Open synovectomy treatment for intra- and extraarticular localized pigmented villonodular synovitis of the knee: a case report

Background Pigmented villonodular synovitis (PVNS) is a rare, benign, proliferative neoplastic process that commonly affects synovial-lined anatomic spaces. The diffuse type (DPVNS) is characterized by invasion of the entire joint synovium, while the localized type (LPVNS) is characterized by a relatively normal synovial appearance. This report describes a unique case of massive intraarticular LPVNS with an extraarticular extension through the lateral patellar retinaculum. No similar cases have been found in the literature. Case presentation A 58-year-old woman had a history of hyperuricemia and knee trauma and presented with unilateral knee acute swelling and pain symptoms with sudden onset. Recent expansion of the LPVNS caused the development of a tender palpable soft tissue mass in the anterolateral aspect of the knee and acute reduced mobility. Preoperative magnetic resonance imaging of the knee revealed the presence of only the soft tissue mass and mild degenerative changes. Open synovectomy was performed successfully to excise the mass. Intraoperatively, macroscopic features of the bright brown inflamed synovium suggested LPVNS, which was confirmed histopathologically. Postoperatively, the symptoms of limited mobility and pain were appreciably relieved. Recurrence was not observed during the clinical follow-up at 1, 6 or 18 months after surgery. Conclusions Here, we report the unique case of localized pigmented villonodular synovitis of the knee in a misdiagnosed patient with intra- and extraarticular lesion, which might be attributed to the history of knee trauma and the focal defect of the lateral patellar retinaculum. Open synovectomy effectively relieved the symptoms of limited mobility and pain and no recurrence was observed prior to 18 months postoperatively. To reduce misdiagnosis, MRI examinations are recommended for all patients suspected of having PVNS, including those who have a history of hyperuricemia.

Long-term functional outcomes of diffuse pigmented villonodular synovitis of the knee after synovectomy with or without adjuvant radiotherapy

Background Diffuse pigmented villonodular synovitis (PVNS) of the knee is a rare benign disease that has a destructive clinical course. Reported treatment options include arthroscopic or open synovectomy with or without adjuvant radiotherapy of various doses. This study compared the long-term functional outcomes and disease control among treatment modalities and discussed 22 years of experience with radiotherapy (RT) as an adjuvant treatment for PVNS of knee.Methods A single-center database was searched for patients who received synovectomy of knee with the pathologic diagnosis of PVNS. General data, treatment modalities, and recurrent status were retrospectively collected from medical records. Functional outcomes were evaluated by Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) through phone interviews by an independent orthopedist.Results From January 1995 to December 2017, 24 patients with diffuse PVNS of knee were identified, including 19 receiving open synovectomy (OP) and 5 undergoing arthroscopic surgery (AS). Adjuvant RT was performed on 14 patients with a median dose of 34.25 Gy (range 20-40 Gy). After median follow up of 6 years, clinically or radiographically confirmed recurrences were recorded in 10 cases. The local recurrence rate was significantly lower in the OP+RT group than the OP group (8.3% vs. 57.1%, p =0.038). Among those with preserved knee joints, there was no significant difference in the WOMAC score and stiffness score between patients in the OP+RT and OP groups.Conclusions In conclusion, for patients with diffuse PVNS of knee, the addition of moderate-dose adjuvant RT to open synovectomy provided excellent local control while maintaining good joint function with limited treatment-related morbidity. Our study emphasized the importance of moderate dose of RT in diffuse PVNS of knee joint.

PO 18254 - Synovial giant cell tumor of the ankle

Introduction: Synovial giant cell tumor is a benign neoplasm that is rarely reported in the form of malignant metastasis. Synovial giant cell tumor most frequently occurs in the hand, hip and knee and rarely occurs in the ankle and foot. The present study describes 2 rare cases of synovial giant cell tumor located in the hindfoot (one with diffuse disease with tibiotarsal and subtalar joint involvement and the other with signs of periarticular ankle involvement) and describes the chosen treatment. Methods: Two consecutive patients were evaluated, and a brief literature review was performed. Results: Open synovectomy was performed in both cases, with complete tumor resection and satisfactory patient progression. Conclusion: Open synovectomy was found to be a good method for the treatment of these lesions because it enabled a satisfactory approach, with good visualization of the ankle compartments and underlying joints and the ability to efficiently provide marginal excision, total synovectomy and complete tumor resection for arthrotomy, without postoperative complications.

Pigmented Villonodular Synovitis of the Foot and Ankle

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.

Long-term Outcome of Open Synovectomy with Radial Head Resection for Rheumatoid Elbow

Background: We reviewed our surgical results of open synovectomy with radial head resection for rheumatoid elbow. Methods: We reviewed the 20 patients (22 elbows) underwent open synovectomy for rheumatoid elbows retrospectively. The minimum follow-up period is over 10 years, and the average was 13 years 4 months. Surgical outcomes were evaluated using the VAS pain scale, range of motion, and radiologic outcomes including Larsen’s grade and carrying angle. Results: The mean VAS score was 39 (range, 10–90) at last follow-up. The only one patient underwent revision surgery. The mean flexion-extension range of elbow was -28°–112° and arc of motion was 82° before surgery. The mean flexion-extension range of elbow was -23°–114°, and arc of motion was 90° at last follow-up. Radiologic findings of nine elbows in 21 elbows worsened at last follow-up according to the Larsen–s grade. Carrying angle increased by mean 4.2°, and it increased by 10° or more in four elbows. Conclusions: Our results show that open synovectomy with radial head resection resulted in functional motion maintenance and pain control for a long time, but often resulted in an elbow valgus deformity. Our findings suggest open synovectomy can be considered as palliative treatment for painful rheumatoid elbow.