Clinical Symptoms of Villous Synovitis
The onset is gradual and insidious. Stiffness is the salient symptom, but sometimes the subject is more distressed by a sense of weakness, distension and unreliability. Pain is slight or absent, save when during walking pseudo-locking occurs. The mobility of the joints is usually unimpaired, and if any limitation exist it is the power of full extension that is usually restricted.
Objectively the joint shows either general enlargement or swelling localised to the supra- or infra-patellar regions. Intra-articular effusion which comes and goes is a very characteristic feature. On palpation a peculiar soft silken crepitus will be heard and felt as the patient alternately flexes and extends the limb. The enlarged fringes are also easily to be felt as knots or nodules which can be moved up or down on the underlying bone. The ease with which they can be appreciated depends upon the degree of effusion present at the time. Judging from their symptomatology, it seems probable that some of the cases included in Sir Dyce Duckworth’s category, chronic deforming gout, are of this description.
The diagnosis of villous synovitis should not be considered complete without skiagraphy being undertaken to reveal or exclude osteophytic outgrowths. For the subjective symptoms and signs of early osteoarthritis are practically identical with those of villous arthritis, and although the presence of osteoarthritic lesions elsewhere would be suggestive, skiagraphy alone will enable us to effect a differentiation with certainty. Indeed, Bassett Jones and myself are strongly of the opinion that the life history of osteoarthritis involves two stages: (1) a primary or pre-osteophytic phase, often of prolonged duration, whose clinical characteristics are those of villous hypertrophy; (2) a secondary or terminal stage, in which bony and cartilaginous outgrowths make their appearance.
Other symmetrical disorders of the knees that may be wrongly ascribed to gout are hydrarthrosis and gummatous synovitis.
Bilateral Hydrarthrosis.—Given effusion into both knees which is passive, copious, and persistent rather than recurrent, then its possible infective origin must be carefully canvassed. The common sources are gonorrhœa, syphilis, and tubercle. The history or presence of an urethral discharge and detection of the gonococcus will identify the first named. In syphilis the existence of other lesions, the response to Wassermann’s test and specific treatment are the points on which to rely, and in tubercle, the detection of visceral foci and the sero-reaction will give the clue.
As to the intermittent type of hydrarthrosis, the remarkable periodicity in incidence of the effusion will suffice to obviate any possibility of confusion.
Peri-synovial and Peri-bursal Gummata.—Affecting as they do commonly the knee joints of adults, these may, in the absence of a history of infection, be a source of error. The uneven and nodular swelling may quite easily be confounded with uratic deposits. Pain is slight and mobility but little impaired. The presence of neighbouring scars, a positive Wassermann reaction, and a favourable response to anti-syphilitic therapy will clear up the diagnosis.