This study in the Journal of Arthroplasty analyzed results of medial unicompartmental knee arthroscopy (medial UKA) or partial knee replacements and determined that at one year post surgery, patients had the same results whether or not they also had degeneration of arthritis of the front of their knee (patellofemoral joint).
In my practice, whether or not I recommend a partial knee depends on where a patient has symptoms. If the majority of symptoms are on the medial or inside part of the knee and the patient is a candidate for a partial knee replacement, then I think it is reasonable to proceed. The only issue is that insurance companies do not understand this and we are getting more and more denials due to the fact that the X-ray or MRI shows patellofemoral degeneration.
Read more in this Healio article: “Medial UKA improved pain, function despite patellofemoral joint degeneration” or in The Journal of Arthroplasty: “What Role Does Patello-Femoral Joint Degeneration Have on Pain and Function After Unicompartmental Knee Arthroplasty? A Prospective Observational Cohort Study.”