Femoral medullary infarction prevalence with the Zurich Cementless Canine Total Hip arthroplasty.
OBJECTIVE
To document the prevalence of femoral medullary infarction associated with the Zurich Cementless Total Hip Replacement (ZCTHR) system in dogs.


METHODS
Case series.


METHODS
Dogs (n=35) with 41 ZCTHR implants.


METHODS
Medical records (February 1999-December 2002) were reviewed for dogs that had ZCTHR and at least 1 year follow-up with radiographic evaluation. Thirty-five dogs (41 ZCTHR) met the inclusion criteria. Femoral morphologic data, implant to bone relationships, and medullary infarcts were recorded. Data were analyzed for associations between infarct occurrence and morphologic details and dog characteristics.


RESULTS
Eight of 41 femurs had radiographic evidence of infarcts (19.5%). Dogs with infarcts were significantly younger (mean [+/-SD] age, 18.5+/-5.2 months) compared with those without infarction (mean age, 44.4+/-5.6 months; P=.027). None of the other variables were significantly different between dogs with and without infarcts. Three femurs with infarcts ultimately developed stem loosening.


CONCLUSIONS
A higher prevalence of femoral medullary infarcts was identified with ZCTHR compared with incidence reported for other total hip systems. Younger dogs were more likely to develop infarction.


CONCLUSIONS
Femoral infarction appears to be associated with stem loosening. Adjustments in surgical technique or delaying surgery beyond 18 months of age may reduce incidence of infarction but needs further evaluation.
Marsolais
Gregory S
GS
Monterey Peninsula Veterinary Surgical Service, Carmel, CA, USA.
Peck
Jeffrey N
JN
Berry
Clifford
C
Johnson
Ann
A
D000818:Animals; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects / Q000379:methods / Q000662:veterinary*; D004283:Dog Diseases / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000601:surgery; D004285:Dogs; D005260:Female; D005269:Femur / Q000098:blood supply*; D006622:Hip Prosthesis / Q000009:adverse effects / Q000662:veterinary; D015994:Incidence; D007238:Infarction / Q000453:epidemiology / Q000517:prevention & control / Q000662:veterinary*; D008297:Male; D011183:Postoperative Complications / Q000453:epidemiology / Q000517:prevention & control / Q000662:veterinary*; D015995:Prevalence; D011859:Radiography; D012189:Retrospective Studies