Cementless Oxford unicompartmental knee replacement shows reduced radiolucency at one year

Abstract

We randomised 62 knees to receive either cemented or cementless versions of the Oxford unicompartmental knee replacement. The implants used in both arms of the study were similar, except that the cementless components were coated with porous titanium and hydroxyapatite. The tibial interfaces were studied with fluoroscopically-aligned radiographs. At one year there was no difference in clinical outcome between the two groups. Narrow radiolucent lines were seen at the bone-implant interfaces in 75% of cemented tibial components. These were partial in 43%, and complete in 32%. In the cementless implants, partial radiolucencies were seen in 7% and complete radiolucencies in none. These differences are statistically significant (p < 0.0001) and imply satisfactory bone ingrowth into the cementless implants.

The incidence of physiological radiolucency following Oxford unicompartmental knee replacement and its relationship to outcome

“…Thermal necrosis due to the heat of 44 (10) 45 ( polymerisation of cement and the resulting bone resorption has been suggested, 9 although some 23 but not all 24 studies, have reported a higher incidence of tibial radiolucent lines in cementless than in cemented UKRs. 23 There is some evidence that pulsed lavage may reduce the incidence of the former, suggesting that the cementing technique may influence their occurrence.…”

Long-term clinical results of the Oxford medial unicompartmental knee arthroplasty

“…The designers demonstrated recently [16] that their incidence of radiolucent zones at one year was as high as 75%. In contrast, only 23% of the tibial implants in our study showed up a lucent line.…”

Extended sagittal saw cut significantly reduces fracture load in cementless unicompartmental knee arthroplasty compared to cemented tibia plateaus: an experimental cadaver study

“…Another advantage of cementless implants is that operation time can be considerably reduced. Moreover, a published series indicates that the incidence of radiolucent lines could be significantly reduced with the use of cementless, porous, coated components and that cementless Oxford implants seem to be as effective as cemented ones [6,8]. The cementless tibial component of the Oxford implant is identical to the cemented version, except that its lower surface carries a layer of porous titanium with a calcium hydroxyapatite (HA) coating ( Fig.…”

“…The cementless tibial component of the Oxford implant is identical to the cemented version, except that its lower surface carries a layer of porous titanium with a calcium hydroxyapatite (HA) coating ( Fig. 1) [8]. In young and active patients in particular, a high implant durability and biological fixation is desirable.…”