| Abstrakt: |
Objective. Suboptimal fixation of the tibial component is one of the main factors leading to aseptic loosening in unicompartmental knee arthroplasty (UKA). Improvements in primary fixation in cemented UKA have been suggested to be a key issue for long-term survival. In this context, it has been questioned whether specific implant design features influence interface strength, lowering aseptic loosening and post-operative pain rates. The aim of this study is to compare two different tibial tray designs in cemented UKA in terms of clinical outcome, failures, implant survival, and complications. Materials and methods. This is a prospective consecutive study of two different tibial component fixation in 100 cemented UKA. 50 patients received a flat cemented tibial tray design, and 50 a two-peg cemented tibial component UKA. Both groups were similar in terms of age, sex, comorbidities, and BMI. Results. No significant difference was found in clinical outcomes and overall failure rates. In the flat tray group, the mean preoperative KSS was 57.2, which increased at 1-year follow-up after surgery to 92.28, and remained stable at the 3 and 6 year control visits. In parallel, the mean pre-operative KOOS of 59 increased to 87.20. The mean preoperative KSS score in the 2 pegs group was 56.8 and the mean KOOS 58.1. At 1-year follow-up the KSS score increased to 94.1 and the KOOS score to 89.22, remaining stable at the 3- and 6-year follow-ups. Two-peg tibial component showed a significantly lower rate of persistent pain on the tibial side, 8% of patients at 1 year follow-up and 2% at 2 years, compared to 20% at 1 year and 6% at 2-year follow-up in the flat tray group (p < 0.05). In both groups, patients with pain at the 2-year control, 4 patients in total, still complained of mild and intermittent pain, VAS 1 to 2, at the 6 year visit. There was also a lower incidence of radiolucent lines compared to flat design prosthesis, none versus 6 at 3-yeas radiographic control. Radiolucent lines were not related to pain. No difference was detected regarding range of motion between the two groups. Conclusions. This study reveals that the clinical results and failure rates arising from the use of two different tibial components, one flat and one with 2 pegs, are similar. However, a lower rate of pain and radiolucent lines are detected on the tibial side with the use of a two-peg tibial component design. This outcome could denote a better fixation of the 2 peg metal-backed tibial component implant. [ABSTRACT FROM AUTHOR] |
