Synovial chondromatosis is a dysplastic process accompanied by the formation of cartilaginous (chondromic) bodies in the synovial membrane of the joints. Symptoms accompanied by arthralgia, local swelling, crunching during movement, limited mobility of the limb, periodic blockades of the affected joint. Disease is diagnosed by ultrasound, X-ray examination, MRI, CT, arthrography, arthroscopy. Treatment is operative; it involves arthroscopic removal of free intra-articular bodies or synovectomy.
M67 Other lesions of synovial membranes and tendons
Synovial chondromatosis (cartilaginous insular metaplasia of the synovial membrane) is a cartilaginous degeneration of the synovial membrane, as a result of which chondromic or bony bodies ranging in size from a few millimeters to 5 cm are formed in the joint cavity. In clinical rheumatology, synovial chondromatosis is diagnosed quite rarely. The disease is found mainly in middle-aged and older men, but there are cases of congenital pathology detected in children of the first year of life. The synovial membranes of large joints are most often subjected to cartilaginous metaplasia: knee, hip, elbow, shoulder; the ankle and wrist joints are less often affected.
The etiology of synovial chondromatosis is not completely clear. It is assumed that the congenital form of the disease is based on a violation of the embryonic differentiation of joint tissues. Acquired cartilaginous insular synovial metaplasia occurs in response to any external causes that disrupt biochemical and metabolic processes in the tissues of the joint. Provoking factors can be simultaneous or repeated joint injuries, constant physical exertion, infectious diseases.
With synovial chondromatosis, synovial membrane cells with a normal histological structure undergo cartilaginous metaplasia, resulting in the formation of cartilaginous nodules. Macroscopically, areas covered with dense tubercles are found in the synovial membrane; sometimes the nodules look like polyps on the pedicle. Initially, these metaplastic islets are associated with the synovial membrane, but after lacing they become free intra-articular bodies (“articular mouse”).
Chondromic corpuscles usually have a rounded shape, their sizes vary from a few millimeters to 5 cm. The number of free intra-articular bodies can reach several tens or even hundreds. In rare cases, synovial chondromatosis undergoes malignancy.
Microscopic changes in the synovial membrane are characterized by its thickening, villous hyperplasia, lymphoid and plasma infiltration caused by reactive synovitis, the presence of chondromatous islets. Free chondromic bodies are morphologically represented by hyaline cartilage with foci of calcification.
First of all, all variants of joint chondromatosis are divided into congenital and postnatal. Congenital chondromatosis refers to true joint dysplasia and can occur with the formation of intra-articular bone bodies or bone-cartilage conglomerates. Postnatal synovial metaplasia can be benign tumor-like (chondroma) or malignant (chondrosarcoma).
In addition, there are stable, progressive and rare forms of synovial chondromatosis.
The stable form can occur with the presence of single bodies (up to 8-10) or primary multiple bodies (up to 20-25). At the same time, the formation of new cartilaginous bodies is either sharply inhibited, or does not occur at all.
The progressive form of joint chondromatosis is characterized by the continuous formation of new chondromic bodies, the number of which can reach several tens and hundreds.
Rare forms include osteomatosis, chondromatosis of tendon sheaths and mucous bags.
Clinically, synovial chondromatosis proceeds as subacute arthritis. At the same time, patients are concerned about moderate arthralgia, limited mobility in the limb, crunching during movements. In the case of accumulation of effusion in the joint cavity, there is swelling of soft tissues, a local increase in temperature over the affected joint.
When a “joint mouse” is formed, its infringement between the articular surfaces may occur, leading to partial or complete blockage of the joint. After the release of the chondromic body into the lumen of the capsule, the volume of movements in the joint is restored. Frequent or prolonged “jamming” of the joint can lead to the formation of stiffness, contracture and atrophy of the limb muscles. The consequence of the constant traumatization of epiphyseal cartilage by free chondromic bodies is deforming osteoarthritis (gonarthrosis, coxarthrosis, etc.).
Synovial chondromatosis is diagnosed on the basis of clinical data, the results of instrumental studies, histological analysis of the synovial membrane.
- Non-invasive studies. Radiographs show multiple spherical or oval shadows with clear contours. However, an overview radiography of the joints reveals only intra-articular bodies containing calcium salts. Additional information regarding the number, size and location of cartilaginous bodies can be obtained using ultrasound of the joints, thermography, arthrography, MRI and CT of the joints.
- Invasive diagnostics. Reliable confirmation of joint chondromatosis is possible only with arthroscopy and synovial membrane biopsy. Diagnostic surgery makes it possible to visually verify the presence of chondromic bodies, assess the condition of the synovial membrane and the degree of damage to the articular surfaces.
Differential diagnosis of suspected synovial chondromatosis should be carried out with chronic arthritis, chondrocalcinosis.
Treatment of cartilaginous insular metaplasia of the synovial membrane can only be operative. At the same time, the volume of surgical intervention depends on the form of synovial chondromatosis. In the case of a stable form with single chondromic bodies, it is possible to limit the arthroscopic removal of intra-articular bodies and partial synovectomy, during which metaplastic areas of the synovial membrane are excised.
With a progressive form of synovial chondromatosis, in order to avoid recurrence of the disease, arthrotomy and total synovectomy are justified. In the postoperative period, physiotherapy, exercise therapy, and training on simulators are prescribed to restore the full range of movements in the joint.
Deforming arthrosis is an indication for arthroplasty or joint replacement; in some cases, arthrodesis. With a malignant form of chondromatosis, radical resection of the joint with subsequent total endoprosthetics is indicated, and if resection is impossible within healthy tissues, amputation of the limb is indicated.
The prognosis for the restoration of joint function depends on the degree of damage. After non-radical surgical treatment of joint chondromatosis, relapses of the disease may occur.