The University College Hospital in London researchers were trying to reel in some of the surgical trauma inherent in all surgery. That trauma, better known as local inflammatory response, could be, they hypothesized, a cause of sub-optimal TKA patient outcomes.

A team from University College Hospital in London, United Kingdom designed a study to check that hypothesis and the results, “Inflammatory Response in Robotic-Arm-Assisted Versus Conventional Jig-Based TKA and the Correlation with Early Functional Outcomes.” was published in the November 2, 2022, edition of The Journal of Bone and Joint Surgery. And the study was reviewed in an article just published in Orthopedics This Week (OTW).

Andreas Fontalis, M.D., M.Sc., M.R.C.S. co-author on the research explained to OTW, “There is high incidence of patient dissatisfaction following total knee arthroplasty (TKA), with up to 20% of patients reporting dissatisfaction in an otherwise uncomplicated TKA. The exact etiology is unclear; however, it has been speculated that the local inflammatory response precipitated by surgery may be implicated.”

“Our group recently conducted and disseminated the results of a randomized controlled trial studying the systemic inflammatory response in robotic-arm-assisted versus conventional TKA. We found that robotic-arm-assisted TKA was associated with a transient reduction on the 7th postoperative day and with less iatrogenic soft tissue injury and bone trauma. Conceptually, we hypothesized that it could also be associated with a reduction in local inflammation.”

“Furthermore, robotic-arm assistance has features that could translate to a reduced local inflammatory response such as the haptically controlled saw blade and stereotactic boundaries.”

“The surgical workflow during the conventional technique also involves the use of intramedullary femoral referencing and cutting blocks associated with production of substantial metal debris; all of which could be responsible for a more pronounced inflammatory response.”

“We therefore thought it important to objectively study the local inflammation incited by the two procedures and investigate whether any correlation was evident with functional outcomes.“

The researchers looked at 30 patients who had TKA for knee osteoarthritis – 15 of whom had traditional TKA and 15 who had robotic-arm-assisted TKA. They obtained data on the inflammatory markers IL-6, IL-8, and tumor necrosis factor (TNF)-alpha.

“In our study,” commented Dr. Fontalis to OTW, “robotic-arm assistance was associated with lower postoperative levels of IL-6 measured in the drain fluid at 6 and 24 hours and lower levels of IL-8 in the drain fluid at 6 hours. We also noticed that pain scores in the robotic-arm-assisted group were significantly lower on days 1,2 and 7 and that both the local and the systemic responses were correlated with pain.”

“We were surprised by how pronounced the differences were with respect to IL-6 levels at the 24-hour post-operative mark, which could reflect the ability of robotic technology to reduce bone and soft-tissue injury by averting multiple cuts and by more precisely executing the preoperative plan.”

“Our study furthers evidence of the advantages of robotic arm surgery. Larger studies and clinical correlation may lead to the increased adoption of enhanced technologies such as robotic-arm-assisted surgery in order to improve patient outcomes.”