Abstract
Introduction and aims: The extent of primary total hip and knee replacement revisions in the first 2 weeks following surgery is unknown. This study reports the incidence and reasons for revision of primary total hip and knee replacements within that period.
Method: Data was obtained from the Australian Orthopaedic Association National Joint Replacement Registry (AOA NJRR). The AOA NJRR began data collection in September 1999, becoming national during 2002. This is an analysis of patients whose conventional primary total hip and/or primary total knee replacement and subsequent revision are recorded by the AOA NJRR with a procedure date on or before the 31st December 2006. Patient demographics, method of fixation used in the primary procedure as well as reasons for revision, and type of revision (major or minor) were analysed.
Results: The analysis involved 104,234 conventional primary THR and 134,799 primary TKR. There were 286 revisions (0.27%) of primary THRs and 102 revisions (0.076%) of primary TKRs in the first 2 weeks following surgery. The risk of revision was significantly higher for THR than TKR (P< 0.0001).
Dislocation (44.1%) was the main reason for revision of primary THR in the first 2 weeks after surgery followed by fracture (26.8%) and loosening (16%). The main reason for revision of primary TKR was infection (39%) followed by loosening (18%) and fracture (8.6%).
Most revisions of primary THRs in the first 2 weeks were major (66.4%). When only one major component was revised it was mainly the femoral stem (32.9% of all revisions). Almost all of these were cementless (94.7%). When a revision of a primary TKR occurred the majority were minor (69.6%) (p< 0.001). The insert (64.7% of all revisions) was the main component revised.
Risk factors associated with primary THR revision include a diagnosis of developmental dysplasia (P=0.030) and cementless procedures had a significantly higher risk of revision than either cemented (P< 0.0001) or hybrid (P< 0.0001) procedures. We did not identify any risk factors associated with primary TKR in the first 2 weeks following surgery.
Conclusions: The number of revisions of primary THR and TKR within the first 2 weeks of surgery remains small with approximately 1.6 per 1,000 procedures revised. The risk of revision was significantly greater for THR than TKR. Surgical technique was the main reason for revision of primary THR and infection for primary TKR.
The abstracts were prepared by David AF Morgan. Correspondence should be addressed to him at davidafmorgan@aoa.org.au
Declaration of interest: a
