It has been postulated that orthopedic implants might predispose dogs and humans to subsequent bone tumor formation. The mechanism is thought to be related to bone turnover, chronic inflammation, or presence of metallic implants. However, a direct causal relationship has not been established. This case control study reviewed 19040 cases of dogs that underwent open fracture repair, those that had surgical treatment of a joint luxation, and those that developed osteosarcoma (OSA). OSA cases were only included if they were diagnosed >1 year after fracture repair. During the 30-year time period, 19 040 dogs underwent fracture repair. OSA was diagnosed in 6565 cases, 13 of which had a prior fracture at the site >1 year prior to the time of OSA diagnosis. The femur was affected in 12/13 cases, and the remaining case involved the carpus. The risk of OSA in dogs with fracture repair was no greater than those with a joint luxation reduction; in both cases, the relative risk was 1.0.