DOS Kongressen 2014 ·
185
Preparation of the femoral bone cavity for
cementless stems: Broaching versus Compaction.
A 5 year randomized RSA and DXA study of 40
bilateral 1-stage operations
Mette Holm Hjorth , Maiken Stilling , Kjeld Søballe , Poul Torben Nielsen,
Poul Hedevang Christensen, Søren Kold
Department of Orthopaedics , Aarhus University Hospital
Background:
Experimental studies have shown superior implant fixation after
bone compaction (C) compared to conventional broaching (B).
Purpose / Aim of Study:
To investigate potential advantages and disadvan-
tages of C compared to B in a randomized clinical trial (RCT)
Materials andMethods:
1-stage bilateral cementless THA (Bi-Metric, Biomet)
was performed in 20 patients (13 M), mean age 58 (36-70) years. Patients
were randomized to bone preparation with C on one side and B on the other
side. Patients were followed with RSA and DXA at baseline, 6 and 12 weeks, 1,
2 and 5 years. The subjective part of Harris Hip Score (HHS) and complications/
revisions throughout the observation period were obtained at mean 6.3 (3-9.5)
years after surgery.
Findings / Results:
At 6 weeks, mean absolute mean medio/lateral transla-
tions of 0.22 (CI: 0.12 to 0.32) mm in the C group was higher (p=0.04) than
0.11 (CI: 0.07 to 0.16) mm in the B group. At 5 years, the difference was more
pronounced (p=0.01) with mean absolute medio/lateral translations in the C
group of 0.34 (CI: 0.18 to 0.39) mm versus 0.13 (CI; 0.05 to 0.28) mm in
the B group. At 2 years, mean values of percentage change in periprosthetic
bone since baseline in Gruen zone 3 was inferior in the C group of 92.6 (CI:
88.1 to 97.1) % versus 100.7 (CI: 93.6 to 107.8) % in the B group (p=0.04).
Intraoperative fractures occurred in 2/20 in the C group and in 0/20 in the B
group (p=0.02). Clinical outcomes of HHS and dislocations (1 C, 2B) were simi-
lar between groups (p>0.59). No stems were revised at 5 years after surgery.
Conclusions:
Bone compaction as compared to broaching prior to insertion of
the cementless Bi-Metric femoral stem results in more absolute medio/lateral
translation, starting already 6 weeks and continuing until 5 years follow-up. In
this RCT intraoperative femoral fractures only occurred with bone compaction.
132.
