Science of Pain

Subchondroplasty gets patients moving again.

Imagine your worst toothache, but instead the pain is deep inside your knee and pulses to the surface each time you take a step. It happens every day. You go for months with no relief.

Now imagine you are walking — maybe even running — pain free just a few weeks after a quick trip to the doctor.

That scenario is becoming possible for several area residents thanks to a new surgery making its way across America. Subchondroplasty, a five-syllable procedure that sounds more like a disease than a cure, has several area orthopedic experts thrilled about its future in mid-Missouri.

One such expert is Dr. Byron Tarbox, a surgeon at Columbia Orthopaedic Group. “It’s a nice, easy process that has proven to be very helpful for patients,” he says. Tarbox may have made history in this part of the country last February; those familiar with the procedure say he was the first physician to perform the surgery west of the Mississippi River. Since then he has conducted at least 10 such operations. His colleague at the orthopedic group, Dr. Mark Adams, has also performed a subchondroplasty.

Pinpointing the procedure
Subchondroplasty comes from “sub,” meaning “below” and the Greek word “chondros,” meaning “cartilage.” A person becomes a candidate for the surgery if he or she has suffered a very small fracture within the knee. Radiologists use the term “bone marrow edema” to describe the damage.

“It’s essentially swelling in the soft bone just underneath a joint’s surface,” Tarbox says.

Before this year, the only solution was to modify a person’s activity, provide a brace and put he or she on crutches. When surgery was involved, it meant inserting screws into the knee. “That might take up to eight months to heal,” Tarbox says. “With this procedure, you can be back to normal in six to eight weeks.”

Standard X-rays are not sufficient in capturing these types of fractures and accompanying swelling. However, if a physician orders what is known as a T2 fat-suppressed MRI image, things are much clearer, and so are the options. “With that kind of imaging, the BME (swelling) lights up like Christmas,” says Chad Martin of Curtis Medical, a distributor of orthopedic implants in Columbia. “Now doctors have a great solution to offer up.”

The procedure involves putting the patient under general anesthesia and then making a total of three holes in the knee (one more than a regular knee scope). Imaging and a special device help pinpoint exactly where the damage has occurred. A needle is then inserted over the spot, and a small amount of calcium phosphate (resembling toothpaste) is injected into the area and hardens in less than 10 minutes. The operation takes a total of 30 to 45 minutes.

After the substance hardens, it becomes as strong as the surrounding bone, which provides support for the knee again. Without the surgery, it would just be a matter of time before the collapsing bone would break apart.

BME and the presence of pain
Tarbox’s patient list is diverse: A man in his mid-60s with severe pain after walking up and down stairs while moving into a new home, a person who had injured a leg after stepping off a hay bale and a 36-year-old with a shin injury who was walking without pain just two weeks after surgery.

Although Tarbox has only performed subchondroplasties in knee joints, he hopes to do the procedure on those with hip problems. Other physicians have performed the specialized surgery on ankles and shoulders. To date, more than 200 surgeons in the United States have performed 1,200 of these types of surgeries, according to Meenal Lele, the director of clinical evidence at Knee Creations, an orthopedic medical device company in Philadelphia. Lele’s company provides the surgical equipment and implants that Columbia Orthopaedic uses in its procedures.

Lele says the concept of subchondroplasty began with a question that seemingly had no answer: Where does knee pain originate? It was asked by orthopedic surgeon Peter Sharkey of Philadelphia’s Rothman Institute. Sharkey and his team knew something was happening in cartilage, but the source of the agony baffled them. After research, they found a strong correlation with BME and the presence of pain.

Around 2008, Sharkey developed the concept of subchondroplasty as a treatment. The first patient was a hairdresser who suffered pain from being on her feet all day. She continues to do well nearly five years after her operation. Lele says in a few short years, the substance injected into patients actually gets absorbed and turns into natural bone.

Martin services a handful of orthopedic surgeons who perform subchondroplasties in Missouri, particularly along the Highway 63 corridor, including Moberly, Columbia and Jefferson City. He says Kansas is likely to have its first procedure soon.

Columbia back on its feet
The world of sports is rife with knee injuries, and that’s where many of Tarbox’s regular list of patients originates. In fact, he and another surgeon, Dr. Kevin Marberry, share a link with the University of Missouri, where they have served as team physicians. Tarbox is the doctor for MU’s wrestling team. In addition, Marberry has treated athletes from the NFL’s Indianapolis Colts and the U.S.A. National Swim Team. He currently works at the College of Osteopathic Medicine in Kirksville.

Regardless of how people believe they got injured, experts advise that those with chronic knee pain consult their doctor to determine a course of remedy. Treatment may range from lifestyle changes, medication, knee braces and crutches to complex surgery. About 600,000 total knee replacements are performed each year in the United States, and though a subchondroplasty may slow down or help avoid major knee surgery, the new procedure isn’t for everybody. Still, it will likely grow in popularity because it saves time, both for the surgeons in the operating room and for patients in their recovery. It’s also about one-fourth the cost of a knee replacement, according to Lele, who adds that most insurance companies cover the procedure.

Tarbox has added about one subchondroplasty a month to his already vigorous routine. A typical week sees him in surgical scrubs 12 times, not counting his nearly weekly 50 clinical visits. And when not helping mid-Missourians get back on their feet, he can be seen watching his teenage daughters spin on theirs; both girls dance competitively for their local schools.

“I’m a dance daddy,” he says, “and I stay pretty busy for sure.” Many people in the Columbia area are grateful for the schedule he keeps.

No (painful) bones about it.