Continuing Education Activity

Synovial chondromatosis typically presents with large joint effusion(s), and joints may appear deformed due to swelling or synovial hypertrophy. Synovial chondromatosis can result in severe disability and dysfunction. However, most cases are benign and this condition rarely undergoes malignant transformation. The initial diagnosis of synovial chondromatosis is made through thorough history and physical examination and radiological evaluation of an affected joint. Involved joints are painful at rest and pain is worsened with motion. The range of motion is usually decreased, and x-ray evaluation reveals multiple loose radio-opaque chondroid bodies of varied sizes within the joint. This activity addresses the presentation, evaluation, and management of synovial chondromatosis and examines the role of an interprofessional team approach to the care of affected patients.

Objectives:

• Identify the presentations of the primary and secondary forms of synovial chrondromatosis.
• Describe the pathophysiology of synovial chondromatosis.
• Outline the management of the primary and secondary forms of synovial chrondromatosis.
• Summarize interprofessional team strategies for improving care coordination and communication to enhance outcomes for patients affected by synovial chondromatosis.

Introduction

Synovial chondromatosis is a benign condition that can result in severe disability and dysfunction of an involved synovial joint. Observation of involved cases indicates that this benign condition rarely undergoes malignant degeneration. The initial diagnosis is made through a thorough history and physical examination and radiological evaluation of an affected joint. These joints usually present as having a large effusion and sometimes appearing deformed due to swelling or synovial hypertrophy. They are painful at rest and are more painful with motion. The range of motion is usually decreased. X-ray evaluation reveals multiple loose radio-opaque chondroid bodies of varied sizes in a joint.  MRI arthrogram enables better evaluation of the process and the extent of involvement within the joint and surrounding tissue. Synovial chondromatosis is usually monoarticular although rare cases of multiple joint involvements occur. The process may occur in two forms: primary synovial chondromatosis (also referred to as Reichel syndrome) and secondary synovial chondromatosis). The primary and secondary forms have different presentations, and as such are treated differently. In rare cases, an extra-articular form of the condition can be identified. In these cases, the lesions are found to be in bursal tissue and/or in tenosynovial tissue in proximity to an involved joint.[1][2][3][4]

Etiology

The etiology of the primary form has not been determined. Elevated levels of bone morphogenic protein in the loose body lesions and the affected synovial joints of patients with primary synovial chondromatosis have been documented. However, the etiological importance of this has not been determined. Similarly, elevated levels of interleukin-6 and vascular endothelial growth factor-A have been found in these joints, but the importance of these findings is not certain.  Secondary synovial chondromatosis is felt to occur ar a result of mechanical changes in a joint due to arthropathy. The formation of loose chondral bodies is thought to be part of the degenerative process in these joints.

Epidemiology

Men are reported to be affected with synovial chondromatosis up to four times more commonly than women. The knee is most common joint affected. However, synovial chondromatosis can affect any synovial joint (the hip, the elbow, the shoulder, the temporal mandibular joint, and the ankle may also be affected). A rare occurrence is an extra-articular presentation of synovial-chondral lesions. This occurs in synovial lined bursal tissue or tenosynovium in which the typical chondral loose bodies form. These are referred to as tenosynovial chondromatosis or bursal chondromatosis. Synovial chondromatosis occurs most commonly in the fifth decade of life, it is rarely present before the age of 20, and it is very rare in children. Reference to both primary form (no evidence of concurrent joint pathology) and secondary form (occurring in the setting of joint degeneration) is made in the literature. The secondary form occurs more common and usually, in older individuals.

Pathophysiology

X-ray examination reveals irregularly shaped loose bodies within a synovial joint. This number varies anywhere from two or three loose bodies to several dozens. They present in varied sizes and several loose bodies may combine to form larger bodies. The number of intraarticular lesions is greater in the primary type than the secondary type. The gross and microscopic evaluation of the loose bodies reveals lobulated masses of hyaline cartilage surrounded by a layer of synovial tissue. The hyaline cartilage is hypercellular, and the cells are often atypical. These atypical changes are multinucleated cells, myxoid degeneration of matrix, crowding of cell nuclei, and large nuclei. In long-standing disease, the lobules can undergo peripheral ossification. High levels of bone morphogenic protein have been found in the loose cartilaginous bodies and synovial tissue. The loose bodies may create pathological mechanical wear on joint surfaces and result in various types of erosion of articular surfaces. The process is classified as a benign neoplastic rather than a metaplastic lesion.

History and Physical

Patients typically present with joint pain as a chief complaint. This usually is coupled with complaints of joint swelling.  It most frequently is monoarticular in the primary form and may be multi-articular in the secondary form. Occasionally the patient will experience locking or catching in the joint. Pain is increased with weight bearing and may also be present at rest. Primary chondromatosis can rarely recur. In the secondary form, a history of osteoarthritis, post-traumatic arthritis, or rheumatoid arthritis may be present. Joint effusion may increase with increased activity. With increased joint effusions, pain can also increase.

Evaluation

Radiographic findings enable differentiation of primary from secondary types. If radiographs indicate no underlying joint pathology, the primary type can be diagnosed. MRI and MRI arthrography are also helpful in making the diagnosis. MRI can help differentiate and diagnose bursal extension of the disease process. In the hip bursal extension into the iliopsoas and obturator externus, bursa has been identified in up to 71% of the cases. An evaluation of patients with findings that suggest secondary synovial chondromatosis should include an attempt to identify underlying arthritic processes.[5][6][7][8][9]

Treatment / Management

Management of primary synovial chondromatosis is surgery. Current arthroscopic surgical techniques allow for arthroscopic surgical management, however, occasionally open procedures may be necessary.  Removal of loose bodies with partial synovectomy of the involved joints results in decreased pain, improved mechanical function, and decreased swelling in most cases. Open procedures have similar results, but surgical morbidity is greater. Post-operative management includes a progressive range of motion and strengthening of peri-articular muscle groups. The use of post-operative non-steroidal anti-inflammatory medication is not confirmed as being beneficial. Rare re-occurrence is reported following surgical management with partial synovectomy.

Secondary synovial chondromatosis is managed by anti-inflammatory medication with the additional management of the inflammatory joint symptoms until or unless mechanical symptoms prohibit adequate function. At this point, surgical management is indicated. Surgical management should address improving long-term function and prognoses. As such, joint reconstruction or arthroplasty in addition to removal of loose bodies is indicated.

Differential Diagnosis

Differential diagnosis should also consider the possibility of a malignant lesion. Interosseous low-grade chondrosarcoma that extends into a joint and synovial cell sarcoma can be considered if the lesions involve bone adjacent to a joint. MRI findings help differentiate possible malignant. Marrow invasion is not usual with synovial chondromatosis. It is more likely to be present with malignant lesions.

Prognosis

There is rarely reoccurrence of primary synovial chondromatosis after surgical management with the removal of the loose bodies and partial synovectomy. Reoccurrence has been reported in a case involving the temporal mandibular joint.

Enhancing Healthcare Team Outcomes

When patients present to the primary care provider or nurse practitioner with joint pain, the differential diagnosis is huge. Synovial chondromatosis is one condition that can present with joint pain and is best managed by an orthopedic surgeon. The management of primary synovial chondromatosis is surgery. Current arthroscopic surgical techniques allow for arthroscopic surgical management, however, occasionally open procedures may be necessary. 

Post-operative management includes a progressive range of motion and strengthening of peri-articular muscle groups. Secondary synovial chondromatosis is initially managed by anti-inflammatory medication unless mechanical symptoms prohibit adequate function. At this point, surgical management is indicated. Surgical management should address improving long-term function and prognoses. As such, joint reconstruction or arthroplasty in addition to removal of loose bodies is indicated.[10][11][12]