DOS Kongressen 2014 ·
191
HA-coating may decrease screw migration in the
femoral head following hip fracture surgery –
a double blinded RSA study
Henrik Palm, Kim Holck, Steffen Jacobsen, Søren Bøvling, Torben Bæk-Hansen,
Maiken Stilling
Dept. of Orthopedics, Copenhagen University Hospital Hvidovre
Background:
Sliding hip screw (SHS) migration in the femoral head after hip
fracture surgery may lead to fracture collapse and/or screw cut- out neces-
sitating a reoperation.
Purpose / Aim of Study:
To investigate if a hydroxyapatite (HA) coated thread
could reduce SHS migration.
Materials and Methods:
37 patients (31 female) at mean age 79 (range 56-
96) years with stable trochanteric fractures were operated in two centers with
a 4-hole 135-degrees SHS (HipLoc, Biomet) and randomly allocated to slid-
ing screws with either a non-coated (n=19) or an HA- coated (Bonemaster,
Biomet) screw-thread (n=18). Patients and assessors were blinded for choice
of screw. Patients were followed after 1.5, 3 and 6 months with marker-based
RSA comparing migration between 1) The sliding screw marked with 4 beads
and 2) The femoral head marked with 3-5 beads inserted through the drilled
SHS canal. Demographic, surgical and radiological parameters (TAD, fracture
reduction sum and screw placement in the femoral head) were prospectively
collected.
Findings / Results:
Mean TAD of 2.1 (sd 0.66) mm, fracture reduction sum in
AP and LA of mean 0.66 (sd 0.87) mm and screw position in the femoral head
were similar between groups (p>0.28). Screws with HA-coated thread had less
varus rotation (4.1 vs. 0.3 degrees, p=0.03) after 1.5 months and a reduced
lateral translation (0.6 vs. 0.01 mm, p=0.046) after 6 months, with a tendency
after 1.5 months (0.4 vs. 0.2 mm, p=0.08). Other translations and rotations
were not different and there were no correlation to radiological parameters. No
cut-outs or revisions.
Conclusions:
Coating the SHS thread with HA reduced screw migration in the
femoral head at short- term follow-up. Missed late follow-ups might under-
power statistics at 3 and 6 months. Migrations were small and larger clinical
studies are warranted for evaluation of long- term benefits.
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