Canine total hip replacement using a cementless threaded cup and stem: a review of 55 cases

Abstract

Objectives: To determine the long-term results and complications associated with the Helica^® cementless hip endoprosthesis system.

Materials and methods: Retrospective study of 55 consecutive Helica total hip replacements performed between January 2010 and February 2015.

Results: A total of 55 total hip replacements were performed in 50 dogs; 45 dogs had unilateral hip replacements, and five had staged bilateral replacements. A total of 23 first-generation short femoral stems were implanted in 22 dogs, of which nine cases (39%) experienced complications and 19 (86%) recovered satisfactorily when revisions were included; 31 second-generation femoral stems were implanted in 28 dogs, of which 10 cases (32%) experienced complications, and 26 (93%) made satisfactory recoveries, including revisions. In 36 dogs for which data were available, postoperative Liverpool Osteoarthritis in Dogs scores were significantly reduced compared to preoperative scores. Complications occurred in a total of 19 cases (34·5%; 95% confidence interval: 22 to 47·1%); the most common was aseptic loosening of the femoral stem [11 cases (20%; 95% confidence interval: 9·4 to 30·6%)]. Following multivariable analysis, no risk factors were identified for overall complications, but there was a significant association of implant type (first-generation short stem) with loosening (odds ratio 4·9, 95% confidence interval: 1·1 to 22·1, P=0·034).

Clinical significance: This study found the Helica hip endoprosthesis system to be effective in the management of hip dysplasia and osteoarthritis in dogs. Aseptic loosening of the femoral stem remains the most common complication but appears to have been significantly reduced with the introduction of the second-generation stem.