Intraoperative fracture of the femur in revision total hip arthroplasty with a diaphyseal fitting stem.
BACKGROUND
In revision total hip arthroplasty, intraoperative split fractures and cortical perforation fractures are becoming a more common concern with the increasing use of diaphyseal fitting cementless stems. The purpose of this study was to evaluate the risk factors and frequency of intraoperative fractures with the use of these stems and their effect on radiographic and functional outcomes.


METHODS
We performed a retrospective case-control study of 211 consecutive patients who had undergone revision hip arthroplasty with a diaphyseal fitting cementless stem between December 1998 and March 2002. Sixty-four patients sustained an intraoperative fracture of the femur. One hundred and fifteen patients were followed for a minimum of two years; function was analyzed with self-administered outcome questionnaires, and radiographs were evaluated for evidence of bone ingrowth into the femoral stem.


RESULTS
Risk factors associated with an intraoperative fracture were a substantial degree of preoperative bone loss, a low femoral cortex-to-canal ratio, underreaming of the cortex, and the use of a large-diameter stem. The majority of the diaphyseal undisplaced linear fractures occurred at the distal end of an extended trochanteric osteotomy during stem insertion. Fracture due to cortical perforation occurred most often during cement removal. These intraoperative fractures had no significant effect on the functional outcome or radiographic evidence of bone ingrowth.


CONCLUSIONS
There was a surprisingly high rate of intraoperative femoral fractures associated with the use of a diaphyseal fitting stem in revision total hip arthroplasty. Identification of risk factors such as preoperative bone loss and a low cortex-to-canal ratio may permit planning to avoid such fractures. However, the final functional and radiographic outcomes appear to have been unaffected by the fracture when it had been managed appropriately.


METHODS
Prognostic study, Level II-1 (retrospective cohort study). See Instructions to Authors for a complete description of levels of evidence.
Meek
R M Dominic
RM
Southern General Hospital, 1345 Govan Road, Glasgow, Scotland. rmdmeek@doctors.org.uk.
Garbuz
Donald S
DS
Masri
Bassam A
BA
Greidanus
Nelson V
NV
Duncan
Clive P
CP
D000203:Activities of Daily Living; D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects* / Q000295:instrumentation / Q000379:methods; D001843:Bone Cements; D001862:Bone Resorption / Q000209:etiology; D015897:Comorbidity; D018483:Diaphyses; D005260:Female; D005264:Femoral Fractures / Q000145:classification / Q000000981:diagnostic imaging / Q000209:etiology* / Q000601:surgery; D005593:Fracture Fixation, Internal / Q000295:instrumentation / Q000379:methods; D006622:Hip Prosthesis / Q000009:adverse effects*; D006801:Humans; D008297:Male; D015207:Osteoarthritis, Hip / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery; D010027:Osteotomy / Q000009:adverse effects / Q000379:methods; D011474:Prosthesis Design; D011475:Prosthesis Failure; D011859:Radiography; D012086:Reoperation / Q000009:adverse effects*; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D016896:Treatment Outcome
D001843:Bone Cements