Knee Replacement Surgery Outcomes Improved By Computer Navigation: Study

The findings of new research suggests that computer assisted navigation may be the best way to properly align new knee replacement implants, as opposed to things like patient-specific instrumentation, like cutting guides. 

In a study published last month in the journal Orthopaedics & Traumatology: Surgery & Research, German researchers sought to prove that patient-specific instrumentation would be the best way to ensure that implants used during total knee arthroplasty (TKA) were optimally aligned.

Researchers conducted a retrospective cohort study of 385 knee replacement procedures in low-volume centers, in which 30% relied on conventional instrumentation, 54% relied on computer navigation, and 15% relied on patient-specific instrumentation.

According to the findings, when compared to conventional instrumentation, computer navigation reduced the risk of postoperative alignment problems by 89%. However, patient-specific instrumentation resulted in no discernable improvement from conventional approaches.

In addition, when it came to tibial component alignment, the risk of problems doubled with patient-specific instrumentation.

“Navigated TKA improved postoperative alignment, No evidence of improved alignment was seen with patient-specific instrumentation,” the researchers determined. “The routine use of patient-specific instrumentation in low-volume centers is not supported by the currently available data.”

Patient-specific instrumentation often refers to medical devices like cutting guides when it comes to knee replacement surgery. The guides, cut for each specific patient, are used to help doctors make accurate cuts during knee-replacement surgery. However, in recent years they have been linked to a number of problems.

In December 2014, OtisMed, a subsidiary of Stryker Corp., pleaded guilty to illegally selling cutting guides that were never approved by the FDA. The sales came after the FDA rejected approval of the devices in September 2009, saying they were neither safe nor effective.

The findings also come on the heels of a study published in February, which found that obesity, abnormal bone shapes and bone loss all play a role in catastrophic knee implant failures and the need for revision surgery.

That study found that 26 out of 27 patients who underwent revision surgery had preoperative bone deformities and that the average body mass index of those patients indicated they were severely obese.

While knee replacement surgery is often recommended as a solution for problems experienced with a bad joint, the findings add to increasing concerns in recent years about design problems associated with several widely used implants.

Over the past year, a growing number of individuals have begun evaluating potential knee replacement lawsuits over problems associated with several different types of systems widely used in recent years, which have been linked to high rates of implant failure, resulting in the need for knee revision surgery; including DePuy Attune Knee,Exactech Optetrak Knee, and Arthrex iBalance Knee. Many of the problems with these implants have been linked to tibial loosening and tibial baseplate failures.