EARLY EXPERIENCES WITH CRUCIATE RETAINING HIGH-FLEX-TKA

Abstract

Connected to an increasing number of TKAs there is an increase of different indications and variety of patients.

Considering this it may be useful to deal with different techniques and implants for individual treatment.

Good and excellent results are documented with cruciate-retaining and -sacrificing systems. One question is whether using a CR-High-Flex-TKA can give additional advantages.

Potential advantages are additional design features based on a reliable knee system as minus size femoral components to support balancing the flexion gap, an extended posterior condyle to avoid early edge contact in flexion, a patella-tendon cutout on articular surfaces to avoid impingement and using highly crosslinked polyethylene to reduce wear.

The discussed potential disadvantages of a CR-System like posterior impingement and potential increase of patello-femoral pressure due to a different roll-back mechanism may be balanced out by alteration of the lateral femoral condyle and using a highly constrained articular surface with anterior and posterior elevation (Launch 2005). Correct patella tracking and balancing is indispensable.

In Ostseeklinik Damp TKA was done in 980 cases in 2003, mainly performed by 5–7 orthopedic surgeons.

From 09.2003 to 09.2004 40 patients with osteoarthritis (Varus:Valgus=80%:20%) received a Nex Gen CR-Flex-TKA (ZIMMER LTD.) in cemented technique without patella-resurfacing.

In 25 cases a femoral minus-component was used.

Average flexion ability increased from 105° pre-operatively to 125° after 1 year.

This is an early trend, currently knee-score-data are not yet ready.

The early results are absolutely comparable to our experience with cruciate sacrificing knee systems, classic and so-called high-flex ones, which are in use in our clinic.

Conclusion is, that a cruciate retaining high flex knee system is a meaningful additional option in TKA.