DOS BULLETIN - Dansk Ortopædisk Selskab

2010-378_DOS nr. 3 2010 29/09/10 10:08 Side 97
Bone density in relation to failure in patients with
osteosynthesized femoral neck fractures
Bjarke Viberg, Jesper Ryg, Jens Lauritsen,
Søren Overgaard, Ole Ovesen
Department of Orthopaedic Surgery and Traumatology, Odense University
Hospital and Institute of Clinical Research, University of Southern
Denmark; Department of Geriatrics, Odense University Hospital
Background: The treatment of femoral neck fracture with internal fixation
(IF) is recommended in younger patients and has compared to
arthroplasty the advantage of retaining the femoral head. A big problem
with osteosynthesis is though failure. Finding predictors for fixation
failure is still an ongoing process and osteoporosis has been suggested
as a predictor.
Purpose: To correlate bone mineral density (BMD) in regard to failure
of IF in osteosynthesized femoral neck fractures.
Methods: In a health technology assessment study from 2005-2006 at
Odense University Hospital, Department of Orthopaedic Surgery and
Traumatology, 177 patients with femoral neck fractures accepted DEXA
–scanning of the hip and lumbar spine assessing BMD. Final follow-up
were 01.08.2010 and 142 patients with IF comprised the final cohort.
The cohort consisted of 106 females and 36 males with a mean (CI) age
of 77,1 (75,3-78,9). Failure is defined as revision surgery or new fracture.
Findings: 69 patients had a t-score (total hip) below -2,5 SD as defined
for osteoporosis. At 1 year the overall (dislocated) failure rate was 34,3
% (44,2 %), at 2 years 45,1 % (59,4 %) and at end of follow-up 49,2 %
(62,1 %). In the cox regression analysis the following factors for failure
were significant: dislocated fracture, osteosynthesis placement and prior
fracture. There were no association for total hip BMD, neck BMD, age,
sex, quality of fracture reduction, walking disability, independent living,
alcohol or smoking. A cox regression sub analysis of the undisplaced
fractures showed significant result only for osteosynthesis placement.
Conclusion: There is no association between BMD and failure of internal
fixation in osteosynthesized femoral neck fractures.
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