News from AAOS: Smith & Nephew Debut New Solutions for Hip, Knee Repairs

In many respects, the American Academy of Orthopaedic Surgeons (AAOS) annual meeting is all about tradition.

Each year, for instance, the organization names a Guest Nation to recognize the contributions of foreign orthopedic surgeons (the current honoree is France). Each year, members elect and install a new president. And each year, before the meeting even starts, surgeons roll up their sleeves to build a “safe and accessible” playground for the host city’s children.

Attendees have traditions as well. Many OEMs use the event to launch new products: Zimmer Holdings Inc., Stryker Corp., DePuy Synthes and Biomet Inc. all have unveiled replacement joints, implant components or orthobiologic repair materials at previous shows.

Smith &Nephew plc continued its new product launch tradition this year with the debut of the Journey IICruciate Retaining knee replacement and Dyonics Plan Hip Impingement Planning System.

The new Journey implant extends the Journey II Total Knee System to procedures that preserve the posterior cruciate ligament (PCL), which accounts for approximately half of all knee replacement procedures, Smith &Nephew notes.

The Journey II CR knee, like the Journey II Bi-cruciate Stabilized (BCS) knee launched at last year’s AAOS meeting, restores more normal motion for patients through the reproduction of both the shapes of the joint’s hard surfaces and the normal force behavior of the soft tissues, such as ligament and muscle firing patterns. As a result, the soft tissue’s readjustment to new shapes and forces after surgery is minimized, helping to return the patient’s stride to its natural motion, Smith &Nephew executives explain.

“Access to this next-generation technology has been remarkable for my practice,” claims Jeff Geller, M.D., of Columbia Presbyterian Hospital in New York, N.Y. “I choose a cruciate retaining knee replacement whenever possible for my patients, and this is the first time I’ve been confident they’re receiving a device that’s kinematically correct. Most importantly, my patients confirm this in our follow-up discussions.”

The Journey II CR knee is touted as the first PCL-sparing total knee replacement designed to provide normal kinematics and increased patient satisfaction through physiological matching technology. Thisapproach to implant development uses the company’s Lifemod human simulation software to analyze the bone, ligament and muscle forces that impact the knee, and then account for those forces within the design of an implant intended to help restore anatomic shapes and normal motion.

“The Journey II CR knee will be a key component of our total knee replacement portfolio,” said Gaurav Agarwal, president of Orthopaedic Reconstruction for Smith & Nephew. “The patient benefits of the Journey II BCS knee have made it among the most popular implants we’ve ever introduced, and since our customers choose a PCL-sparing device in approximately one-half of knee replacement cases, we expect the new Journey II CR to further drive adoption of the Journey II system.”

The Journey II CR knee is made from Smith & Nephew’s Verilast technology. The combination of two wear reducing materials, proprietary oxinium alloy and a highly cross-linked plastic liner, Verilast technology significantly reduces implant wear compared to traditional bearing couples on the market.On traditional plastic liners, laboratory testing has demonstrated that oxinium material is 4,900 times more abrasion-resistant than cobalt chrome and reduces knee replacement wear on traditional liners by up to 85 percent compared with cobalt chrome components.

Dyonics Plan

Smith &Nephew’s Dyonics Plan is a revolutionary 3-D software system that allows surgeons to visualize, assess and generate a comprehensive surgical report for each patient’s unique Femoroacetabular impingement (FAI) surgery before that patient ever enters the operating room.
FAI is a condition where the bones of the hip are abnormally shaped. Because they do not fit together perfectly, the hip bones rub against each other and cause damage to the joint, including cartilage damage and bone spurs.

“Performing impingement surgery in the hip without the report is like putting in a total knee without cutting guides,” said Bryan Kelly, M.D., of New York, N.Y. “Dyonics Plan takes the guesswork out of every case.”

Dyonics Plan provides a standardized and repeatable way of assessing hip impingement treatment options based on data from low-dose computed tomography scans. The software, installed on a surgeon’s computer, also allows for interactive adjustments based on a surgeon’s clinical experience.

Using the Dyonics Plan 3-D model of the patient’s joint, a surgeon can perform various dynamic range-of-motion (ROM) simulations to identify the degree and location of hip impingement. The ROM feature also can be used to individualize a surgical plan based on a patient’s lifestyle or sports-specific motion, or to assess impact of different surgical strategies on patient outcomes. Once finalized, the system generates a comprehensive surgical plan than can be exported into either HTML or PDF format.

“Dyonics Plan offers surgeons the ability to understand and address a patient’s hip impingement on a level that goes beyond anything possible with standard imaging tools,” explained Brad Cannon, president of Endoscopy, Trauma and Extremities for Smith & Nephew. “Because it tells a more complete story about each patient’s impingement and how best to surgically treat it, it also provides a visual tool for patient communication.”

Dyonics Plan was designed in conjunction with four hip arthroscopy surgeons: Asheesh Bedi, M.D., of Ann Arbor, Mich.; J.W. Thomas Byrd, M.D., of Nashville, Tenn.; Bryan Kelly and Christopher Larson, M.D., of Edina, Minn.