Synovial Chondromatosis

Introduction

Synovial chondromatosis is a rare, non-cancerous joint condition where the lining of the joint (called the synovium) starts to produce small nodules of cartilage. These nodules can sometimes break off and form loose bodies that float within the joint. This condition most often affects large joints such as the knee, hip, shoulder, or elbow. Symptoms include joint pain, swelling, stiffness, and sometimes a catching or locking sensation when moving the joint. The exact cause isn’t fully understood, but it is thought to result from abnormal activity in the synovium.

Symptoms of Synovial Chondromatosis

The symptoms of synovial chondromatosis can vary but often include persistent pain, swelling, reduced range of motion, and joint stiffness. Patients may notice clicking, catching, or locking if the loose cartilage bodies get caught between the bones. Over time, the constant irritation from these loose bodies can wear down the joint surface, leading to arthritis-like symptoms. Because the condition develops slowly, people may not realize something is wrong until the joint becomes very uncomfortable or difficult to move.

Diagnosing Synovial Chondromatosis

To make the diagnosis, a doctor will begin by asking about symptoms such as pain, stiffness, or locking of the joint, and how long these have been present. During the physical exam, they may check for swelling, tenderness, and limited movement. Imaging studies are very important. X-rays can sometimes show the loose cartilage nodules if they have calcified (hardened with minerals). An MRI or CT scan may be ordered to better see the nodules and assess the health of the joint. In some cases, the diagnosis is only confirmed during surgery when the nodules are directly visualized.

Treatment of Synovial Chondromatosis

The treatment depends on the severity of symptoms and how much the joint is affected. If the symptoms are mild, doctors may recommend observation, activity modification, and medications to manage pain and swelling. However, because the condition involves abnormal cartilage growth, symptoms often persist or worsen over time, and surgery may eventually be needed.

When Surgery is Required to Treat Synovial Chondromatosis

Surgery is usually recommended if pain, stiffness, or locking becomes severe or if the joint is at risk of developing arthritis. The goal of surgery is to remove the loose cartilage nodules and, if necessary, remove or clean up the affected synovium (a procedure called synovectomy). Surgery can be done arthroscopically (using small instruments and a camera through tiny incisions) or through an open procedure, depending on the extent of the condition.

Prognosis and Long-Term Outlook

Most people do well after treatment, especially if the condition is caught before the joint develops significant arthritis. However, synovial chondromatosis can sometimes come back, even after surgery. Long-term complications may include chronic pain, stiffness, or arthritis in the affected joint. Regular follow-up with a doctor is important to monitor symptoms and manage any recurrence.

Edited by Stephen Pinney MD, September 13th 2025.