Abstracts Posters SICOT-SOF meeting Gothenburg 2010 _2_

Poster
Topic: Trauma - Hip
Abstract number: 23773
PREDICTIVE CHANGE TO SALVAGE SURGERY OF THE DHS DEVICE
Mohd Mashfiqul Arafin SIDDIQUI, Joyce KOH, Merng Koon WONG, Tet Sen HOWE
Singapore General Hospital, Singapore (SINGAPORE)
INTRODUCTIONThe dynamic hip screw (DHS) is a standard device for fixation of
intertrochanteric hip fractures. Cut out is one of the commonest mode of mechanical
failure for this device. In the literature, contributory factors to cut out are
osteoporosis, fracture type, fracture reduction and implant position.The aim of this
study is to determine if there are pre-operative factors which determine likely failure
of the DHS device and thus salvage surgery.METHODOLOGYAll patients who had a
DHS fixation for intertrochanteric fracture from July 2003-May 2005 were
retrospectively identified. Patients lost to follow-up or without appropriate radiographs
were excluded. X-rays were reviewed pre-operatively and post-operatively.
Osteoporosis, fracture pattern and quality of reduction were co-related with risk of cut
out.RESULTSThere were 155 patients. Seven patients cut out. Median time to cut
out was 26(SD12.6) weeks and median time to union was 2(SD1.1) months. There
was an increased risk of the DHS cut out if the medial calcar was not intact(p=0.007)
and tendency to cut out with fracture comminution(p=0.08).CONCLUSIONOur study
highlights the importance of an intact medial calcar and sufficient bony support in the
intertrochanteric region for the success of the implant. This is likely due to the fact
that the DHS is a sliding device that depends on compression around the
intertrochanteric region for fracture union. Patients with deficient medial calcar may
benefit from bone grafting, new implant design or even a hemiarthroplasty at initial
surgery.
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