Research Summary

High Long-term Survivability, Patient Satisfaction After Robotic-arm—assisted Medial UKA

Anthony Calabro, MA

According to the results of a recent prospective multicenter study1, robotic-armassisted unicompartmental knee arthroplasty (UKA) offers long-term survival and high patient satisfaction rates at 10 years' follow-up.

Unicompartmental knee arthroplasty is generally used to surgically treat osteoarthritis in one of the three main compartments of the knee, most commonly the medial compartment of the knee. A total knee arthroplasty (TKA), on the other hand, is used to treat osteoarthritis in all three compartments of the knee. Further, UKA is generally considered a minimally invasive procedure that has a smaller surgical incision compared with TKA, and robotic-assisted techniques aim to improve the surgical precision of this operation.2

In their study, researchers evaluated 366 patients (411 knees) who underwent robotic-armassisted medial UKA. Researchers contacted patients at 10-years follow-up to determine implant survivorship and overall patient satisfaction. They analyzed survival by using Kaplan-Meier models. Regarding the procedure, surgeons used a cemented, fixed-bearing system with a metal-backed onlay tibial implant in all patients.

The study revealed promising results regarding the 10-year survivorship of robotic-arm-assisted UKA. The implant survivorship rate at 10 years was 91.7% (95% confidence interval, 88.8%-94.6%), indicating high durability of the procedure. In their follow-up, the authors found a total of 29 revisions, and of those revisions, 26 were converted to TKA. The authors noted that “pain and fixation failure remained common causes for revision following cemented fixed-bearing medial UKA, despite the use of a robotic-arm-assisted technique.”1

Still, patient-reported outcomes were high for those without revisions. Indeed, of those without revision, 91% were either satisfied or very satisfied with their overall knee function.

“This prospective multicenter study found high 10-year survivorship and patient satisfaction following robotic-arm-assisted medial UKA," the authors concluded.


1.     Bayoumi T, Kleeblad LJ, Borus TA, et al. Ten-year survivorship and patient satisfaction following robotic-arm-assisted medial unicompartmental knee arthroplasty: a prospective multicenter study. J Bone Joint Surg Am. Published online May 5, 2023. doi:10.2106/JBJS.22.01104.

2.     Luo TD, Hubbard JB. Arthroplasty Knee Unicompartmental. StatPearls Publishing; 2022. Accessed May 30, 2023.