ConforMIS released results from six clinical studies on their patient-specific implants for total knee replacement.
Here are five things to know:
1. Researchers at seven facilities across the United States performed an interim analysis of 295 consecutively enrolled total knee replacement patients using a variety of functional tests and the Knee Society Score. The patients with the iTotal CR knee replacements were 1.7 times more likely to achieve an "excellent" or "good" objective on KSS and patients with "off-the-shelf" knee replacements were 2.6 times more likely to achieve a "poor" objective.
2. A second test administered during the original study — the aggravated locomotive function test — examined the patients' ability to perform daily living activities like standing, walking and climbing stairs. The researchers found patients with the iTotal CR knee replacement had statistically significantly better ALF scores than patients with other knee replacements. Additionally, patients with iTotal CR walked statistically significantly faster than patients with other implants.
3. Two separate studies examined real-time x-ray imaging with mobile fluoroscopy to study movement of the knee during deep knee bend and chair rise in patients with iTotal CR knee replacements compared with other implants. The first study examined 63 total knee replacements and investigators found the knee motion was more consistent with the normal knee when iTotal was used. The iTotal CR knee replacement patients also achieved greater weight bearing flexion during the deep knee bend.
4. In the second study using the real-time x-ray imaging with mobile fluoroscopy, 38 patients with total knee replacements were examined. Thirty-five percent of the patients with "off-the-shelf" implants reported implant lift-off in early flexion during the knee bend, whereas none of the iTotal patients experienced implant lift-off in early flexion. The lift-off in early flexion is correlated with mid-flexion instability, a common source of patient dissatisfaction.
5. There were also studies using the company's partial knee replacements — ConforMIS iUni and iDuo — presented at the conference. In the iUni study there was an improved range of motion and high functional scores at two years after surgery and 89 percent of the patients said movement felt natural. The majority of patients in the study examining iDuo also reported good or excellent results, and 97 percent said they would undergo the same surgery again.
"After performing several thousand total knee replacements, I have seen firsthand that using a customized implant designed specifically for each patient could have a significant impact on restoring function and improving overall patient satisfaction and ability to perform daily activities," said Robert Tait, MD, chief of staff at St. Rose Dominican Hospital Siena in Henderson, Nev. "This new data provides additional clinical evidence demonstrating that customized knee implants can deliver measurable advantages for patients that have a direct and positive impact on patient quality of life."