Contemporary knee arthroplasty: one fits all or time for diversity?

Introduction Total knee arthroplasty (TKA) has historically been the preferred solution for any type of knee osteoarthritis, independently of the number of compartments involved. In these days of patient-specific medicine, mono-compartmental disease could also be approached with a more individualized treatment, such as partial knee arthroplasty (PKA). Off-the-shelf (OTS) implants are often the compromise of averages and means of a limited series of anatomical parameters retrieved from patients and the pressure of cost control by limited inventory. Personalized medicine requires respect and interest for the individual shape and alignment of each patient. Materials and methods A Pubmed and Google Scholar search were performed with the following terms: patient-specific knee and arthroplasty and custom implant and total knee replacement and partial knee replacement and patellofemoral knee replacement and bicompartmental knee replacement. The full text of 90 articles was used to write this narrative review. Results Unicondylar, patellofemoral and bicompartmental knee arthroplasty are successful treatment options, which can be considered over TKA for their bone and ligament sparing character and the superior functional outcome that can be obtained with resurfacing procedures. For TKA, where compromises dominate our choices, especially in patients with individual variations of their personal anatomy outside of the standard, a customized implant could be a preferable solution. Conclusion TKA might not be the only solution for every patient with knee osteoarthritis, if personalized medicine wants to be offered. Patient-specific mono-compartmental resurfacing solutions, such as partial knee arthroplasty, can be part of the treatment options proposed by the expert surgeon. Customized implants and personalized alignment options have the potential to further improve clinical outcome by identifying the individual morphotype and respecting the diversity of the surgical population.

Automated summary

Total knee arthroplasty has historically been the preferred solution for knee osteoarthritis, but personalized medicine is now allowing for more individualized treatments like partial knee arthroplasty. Off-the-shelf implants are a compromise based on averages, while customized implants and personalized alignment options show potential to improve clinical outcomes by respecting individual diversity.