By Whitney Lowe
There are numerous causes of anterior knee pain. Some of them are more common than others. Osteochondritis dissecans is not a very common condition. It is, however, something that the massage practitioner should be aware of as a possible cause for knee pain. OCD is most often seen in younger patients. The most common age is between 13 and 21 years old and it affects males more often than females. Osteochondritis dissecans (OCD) may occur in several regions of the body. The most common locations are the knee, the capitellum of the elbow, and the talar dome of the foot. This article will focus on OCD at the knee.
DESCRIPTION OF PATHOLOGY
The tibia and femur are covered by a layer of hyaline cartilage on their ends that helps reduce friction and wear at the joint. OCD is a condition where a section of hyaline cartilage (and sometimes the underlying bone, called subchondral bone) separates from the remainder of the deeper bone. The bone or cartilage fragment that separates may float freely within the joint causing locking, pain, clicking or crepitus during movement.
Originally when this condition was named, it was thought to have an inflammatory component, hence the suffix – itis in osteochondritis. The current understanding is there is no significant inflammation associated with the cartilage and bone damage.1 Several authors have suggested that a more appropriate name for this condition would be osteochondrosis dissecans. The suffix –osis means abnormal condition, so this term would actually mean abnormal condition of the bone and cartilage instead of inflammation of the bone and cartilage.
In the knee, OCD most commonly affects the lateral side of the medial condyle of the femur. During various knee motions there can be repetitive contact of the medial condyle against the tibial spine. The tibial spine is where the anterior cruciate ligament attaches to the tibia.
It is unclear exactly how the process of cartilage degeneration and separation from the bone starts. There is some evidence that it may come from previous trauma, repetitive impact loading, or abnormal ossification of the bone. In addition, it is thought that tensile forces of the cruciate ligament attachment may pull on the bone enough to weaken the osteochondral interface.
Most likely it comes from several causes that may be present at the same time. In some cases avascular necrosis may develop and precede the cartilage separation. Avascular necrosis is a process where blood supply to an area is decreased for some reason and the result is local tissue damage and tissue death (necrosis).
There is some evidence that a discoid meniscus may play a role in the development of OCD. A discoid meniscus refers to the shape of the meniscus of the knee. A normal medial meniscus is somewhat round when the individual is very young and then it opens up into a "C" shape as the person ages (see Figure 3). A discoid meniscus maintains much more of its round or "O" shape. Maintaining the "O" shape will affect the way the femoral condyle tracks with the meniscus. Some MRI investigations also showed evidence of meniscal damage in patients with OCD.
OCD in the knee is easy to mistake for other knee problems. The most accurate way to identify it is with a good X-ray or MRI. There are, however, several other important signs and symptoms that can be picked up through physical examination that will help determine if the client should be referred for further evaluation.
When evaluating active or passive range of motion in the knee, clicking or crepitus may be evident with flexion or extension movements, both passively and actively. There may be pain associated with the clicking movements if a loose piece of cartilage is floating around in the knee. The pain may often be described as deep within the knee joint.
Thigh atrophy is another factor that is often used to identify knee pathology. As a result of joint dysfunction there is often some atrophy of the quadriceps muscles. Although a difference in thigh girth measurements does not specifically indicate OCD, it is a common finding with this condition.
Another valuable method for identifying OCD that is affecting the medial condyle of the femur is the Wilson test (see Figure 4). In this procedure the knee is extended while held in internal rotation. If pain is felt at around 300 of flexion, this indicates a lesion on the medial condyle. The tibia is then moved into external rotation. If the pain is relieved with the external rotation, this is a positive test. This test is described both as an active movement and also with the knee being extended against resistance. If any internal joint clicking, crepitus, or group of signs and symptoms indicating possible OCD exist, the individual should be referred to a physician for further evaluation.
There are a number of other knee complaints that may have similar symptoms and should also be considered. Meniscal tears, internal ligament sprains, and injury to the coronary ligaments that hold the menisci in place may have pain felt deep in the joint similar to OCD. Chondromalacia patellae may cause crepitus and grinding sensations. Patellar tracking disorders are also likely to cause quadriceps atrophy that may show up with thigh girth discrepancies and diffuse anterior knee pain. Osteoarthritis may also have similar joint pain sensations.
As mentioned earlier, the majority of patients who develop this condition are young. Conservative treatment with this population is often effective because they are skeletally immature and can address the symptoms with activity modifications that will reduce the biomechanical stresses. With older patients, conservative treatment appears to be less effective and there is a greater likelihood that surgery will be necessary.
Conservative treatment often includes patellar taping and exercises for the vastus medialis obliquus muscle. The primary goal of these treatment approaches is to improve biomechanics of the knee joint, which will decrease aggravation of the osteochondral lesion.
Surgical procedures that may be used to treat OCD are primarily arthroscopic. That means there will be a minimal level of irritation and a quicker recovery. The surgeon may perform a chondroplasty, a procedure where damaged cartilage is removed. However, in some cases there may still be pain and crepitus with movement. In addition, once cartilage has been removed in an area, there is a greater chance that the individual may have some problems with osteoarthritis later in life due to greater friction between the joint surfaces.
It is not clear whether massage is of significant benefit for this condition. What is most important, however, is to make sure massage is not contraindicated for the problem. There does not appear to be anything in the etiology of OCD that suggests massage can be harmful when applied to someone with this condition. Local and specific massage applications to the knee joint may prove beneficial in helping reduce pain in the region. It is still unclear if massage would have any benefit for aiding the restoration of adequate blood flow in the region.
Time can be an important factor in getting good results from treatment. The longer that joint microtrauma persists, the greater is the potential damage in the region. Clients exhibiting symptoms of OCD should be referred to a physician as soon as possible so the condition can be appropriately evaluated and the necessary treatment can begin. As noted, massage is not contraindicated for this problem and may be of benefit in reducing pain from the articular damage.
1. Grimm NL, Weiss JM, Kessler JI, Aoki SK. Osteochondritis dissecans of the knee: Pathoanatomy, epidemiology, and diagnosis. Clin Sports Med. 2014;33(2):181-188. doi:10.1016/j.csm.2013.11.006.