Call Us: (802) 888-8888

Clinical Research

Preventing Intraoperative Blood Loss

Tranexamic acid, TXA, is a synthetic analog of the amino acid lysine. It is used to prevent excess blood lost during surgery. At Copley Hospital, we evaluated 20 patients who received TXA prior to knee replacement surgery and 27 patients who did not receive TXA. We found that TXA had a significant benefit in blood loss. When TXA was used there was a 17.31 and 12.00% improvement with the hemoglobin and hematocrit, the percentage of red blood cells in the patient’s blood. No blood transfusions were required for the 20 patients who received TXA. We have also seen significant decrease in knee swelling and dressing changes in patients receiving TXA. The decrease in knee swelling has significant impact on function and flexion (bending) gains postoperatively. This data supports TXA being routinely used in joint replacement surgery and is consistent with current literature.

New Technology Tested to Treat Broken Shoulder (proximal humeral fracture, or PH fracture)

A majority of proximal humeral fractures are preferably treated conservatively. However, surgical management may be beneficial in fractures with significant displacement. Current surgical procedures have complication rates that can be unacceptably high. A new technology, termed the PH Cage, addresses the technical limitations associated with current available technologies. In December 2016, Dr. Macy presented his first experience with the PH Cage for the fixation of a PH fracture, which had previously failed conservative management.

The case presented involved a 70-year-old, right hand dominant, otherwise healthy and active, female presented to our clinic three months after falling onto her left shoulder. Initial treatment was non-operative; sling immobilization and limited physical therapy. She complained of persistent lateral shoulder pain and limited function in her left arm. Using a shared-decision making process, she elected to proceed with surgical management using the PH Cage. There were no intra-operative or post-operative complications. Her most recent follow-up x-rays obtained at 6 month post-op revealed a well-healed fracture with anatomical alignment and no hardware complications or avascular necrosis. The patient exhibited excellent range of motion, strength and function. She had no significant pain at last follow up. This is a retrospective case review of one difficult proximal humerus fracture malunion that went on to anatomic healing and an excellent patient-reported outcome. Dr. Macy is currently performing a prospective study evaluating the radiographic and clinical outcome of the PH Cage technology in comparison to existing technologies for the treatment of broken shoulders.

Analyzing Outcomes of Bicompartmental Knee Replacement Device

We looked at the ConforMis iDuo G2 knee replacement, a bicompartmental device composed of Femorotibial and Patellar components. [Note: a partial knee replacement is surgery to replace one or two parts of the knee. The Femorotibial refers to the weight bearing joint between the tibia and femur; the Patellar is the kneecap.] Twelve patients who underwent iDuo knee replacement by Dr. Bryan Huber were evaluated.

Normal range of motion at the knee is considered to be 0 degrees of extension (completely straight knee joint) to 135 degrees of flexion (fully bent knee joint). One year after surgery, the average knee flexion was 130 degrees. None of the 12 patients required a blood transfusion. Six weeks after surgery, 81% of patients said their knee felt “sometimes” or “always” normal. At 12 weeks after surgery, 100% of patients said their knee felt “sometimes” or “always” normal. At 12 weeks after surgery, 55% of patients reported no pain. This study showed that patients with a customized bicompartment knee replacement can excel postoperatively.

Analyzing Outcomes of Tri-Compartment Custom Knee Replacement Devices

Patient specific customized total knee arthroplasty implants are now available as an alternative to off-the-shelf implants. A goal of this technology is to provide superior clinical outcomes while reducing complications. The ConforMis iTotal CR and PS are a tri-compartment custom knee replacement constructed of cobalt chrome and is designed to conform to the surface of the patient’s femoral condyle (inside of the knee) and proximal tibia (shinbone). The ConforMis iTotal PS is a replacement for use in patients who experience a lack of or attenuated posterior cruciate ligament (PCL).

Sixty-seven (67) patients who underwent ConforMIS iTotal CR knee replacement by Dr. Bryan Huber were evaluated. One year after surgery, 60% of patients said their knee “always” felt normal. Normal range of motion at the knee is considered to be 0 degrees of extension (completely straight knee joint) to 135 degrees of flexion (fully bent knee joint). The average knee flexion was 117 degrees at six weeks after surgery and 125 degrees. Patients reported no pain with walking or climbing stairs one year after surgery. None of these patients required a blood transfusion.
Results from this study support previous findings that patients implanted with the custom total knee arthroplasty (TKA) experience significant improvements in Knee Society Score (KSS), Knee Injury an Osteoarthritis Outcome Score (KOOS) and higher range of motion from baseline.

Analyzing Outcomes of Unicompartmental Knee Replacement Device

This study looked at the Triathlon Partial Knee Replacement (PKR) device. The study was a prospective, post-market evaluation studying 18 patients who underwent PKR surgery with Dr. Bryan Huber.

Reported pain during activities, on a scale of 1 – 10, dropped from 6.7 at two weeks down to 3.3 at three months. Overall, pain dropped from 3.8 at two weeks to 1.2 by three months. Patient satisfaction was 9.4 at one year post operatively. The average flexion of the knee increased from 106 degreees at two weeks to 127 degrees at the 3-month mark. [Normal range of motion at the knee is considered to be 0 degrees of extension (completely straight knee joint) to 135 degrees of flexion (fully bent knee joint).] None of the 18 patients required blood transfusion and most left the hospital the day after surgery. Partial knee replacement can be a very successful operation with excellent outcomes.

Dr. Huber is a paid consultant to Conformis and Dr. Macy is a paid consultant to Conventus Orthopaedics. However, no benefits have been or will be received for the subject of their research.