Innovative Clinical Trial Underway Which Studies New Technology and Technique to Improve Total Knee Replacement Results

Total Knee Replacement has been a well-established and successful procedure for over 50 years and has helped millions of people worldwide. More than 750,000 TKRs are performed each year in the United States and recent studies indicate that number is expected to increase more than 650 percent from 2005 through 2025.

 

While the vast majority of patients are very pleased with their outcome, multiple studies have revealed that 20-30 percent of individuals are not satisfied following TKR, when measured with validated patient reported outcome measures (PROM). Component malposition, malrotation, and soft tissue imbalance can result in pain, stiffness and instability and are common reasons for dissatisfaction after TKR. These conditions are often difficult to recognize at the time of surgery and difficult to correct until now.

 

For the last several years, I have been utilizing a new FDA approved technology, VERASENSETM by OrthoSensor Inc., which incorporates microelectronics and sensors to measure real-time kinetics and intercompartmental loading during total knee arthroplasty (TKA). A computer microchip and load sensors are incorporated into trial tray inserts whose geometries match exactly the geometry of the final plastic insert provided by the manufacturer. These sensor trials are placed in the tibial tray both during the “trialing phase” and after the final components are implanted for “final trialing.”

 

Holy Cross Hospital is currently heading up a multicenter study using VERASENSE to evaluate Revision TKR. This study attempts to draw relationships between the soft-tissue related complications contributing to early TKA revision and the loading and positional patterns observed using intraoperative tibial trial sensors.

 

Over the last several years I have been using VERASENSE during revision TKR. A few colleagues and I looked at a series of revision cases retrospectively to determine if the integration of intraoperative sensing data had the potential to decrease the need for all component revision. In this review, approximately 88 percent of intended total component revisions were changed to partial revisions based on the surgeons’ interpretation of the sensor feedback. This sparing of components saved an estimated $4,990 in healthcare provider implant costs, per case. Because only one component was changed and not two, patients benefited by requiring less operative dissection, less bone loss, less operative time and often a faster and easier recovery.

 

As the surgeon takes the knee through a range of motion (ROM), dynamic load measurements are generated for the lateral and medial tibial compartments. A reference location of the load in each compartment throughout the ROM can also be used to evaluate knee kinematics. Armed with this data, Dr. Leone will be able to determine if compartmental loading and knee kinematics are desirable or if further resection or soft-tissue releases are indicated.

 

The most consistent and best results after TKR are in those patients whose knee movement after TKR most closely matches their natural knee movement before TKR and when soft tissue loads medially and laterally are nearly equal and physiologic. These patients are also most likely to report that their TKR feels natural and comfortable.

 

The data from the sensors may enable the surgeon to address such soft-tissue abnormalities that may otherwise be unknown during traditional total knee revision procedures. Furthermore, the economic implications from converting a total revision to a partial revision could have a profound effect on the patient and healthcare provider, such as decreased rehabilitation regimes and opportunity for cost savings. Eligible revision patients who agree to participate will be followed for a period of 12 months after the revision procedure. I have outlined the patient eligibility criteria below.