Deposition of apatite crystals can be observed as calcific periarthritis and articular calcifications. Deposition of these crystals in the tendons and bursae of the rotator cuff of the shoulder is found in about 3% of adults; it is most of the time asymptomatic. Calcifications often totally disappear after an acute flare up. Intraarticular apatite crystals can be identified in synovial fluids of patients with severe destructive osteoarthrosis, mainly of the shoulder joints. Management with NSAID's and local corticosteroid injections is often very helpful. In rare cases the aspiration with a needle of a calcification or an operative removal is necessary.
In Brief Identification of crystals in the synovial fluid (SF) is mandatory for the diagnosis of a microcrystal deposition arthropathy. In some cases, this analysis can be troublesome, especially in medical centers where a qualified practitioner is not continually present. Therefore, we investigated a method for preservation of a wet preparation of SF for 24 hours at room temperature. The procedure consisted in storing the preparation in a closed Petri plate whose bottom was covered by a cellulose compress moistened with saline (0.9% sodium chloride) separated from the slide by 2 wooden or glass sticks. The joint aspirates of 20 consecutive patients with various microcrystal arthropathies were read immediately after aspiration and reviewed after 24 hours on the slides stored according to the previously mentioned procedure. For 11 of the 20 cases, a second SF preparation was stored in normal conditions. The amounts of crystals were estimated semiquantitatively.Preparations stored in the Petri plates were clearly readable after 24 hours and crystals still identifiable on each slide. The amounts of crystals were still the same. After 24 hours, the preparations stored in normal conditions were dry, the shapes of the crystals were blurred, their amount was reduced, and birefringent artifacts were seen. In conclusion, when the amounts of SF are small and a skilled technician or a rheumatologist is not immediately available for reading the preparation, storing the wet preparation of SF in a moistened Petri plate can prove useful. Small amounts of synovial fluid can be preserved for crystal examination as wet drops on slides, kept in a closed Petri dish with a moistened pad.
We report a case of large medial meniscal cyst responsible for symptomatic saphenous nerve compression in a 49-year-old male with a history of mild trauma to the affected knee. We are not aware of any similar cases in the literature. The lesion was delineated by ultrasonography and even more clearly by magnetic resonance imaging. At surgery, the saphenous nerve was seen to be displaced by the cyst. Cystectomy and partial meniscectomy were performed. The outcome was favorable.
