Treatment of pigmented villonodular synovitis of the knee

Neoplastic and Non-neoplastic Soft Tissue Lesions Around the Knee

Neoplastic and non-neoplastic soft tissue masses around the knee are often incidental findings. Most of these lesions are benign with typical imaging characteristics that allow a confident diagnosis. However, some of these incidental neoplastic masses are characterized by morbidity and potential mortality. This review highlights the typical aspects of these lesions, facilitating a correct diagnosis.

Recurrence-Free Survival after Synovectomy and Subsequent Radiosynoviorthesis in Patients with Synovitis of the Knee-A Retrospective Data Analysis

BACKGROUND

Persistent knee synovitis leads to joint discomfort, incapacitating inflammation, and functional limitations. The conventional approach has involved surgical procedures to eliminate the actively inflamed synovial membrane. This study aims to investigate the recurrence-free survival and functional outcome after synovectomy and subsequent radiosynoviorthesis (RSO) in patients with knee synovitis.

METHODS

Thirty-seven knees diagnosed with pigmented villonodular synovitis (PVNS), rheumatoid arthritis (RA), and peripheral spondyloarthritis underwent synovectomy and subsequent RSO between May 2005 and October 2016. The mean age was 34.9 ± 15.1 years, and the mean follow-up period was 84 ± 36.4 months. Clinical outcomes were assessed using the Oxford Knee Score and the presence of swelling and pain at the last follow-up. Recurrence-free survival denotes the duration from synovectomy to surgical re-synovectomy.

RESULTS

In general, twelve knees underwent re-synovectomy after a mean follow-up of 34.8 ± 24.9 months. The recurrence-free survival was 83.8% at two years, 71.3% at five years, and 61.7% at ten years. The subgroup analysis revealed recurrence-free survival at two years in 63.6% of patients with PVNS, 86.7% of those with RA, and 100% of individuals with peripheral spondyloarthritis.

CONCLUSIONS

This study demonstrates that combined therapy for synovitis is an effective approach, significantly improving clinical outcomes.

Oncological and functional outcomes of modified arthroscopic resection for intra-articular tenosynovial giant cell tumor of the knee using multiple portals

BACKGROUND

Arthroscopic resection of tenosynovial giant cell tumor (TS-GCT) presents favorable outcomes. However, there are reportedly higher recurrence rates in patients who had incomplete resection. To minimize incomplete resection, we established a multiple portal approach depending on the location of the disease. In this study, we aimed to retrospectively evaluate the clinical outcomes of arthroscopic resection for both localized and diffuse types of TS-GCT of the knee.

METHODS

From 2009 to 2019, 13 patients who underwent arthroscopic synovectomy of the knee and were histologically diagnosed with TS-GCT were included in this study. The pre- and postoperative range of motion (ROM) of the knee was measured. The Japanese Orthopaedic Association (JOA) score and the Knee Injury and Osteoarthritis Outcome Score (KOOS) were assessed at the final follow-up examination. Magnetic resonance imaging was performed to detect incomplete resection or local recurrence.

RESULTS

Among the 13 patients, seven and six had localized and diffuse type TS-GCT, respectively. Regarding the knee ROM, preoperative knee flexion in patients with the localized type was limited compared with that in those with the diffuse type. However, the ROM was significantly improved in patients with both types postoperatively. The JOA score and KOOS of patients with both types at the final follow-up were favorable, and there were no significant differences between both types. There was neither recurrence nor incomplete resection in any patient for both types.

CONCLUSION

All patients, regardless of the TS-GCT type, achieved favorable outcomes after arthroscopic surgery; especially, the failure rate was 0%.

Recurrent diffuse tenosynovial giant cell tumor of the knee treated with adjuvant radiotherapy: A case report

INTRODUCTION

TGCT (tenosynovial giant cell tumor) is a mono-articular proliferative condition that begins in the synovial membranes. Diffuse TGCT (DTGCT) has more prominent symptoms with high risks of recurrency.

CASE PRESENTATION

In this case, we presented a 32-year-old male with recurrent case of DTGCT. The patient has been treated with arthroscopic synovectomy with the recurrence of disease. The patient was finally treated by open synovectomy combined with arthroscopy followed by adjuvant radiotherapy.

DISCUSSION

The aim of this case is to report the success of open synovectomy combined with arthroscopy followed by 31 cycle of adjuvant radiotherapy in the recurrent case of DTGCT.

CONCLUSION

Open synovectomy combined with arthroscopic synovectomy followed by adjuvant RT is a promising treatment modality in patient with DTGCT.

Prediction of local recurrence in tenosynovial giant cell tumor of the knee: Based on preoperative MRI evaluation into disease subtypes and severity

OBJECTIVE

Tenosynovial giant cell tumors (TSGCTs) of the knee differ in their clinical outcome according to disease subtypes and severity. The aim of this study was to determine the predictive MRI features related to local recurrence in TSGCT of the knee regarding disease subtypes and severity.

METHODS

This retrospective study included 20 patients with pathology-proven TSGCT of the knee who underwent preoperative MRI and surgery from Jan. 2007 to Jan. 2022. The anatomical point of the lesion was determined with a knee mapping. And then MRI features related to disease subtype including nodularity (single vs. multinodular); margin (circumscribed vs. infiltrative); peripheral hypointenseity (present vs. absent); internal hypointensity reflecting hemosiderin deposition (speckled vs. granular) were assessed. Third, MRI features related to disease severity including involvement of bone, cartilage, and tendon were evaluated. MRI features for predicting local recurrence of TSGCT were tested using chi-square test and logistic regression analysis.

RESULTS

Ten patients with diffuse-type TSGCT (D-TSGCT) and 10 patients with localized-type TSGCT (L-TSGCT) were included. There were six cases of local recurrence and all of them were D-TSGCT and none for L-TSGCT with statistical difference (P = 0.015). D-TSGCT that was direct risk factor for local recurrence showed more multinodular (80.0% vs. 10.0%; P = 0.007), infiltrative margin (90.0% vs. 10.0%; P = 0.002), and absent peripheral hypointensity (100.0% vs. 20.0%; P = 0.001) than L-TSGCT. Multivariate analysis showed infiltrative margin (odds ratio [OR], 81.0; P = 0.003) was independent MRI factor for D-TSGCT. Disease severity for risk of local recurrence included cartilage (66.7% vs. 7.1%; P = 0.024) and tendon (100.0% vs. 28.6%; P = 0.015) involvement compared to no local recurrence. Multivariate analysis showed tendon involvement (OR, 12.5; P = 0.042) was predictive MRI parameter for local recurrence. By combining tumor margin and tendon involvement, local recurrence was predicted sensitively on preoperative MRI (sensitivity, 100%; specificity, 50%; accuracy, 65%).

CONCLUSION

D-TSGCTs was associated with local recurrence and showed multinodularity infiltrative margin, and absent peripheral hypointensity. Disease severity including cartilage and tendon involvement was associated with local recurrence. Preoperative MRI evaluation by combining disease subtypes and severity can predict local recurrence sensitively.

A rare case of long-term joint swelling caused by pigmented villonodular synovitis in a 3-year-old girl: a case report

The clinical symptoms of pigmented villonodular synovitis (PVNS) are usually insidious and non-specific; therefore, delays in diagnosis and treatment are common. Here, we describe a case of a 3-year-old patient presenting with long-term joint swelling to highlight the significance of considering PVNS as a differential diagnosis in children to prevent misdiagnosis and ensure early treatment. After arthroscopic debridement, our patient had a favorable clinical outcome and was free of recurrence.

Midterm outcomes of 18 patients with primary intra-articular diffuse tenosynovial giant cell tumor (TGCT) of the knee treated with complete arthroscopic synovectomy and postoperative low-dose radiotherapy at a mean follow-up of 68 months

OBJECTIVE

To evaluate the long-term clinical outcome of the treatment of complete arthroscopic synovectomy combined with low-dose external radiotherapy in the knee affected by primary intra-articular diffuse tenosynovial giant cell tumor (TGCT).

METHODS

From May 2009 to January 2016, 18 patients with intra-articular diffuse TGCT underwent complete arthroscopic synovectomy and low-dose external-beam radiotherapy in Zhongnan Hospital were enrolled in this retrospective study. The preoperative symptoms of patients, the complications during or after the arthroscopic procedure and the recurrence were collected and recorded. Each patient was evaluated before treatment and at the follow-up visit. Efficacy evaluation criteria were based on Ogilvie-Harris score, and the evaluation of the functional ability of knee was based on the International Knee Documentation Committee (IKDC) Score.

RESULTS

The mean time from symptom onset to surgery was 9.1 ± 5.8 months (range from 3 to 29 months). The most frequent preoperative symptoms were joint effusion (100%), diffuse non-specific knee pain (66.7%), and a decreased range of motion (83.3%). Mean follow-up time was 68.0 ± 18.1 months (range from 35 to 120 months). The mean evaluation score according to the Ogilvie-Harris criteria before treatment was 3.19 ± 0.74, which corresponded to a rating of "poor". The mean score after treatment was 8.79 ± 1.57, rated as "good". The Ogilvie-Harris score was significantly increased after treatment (P = 0.003). The IKDC score of all patients increased significantly from 37.1 ± 3.8 before treatment to 83.9 ± 11.3 after treatment. The IKDC score was obviously increased after treatment (P = 0.001). No recurrence was noted at final follow-up. There were no complications during or after the arthroscopic procedure.

CONCLUSION

The outcome of this study proved that complete arthroscopic synovectomy combined with low-dose external radiotherapy was appropriate for treating primary intra-articular diffuse TGCT of the knee joint. It could be safely and reliably used with minimal complications, fast postoperative recovery and satisfactory control of recurrence rates.

Best clinical management of tenosynovial giant cell tumour (TGCT): A consensus paper from the community of experts

Tenosynovial giant cell tumour (TGCT) is a rare, locally aggressive, mesenchymal tumor arising from the joints, bursa and tendon sheaths. TGCT comprises a nodular- and a diffuse-type, with the former exhibiting mostly indolent course and the latter a locally aggressive behavior. Although usually not life-threatening, TGCT may cause chronic pain and adversely impact function and quality of life (QoL). CSFR1 inhibitors are effective with benefit on symptoms and QoL but are not available in most countries. The degree of uncertainty in selecting the most appropriate therapy and the lack of guidelines on the clinical management of TGCT make the adoption of new treatments inconsistent across the world, with suboptimal outcomes for patients. A global consensus meeting was organized in June 2022, involving experts from several disciplines and patient representatives from SPAGN to define the best evidence-based practice for the optimal approach to TGCT and generate the recommendations presented herein.

Immune Cell Infiltration Characteristics of Pigmented Villous Nodular Synovitis and Prediction of Potential Diagnostic Markers Based on Bioinformatics

Background

Pigmented villous nodular synovitis (PVNS) is a tumor-like proliferative disease characterized by impairment of daily activities, decreased quality of life, and a high recurrence rate. However, the specific pathological mechanisms are still ill-defined and controversial. The purpose of this study was to define potential diagnostic markers and evaluate immune cell infiltration in the pathogenesis of PVNS.

Method

The expression profile of GSE3698 was reanalyzed in the Gene Expression Omnibus (GEO) database. First, differentially expressed genes (DEGs) were identified using the R package “limma” and analyzed by Gene Ontology (GO) functional annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment. Next, the DEGs were imported into the STRING database and Cytoscape to construct a protein–protein interaction (PPI) network. Then, cytoHubba and ROC curve analyses were used to determine potential diagnostic biomarkers of PVNS. Finally, we used CIBERSORT to estimate the proportions of 22 immune cell subtypes in PVNS and analyzed the correlation between diagnostic markers and infiltrating immune cells.

Result

We found 139 DEGs (including 93 upregulated genes and 46 downregulated genes). TYROBP, FCER1G, LAPTM5, and HLA-DPB1 were identified as potential diagnostic biomarkers of PVNS. Immune cell infiltration analysis indicated that neutrophils and M2 macrophages might be associated with the genesis and progression of PVNS. Furthermore, our correlation analysis of diagnostic markers and infiltrating immune cells found that TYROBP, FCER1G, LAPTM5, and HLA-DPB1 were positively correlated with M2 macrophage infiltration and that neutrophils, TYROBP, FCER1G, and LAPTM5 were negatively correlated with plasma cell infiltration.

Conclusions

We identified TYROBP, FCER1G, LAPTM5, and HLA-DPB1 as potential diagnostic markers for PVNS and concluded that immune cell infiltration plays an important role in the genesis and progression of PVNS.

Tenosynovial giant cell tumors (TGCT): molecular biology, drug targets and non-surgical pharmacological approaches

INTRODUCTION

Tenosynovial giant cell tumor (TGCT) is a mono-articular, benign or locally aggressive and often debilitating neoplasm. Systemic therapies are becoming part of the multimodal armamentarium when surgery alone will not confer improvements. Since TGCT is characterized by colony-stimulating factor-1 (CSF1) rearrangements, the most studied molecular pathway is the CSF1 and CSF1 receptor (CSF1R) axis. Inhibiting CSF1-CSF1R interaction often yields considerable radiological and clinical responses; however, adverse events may cause treatment discontinuation because of an unfavorable risk-benefit ratio in benign disease. Only Pexidartinib is approved by the US FDA; however, the European Medicines Agency has not approved it due to uncertainties on the risk-benefit ratio. Thus, there is a need for safer and effective therapies.

AREAS COVERED

Light is shed on disease mechanisms and potential drug targets. The safety and efficacy of different systemic therapies are evaluated.

EXPERT OPINION

The CSF1-CSF1R axis is the principal drug target; however, the effect of CSF1R inhibition on angiogenesis and the role of macrophages, which are essential in the postoperative course, needs further elucidation. Systemic therapies have a promising role in treating mainly diffuse-type, TGCT patients who are not expected to clinically improve from surgery. Future drug development should focus on targeting neoplastic TGCT cells.

Giant Cell Tumor of Bone Versus Tenosynovial Giant Cell Tumor - Similarities and Differences

Giant cell tumor of bone (GCTB) and tenosynovial giant cell tumor (TGCT) share misleadingly similar names, soft texture and brown color macroscopically, osteoclast-like multinucleated giant cells microscopically and localisation in the musculoskeletal system. However, these two tumor types are biologically and clinically two distinct entities with different natural courses of progression and considerably different modes of surgical and medical treatment. In this article, we provide a detailed update on the similarities and the differences between both tumor types.GCTB is a locally aggressive osteolytic bone tumor, commonly seen in patients in their third decade of life. It usually occurs as a solitary lesion in the meta-epiphyseal region of long bones. It can be diagnosed using plain radiographic imaging, CT radiography or MRI to estimate the tumor extent, soft tissue and joint involvement. GCTB is usually treated with intralesional excision by curettage. Systemically, it can be treated with bisphosphonates and denosumab or radiotherapy.TGCT is a rare, slowly progressing tumor of synovial tissue, affecting the joint, tendon sheath or bursa, mostly seen in middle-aged patients. TGCT is usually not visible on radiographs and MRI is mostly used to enable assessment of potential bone involvement and distinguishing between two TGCT types. Localised TGCT is mostly treated with marginal surgical resection, while diffuse TGCT is optimally treated with total synovectomy and is more difficult to remove. Additionally, radiotherapy, intraarticular injection of radioactive isotopes, anti-TNF-α antibodies and targeted medications may be used.

Clinical outcomes of diffuse PVNS of the knee following arthroscopic complete synovectomy±posterior open resection

Introduction

This study compares recurrence rates and functional outcomes of patients who underwent anterior arthroscopic synovectomy versus combined anterior arthroscopic/posterior open synovectomy for diffuse pigmented villonodular synovitis (DPVNS).

Methods

41 patients were grouped by initial procedure and tracked for disease recurrence and functional outcomes (Lysholm Scale).

Results

24 patients (58.5%) had disease recurrence [16 (57.1%) arthroscopic, 8 (61.5%) combined, chi-square test p = 0.81]. The combined procedure mean Lysholm Score (75.4) exceeded the arthroscopic (68.1) (two-sample t-test p = 0.25).

Conclusions

There is no statistical evidence that the combined procedure harms functionality more than arthroscopic only or that recurrence rates differ between treatment methods.

A case series of intra-articular diffuse pigmented villonodular synovitis of the knee: Prognosis of complete synovectomy under arthroscopic surgery

PURPOSE

The purpose of this study is to evaluate the outcome and prognosis of complete synovectomy performed under arthroscopic surgery in the treatment of diffuse pigmented villonodular synovitis (DPVNS) of the knee.

METHODS

We retrospectively reviewed 7 cases (6 female and 1 male) diagnosed with diffuse pigmented villonodular synovitis (DPVNS) of knee from 2013 to 2017. All of these cases were treated with knee arthroscopy-assisted complete synovectomy. The follow-up period ranged from 36 months to 60 months (average: 48.0 months). The pain score, range of motion and functional outcome of the knee joint were evaluated after surgery. Symptoms and signs were monitored and magnetic resonance imaging (MRI) were routinely requested to note for possible recurrence during clinical follow up.

RESULTS

During and after the surgeries of complete synovectomy under arthroscope by the same surgeon, no complications were noted in the ward or the clinic. Significant improvements were achieved in terms of the range of motion and Lysholm knee function score. There was no recurrence of DPVNS observed in our patients during a follow-up of 4 years.

CONCLUSIONS

Intra-articular DPVNS of the knee can successfully be treated by complete synovectomy under arthroscope. This case series emphasized the technique of multiple portals and cycling different shavers to achieve satisfactory outcomes.

Tumor location and type affect local recurrence and joint damage in tenosynovial giant cell tumor: a multi-center study

Osteochondral destruction and a high recurrence rate after surgery are major concerns that make difficult the treatment course of tenosynovial giant cell tumor. The aims of this study were to elucidate rates of postoperative local recurrence and osteochondral destruction, as correlated with various demographic factors. Eighty surgically treated patients with intra-articular tumors (knee: 49, ankle and foot: 12, hip: 10, others: 9) were included in this study. Factors including age, disease type (diffuse/localized), location, existence of osteochondral destruction were correlated with local recurrence or development/progression of osteochondral destruction. The 5-year local recurrence free survival rate was 71.4%. Diffuse type (n = 59, localized: n = 21) (P = 0.023) and knee location (P = 0.002) were independent risk factors for local recurrence. Diffuse type (P = 0.009) was a significant risk factor, and knee location (P = 0.001) was a negative factor for osteochondral destruction at the initial examination. Progression of osteochondral destruction was observed more often in cases with local recurrence (P = 0.040) and findings of osteochondral destruction at the initial examination (P = 0.029). Diffuse type is a factor that should be noted for both local recurrence and osteochondral destruction, while local recurrence occurs but osteochondral destruction is less observed in the knee.

Pigmented Villonodular Synovitis Around the Elbow Joint That Required Upper Arm Amputation

Pigmented villonodular synovitis (PVNS) is a relatively rare benign proliferative disorder of the synovium, and it commonly occurs in the knee joint. A unique case of huge PVNS originating around the elbow joint that required upper arm amputation is reported. A 74-year-old woman had a 5-month history of right elbow pain and noticed a mass measuring 8 × 5 cm on the olecranon side. She had a past history of undergoing tumor resection and flap surgery 9 years earlier, diagnosed as a giant cell tumor involving the right elbow region. She had chronic renal failure, with a shunt on the right forearm. On magnetic resonance imaging, the tumor around the elbow joint showed low signal intensity on T1-weighted images and low to high intensity on T2-weighted images. It was thought that it was difficult to preserve the limb because of the size of the tumor and the shunt blood vessel. Therefore, upper arm amputation was performed. The histological diagnosis was PVNS. There was no recurrence of PVNS postoperatively. In the treatment of PVNS, initial surgery with complete resection of the synovial membrane and careful postoperative follow-up are considered important.

Bilateral Mirror-Symmetrical Giant Cell Tumor of the Tendon Sheath in the Foot and Ankle: A Case Report

Giant cell tumor of the tendon sheath is a slowly growing benign tumor. It usually arises from the tendon sheath and periarticular soft tissue of small joints. However, it may infrequently involve the large joints emerging around the knee, elbow, and hip joints. Giant cell tumor of the tibialis tendon sheath is rarely reported in the foot and ankle joint. Here, we report the first case in the medical literature of bilateral mirror-symmetrical giant cell tumor of the tendon sheath in the foot and ankle. A 12-year-old male presented with a bilateral and mirror-image mass on his ankles extending to the foot. It was painless but affected his gait and footwear. Staged complete resection was done first on the right then on the left side, with no recurrence after 1 year. The role of genes can be argued for this presentation and giant cell tumor's etiology, owing to the bilateralism and mirror-image presentation. Studies are needed to explore this genetic aspect and its role in management.

Gene Expression Profiles Analyzed Using Integrating RNA Sequencing, and Microarray Reveals Increased Inflammatory Response, Proliferation, and Osteoclastogenesis in Pigmented Villonodular Synovitis

Background

Pigmented villonodular synovitis (PVNS) is a rare condition that involves benign proliferation of the synovial tissue and is characterized by severe joint destruction and high recurrence even after surgical resection. However, poor understanding of the pathogenesis limits its effective therapy.

Method

In this study, gene expression profiles of six patients with PVNS, 11 patients with osteoarthritis (OA), nine patients with rheumatoid arthritis (RA) (E-MTAB-6141), and three healthy subjects (GSE143514) were analyzed using integrating RNA sequencing (RNA-seq) and microarray to investigate the PVNS transcriptome. Gene ontology, string, and cytoscape were used to determine the gene functional enrichment. Cell functional molecules were detected using flow cytometry or immunohistochemical test to identify the cell subset and function. CD14⁺ cells were isolated and induced to osteoclast to evaluate the monocyte/macrophage function.

Results

The most obvious local manifestations of PVNS were inflammation, including increased immune cells infiltration and cytokine secretion, and tumor phenotypes. High proportion of inflammatory cells, including T cells, natural killer (NK) cells, NKT cells, and B cells were recruited from the blood. Th17 and monocytes, especially classical monocytes but not nonclassical monocytes, increased in PVNS synovium. An obvious increase in osteoclastogenesis and macrophage activation was observed locally. Elevated expression of MMP9, SIGLEC 15, and RANK were observed in myeloid cell of PVNS than OA. When compared with RA, osteoclast differentiation and myeloid cell activation are PVNS-specific characters, whereas T cell activation is shared by PVNS and RA.

Conclusion

The transcriptional expression characteristics of PVNS showed increased immune response, cell migration, and osteoclastogenesis. Osteoclast differentiation is only observed in PVNS but not RA, whereas T-cell activation is common in inflammatory arthritis.

Pigmented Villonodular Synovitis as an Atypical Cause of Deep Motor Branch Neuropathy

Objectives

Compression of the ulnar nerve in Guyon's canal results in ulnar tunnel syndrome (UTS). The patient may present with sensory and motor deficits (zone 1), motor deficit (zone 2), or sensory deficit (zone 3). The most common causes of UTS include ganglion cysts, idiopathic ulnar nerve compression, occupational pressure neuritis (repetitive compression), prolonged compression, hook of hamate fractures, and arterial thrombus or aneurysm.

Case Report

We report an atypical cause of UTS involving pigmented villonodular synovitis (PVNS) with a review of the literature. Surgical decompression of the ulnar nerve at Guyon's canal has resulted in resolving motor weakness and improved interosseous strength at latest follow-up.

Conclusion

The most common causes of UTS are ganglion, occupational neuritis, prolonged compression, and ulnar artery thrombi/aneurysms. However, other more rare causes such as PVNS should be considered in the appropriate patient.

Tenosynovial Giant-Cell Tumor Presenting as Septic Arthritis of the Knee

Tenosynovial giant-cell tumor (TGCT) is an intraarticular giant-cell tumor of the synovial tissue and tendon sheaths which often mimics multiple conditions on presentation. This case report describes a previously asymptomatic 67-year-old man with preliminary clinical and laboratory evaluation suggestive of septic arthritis; however, arthroscopy revealed diffuse synovitis, and biopsy confirmed TGCT. To our knowledge, this is the first report of TGCT presenting as septic arthritis in an adult patient. This diagnosis should be considered in evaluation of acute, atraumatic knee pain with associated inflammatory marker elevation.

Long-term functional outcomes of diffuse pigmented villonodular synovitis of knee: The role of adjuvant radiotherapy

Diffuse pigmented villonodular synovitis (PVNS) of knee is a rare benign disease that has a destructive clinical course. Synovectomy and adjuvant radiotherapy (RT) have been reported as treatment options but literatures reporting functional outcomes were sparse. This study aimed to evaluate the long-term functional outcomes and disease control among treatment modalities through the 22 years of experience.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 through phone interviews by an independent orthopedist.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. Adjuvant RT was performed on 14 patients with a median dose of 35 Gy (range 20-40 Gy). After median follow up of 6 years, recurrences were recorded in 10 cases. The recurrence rate was significantly lower in the OP + RT group than the OP group (8.3% vs 57.1%, P = .038). Among those with preserved knee joints, there was no significant difference in the Western Ontario and McMaster Universities Osteoarthritis Index score and stiffness score between patients in the OP + RT and OP groups.For patients with diffuse PVNS of knee, the addition of moderate-dose adjuvant RT following OP provided excellent local control while maintaining good joint function with limited treatment-related morbidity. Our study emphasized the importance of moderate dose RT in diffuse PVNS of knee joint.

Systematic review: total knee arthroplasty (TKA) in patients with pigmented villonodular synovitis (PVNS)

Background

To determine the functional outcomes, complications and revision rates following total knee arthroplasty (TKA) in patients with pigmented villonodular synovitis (PVNS).

Materials and methods

We conducted a systematic review of the literature. Five studies with a total of 552 TKAs were included for analysis. The methodological quality of the articles was evaluated using the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) scale. Functional outcomes, complications and revision rates were assessed. The mean age was 61 years (range 33–94 years) and the mean follow-up period was 61.1 months (range 0.2–35 years).

Results

All the studies reported improvement in knee function following TKA. Post-operative stiffness was the most frequently reported complication, affecting 32.7% (n = 32) of patients in our review. Symptomatic recurrence of PVNS, component loosening, tibial-component fracture, instability and periprosthetic infection were the main factors leading to the need for revision TKA.

Conclusion

The findings of this review support the use of TKA to alleviate the functional limitations and pain due to knee degeneration in patients with PVNS. The operating surgeon should be aware of the increased risk of post-operative stiffness, as well as a potentially higher risk of infection. Implant survival should also be considered inferior to the one expected for the general population undergoing TKA.

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.

Suspected intra-articular soft-tissue tumours and tumour-like lesions: Performance of image-guided core needle biopsy

PURPOSE

To determine the efficacy of image-guided core needle biopsy (IGCNB) in patients presenting with suspected intra-articular soft tissue tumours or tumour-like lesions.

METHODS

Retrospective study of patients referred to a musculoskeletal oncology service between January 2019 and May 2020 with a suspected intra-articular soft tissue tumour over a 16-month period. Data collected included patient age, gender, joint involved and maximal lesion size. Type of image-guidance (ultrasound or computed tomography), type of needle and type of anaesthesia, general anaesthetic (GA) or local anaesthetic (LA), were recorded, as was the histological diagnosis. For patients who proceeded to surgical excision, the IGCNB histology result was correlated with resection histology. Descriptive statistics were used and complications were also noted.

RESULTS

By the termination of data collection 91 patients underwent IGCNB, 32 (35.2 %) males and 59 (64.8 %) females with a mean age of 41.4 years (age range 3-86 years). The joints involved were the knee (n = 73; 80.2 %), ankle (n = 12; 13.2 %), hip (n = 3; 3.3 %), shoulder (n = 1; 1.1 %), elbow (n = 1; 1.1 %) and wrist (n = 1; 1.1 %). Biopsy types were as follows: US-guided GA (n = 29; 31.9 %), US-guided LA (n = 37; 40.7 %), CT-guided GA, (n = 23; 25.3 %), CT-guided LA (n = 2; 2.2 %). Mean maximal tumour dimension for 76 focal lesions was 36.5 mm (range 18-113 mm). IGCNB yielded a definitive histological result in 85 of 91 cases (93.4 %), 44 of whom went on to surgical resection. Concordance between IGCNB and resection histology was achieved in 42 of 44 cases (95.5 %). The commonest diagnosis was tenosynovial giant cell tumour, with only a single malignant lesion identified. There were no recorded immediate or delayed complications.

CONCLUSIONS

IGCNB of suspected intra-articular tumours or tumour-like lesions is a highly effective and safe technique.

Cadherin-11 cooperates with inflammatory factors to promote the migration and invasion of fibroblast-like synoviocytes in pigmented villonodular synovitis

Rationale: Pigmented villonodular synovitis (PVNS) is a destructive benign tumor-like hyperplastic disease that occurs in synovial tissue. Fibroblast-like synoviocytes (FLS) are the predominant cell type comprising the structure of the PVNS synovial lining layer. Due to a high recurrence rate, high invasion, migration, and cartilage destruction ability, PVNS causes substantial damage to patients and the efficacy of surgical resection is not satisfactory. Therefore, exploring the pathogenesis and identifying novel therapeutic targets for PVNS are urgently required. Currently, the pathogenesis of PVNS remains unclear, and there is uncertainty and controversy regarding whether PVNS is an inflammatory or a neoplastic disease. Cadherin-11 is a classical molecule that mediates hemophilic cell-to-cell adhesion in FLS and plays an important role in the normal synovium lining layer formation. This study aimed to explore the role of inflammation and cadherin-11 in PVNS pathogenesis and determine the effects of cadherin-11 as a molecular target for PVNS treatment.

Methods: FLS were primarily cultured from PVNS patients during arthroscopic synovectomy. The level of cytokines in the PVNS synovial fluid was evaluated using a human antibody array. Cadherin-11 expression of PVNS FLS was detected by qPCR, Western blots, tissue immunohistochemistry, and cell immunofluorescence. Cadherin-11 was down-regulated by siRNA or up-regulated with a plasmid, with or without inflammatory factor stimulation, and PI3K/Akt was inhibited with LY294002. The capacity of migration and invasion of PVNS FLS was tested using Transwell and wound-healing assays. Activation of the nuclear factor-kappaB (NF-κB) and mitogen-activated protein kinase (MAPK) pathways was detected by Western blots. Chondrocyte damage by PVNS FLS was assessed with a co-culture assay.

Results: Inflammatory factors (IL-1β and TNF-α) in the synovial fluid of PVNS patients were significantly up-regulated. Cadherin-11 was highly expressed in the FLS of PVNS patients, and positively correlated with recurrence, extra-articular migration, and cartilage destruction of PVNS. Knocking down of cadherin-11 inhibited the migration and invasion of PVNS FLS. Moreover, inflammatory factors up-regulated the expression of cadherin-11, which activated the NF-κB and MAPK signaling pathways and led to cartilage destruction. Inhibition of cadherin-11 blocked IL-1β- and TNF-α-induced activation of the above pathways, migration and invasion of PVNS FLS, and damage of chondrocyte. In addition, the elevation of cadherin-11 expression, together with the migration and invasion, of PVNS FLS was down-regulated by the inhibition of the PI3K/Akt signaling pathway.

Conclusions: Cadherin-11 plays an important role in the pathogenesis of PVNS and forms a positive feedback loop with inflammatory factors, which further activates the NF-κB and MAPK pathways to trigger an inflammatory cascade. Cadherin-11-mediated inflammation results in PVNS with high recurrence, invasiveness, and strong cartilage destruction ability, and eventually promotes the transformation of PVNS from the initial inflammatory disease to neoplastic disease. Thus, inhibition of cadherin-11 together with its related inflammatory reaction, represents a new therapeutic strategy for PVNS.

Localized Pigmented Villonodular Synovitis of the Knee Co-existing with Extra-articular Nodular Synovitis of the Popliteus Tendon Sheath: A Case Report

Pigmented villonodular synovitis (PVNS) is a rare proliferative disorder affecting the synovial membranes of joints, bursae, and tendons. The knee joint is one of the most common locations for an intra-articular type of PVNS and this is usually of the diffuse type of PVNS or diffuse pigmented villonodular synovitis (DPVNS). DPVNS tends to be more associated with affectation of contiguous structures. We report a case of a localized form of the disease affecting the knee joint coexisting with an extra-articular lesion of the same nature involving the popliteus tendon sheath of the same knee. The clinical condition was managed with a combined surgical approach of arthroscopic marginal excision for the intra-articular lesion and excision biopsy for the extra-articular lesion.

Mid-Term Results of Arthroscopic Synovectomy for Pigmented Villonodular Synovitis of the Hip

PURPOSE

To analyze mid-term outcomes after arthroscopic synovectomy of both diffuse and nodular hip pigmented villonodular synovitis (PVNS).

METHODS

This is a retrospective case series of patients that underwent hip arthroscopy for hip PVNS with a single senior surgeon between 2007 and 2016. Inclusion criteria were magnetic resonance imaging evidence, arthroscopic visualization, and/or histologic confirmation of PVNS; and a minimum of 3 years of follow-up. Concomitant pathology such as femoroacetabular impingement also was treated at the time of surgery. Primary outcome measures were recurrence of hip PVNS and the rate of revision hip surgery. Secondary outcomes were complications, visual analog scale pain score, pain relief, and patient satisfaction, and 6 patient-reported outcome measures were collected at latest follow-up.

RESULTS

In a case series of 14 patients consisting of 6 (42.9%) male and 8 (57.1%) female patients, the mean operative age was 32.69 ± 12.73 years with a mean follow-up was 6.66 ± 1.87 years. PVNS type was determined intraoperatively: 5 (35.7%) patients had diffuse hip PVNS and 9 (64.3%) had nodular type. There was only 1 case (7.14%) of recurrence that was treated arthroscopically and no cases (0%) progressed to revision open synovectomy or arthroplasty. Mean patient-reported outcome measure scores were notable for a modified Harris Hip Score of 74.08 ± 16.84. The mean visual analog scale pain score decreased by 4.9 ± 1.7, which was significant with a P < .001, with a larger decrease in patients with localized type.

CONCLUSIONS

This study presents a large case series of hip PVNS managed arthroscopically with mid-term follow-up of slightly over 6.5 years. The survival rate was 93%, with only 1 (7%) recurrence and 0 (0%) progression to revision open synovectomy or arthroplasty with 0 (0%) complications. We conclude that arthroscopic synovectomy is a reliable and effective treatment of hip PVNS.

LEVEL OF EVIDENCE

Case Series, Level IV.

Arthroscopic Technique for the Treatment of Localized Pigmented Villonodular Synovitis of the Knee

Pigmented villonodular synovitis (PVNS) is caused by a proliferation of the synovial membrane and can be a rare cause of pain and locking of the knee. In its localized form, it can be removed arthroscopically. We describe in detail a step-by-step arthroscopic technique applied to treat a 27-year-old patient who had been suffering from pain and episodes of locking for a year and whose left knee MRI revealed an intra-articular mass. The formation was completely enucleated arthroscopically and histological analyses confirmed the diagnosis of localized PVNS. There were no complications, and the patient was symptom-free at the six-month follow-up with no clinical or radiological evidence of recurrence.

Recurrence of pigmented villonodular synovitis of the knee: A case report with review of literature on the risk factors causing recurrence

RATIONALE

Pigmented villonodular synovitis is a rare disease which may involve any joints. It has localized and diffuse forms, and the latter is more aggressive with a higher recurrence rate. Different treatments are applied to each form of the disease, but there is no standard surgical procedure or any consensus on whether adjuvant therapy should be used. Many factors may lead to recurrence of the disease; however, there is no reliable way to predict the recurrence.

PATIENT CONCERNS

A 21-year-old female patient presented with a one-year history of progressive pain of the right knee.

DIAGNOSES

Pigmented villonodular synovitis.

INTERVENTIONS

We performed an anterior approach arthroscopic synovectomy and a posterior approach open synovectomy in the popliteal fossa, but the patient declined to take radiotherapy as a post-surgical adjuvant therapy. Then, she received a repeat arthroscopic synovectomy 20 months later because of the recurrent lesions, and a radiotherapy was performed 6 weeks after the second surgery.

OUTCOMES

There were no abnormal signs in the right knee on magnetic resonance imaging scanning 6 months after the second surgery. The range of motion of her right knee was normal.

LESSONS

Pigmented villonodular synovitis is a rare disease which may involve any joints. Surgical resection plus adjuvant therapy is recommended for patients with risk factors of recurrence.

Results of muscle strength and range of motion after total open knee synovectomy

AIM OF THE STUDY

Scar tissue formation after synovectomy limits range of motion and causes muscle atrophy. The functional results for patients who underwent total open knee synovectomy often included questionnaires, and assessment of muscle strength was lacking in the literature. Therefore, we aimed to identify the strength and range of motion outcomes for patients who underwent total open synovectomy and to compare the results with the contralateral limb and healthy individuals.

METHOD

Knee range of motion and muscle strength were assessed in fourteen patients that underwent total (anterior and posterior) open knee synovectomy and were compared with the contralateral limb and with 14 healthy individuals matched by sex, age, height, and weight.

RESULTS

The range of motion of flexion decreased 8.4% compared with the contralateral limb (95% CI - 18.9 to - 4.7, p = 0.002) and 9.9% compared with the control group (95% CI 3.9-14.9, p < 0.01). Knee extension strength decreased by 35% compared with the contralateral limb (95% CI 11.1-77.2, p = 0.01) and 37% compared with the control group (95% CI - 112.4-12.1, p = 0.01).

CONCLUSION

Despite the aggressiveness of the surgical procedure, the patients achieved satisfactory functional results.

Risk factors for early osteoarthritis in tenosynovial giant cell tumour

OBJECTIVE

Tenosynovial giant cell tumour (TGCT) is locally aggressive entity affecting young people (around 4^th decade of life) and can cause joint destruction. It could be nodular or diffuse. These two varieties are histological and genetically similar, but present a different prognosis. The aim of this study is to identify risk factors for local recurrence and predisposing factors for the development of early osteoarthritis in patients with TGCT.

MATERIAL AND METHODS

We conducted a retrospective study of 35 patients with an anatomopathological diagnosis of TGCT in our Institution from 1991 to 2017. The mean follow-up was 8.2 years. Demographic variables, characteristics of the primary tumor and its evolution were collected to assess the risk factors for local recurrence and early osteoarthritis.

RESULTS

The diffuse type was identified as a risk factor for the development of osteoarthritis (p=0.01) and for local recurrence (p=0.015). Osteoarthritis was more frequent in the hip and ankle than in the knee (p=0.03). A difference of 16 months in the duration of symptoms prior to diagnosis between those who developed osteoarthritis and those who did not was observed (p=0.05).

CONCLUSIONS

The diffuse type is more aggressive than the nodular type; it is associated with a higher risk of osteoarthritis and local recurrence. The hip and ankle present a higher risk of osteoarthritis than other joints. The time of evolution of the symptoms before diagnosis and adequate treatment, negatively influences the development of osteoarthritis.

Pigmented villous nodular synovitis mimicking metastases on 18F-FDG PET/CT in a patient with rectal mucosal melanoma: a case report

BACKGROUND

Mucosal melanomas are rare and have a high potential for metastasizing. Surgical resection is the treatment of choice for single distant metastases. Malignant melanoma usually shows the highest uptake of fluorine-18 fluorodeoxyglucose (¹⁸F-FDG). ¹⁸F- FDG positron emission tomography /computed tomography (PET/CT) is usually used for melanoma staging. An extensive literature review revealed only 4 published case reports and an original paper involving 8 cases (12 cases in total) of patients with skin melanomas in whom pigmented villous nodular synovitis (PVNS) mimicked metastatic melanoma, however, none of the melanomas reported were of rectal mucosal origin.

CASE PRESENTATION

A 60-year-old woman presented with recent diagnosis of rectal mucosal melanoma, two additional ¹⁸F-FDG-avid lesions in the left ankle and left foot were detected on ¹⁸F-FDG PET/CT. Metastases were initially suspected; however, the final diagnosis was PVNS.

CONCLUSIONS

This is the first report of PVNS mimicking metastases on ¹⁸F-FDG PET/CT in a patient with rectal mucosal melanoma. Although high ¹⁸F-FDG-avid lesions in patients with rectal mucosal melanoma are highly suspected to be metastasis and warrant an meticulous examination, the present case is a reminder that in such patients, not all lesions with high ¹⁸F-FDG uptake, especially those near a joint, are metastases and that more extensive resection is unnecessary.

The effects of radiosynoviorthesis in pigmented villonodular synovitis of the knee

INTRODUCTION

Tenosynovial giant-cell tumor also known as pigmented villonodular synovitis (PVS) is a benign but aggressive synovial proliferative disease most often affecting the knee joint. The mainstay of therapy is surgical resection. Due to a high rate of local recurrence, radiosynoviorthesis (RSO) is used as an adjuvant method in many cases. The aim of this study was to compare local recurrence (LR) rates after surgical synovectomy with and without adjuvant RSO.

MATERIALS AND METHODS

From 1996 to 2014, 37 surgical interventions were performed in 32 patients with diffuse pigmented villonodular synovitis of the knee. All patients underwent open synovectomy. Adjuvant radiosynoviorthesis (RSO) was applied in 26 cases, the control group consists of 11 cases without RSO.

RESULTS

9 (24%) lesions recurred within a median of 19 months after surgery. Of those 9 recurrences, 3 (17%) were seen in primary disease, 6 (32%) in already recurring cases (n.s.). In 26 RSO treated patients 6 (23%) recurred, in 11 patients of the control group, 3 (27%) recurred (n.s.).

CONCLUSIONS

RSO is effective in PVS as also shown in some smaller reports in the literature. But surgery is still the mainstay of therapy. RSO is not a method of compensating for an insufficient surgical approach, but it may reduce the high rate of LR in patients with large and even recurrent diffuse forms of the disease.

Diagnostic Imaging and Management of Common Intra-articular and Peri-articular Soft Tissue Tumors and Tumorlike Conditions of the Knee

Intra-articular (IA) and peri-articular (PA) tumors of the knee are frequently encountered by orthopaedic surgeons. Nonetheless, due to the possibility of great morbidity and potential mortality, it is important to recognize and differentiate between benign and malignant lesions in a timely manner. Therefore, the purpose of this article is to provide a concise, practical, and updated review of commonly encountered IA and PA tumors including intratendinous gout, synovial chondromatosis, schwannoma, pigmented villonodular synovitis, and synovial sarcoma, and a detailed description of differentiating features to include various imaging modalities.

Osteochondral Lesion in Diffuse Pigmented Villonodular Synovitis of the Knee

Pigmented villonodular synovitis (PVNS) is a rare benign condition that is locally aggressive and may destructively invade the surrounding soft tissues and bone causing functional loss of the joint and the limb. The knee is the most affected joint (range, 28% to 70%) but involvement of the bone is not a common feature seen at this site. We present a rare case of diffuse PVNS of the knee associated with subchondral cyst of the lateral femoral condyle. This posed a diagnostic dilemma because of bone invasion. The radiological image of synovitis was pathognomonic of PVNS but etiology of the osteolytic lesion was confirmed only on histopathology. The large osteochondral defect was eventually managed in a staged manner with bone grafting and osteochondral autograft transfer.

Endoscopic Approach for the Excision of Giant Cell Tumor of Tendon Sheath Involving the Hindfoot: A Case Report

Giant cell tumor of tendon sheath (GCT-TS) is an often benign neoplasm that is relatively uncommon in the foot and ankle when compared to the upper extremities. Magnetic resonance imaging aids in characterizing the lesion, but diagnosis is confirmed with biopsy. Surgical excision is the preferred treatment. There is a lack of studies examining the long-term outcomes of endoscopic excision of GCT-TS, especially lesions found in the foot and ankle. The present study describes a case of a 42-year-old male with GCT-TS of the hindfoot treated with an endoscopic excision through a sinus tarsi approach. The patient was asymptomatic with no local signs of recurrence at the 67-month follow-up visit.

Complications After Total Knee Arthroplasty in Patients With Pigmented Villonodular Synovitis

BACKGROUND

Pigmented villonodular synovitis (PVNS) is a locally destructive histiocytic proliferation most commonly occurring in the knee. Extensive local joint destruction can indicate the need for a total knee arthroplasty (TKA). The objective of this study is to evaluate PVNS of the knee as a risk factor for complication after TKA.

METHODS

Patients who underwent TKA with a diagnosis of PVNS of the knee from 2007 to 2016 were identified in a national private payer insurance database. Complication rates for emergency room visits, readmission, revision, stiffness, infection, and death were calculated and compared to a control population of patients who received TKA for osteoarthritis (OA).

RESULTS

Four hundred fifty-three patients were diagnosed with PVNS of the knee and underwent TKA during the time period and compared with a matched control cohort of 1812 patients who underwent TKA for OA. The rate of revision TKA at 2 years, emergency room visits, readmission, and death did not differ between the PVNS group and the control cohort. The PVNS group had stiffness at 1 year compared to the OA group (6.84% vs 4.69%, odds ratio 1.48, P = .023). The infection rate at 2 years was 3.31% in the PVNS group and 1.55% in the OA group (odds ratio 1.73, P = .011).

CONCLUSION

The complication rates for TKA in patients with a diagnosis of PVNS of the knee have not been previously demonstrated. These patients have a higher rate of stiffness and infection when compared to a control cohort, so they may have a more complicated postoperative course.

Distinct extra-articular invasion patterns of diffuse pigmented villonodular synovitis/tenosynovial giant cell tumor in the knee joints

PURPOSE

Pigmented villonodular synovitis (PVNS)/tenosynovial giant cell tumor (TGCT) is a benign, proliferative lesion of the synovium, the bursa, and the tendon sheath. Little is known about the anatomical distribution pattern of diffuse extra-articular PVNS/TGCT around the knee joint. In this retrospective study, anatomical distribution of PVNS/TGCT using magnetic resonance imaging (MRI) and arthroscopy was analyzed.

METHODS

This study was designed as a retrospective, observational cross-sectional study based on MRI and arthroscopy. Twenty-four PVNS/TGCT patients (24 knees) who underwent arthroscopic or posterior open surgery between 2009 and 2016 were enrolled. Of these, eight intra-articular and 16 diffuse extra-articular PVNS/TGCT of the knee were classified. The anatomical locations of the PVNS/TGCT masses were determined with a newly devised mapping scheme. Analysis was performed on the prevalence of each compartment and agreement rates between each compartment.

RESULTS

The point prevalence of intra-articular posterior compartment was higher in diffuse extra-articular PVNS/TGCT group compared with intra-articular PVNS/TGCT group. The point prevalence of diffuse PVNS/TGCT was most prevalent in the extra-articular posterolateral compartment (12 out of 16 diffuse extra-articular PVNS/TGCT patients, 75%) and second most common in the below to joint capsule compartment (11 out of 16, 68.8%). The agreement rate was the highest between intra-articular posterolateral and extra-articular posterolateral compartments (75%).

CONCLUSION

Extra-articular invasion of diffuse PVNS/TGCT occurred in specific patterns in the knee joint. Extra-articular lesions were always accompanied by lesions in intra-articular compartments. In particular, lesions in the intra-articular posterior compartments were observed in all of the diffuse extra-articular PVNS/TGCT patients. The point prevalence of diffuse extra-articular PVNS/TGCT for each compartment was the highest [12 out of 16 (75%)] in extra-articular posterolateral compartment. In contrast, invasion to the extra-articular posteromedial side was less frequent [5 out of 16 (31.3%)] than to the extra-articular posterolateral side. Knowing where the lesions frequently occur may provide important information for deciding the timing, method, and extent of surgery.

LEVEL OF EVIDENCE

Level IV.

Pigmented Villonodular Synovitis: A Comprehensive Review and Proposed Treatment Algorithm

Evidence now exists suggesting a neoplastic origin for pigmented villonodular synovitis, including a thorough description of the translocations involved. Arthroscopic excision for localized pigmented villonodular synovitis allows for both minimal recurrence and morbidity when compared with open excision; however, open excision still plays an important role in treating posterior compartment nodules. The optimal surgical treatment for diffuse pigmented villonodular synovitis is still a matter for debate, with combined anterior arthroscopic and open posterior excision being considered the preferred method. Radiation therapy has re-emerged as an additional treatment method for pigmented villonodular synovitis; however, the potential for serious toxicity makes it a questionable option, especially for such a benign condition. Small molecule and monoclonal antibody targeted therapies are being investigated as novel treatment methods for pigmented villonodular synovitis, with promising results.

Lowering the recurrence rate in pigmented villonodular synovitis: A series of 120 resections

Objectives

Tenosynovial giant-cell tumour or pigmented villonodular synovitis is an aggressive synovial proliferative disease, with the knee joint being the most commonly affected joint. The mainstay of therapy is surgical resection. The aim of this study was to evaluate the main patient characteristics, treatment and outcomes in a large single-centre retrospective study, focusing on meticulous aggressive open surgical procedures.

Methods

From 1996 through 2014, 122 surgical interventions were performed in 105 patients. All patients underwent open synovectomy and when the knee joint was affected, combined anterior and posterior synovectomy. Radiotherapy was applied in 2 patients, radiosynoviorthesis in 27 patients.

Results

In histopathology, the diffuse type was seen in 66 (54%) lesions. Two patients were lost during follow-up. At a median follow-up time of 71 months (range: 13-238), 22 (18%) lesions recurred within a median of 18 months, >90% in the first 3 years. Out of those 22 recurrences, 9 (11%) were seen in primary disease and 13 (34%) were a second recurrence. After renewed resection, 6 (5%) out of the 120 resections had persistent tumour at the end of follow-up. Based on the number of patients with complete follow-up (n = 103), this represents 5.8%.

Conclusion

In diffuse-type pigmented villonodular synovitis, total synovectomy might be difficult to achieve. As shown in our results and also in the literature, meticulous open resection, especially in difficult to approach areas such as the popliteal space, reduces local recurrence rates. External beam radiation is an option in prevention of otherwise non-operable local recurrences or in non-operable disease.

Localized pigmented villonodular synovitis of posterior compartment of the knee

Pigmented villonodular synovitis (PVNS) is an uncommon entity involving articular or extra-articular tissues and maybe localized or diffuse in extent. The knee is by far the commonest joint to get involved. Localized PVNS of the knee can occur in any location but its confinement to the posterior compartment is infrequent. We present our experience of managing localized posterior compartment PVNS of the knee. There were 10 patients (7 males and 3 females) with average age of 33 years. These patients had symptoms of pain, locking, or swelling for a mean of 13.9 years before diagnosis. All the patients underwent arthroscopic synovectomy without adjuvant therapy, and PVNS was proven on histopathology. At an average follow-up of 23 months, no patient had recurrence of symptoms. The average International Knee Documentation Committee (IKDC) score at last follow-up was 85.21. Magnetic resonance imaging evaluation at final follow-up did not reveal any residual disease or recurrence in any patient.

Inconclusive benefit of adjuvant 90Yttrium hydroxyapatite to radiosynovectomy for diffuse-type tenosynovial giant-cell tumour of the knee

Aims

Intra-articular 90Yttrium (90Y) is an adjunct to surgical treatment by synovectomy for patients with diffuse-type tenosynovial giant-cell tumour (dtTGCT) of the knee, with variable success rates. Clinical information is, however, sparse and its value remains unclear. We investigated the long-term outcome of patients who underwent synovectomy with and without adjuvant treatment with 90Yttrium.

Patients and Methods

All patients with dtTGCT of the knee who underwent synovectomy between 1991 and 2014 were included in the study. Group A patients underwent synovectomy and an intra-articular injection of 90Yttrium between six and eight weeks after surgery. Group B patients underwent surgery alone.

Results

There were 34 patients in group A and 22 in group B. Recurrence of dtTGCT was identified by MRI, which was undertaken in patients with further symptoms. At a mean follow-up of 7.3 years (2.5 to 25.4), there was residual disease in 15 patients in group A and 11 in group B (p < 0.363). The mean Musculoskeletal Tumor Society (MSTS) score at final follow-up was 85% and 83%, respectively (p < 0.91).

Conclusion

There were no significant differences in outcome between patients treated surgically for dtTGCT of the knee with or without an adjuvant intra-articular injection of 90Yttrium. We were unable to provide conclusive evidence of any benefits derived from the adjuvant treatment. Cite this article: Bone Joint J 2018;100-B:984–8.

BILATERAL LOCALIZED PIGMENTED VILLONODULAR SYNOVITIS OF THE KNEE: CASE REPORT AND REVIEW

Objectives

Several cases of bilateral diffuse pigmented villonodular synovitis (PVNS) or tenosynovial giant cell tumor have been described in the literature. Nevertheless, some presentations are rare and differential diagnoses are necessary.

Methods

The purpose of this study was to perform a systematic review of the literature related to PVNS and to report a rare supra-patellar bilateral and focal presentation. We performed a systematic data review in the Pubmed Clinical Queries database using MeSH and keywords related to PVNS and tenosynovial giant cell tumor.

Results

Two cases of bilateral and local PVNS had been previously described, but neither was localized in the supra-patellar compartment. To our knowledge, this case report is the first to describe supra-patellar bilateral and localized PVNS of the knee. This case involves a 28 -year-old woman with bilateral localized PVNS of the supra-patellar recess of the knee. MRI showed a low-signal intensity nodule in T1- and T2-weighted images. These were associated with hemosiderin pigmentation.

Conclusion

The most important finding of the case reported is related to rarity and location. Histopathology analysis confirmed a rare case of hemosiderin pigmentation in the capsular nodule with internal non-pigmented villous content. Lipoma arborescens in the supra-patellar form must be ruled out as a differential diagnosis since it occurs in the same site. Level of Evidence IV; Case series.

Necessity of adjuvant postoperative radiotherapy for diffuse pigmented villonodular synovitis of the knee: A case report and literature review

RATIONALE

Pigmented villonodular synovitis (PVNS) is an idiopathic, proliferative disorder lesion of synovial tissue, which is regarded as a benign disease, but has a local invasion. Up to now, these are no consensus about the etiology and pathogenesis of PVNS. Because of the lack of typical clinical features, misdiagnosis and delayed diagnosis are not uncommon, magnetic resonance imaging (MRI) can assist diagnosis and histopathological examination is recognized as the gold standard for the final diagnosis. Because this disease is so rare, there is no standard treatment. Surgical resection of the lesion is considered the preferred treatment, but postoperative recurrence is a problem that cannot be ignored. Postoperative radiotherapy is necessary, especially for patients with diffuse PVNS of the knee.

PATIENT CONCERNS

A 27-year-old female teacher presented with 3 years chronic pain of the right knee, and progressive swelling aggravated for 1 week. The range of motion of the knee was limited.

DIAGNOSES

Clinical and laboratory examination failed to provide definitive diagnosis. Imaging can assist in diagnosis, and pathology is the gold standard. Erythrocyte sedimentation rate (ESR), antihemolytic streptococcus O (ASO), and rheumatoid factors (RF) were all negative. Joint puncture revealed giant cell tumor of the synovial membrane. PVNS was confirmed by postoperative pathology. The characteristic T2 weighted low signal of MRI suggests the recurrence of PVNS.

INTERVENTIONS

The patient underwent 2 stages of treatment: open synovectomy was performed in the first place and postoperative external radiotherapy was not considered. After 2 years of disease-free remission, she was diagnosed with a recurrence of the disease by MRI. Further, arthroscopic total synovectomy of the right knee was performed and external beam radiotherapy was carried out after the operation.

OUTCOMES

Up to now, the patient was followed up for 3 years without any sign of recurrence.

LESSONS

Adjuvant postoperative radiotherapy can improve the local control rate, it is a reliable treatment method for diffused PVNS.