I went through an extensive set of medical tests to figure out what was wrong with my wrist. The surgeons were especially excited to know if I had Preiser’s disease. Turns out I had a rare case of osteochondritis dissecans (OCD). What’s the difference between these two problems?

There are some experts who consider these two problems to be one and the same with just a few differences. You might say they are two conditions on a continuum. Others view them as separate entities.

Preiser’s disease was named for the physician who first described it in 1910. It is a condition of osteonecrosis (death of bone) of the scaphoid bone in the wrist. The scaphoid is the first bone in the wrist next to the radius (forearm bone on the thumb side).

Osteonecrosis refers to death of the bone caused by a loss of blood supply. Avascular necrosis (AVN) is a term used to refer to loss of blood to the bone with subsequent death of the bone.

Some experts say this is a spontaneous condition. In other words, it happens without any apparent reason. Others suggest a small fracture or other trauma is the main cause of Preiser’s disease.

With osteochondritis dissecans (OCD), there is a loss of blood supply to the scaphoid but that’s not how the problem got started — that’s a result of the main problem. A piece of the articular cartilage detaches or separates from the underlying layer called the subchondral bone.

Basically, OCD is a separation of the joint lining from the first layer of bone underneath. When the subchondral bone just under the cartilage surface is injured, there is also damage of the blood vessels to the bone. Without blood flow, the area of damaged bone actually dies. This area of dead bone can be seen on an X-ray and is sometimes referred to as the osteochondritis lesion.

Symptoms are pretty much the same for both conditions. There is wrist pain at rest and with movement. Tenderness over the scaphoid bone is common. Decreased grip strength is often reported.

Clinical tests can’t differentiate between the two problems. Imaging studies such as X-rays, CT scans, and MRIs are used to diagnose the problem. The main difference is that osteochondritis dissecans is a focal problem — meaning the damage is just located on one part of one bone. With Preiser’s, there are multiple places on the scaphoid where the bone has broken into pieces or fragments because of a loss of blood supply.

The final diagnosis may not be possible until the surgeon looks inside the joint arthroscopically. Seeing the whole scaphoid bone and examining the damage, location, and effects of the lesions aids in making a clear call on what is causing the patient’s symptoms.