The growing body is subject to a long list of overuse conditions, from stress fractures to throwing injuries to growth plate damage. One condition becoming more common in physical therapy circles is osteochondritis dissecans, often abbreviated OCD.
"We're seeing more of these cases, both nonoperative and post-surgery," said Lisa Drefus, DPT, advanced clinician at Hospital for Special Surgery (HSS) in New York City. "Five years ago, we may have seen a few patients a year with OCD. Now our surgeons at HSS operate weekly for this condition and we're seeing patients in all phases of rehab. It's still fairly uncommon in the overall population, but it's starting to enter the picture."
'Soft Spot on an Apple'
OCD is classified as an overuse injury. While there's often no predisposing factors or family history, it tends to arise in adolescents who are active in sports. OCD mostly affects the femoral condyles of the knee, the rounded end of the lower thighbone (femur). The bone just under the cartilage surface is injured, leading to damage to the blood vessels of the bone.
Without blood flow, the area of damaged bone will begin to die, and can cause pain and debility, leading to osteoarthritis if the defect is not corrected.
"To help patients visualize, I explain to them that it's like a soft spot on an apple," said Ted Ganley, MD, attending surgeon and director of sports medicine at the Children's Hospital of Philadelphia (CHOP). "The spot can be small, or it can be progressed to the point that there's a flap that separates from the main part of the bone." In severe cases, the bone defect can break off and float inside the joint.
Depending on the progression of the condition, physicians can choose from several different techniques, explained Ganley. Mild lesions can typically heal with a course of conservative therapy, which involves activity modification, physical therapy to strengthen the area and improve flexibility, and often an immobilization device. More involved cases must be corrected surgically, either through microfracture of the bone behind the cartilage, repair of a hinged flap using plugs of bone or screws and, in severe cases, removing broken fragments and filling the site with autograft tissue from elsewhere on the patient's body.
"If there's a clear defect that one could describe as looking like a crater, there are things you can do surgically to fill the defect and repair the structure," Ganley said. "But our goal is always to intervene early when cartilage is still intact with the least invasive methods available."
One Patient's Story
Thirteen-year-old Nick Silenok of Langhorne, Pa., began complaining of pain in his right knee in October 2012. His parents chalked it up to growing-related pain or perhaps a nagging injury as a result of playing baseball, basketball and football. But when the pain persisted and began to interfere with sports, Nick underwent an X-ray in January 2013 and received an immediate diagnosis of OCD.
"You could see it pretty clearly under the kneecap," said his mother Nancy of the dark-colored lesion that's a hallmark of the condition. "Doctors knew right away what it was."
Fortunately, Nick's case was classified a Grade 1 injury, the mildest. Typical of most mild cases of OCD, Ganley recommended a round of conservative care first. Nick spent six weeks in an immobilizing brace and was removed from all sports activity to give the joint a chance to rest and recover, along with six weeks of physical therapy sessions to improve strength and range of motion surrounding the joint.
But when subsequent X-rays showed minimal improvement and the symptoms persisted, Nick's parents and care team decided that further intervention was necessary. In May, he underwent microfracture surgery at CHOP, during which Ganley drilled the bone beneath the cartilage to promote blood flow and healing.
"If we continue with the apple analogy, this is like piercing a safety pin through the skin of the apple," said Ganley. "Mother Nature then says, 'there's bleeding of the bone in there, let's heal that."
Ganley estimates that about one-third of his patient population receives microfracture, one-third receives surgical correction of a hinged piece, and the remaining third requires some form of procedure to fill a defect.
Role of Rehab
Many times, mild cases of OCD identified on X-ray are given a course of conservative care in hopes of healing the lesion and avoiding surgery. Physical therapists will have the patient reduce or eliminate weight-bearing activities, work on strength and flexibility, examine balance, and work on alignment issues at the knee, lateral hip and entire kinetic chain.
"A lot of times, kids will be referred [to us] pre-surgically," said Jaime Kahmar, DPT, Cert. MDT, physical therapist at Bucks Physical Therapy in Newtown, Pa., who treated Nick both pre- and post-op. "We're seeing more physicians refer these cases before surgery." Children often have a better chance of nonsurgical healing than adults, due to better vascularization of the area, she said.
Jaime Kahmar, DPT, Cert. MDT, of Bucks Physical Therapy in Newtown, Pa., guides 13-year-old Nick Silenok through balance and core-strengthening movements on a physioball. Silenok was diagnosed with osteochondritis dissecans (OCD) and underwent microfracture surgery in May 2013. Due to more rigorous sports schedules, physical therapists are witnessing a rise in OCD cases.
Most of Kahmar's postop patients have undergone the microfracture procedure. After a six-week period of rest and immobilization, Kahmar will see them three times per week and progress from mild passive mobility to strengthening and balance, and ultimately to running and sport-specific activity.
In the early stages, pain control is a key goal and patients are issued an NMES device for home use. Many patients receive a continuous passive motion (CPM) machine to preserve joint mobility. Therapists work to counter the effects of immobilization and improve gait.
When the patient is pain-free and full ROM and strength have returned - usually in the four-to-six-month range - therapists and the surgeon can set their sights on returning the patient to full sports activity.
"It can take a year to come back from this fully," said Kahmar. "For adults, it can sometimes take even longer. It's a condition that you want to be completely certain has healed."
What's Causing the Rise?
While OCD has not reached epidemic levels, the rise in rates of the condition are concerning, leading Ganley and his fellow researchers at CHOP to examine the reasons behind it. One common theme is the structure of competitive sports.
"We tend to be a country of extremes," Ganley said. "On the one hand we have a childhood obesity problem, in part from sedentary lifestyles and unhealthy diets. But we also have the other extremes of overuse injuries from year-round sports at younger and younger ages. Another factor is early sports specialization with young children focusing on a single sport year-round."
Gone are the days when on a daily basis, children would go outside, form an impromptu game, climb a tree or ride a bike, with each day being a different activity, said Ganley. Some element of variety is critical to avoid common overuse patterns.
"I wouldn't call OCD an epidemic, but if you look at overuse injuries long term, with each generation we've eliminated some element of free play," Ganley said. "There's a heathy balance between sedentary and year-round overuse that we need to better develop."
Drefus doesn't see one sport being more problematic than another, but often notes that dedicated athletes who participate in high-demand, repetitive sports are most susceptible to it.
"It's sometimes hard to keep [these patients] away from their sports," said Drefus, adding that in some cases, a weaker core and gluteals contributes to it. "We try to work on some cross-training and activity modification to keep them involved while protecting the area."
"The time in the immobilizer was difficult [for Nick]," said Silenok, of the six-week period during which Nick wore a brace 24 hours a day and could not participate in sports. "We had to find other ways to keep him busy and active." Nick is currently in the final phases of rehab and hopes to be cleared to play this fall.
First Line of Defense
As Drefus explained it, the common denominator for successful rehab is open communication with the patient, the family and the physician. "Physician postop protocols commonly vary, and patients respond differently to rehab progression," she said. "You want to keep the lines of communication open for optimal recovery."
"Physical therapy is critical on many levels," said Ganley, who has researched prevention protocols and devised a lower-extremity prevention program at CHOP. "The key one is prevention. Every visit to a physical therapist is not just [an opportunity] to treat an injury, but to teach lifelong lessons. In my mind, there's no better way to maximize the potential of our young athletes. I'm a huge fan of physical therapy professionals and the difference they can make."
Jonathan Bassett is on staff at ADVANCE. Contact: firstname.lastname@example.org