The Tough Problem of Arthrofibrosis; #1 Predictor: Smoking

One, just one. Can we take just one preventable complication off the table?

If, as some optimistic forecasters expect, 3 million annual total knee arthroplasties (TKA) will be scheduled and performed in just 8 years (by 2030), then, says a research team from Georgetown University and MedStar Union Memorial Hospital in Baltimore, can we focus on one preventable complication—excess fibrous scar tissue (arthrofibrosis)—and make one of medicine’s most routinely successful procedures, even better?

Their work, “Comparison of manipulation rates for robot-assisted, customized, and conventional total knee arthroplasty: a retrospective cohort study,” was published in the September 7, 2022, edition of Current Orthopaedic Practice.

Arthrofibrosis, which can manifest as reduced range of motion and varying levels of continuing pain, can be treated with manipulation under anesthesia as it breaks up the scar tissue.

As the research team noted in the study, however, there are risks associated with that approach, such as fractures, wound dehiscence, patellar tendon avulsions, quadriceps strain or rupture, hemarthroses, heterotopic bone formation, and pulmonary embolism.

But, could new implants, new techniques like robotic assist, play a role in reducing the risk of arthrofibrosis? The team designed a study to compare manipulation under anesthesia with the latest implants and techniques and, in a retrospective review, find, perhaps, promising data that modern robotics and other advanced instrumentation moving one complication off the table.

For this retrospective review, the team collected data from 1,260 primary knee arthroplasty cases (717 conventional, 217 customized, and 326 robot-assisted) which had been performed by a single orthopedic surgeon from January 1, 2016 to May 31, 2020.

Overall, the team found, the surgeon’s manipulation rate was 1.3% (n=17), and that the manipulation rates for conventional, customized and robot-assisted TKAs did not vary significantly (1.84%, n = 6; 0.46%, n = 1; 1.39%, n = 10, respectively).

Also, the research team found no statistically significant difference in the odds of manipulation depending on the type of implant. They did find, however, that smokers were four times more likely to undergo manipulation (Odds Ratio: 4.187, 95% Confidence Interval: 1.119 to 15.673); those who had undergone prior surgery were 2.8 times as likely to undergo manipulation (Odds Ratio: 2.808, 95% Confidence Interval: 1.039 to 7.589).

Henry Boucher, M.D., chairman of orthopaedics at MedStar Union Memorial Hospital, told OTW, “The most important result we found was that there were no differences in manipulation rates among patients who received conventional, customized, and robot-assisted TKAs. For us, this was not necessarily a surprise since the problem of arthrofibrosis in TKA is multifactorial and we did not believe that technological advances alone could remedy this issue.”

While Dr. Boucher told OTW that the findings from this manuscript alone would not necessarily alter our practice, he added, “It will continue to be important for the orthopaedic community to consider and weigh new technology given the proliferation of technological advances. Additionally, we hope to continuously critically evaluate new technology to address common problems we encounter in arthroplasty like we did through our manuscript.”

And so, the search continues. One, just one preventable complication. Can we take it off the table?