The Frank Stinchfield Award: Dislocation in revision THA: do large heads (36 and 40 mm) result in reduced dislocation rates in a randomized clinical trial?
BACKGROUND
Dislocation after revision THA is a common complication. Large heads have the potential to decrease dislocation rate, but it is unclear whether they do so in revision THA.


OBJECTIVE
We therefore determined whether a large femoral head (36 and 40 mm) resulted in a decreased dislocation rate compared to a standard head (32 mm).


METHODS
We randomized 184 patients undergoing revision THA to receive either a 32-mm head (92 patients) or 36- and 40-mm head (92 patients) and stratified patients by surgeon. The two groups had similar baseline demographics. The primary end point was dislocation. Quality-of-life (QOL) measures were WOMAC and SF-36. The mean followup for dislocation was 5 years (range, 2-7 years); the mean followup for QOL was 2.2 years (range, 1.6-4 years).


RESULTS
In the 36- and 40-mm head group, the dislocation rate was 1.1% (one of 92) versus 8.7% (eight of 92) for the 32-mm head. There was no difference in QOL outcomes between the two groups.


CONCLUSIONS
Our observations confirm a large femoral head (36 or 40 mm) reduces dislocation rates in patients undergoing revision THA at short-term followup. We now routinely use large heads with a highly crosslinked polyethylene acetabular liner in all revision THAs.


METHODS
Level I, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
Department of Orthopaedics, University of British Columbia, 910 West 10th Avenue, Room 3114, Vancouver, BC V5Z 4E3, Canada. garbuz@shaw.ca
Donald S
DS
Garbuz
Bassam A
BA
Masri
Clive P
CP
Duncan
Nelson V
NV
Greidanus
Eric R
ER
Bohm
Martin J
MJ
Petrak
Craig J
CJ
Della Valle
Allan E
AE
Gross
D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects / Q000295:instrumentation*; D001363:Awards and Prizes; D002170:Canada; D005260:Female; D005270:Femur Head / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D006622:Hip Prosthesis; D006801:Humans; D004204:Joint Dislocations / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D008297:Male; D020959:Polyethylene / Q000737:chemistry; D011446:Prospective Studies; D011474:Prosthesis Design; D011788:Quality of Life; D011859:Radiography; D020127:Recovery of Function; D012086:Reoperation; D011795:Surveys and Questionnaires; D013997:Time Factors; D016896:Treatment Outcome
D020959:Polyethylene