title: Variables affecting initial stability of impaction grafting for hip revision.
abstract: Impaction grafting allows restoration of bone stock in hip revision, but there are reports of massive early subsidence. The aim of this study was to determine prognostic factors for stem and cup migration in a group of 56 consecutive patients followed up from 1 to 5 years. Cup and stem migration was correlated with 13 predictors including stem design, stem positioning, femoral anatomy, patient characteristics, and bone graft density. All migration occurred mainly during the first 3 months after surgery. Stem alignment changed by an average of 4.8 degrees . Fifty percent of the change in stem alignment was explained by four variables: age, femoral diameter, stem design, and density of the graft at the tip of the stem. Stem subsidence averaged 2.7 mm, and cup migration averaged 3.0 mm. None of the predictors explained the wide variation of migration of the cup or distal migration of the stem. It may be necessary to determine implant stability at the time of surgery.
authors.affiliation: Princess of Wales Hospital, Bridgend, UK.
authors.forename: Satish
authors.initials: S
authors.lastname: Gokhale
authors.forename: Ayman
authors.initials: A
authors.lastname: Soliman
authors.forename: João Pedro
authors.initials: JP
authors.lastname: Dantas
authors.forename: James Bruce
authors.initials: JB
authors.lastname: Richardson
authors.forename: Frank
authors.initials: F
authors.lastname: Cook
authors.forename: Jan-Herman
authors.initials: JH
authors.lastname: Kuiper
authors.forename: Peter
authors.initials: P
authors.lastname: Jones
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000379:methods*; D019544:Equipment Failure Analysis; D005260:Female; D005500:Follow-Up Studies; D005548:Foreign-Body Migration / Q000517:prevention & control; D006621:Hip Joint / Q000000981:diagnostic imaging; D006801:Humans; D007593:Joint Instability / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D010043:Outcome and Process Assessment, Health Care; D011474:Prosthesis Design; D011475:Prosthesis Failure; D011859:Radiography; D016896:Treatment Outcome