Abstract
Aim
The purpose of this study was to perform a randomised controlled trial (RCT) to compare the >20 year outcomes of cemented versus cementless Mallory Head total hip replacements (THRs).
Methods
Two hundred and fifty patients with unilateral osteoarthritis of their hip, a mean age of 64 years and 48% of whom were female were randomised to receive either a cemented (n=124) or cementless (n=126) THR.
Results
At >20 years follow-up, the cementless Mallory Head THR outperformed its cemented counterpart in terms of overall Kaplan Meier survivorship (p=0.01), socket survivorship (p=0.009) and stem survivorship (p< 0.0001). Age significantly affected acetabular socket revision rates for both cementless (>65 - 12% versus < 65 - 36%, p=0.003) and cemented (>65 - 19% versus < 65 - 55%, p< 0.0001) sockets. Male gender adversely affected cementless (males - 31% versus females - 12%, p=0.01), but not cemented (males - 35% versus females - 36%, p=1.000) socket survivorships. For the femoral stems, age did not affect cementless stem survivorship (>65 - 0% versus < 65 - 2%, p=0.465), but did so with cemented stems (>65 - 16% versus < 65 - 33%, p=0.001). Gender did not influence cementless or cemented stem survivorships.
Conclusion
This RCT has demonstrated that cementless THRs offer significantly better overall, socket and stem survivorships at 20 or more years. The cementless tapered femoral stem performed particularly well with 100% survivorship at 20 years, excluding infections. Caution should be taken in generalising these results to other cemented and cementless THRs.
