title: Acetabular cup liner and prosthetic head exchange to increase the head diameter for management of recurrent luxation of a prosthetic hip in two dogs.
abstract: Component malalignment and impingement are possible causes of recurrent luxation following total hip replacement in the dog. In the two cases presented in this report, luxation that was probably due to impingement was managed by exchanging the standard 17 mm prosthetic head for a 24 mm prosthetic head. This required removal of the original acetabular cup liner and placement of a new polyethylene liner that would accept the 24 mm head into the stable acetabular shell. In the first case, a 50 kg Malamute dog, recurrent luxation was initially managed by component alignment revision, iliofemoral suture, triple pelvic osteotomy and a novel lasso technique, without long-term success. After exchanging the head and cup liner, luxation did not recur over a 12-month period. In the second case, a 65 kg Newfoundland dog, impingement was suspected after a second luxation event. Luxation did not recur during the nine months after exchange of the head and cup liner. The larger prosthetic head used in these two cases increased the impingement-free range-of-motion of the joint and increased the translation distance required for luxation (jump distance).
authors.affiliation: Dr. Simon Roe, BVSc, PhD, DACVS, Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, 1052 William Moore Drive, Raleigh, NC, 27607, United States, Phone: +1 919 513 6334, Fax: +1 919 513 6336, E-mail: Simon_Roe@ncsu.edu.
authors.forename: S C
authors.initials: SC
authors.lastname: Roe
authors.forename: C
authors.initials: C
authors.lastname: Sidebotham
authors.forename: D J
authors.initials: DJ
authors.lastname: Marcellin-Little
mesh_terms: D000077:Acetabulum / Q000601:surgery*; D000818:Animals; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects / Q000295:instrumentation / Q000662:veterinary*; D004283:Dog Diseases / Q000601:surgery*; D004285:Dogs; D005260:Female; D006622:Hip Prosthesis / Q000662:veterinary; D004204:Joint Dislocations / Q000601:surgery / Q000662:veterinary*; D008297:Male; D011475:Prosthesis Failure; D012008:Recurrence
keywords: Total hip replacement; cup liner exchange; head diameter; impingement; luxation