History

A complete history is important in the evaluation of patients with synovial disorders. The presence of other affected joints, the length of time symptoms have been experienced, exacerbating symptoms, and the amount of disability experienced by the patient on a daily basis are important pieces of information. Patients with rheumatoid arthritis may have more systemic complaints, including morning stiffness and other affected joints, particularly the small joints of the hands and feet. Pigmented villonodular synovitis (PVNS) is typically a monoarticular process that affects adults in the third or fourth decade of life. Symptoms are mechanical in nature and may be similar to those seen in patients with meniscal tears. Clinically patients have the insidious onset of localized warmth, swelling, and stiffness with occasional locking and a palpable mass. Plica syndrome is a finding in patients with anteromedial knee pain. Patients experience tightness, snapping, giving way, and pain with repetitive activities. Clinically it is difficult to distinguish plica syndrome from other causes of knee pain such as meniscal tears, patellar tendinitis, or patellofemoral pain syndrome.

Physical Examination and Laboratory Tests

A full rheumatologic workup should be completed for patients with systemic diseases, and appropriate laboratory tests should be up to date. Patients with hemophilia require a consultation with a hematologist. If surgical treatment is to be pursued, it is essential to have a well–thought-out plan for perioperative management of clotting factors.

Other joints may be affected in patients with rheumatic or autoimmune disorders, and these joints should be evaluated. Patients with rheumatoid arthritis often have a flexion contracture and quadriceps atrophy in the knee region. The skin should be examined and previous incisions and subcutaneous nodules should be evaluated. The knee should be examined to determine overall alignment, range of motion, the presence of an effusion, warmth, tenderness, crepitus, strength, meniscal integrity, and stability. Collateral ligament instability or bony malalignment suggests more severe articular loss, and patients with these conditions are poor candidates for a synovectomy.

The physical examination for PVNS is often nonspecific. An effusion is associated with diffuse involvement. Palpation of the joint may show warmth and tenderness. Aspiration of the joint fluid may show a dark-brown fluid that is a result of recurrent bleeding into the joint. Cytologic studies of the aspirate may show hemosiderin pigment and multinucleated foreign body giant cells, but often the findings of these studies are normal. Ligamentous instability is uncommon in persons with PVNS.

Plica syndrome begins insidiously. Tenderness over the medial parapatellar region is common. A plica may sometimes be directly palpated and rolled under the finger, recreating the patient’s symptoms. If the medial border of the patella is palpated while pushing the patella medially with one hand and the other hand produces a valgus stress with external rotation of the tibia, pain may be elicited, suggesting plica syndrome. An effusion is not typically present in persons with plica syndrome.

Imaging

In patients with rheumatoid arthritis, cervical spine flexion and extension views should be obtained in preoperative patients to rule out cervical instability. Radiographs of the knee should be obtained. Patients with rheumatoid arthritis may have periarticular erosions and osteopenia. Radiographs in patients with PVNS can show erosive, cystic, and sclerotic lesions of the articular surface. If enough synovium that contains hemosiderin is present, soft tissue masses may be seen, but often the findings of the films are normal with well-maintained joint spaces. Magnetic resonance imaging is considered to be the most diagnostic study for PVNS. It may show nodular intraarticular masses of low signal intensity on T1- and T2-weighted images and also allows evaluation of the location and extent of disease.