DOS Kongressen 2014 ·
145
RSA-measured rotation across SHS-treated
trochanteric fractures - is the anti-rotation screw
obsolete?
Maiken Stilling, Torben Bæk-Hansen, Bøvling Søren, Steffen Jacobsen,
Kim Holck, Henrik Palm
Department of Orhopaedics, Regional Hospital Holstebro, Hospital Unit West
Background:
Rotation across trochanteric fractures treated by a sliding hip
screw (SHS) remains controversial, and measurement is difficult. Some surgeons
add a so-called anti-rotation screw, but the indication is questionable.
Purpose / Aim of Study:
To investigate the amount of, and possible predictors
for, rotation across SHS-treated stabile trochanteric fractures by use of RSA.
Materials and Methods:
24 patients (21 female) at mean age 76 (56-91)
years with SHS-treated stabile trochanteric fractures were followed postop,
1.5, 3 and 6 months after surgery with marker-based RSA and measurement
of fracture migration between the femoral head/neck and the trochanter/shaft
fragment. EGS- RSA was used to transfer the rotation axis in line with the slid-
ing screw. Screw position within the femoral head was assessed into thirds as
high/central/low in AP and posterior/central/anterior in LA post- operative ra-
diographs.
Findings / Results:
No cut-outs or revisions were observed. Average rotation
across the fracture around the sliding screw was 0.6 (sd 7.1) degrees, and rota-
tion stopped at 6 weeks (p>0.24). 7 patients with non-central screw position
(3 with a low AP screw position, 4 with an LA anterior or posterior screw posi-
tion) had higher rotation compared with 17 patients with central screw place-
ment in two planes (mean 5.3 (sd 4.5) vs. 1.5 (sd 7.1) degrees, p=0.01). Low
positioned screws with mean rotation of 8.8 (sd 3.8) degrees had the most
rotation (p=0.02). Other translations and rotations were not correlated with
screw position.
Conclusions:
Overall rotation across the trochanteric fracture was small, but
depended on SHS position, with most rotation following a low-positioned screw.
If the SHS is correctly positioned in the central third of the femoral head in both
AP and LA radiographs, adding an anti-rotation screw appears obsolete.
92.
