What You Should Know About Subchondral Bone Cysts:
Subchondral bone cysts are benign growths in the bones of your legs or feet. They may appear anywhere along the length of your leg (or foot) but most commonly occur in the tibia and fibula, which form part of the lower leg. They are not tumors, although they do grow outwards from their original location.
They are caused by abnormal cells called osteoblasts that have been left unchecked due to insufficient bone building. These cells produce substances such as calcium phosphate crystals and other minerals, which cause the growth of new bone tissue at the site where they are produced. This leads to a buildup of extra bone in these areas.
The accumulation of excess bone causes pain and swelling around the area, making it painful to walk or even stand for long periods of time.
The symptoms of subchondral bone cysts vary widely depending on the size and location of the cyst. Some people experience no symptoms at all while others develop severe pain with activity, especially when standing up. Other times there may be no signs at all until the cyst ruptures causing deformity or disfigurement.
There is currently no cure for subchondral bone cysts, though surgery may relieve some of the discomfort associated with them.
What Are the Symptoms of a Subchondral Bone Cyst?
The symptoms of a subchondral bone cyst include:
Pain, aching, and tenderness in the affected limb.
Swelling and thickening of the skin in the area.
Muscle atrophy and weakness.
Deformity or disfigurement of the limb.
Difficulty walking or standing for extended periods of time.
What Causes a Subchondral Bone Cyst?
A subchondral bone cyst is caused by an excess of new bone growth in the affected area. This may be due to years of repetitive pressure from physical activity or trauma such as a car accident or sports injury.
Who Is at Risk for Developing a Subchondral Bone Cyst?
Anyone who has experienced years of repetitive pressure on the affected area may be at risk for a subchondral bone cyst. This includes runners, basketball players, joggers, and football players. Subchondral bone cysts are associated with osteoarthritis.
How Is a Subchondral Bone Cyst Diagnosed?
Your doctor will ask you questions about your medical history and give you a physical exam, including an assessment of your range of motion and flexibility. You may also undergo blood tests to determine if you are anemic.
An MRI scan is typically used to diagnose a subchondral bone cyst.
Treatment for a Subchondral Bone Cyst:
Surgery is the most common treatment for a subchondral bone cyst. The cyst must be removed in order to provide long-term relief from the pain and discomfort it causes.
For a subchondral bone cyst in the knee, your surgeon may perform an arthroscopy, which involves making several small cuts in your knee and then inserting a tiny camera and surgical tools to remove the cyst and repair any damaged tissue.
If the cyst is very large, surgery may not be an option because the cyst could grow back. In this case, dealing with the pain and treating the inflammation may be more effective. Some people benefit from wearing a knee brace or an elastic bandage to provide support while the cyst heals.
Others use nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen.
Sources & references used in this article:
Subchondral bone cysts by CG Woods – The Journal of bone and joint surgery …, 1961 – online.boneandjoint.org.uk
The association between subchondral bone cysts and tibial cartilage volume and risk of joint replacement in people with knee osteoarthritis: a longitudinal … by SK Tanamas, AE Wluka, JP Pelletier… – Arthritis research & …, 2010 – Springer
The cause of subchondral bone cysts in osteoarthrosis A finite element analysis by H Dürr, H Martin, C Pellengahr… – Acta Orthopaedica …, 2004 – Taylor & Francis
New surgical treatments for osteochondritis dissecans and subchondral bone cysts by LA Fortier, AJ Nixon – Veterinary Clinics: Equine Practice, 2005 – vetequine.theclinics.com
