Page 169 - DOS Kongressen 2012 - Abstracts

129.
Bone Cement with Initial Slow-Curing Increases Stability of Tibial
Trays in TKR
Maiken Stilling, Frank Madsen, Claus Fink Jepsen, Kjeld Søballe, Anders
Odgaard
Department of Orthopaedics Aarhus University Hospital; Department of
Orthopaedics, Aarhus University Hospital; Department of Orthopaedics,
Aarhus University Hospital; Department of Orthopaedics, Aarhus University
Hospital; Department of Orthopaedics, Aarhus University Hospital
Background:
Viscosity of Refobacin Plus Bone Cement (RP) is slightly
reduced during the initial working-phase, as compared with Refobacin Bone
Cement R (RR), which may reduce porosity of the cement during vacuum
mixing and enhance durability and life-time of cemented prostheses.
Purpose / Aim of Study:
to compare fixation of tibial trays fixed with two
different curing bone cements.
Materials and Methods:
54
patients (21 men) at a mean age of 67 years
(
range 44-83) with knee osteoarthritis (but no osteoporosis) were operated with
the Vanguard® Complete Knee System (Biomet Inc) and were randomly
allocated to implant fixation with either RP or RR. Both cements contained
gentamycin and were mixed with the closed Optipac® mixing system. At 3
and 6 months, 1 and 2 years we evaluated implant migration, periprostheric
bone mineral density (BMD) in 3 regions, and clinical outcomes (AKSS and
OKS).
Findings / Results:
At 2 years follow-up Maximum Total Point Motion was
lower (p=0.04) for tibial trays fixed with RP (0.76 mm, SD 0.65, n=27)
compared to fixation with RR (0.97 mm, SD 0.51, n=27). The periprosthetic
BMD loss up to 2 years was similar between the groups in 3 regions and in
total on AP (p>0.70) and LA DXA scans (p>0.30). The bone loss was 3.5%
(
SD 13%) medial to the stem, 2% (SD 9%) lateral to the stem, 4% (SD 19%)
anterior to the stem, 7% (SD 19%) posterior to the stem and 2% (SD 6%)
below the stem. Mean knee-score (88, SD 10), function-score (84, SD 13),
OKS (39, SD 5) and improvement (pre-op to 2 years) was similar (p>0.18).
Mean flexion was 117° (range 85-145). Satisfaction was high.
Conclusions:
Fixation of tibial trays inserted with the initial slow-curing
Refobacin Plus Bone Cement is superior to fixation with standard-curing
Refobacin Bone Cement R at 2 years follow-up. Loss of periprosthetic BMD
was small and functional results were good.