Pigmented Villonodular Synovitis of the Foot and Ankle

Abstract

Category: Other Introduction/Purpose: Pigmented Villonodular Synovitis (PVNS) is a benign but potentially locally aggressive condition, that results in an increased proliferation of synovium, causing villous or nodular changes of synovial-lined joints and tendon sheaths. The estimated incidence of PVNS is 1.8 new cases annually per million people, of which 2.5% occur in the foot and ankle, reflected by the limited reports of PVNS in the foot and ankle literature. We present our clinical experience of 76 patients presenting with PVNS about the foot and ankle. Methods: Patients with PVNS of the foot and ankle were identified from our tertiary referral hospital patient database from 2007 to 2017. The case notes were carefully reviewed to analyse the clinical, radiological, and histopathological features and to investigate their clinical behaviour, management and the factors influencing recurrence. Results: 76 patients were identified (32 male, 44 female) with a mean age of 39 years and mean follow-up of 5 years. The majority of cases were of localised, nodular PVNS (52%, 40/76) with the diffuse PVNS cases (48%, 36/76) presenting most commonly in the hindfoot. The most common presentation was of a swelling/lump (78%- 62/79), of which pain was an associated feature in 11% (7/62) and restricted range of motion a feature in 10% (6/62). Osteoarthritic change and cortical erosions were more commonly associated with diffuse PVNS. All patients underwent open synovectomy with a recurrence rate of 11% (7/76), all of which were the diffuse type. In those cases where synovectomy was paired with arthrodesis of the joint, there were no cases of recurrence (12%,9/76). Conclusion: We present our tertiary referral experience of PVNS in the foot and ankle as the largest series in the foot ankle ankle literature to date. A high index of suspicion is required in diagnosing PVNS. Nodular PVNS appears more common in the foot whereas diffuse PVNS more common in the ankle and hindfoot. Open synovectomy yields low recurrence rates. Although theorised, there is insufficient evidence to establish whether concurrent arthrodesis of the affected joint reduces risk of recurrence.