The effects of different weight-bearing regimes on press-fit cup stability: a randomised study with five years of follow-up using radiostereometry
Wolf, O., Mattsson, P., Milbrink, J. et al.Hip
Purpose
There is little evidence to support immediate weight bearing after uncemented total hip arthroplasty (THA).
Methods
Thirty-seven patients with unilateral osteoarthritis of the hip received a press-fit cup. Cup stability was assessed with radiostereometry (RSA) over five years. Patients were randomised to immediate full weight bearing, or partial weight bearing for three months.
Results
At five years, we found no difference in micromotion as assessed with radiostereometry. Numerically, there was more proximal translation and increased inclination with immediate weight bearing, but these values barely exceeded the precision limit for the method. Pooled data for the two groups revealed translations of 0.1-0.3 mm and rotations of 0.2-0.3° over the five year follow-up period.
Conclusions
We found no adverse effects of immediate weight bearing after THA in relation to stability of these press-fit cups. Early mobilisation might have other advantages.
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