Long-term outcomes of 10 dogs weighing less than 4 kg after Zurich mini-cementless total hip arthroplasty.

Objective: To assess the long-term clinical outcomes of mini-cementless total hip arthroplasty (THA) for treating various hip joint disorders in dogs weighing <4 kg.

Study design: Retrospective, single-center, consecutive case series.

Animals: A total of 10 dogs from various breeds.

Methods: Medical records from 2022 to 2024 were reviewed for dogs weighing <4 kg with coxofemoral disease that was characterized by degenerative changes and treated with THA using the Zurich cementless total hip mini system (Z-THR mini system). Data collected included findings from follow-up orthopedic examinations and radiography performed at 0, 3, 6, and 52 weeks postoperatively and an owner questionnaire (Helsinki Chronic Pain Index [HCPI]) administered preoperatively and at 52 weeks postoperatively.

Results: A total of 10 THA procedures, nine of which were completed, were performed in eight dogs. Nine THA procedures were considered successful, with no evidence of lameness or decreasing HCPI at the 52-week follow-up. In one case, a cup could not be placed; therefore, THA was not completed.

Conclusion: THA using Z-THR mini resulted in clinically favorable long-term outcomes in dogs weighing <4 kg, based on this study.

Clinical significance: Although femoral head and neck ostectomy is the most commonly used procedure for severe hip disease, particularly in small dogs, our results suggest that THA can be an acceptable alternative to femoral head and neck ostectomy (FHNE), even in dogs weighing less than 4 kg.