UKA (unicompartmental arthroplasty)
UKA - Is there an advantage or disadvantage?
Unicompartmental knee arthroplasty (UKA), specifically medial compartment arthroplasty does have some distinct advantages when performed on the correct surgical candidate there is also one distinct disadvantage. It has a shorter recovery allowing individuals to return to work and activity sooner. It also has no restrictions post-recovery. The distinct disadvantage of UKA versus TKA is that there is a higher revision rate. Although, when revising a UKA to a TKA one can expect the same outcome as having a TKA on a primary knee.
Who is the correct patient for a medial UKA? In our practice that patient is someone who presents with isolated medial compartment pain and has isolated medial compartment degenerative changes on x-rays or advanced imaging. We ask our patients to point with one finger to show us where their knee hurts. If they point directly to the medial compartment, then they may be a candidate for a medial UKA. If they have had an arthroscopic procedure performed prior to seeing us, we will attempt to obtain their intra-operative imaging. Often times we will have them use a medial off-loader brace to see if their pain is well controlled. An MRI of the knee will better demonstrate disease in the lateral and patellofemoral compartments, if there are any concerns of disease in the remaining compartments.
We have a long discussion about the possible requirement for further surgery if they develop lateral or patellofemoral pain post-procedure. They must have an understanding that my surgeon may opt to perform a TKA if there are more advanced degenerative changes in the lateral or patellofemoral compartments than expected.
We use the MAKO robot to perform our UKA. The UKA is a more technical procedure than a TKA because there is no epicondylar axis to use to set your rotation. The use of technology (MAKO) eliminates this concern. There is sparing of the quadriceps tendon with the approach which allows for quicker recovery when compared to the TKA.
Our medial UKA patients are my favorite knee patients to see post-operatively. If someone offered me a UKA and said I would still have to do a TKA in 5-10 years, for me, it would be an easy decision. What are you seeing with your patients? Would you choose a UKA over a TKA if given the option?