Successful Chemical Synovectomy in a Patient with Acquired von Willebrand Syndrome with Chronic Synovitis of knee: A Case Report

Milan, ITLAY: Acquired von Willebrand syndrome (AVWS) is a rare, non-hereditary bleeding disorder related to heterogeneous medical conditions such as hematological malignancies and cardiovascular and autoimmune diseases.

Roberta Gualtierotti et al describe the clinical course of a 62-year-old man with polycythemia vera who experienced post-traumatic knee and leg swelling due to hemarthrosis. The case report has been published in the Rheumatology and Therapy journal.

The patient was treated at another center with low molecular weight heparin due to misdiagnosed deep vein thrombosis further exacerbating the ongoing bleeding. At the author's center, the patient was diagnosed with AVWS with reduced von Willebrand factor (VWF):GPIbR plasma activity and loss of high molecular weight multimers (HMWM). He was treated with compressive bandages, temporary discontinuation of ASA and LMWH, and no transfusion support. A couple of weeks later, after the resolution of hemarthrosis and muscular hematoma, standard therapy was reestablished.

Five months later, on clinical recurrence of knee and leg swelling, knee ultrasound scan showed the presence of chronic synovitis and a hemorrhagic Baker's cyst with signs of rupture. MRI evaluation confirmed synovial thickening with hyperthrophic villous projections of the knee and the presence of a voluminous Baker's cyst.

Laboratory tests were performed, showing normal hemoglobin values (13.6 g/dL), persistent neutrophilia (white blood cells 14,980/ mm3 , neutrophils 11,960/mm3 ) and thrombocytosis (640,000/mm3 ), with FVIII:C and vWF:Ag in normal ranges and persistently decreased VWF activity (VWF:GPIbR 30%).

In order to manage chronic synovitis and to prevent further joint bleeding, the authors decided to perform chemical synovectomy of the affected knee. The patient underwent four weekly intraarticular injections of rifampicin (2 ml), methylprednisolone (40 mg) and lidocaine (1 ml). The procedure was performed through a lateral suprapatellar approach in order to perform a synovectomy of the whole knee, followed by cryotherapy and rest for at least 2 days following each injection. Considering the low levels of VWF activity, the antiplatelet medication was withheld and a prophylaxis with intravenous plasma-derived VWF concentrate was administered prior to each procedure.

After the first injection, significant reduction in joint swelling and relief from pain was reported by the patient, and after two cycles, an ultrasound scan documented the resolution of capsule distension and significant reduction of popliteal cyst dimensions. At the end of the full course of chemical synovectomy, the patient reported complete resolution of knee pain, progressive restoration of function and range of motion of the affected joint, and no need for walking aids. The ultrasound scan documented a complete resolution of Baker's cyst and laboratory test showed a hemoglobin level of 13.8 g/dl, platelet count of 314,000/mm3 , white blood cell count of 11,940/ mmc (neutrophils 9,150/mm3 ), FVIII 132%, vWF:Ag 104% and vWF:GPIbR 64%.

The authors commented - "point-of-care musculoskeletal ultrasound proved a very useful tool in detecting rare complications of AVWS such as hemarthrosis and hemorrhagic Baker's cyst. The latter is often misdiagnosed for DVT in patients with a condition that increases prothrombotic risk, such as myeloproliferative neoplasm (MPN). However, MPN may be associated with the risk of developing an acquired bleeding disorder as well, thus making the identification and management of bleeding events in these patients more challenging. In conclusion, we report the successful management by chemical synovectomy of recurrent hemarthrosis as a rare complication of AVWS in a patient with PV."

Further reading:

Successful Chemical Synovectomy in a Patient with Acquired von Willebrand Syndrome with Chronic Synovitis Due to Recurrent Knee Hemarthrosis: A Case Report

Roberta Gualtierotti, Claudio De Magistris et al Rheumatology and Therapy, 1465–1474 (2022) https://doi.org/10.1007/s40744-022-00477-2