs which present with lameness and/or proximal limb swelling.