Although it is called a "disease," Panner's disease is really a rare but painful bone condition that is linked to overuse of the elbow. Even though recovery can be slow, kids with Panner's disease usually suffer from no long-term problems as a result of the condition.
About Panner's Disease
Panner's disease involves the growth plate in the elbow (growth plates produce new bone tissue and determine the final length and shape of bones in adulthood). The disease occurs in kids who are younger than age 10, typically young athletes, and usually affects the dominant arm.
Panner's disease is part of a family of bone development diseases (known as osteochondroses, or in singular form, osteochondrosis) that occurs in kids and teens. In osteochondrosis, something temporarily disrupts the blood supply to an area of developing bone. When the tissues in the bone do not get enough blood, they begin to die (a process known as necrosis). This leads to deterioration of the bone's growth plate, the area at the end of a developing bone where cartilage cells change over time into bone cells.
When bone development occurs normally, the growth plates expand and unite, which is how bones grow. However, osteochondrosis disrupts this process, leading to cell death and destruction of the newly formed tissue. Although the bone tissue regrows, the process can cause temporary problems in the affected area. Osteochondrosis can affect different areas of the body that have growth plates.
Some doctors believe that Panner's disease is a precursor to a separate but similar condition called osteochondritis dissecans of the capitellum (OCD), which occurs in older kids. OCD is different from Panner's disease because it doesn't involve the growth plate. By the time OCD occurs, the growth plates have fused and the skeleton has finished growing. In OCD, loose bone fragments (also called loose bodies) may develop in the joint as well.
To understand what causes Panner's disease, it's helpful to understand the anatomy of the arm. At the elbow, the humerus (the long bone that extends from the shoulder to the elbow in the upper arm) meets the two bones that make up the forearm, the ulna and the radius. The rounded knob on the end of the humerus, the capitellum, fits into head of the radius, which is shaped like a cup and holds the capitellum.
During childhood, rapid bone growth occurs. However, the blood supply to these areas of bone growth sometimes gets disrupted. Panner's disease results when the blood supply to the entire capitellum is disrupted. When the cells within the growth plate of the capitellum die, the surrounding bone softens and collapses, causing the knob of the capitellum to become flat.
Because bones normally undergo a continuous rebuilding process, old cells are reabsorbed into the bone and new cells begin to form within and rebuild the growth plate within a period of weeks or months. Eventually, through a process called remodeling, they return the capitellum to its normal round shape.
Doctors do not fully understand why some kids get Panner's disease, but many believe that the disease is hereditary. It generally seems to be brought on by repetitive overuse of the elbow that puts pressure on and strains the elbow during this period of rapid bone growth. Such overuse can result from participation in activities that involve throwing or putting strong pressure on the joints, such as baseball and gymnastics. Then these repeated mild traumas cause the area to become swollen and irritated, which causes pain.
The main sign of Panner's disease is dull, aching elbow pain around the outside part of elbow, near the capitellum. The pain generally worsens with activity, such as throwing a ball, and becomes better with rest.
Kids may also experience:
inability to fully straighten the elbow
inability to fully turn the arm around (known as pronation and supination)
Symptoms usually begin unexpectedly and cannot be attributed to any specific event or injury. They may last for several weeks to several months.
To determine whether a child has Panner's disease, the doctor will first gather some information by asking questions about the child's age, activity level, participation in sports, and dominant arm. Then the doctor will examine the elbows, comparing the sore elbow with the healthy elbow. The doctor will press on and around the elbow to see if doing so causes pain. The doctor will also ask the child to move the arm in certain directions to check how well it can move and whether that movement causes pain.
The doctor will probably order X-rays of the elbow to look for irregularities and confirm the diagnosis. X-rays allow the doctor to see the shape of the capitellum, which may appear flat. X-rays may also show that the growth plate looks irregular or fragmented and reveal areas where bone resorption has taken place.
Some doctors may use magnetic resonance imaging (MRI) scans to look at the bone in more detail and gauge the extent of swelling.
Because the bones repair their blood supply and rebuild themselves on their own, most kids with Panner's disease require very little treatment. The immediate goal is to relieve pain, and the best way to do this is to rest the affected elbow. This might mean not participating in certain activities and sports until the elbow has healed. Rest should help to greatly relieve pain and swelling and allow the gradual return of elbow movement.
The doctor will monitor the recovery and determine when a child can begin participating in sports again. Usually, kids don't need to avoid sports for long.
The doctor might also recommend:
applying an icepack (wrapped in a towel) or heat to the elbow to relieve pain and swelling
engaging in physical therapy, especially if the child has difficulty bending and straightening the arm
using an over-the-counter nonsteroidal anti-inflammatory drug to reduce pain and swelling, such as acetaminophen (Tylenol) or ibuprofen (Advil, Motrin)
Note: Kids should not be given aspirin for pain due to the risk of a very serious illness called Reye syndrome.
If rest does not effectively reduce the pain, the doctor might recommend that a child wear a long-arm cast or splint to immobilize the elbow and allow it to heal. The cast might need to be worn for 3 to 4 weeks until the pain, swelling, and tenderness go away.
Although recovery sometimes takes a while, most kids with Panner's disease completely heal without any future problems. Over time (sometimes a period of 1 to 2 years), the child's bones mature, the capitellum grows back into its original shape, and the pain and other symptoms usually disappear completely.
In some cases, though, kids with Panner's disease continue to have trouble straightening out their arms completely, even after treatment.