Pigmented villonodular synovitis/giant cell tumor in the knee.

PURPOSE OF REVIEW: Pigmented villonodular synovitis (PVNS) is a rare diagnosis in pediatric patients and commonly presents with symptoms of swelling and pain. Early diagnosis is important to prevent secondary degeneration into the subchondral bone. This review will analyze the etiology, clinical signs/symptoms, diagnosis, treatment, and recent literature on PVNS in the pediatric population. RECENT FINDINGS: Many theories of PVNS etiology have been described in the literature; however, an inflammatory response has been most widely accepted. PVNS can occur in any joint, but most commonly in the knee. The most common treatment for PVNS is synovectomy, and long-term follow-up is necessary to detect disease persistence or recurrence. SUMMARY: Although uncommon, PVNS does occur in the pediatric population and this diagnosis should be included in the differential of atraumatic joint swelling and pain.

Pigmented Villonodular Synovitis: A Metastatic Melanoma Imitator.

ABSTRACT: A 45-year-old woman with a history of previously treated left plantar foot melanoma presented with a left thigh mass. Fine needle aspiration findings were concerning for metastatic melanoma (MM). Imaging was remarkable for PET-avidity of both the biopsied thigh mass and of a left posterior knee nodule. The knee nodule was also enhancing on MRI, concerning for a site of metastasis. Resection of the thigh mass and intra-articular nodule was performed. The thigh lesion was positive for MM. The specimen obtained from the knee demonstrated a proliferation of spindle and epithelioid cells associated with focal fibrosis and scattered giant cells with brown pigment, raising the possibility of melanoma metastasis with treatment effect. Additional immunohistochemical studies with anti-SOX10 failed to demonstrate melanoma cells in the lesion. The final diagnosis for the knee nodule was pigmented villonodular synovitis. This case highlights the potential for pigmented villonodular synovitis to mimic MM, requiring additional pathologic analysis to yield an accurate diagnosis.

What Are the Recurrence Rates, Complications, and Functional Outcomes After Multiportal Arthroscopic Synovectomy for Patients With Knee Diffuse-type Tenosynovial Giant-cell Tumors?

BACKGROUND: Diffuse-type tenosynovial giant-cell tumor (D-TGCT), formerly known as pigmented villonodular synovitis, is a rare, locally aggressive, invasive soft tissue tumor that primarily occurs in the knee. Surgical excision is the main treatment option, but there is a high recurrence rate. Arthroscopic surgical techniques are emphasized because they are less traumatic and offer faster postoperative recovery, but detailed reports on arthroscopic techniques and outcomes of D-TGCT in large cohorts are still lacking. QUESTIONS/PURPOSES: (1) What is the recurrence rate of knee D-TGCT after multiportal arthroscopic synovectomy? (2) What are the complications, knee ROM, pain score, and patient-reported outcomes for patients, and do they differ between patients with and without recurrence? (3) What factors are associated with recurrence after arthroscopic treatment in patients with D-TGCT? METHODS: In this single-center, retrospective study conducted between January 2010 and April 2021, we treated 295 patients with knee D-TGCTs. We considered patients undergoing initial surgical treatment with multiportal arthroscopic synovectomy as potentially eligible. Based on that, 27% (81 of 295) of patients were excluded because of recurrence after synovectomy performed at another institution. Of the 214 patients who met the inclusion criteria, 17% (36 of 214) were lost to follow-up, leaving 83% (178 of 214) of patients in the analysis. Twenty-eight percent (50 of 178) of patients were men and 72% (128 of 178) were women, with a median (range) age of 36 years (7 to 69). The median follow-up duration was 80 months (26 to 149). All patients underwent multiportal (anterior and posterior approaches) arthroscopic synovectomy, and all surgical protocols were determined by discussion among four surgeons after preoperative MRI. A combined open posterior incision was used for patients with lesions that invaded or surrounded the blood vessels and nerves or invaded the muscle space extraarticularly. Standard postoperative adjuvant radiotherapy was recommended for all patients with D-TGCT who had extraarticular and posterior compartment invasion; for patients with only anterior compartment invasion, radiotherapy was recommended for severe cases as assessed by the surgeons and radiologists based on preoperative MRI and intraoperative descriptions. Postoperative recurrence at 5 years was calculated using a Kaplan-Meier survivorship estimator. The WOMAC score (0 to 96, with higher scores representing a worse outcome; minimum clinically important difference [MCID] 8.5), the Lysholm knee score (0 to 100, with higher scores being better knee function; MCID 25.4), the VAS for pain (0 to 10, with higher scores representing more pain; MCID 2.46), and knee ROM were used to evaluate functional outcomes. Because we did not have preoperative patient-reported outcomes scores, we present data on the proportion of patients who achieved the patient-acceptable symptom state (PASS) for each of those outcome metrics, which were 14.6 of 96 points on the WOMAC, 52.5 of 100 points on the Lysholm, and 2.32 of 10 points on the VAS. RESULTS: The symptomatic or radiographically documented recurrence at 5 years was 12% (95% confidence interval [CI] 7% to 17%) using the Kaplan-Meier estimator, with a mean recurrence time of 33 ± 19 months. Of these, three were asymptomatic recurrences found during regular MRI reviews, and the remaining 19 underwent repeat surgery. There was one intraoperative complication (vascular injury) with no effect on postoperative limb function and eight patients with postoperative joint stiffness, seven of whom improved with prolonged rehabilitation and one with manipulation under anesthesia. No postradiotherapy complications were found. The proportion of patients who achieved the preestablished PASS was 99% (176 of 178) for the VAS pain score, 97% (173 of 178) for the WOMAC score, and 100% (178 of 178) for the Lysholm score. A lower percentage of patients with recurrence achieved the PASS for WOMAC score than patients without recurrence (86% [19] versus 99% [154], OR 0.08 [95% CI 0.01 to 0.52]; p = 0.01), whereas no difference was found in the percentage of VAS score (95% [21] versus 99% [155], OR 0.14 [95% CI 0.01 to 2.25]; p = 0.23) or Lysholm score (100% [22] versus 100% [156], OR 1 [95% CI 1 to 1]; p = 0.99). Moreover, patients in the recurrence group showed worse knee flexion (median 135° [100° to 135°] versus median 135° [80° to 135°]; difference of medians 0°; p = 0.03), worse WOMAC score (median 3.5 [0 to 19] versus median 1 [0 to 29]; difference of medians 2.5; p = 0.01), and higher VAS pain score (median 1 [0 to 4] versus median 0 [0 to 4]; difference of medians 1; p < 0.01) than those in the nonrecurrence group, although no differences reached the MCID. No factors were associated with D-TGCT recurrence, including the use of postoperative radiotherapy, surgical technique, and invasion extent. CONCLUSION: This single-center, large-cohort retrospective study confirmed that multiportal arthroscopic surgery can be used to treat knee D-TGCTs with a low recurrence rate, few complications, and satisfactory postoperative outcomes. Surgeons should conduct a thorough preoperative evaluation, meticulous arthroscopic synovectomy, and regular postoperative follow-up when treating patients with D-TGCT to reduce postoperative recurrence. Because the available evidence does not appear to fully support the use of postoperative adjuvant radiotherapy in all patients with D-TGCTs and our study design is inadequate to resolve this controversial issue, future studies should look for more appropriate indications for radiotherapy, such as planning based on a more precise classification of lesion invasion. LEVEL OF EVIDENCE: Level III, therapeutic study.

Contribution of the Ultrasound Techniques in the Evaluation of Knee Joint Damage in the Case of Pigmented Villonodular Synovitis and Rheumatoid Arthritis.

OBJECTIVES: This is a prospective study to evaluate the clinical value of high-frequency ultrasound (HFUS), superb microvascular imaging (SMI), and contrast-enhanced ultrasound (CEUS) in differentiation of pigmented villonodular synovitis (PVNS) and highly active rheumatoid arthritis (RA). METHODS: Twenty PVNS patients and 24 active RA patients were selected to undergo HFUS, SMI, and CEUS examinations. The characteristics of HFUS, SMI, and CEUS in PVNS and RA were compared, and the differential diagnosis performances of HFUS, SMI, and CEUS in PVNS and RA were evaluated by receiver operating characteristic (ROC) analysis. RESULTS: There were statistically significant in joint effusion, synovial thickness, synovial morphology, synovial echo, synovial vessel shape, synovial enhanced direction, and enhanced pattern between PVNS and RA (P < .05). However, no statistically significant were found in bone erosion, synovial boundary, blood signal grading of synovium, synovial enhanced strength, and CEUS quantitative parameters (including PI, TTP, S, MTT, and AUC) (P > .05). The AUC of HFUS, SMI, and CEUS for differential diagnosis PVNS and RA were 0.832, 0.675, and 0.817, respectively. The AUC of HFUS + SMI, HFUS + CEUS, SMI + CEUS, HFUS + SMI + CEUS were 0.923, 0.940, 0.817, and 0.940, respectively. The AUC of HFUS + SMI and HFUS + CEUS was higher than that of each alone (P < .05). CONCLUSIONS: HFUS, SMI, and CEUS can be used as supplementary methods for diagnosis and differential diagnosis in PVNS and active RA. What is more, the combination of HFUS + SMI and HFUS + CEUS was suggested.

Intra-labral pigmented villonodular synovitis: a rare case in two adult patients.

This article discusses two rare cases of intra-labral pigmented villonodular synovitis (PVNS) of the hip. The hip joint represents the second most common location of pigmented villonodular synovitis, second to the knee [1]. The majority of hip PVNS cases either diffusely involve the synovium or are focal lesions within the joint. The lesions and synovium show foci of low signal intensity related to hemosiderin deposition, a finding that differentiates PVNS from other causes of synovial proliferation. Our case report presents two rare manifestations of PVNS lesions localized within the hip labrum. This presentation could easily be mistaken for a cyst by imaging modality. Despite the rarity of this condition, we highlight the importance of questioning the possibility of intra-labral PVNS, when patients have persistent hip pain not responding to therapy and atypical imaging findings. Highlighting this rare presentation is crucial for establishing the correct diagnosis, guiding treatment, and obtaining the best clinical outcome.

Diffuse pigmented villonodular synovitis treated with arthroscopic total synovial peel.

BACKGROUND: Diffuse pigmented villonodular synovitis (PVNS) is prone to recurrence after surgery, and it is difficult to achieve a long-term complete cure. OBJECTIVE: To reduce the recurrence rate of PVNS, the author pioneered the arthroscopic total synovial peel (ATSP). METHODS: From March 2014 to July 2020, a total of 19 patients (6 males and 13 females) with diffuse PVNS of the knee were treated in our department and underwent ATSP. It's 'peel' rather than simple excision. This method is similar to peeling bark. Relapse rates and functional scores were determined, with follow-ups ranging from 12 to 72 months, on average 36 months. RESULTS: Treatment efficacy was assessed by imaging and functional scores. Imaging results indicated a recurrence rate of 10.5%. In patients without recurrence, the visual analog score (VAS) decreased from 4.76 ± 2.02 preoperatively to 1.56 ± 1.15 postoperatively. The Tegner-Lysholm knee function score (TLS) score increased from 67.76 ± 15.64 preoperatively to 90.32 ± 8.32 postoperatively. Compared with the literature, ATSP significantly reduces the postoperative recurrence rate of diffuse PVNS. The preliminarily findings suggest that this approach could greatly reduce the recurrence rate of postoperative PVNS in follow-up studies. CONCLUSION: This approach may be a viable option for treating diffuse PVNS via arthroscopy and is worthy of clinical consideration.

Transglenoidal Approach in Pigmented Villonodular Synovitis of the Temporomandibular Joint.

Pigmented villonodular synovitis is a benign pathology with locally aggressive behavior caused by an uncontrolled proliferation of the articular synovial membranes. Here the authors present a case of pigmented villonodular synovitis of the temporomandibular joint with middle cranial fossa extension and review the different management options including surgery, which have been proposed to target this condition in the recent literature.

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.

Tenosynovial Giant Cell Tumor (TSGCT) of the hip: MRI accuracy and results of surgical treatment.

Tenosynovial Giant Cell Tumor (TSGCT) or formerly pigmented villonodular synovitis (PVNS) is a rare nonmalignant tumor of the synovia seldom affecting the hip. MRI and surgical resection are the gold standards in its diagnosis and treatment. However, the accuracy of MRI is unknown, and only few reports on its surgical treatment results exist. The goal of the study was to investigate the MRI accuracy, results after surgical treatment, and natural history of untreated MRI-diagnosed hip TSGCT. Twenty-four consecutive patients with suspected TSGCT on hip MRI, between December 2006 and January 2018, were identified from our medical database. Six refused to participate. About 18 patients with a minimal follow-up of 18 months were enrolled. Charts were reviewed for histopathology results, specific treatment and recurrence. At the last follow-up, all patients had a clinical (Harris Hip Score [HHS]) and radiological examination (x-ray and MRI). Out of 18 patients with suspected TSGCT on MRI, with a mean age of 35y (range 17-52), 14 had surgi- cal resection and 4 refused surgery 1 of whom had a CT-guided biopsy. Out of 15 cases with biopsies, in 10 TSGCT was confirmed. Three surgically-treated patients showed recurrence on MRI after 24, 31 and 43 months. Two non-treated patients showed progression after 18 and 116 months. At the last follow-up (65 m; range 18-159), the mean HHS with or without recurrence was 90 and 80pts (ns). Operative vs. non-operative treatment showed HHS of 86 and 90pts (ns). In the conservatively-treated group, HHS with and without progression was 98 and 82pts (ns), respectively. MRI-suspected TSGCT of the hip was confirmed with biopsy in two-thirds of the cases. Surgical treatment showed recurrence in more than one-third of the patients. Two out of four untreated patients showed progression of the TSGCT-suspected lesion.

Treatment updates on tenosynovial giant cell tumor.

PURPOSE OF REVIEW: Diffuse-type tenosynovial giant cell tumor (dt-TGCT) is a benign clonal neoplastic proliferation arising from the synovium. Patients are often symptomatic, require multiple surgical procedures during their lifetime, and have reduced quality of life (QoL). Surgery is the main treatment with relapse rates ranging from 14 to 55%. The treatment strategy for patients with dt-TGCT is evolving. The purpose of this review is to describe current treatment options, and to highlight recent developments in the knowledge of the molecular pathogenesis of dt-TGCT as well as related therapeutic implications. RECENT FINDINGS: TGCT cells overexpress colony-stimulating factor 1 (CSF1), resulting in recruitment of CSF1 receptor (CSF1R)-bearing macrophages that are polyclonal and make up the bulk of the tumor, has led to clinical trials with CSF1R inhibitors. These inhibitors include small molecules such as pexidatinib, imatinib, nilotinib, DCC-3014 (vimseltinib), and the monoclonal antibody RG7155 (emactuzumab). SUMMARY: In conclusion, D-TGCT impairs patients' QoL. The evidence that the pathogenetic loop of D-TGCT can be inhibited has changed the therapeutic armamentarium for this condition. Clinical trials of agents that target CSF1R are currently ongoing. All this new evidence should be taken into consideration within multidisciplinary management.

A prospective real-world study of the diffuse-type tenosynovial giant cell tumor patient journey: A 2-year observational analysis.

BACKGROUND AND OBJECTIVES: Diffuse-tenosynovial giant cell tumor (D-TGCT) is a rare, locally aggressive, typically benign neoplasm affecting mainly large joints, representing a wide clinical spectrum. We provide a picture of the treatment journey of D-TGCT patients as a 2-year observational follow-up. METHODS: The TGCT Observational Platform Project registry was a multinational, multicenter, prospective observational study at tertiary sarcoma centers spanning seven European countries and two US sites. Histologically confirmed D-TGCT patients were categorized as either those who remained on initial treatment strategy (determined at baseline visit) or those who changed treatment strategy with specific changes documented (e.g., systemic treatment to surgery) at the 1-year and/or 2-year follow-up visits. RESULTS: A total of 176 patients were assessed, mean diagnosis age was 38.4 (SD ± 14.6) years; most patients had a knee tumor (120/176, 68.2%). For the 2-year observation period, most patients (75.5%) remained on the baseline treatment strategy throughout, 54/79 patients (68.4%) remained no treatment, 30/45 patients (66.7%) remained systemic treatment, 39/39 patients (100%) remained surgery. Those who changed treatment strategy utilized multimodal treatment options. CONCLUSIONS: This is the first prospectively collected analysis to describe D-TGCT patient treatments over an extended follow-up and demonstrates the need for multidisciplinary teams to determine an optimal treatment strategy.

Radiosynoviorthesis: almost seventy years of experience but still somewhat fameless.

Radiosynoviorthesis (RSO) or radiation synovectomy has been practiced for more than half a century, but in many parts of the world, it is still relatively unknown and not used to its full potential in the standard care for chronic, persistent or recurrent synovitis. The working mechanism of RSO is simple yet elegant. Radiopharmaceutical particles are, after injection in the affected synovial joint, gobbled up by phagocytizing subsynovial inflammatory cells. As a consequence, the synovium will be irradiated locally resulting in synovial cell necrosis and inhibition of cell proliferation, which eventually leads to a decrease in the inflammatory response in the joint cavity. In this review RSO is once again brought to the attention and common indications for RSO are discussed. Also, appropriate activities of the administrated radiopharmaceuticals and coadministrated glucocorticoids are provided. Furthermore, a detailed database-assisted chronological overview of published literature of RSO in inflammatory and non-inflammatory diseases, like rheumatoid arthritis, psoriatic arthritis, osteoarthritis and osteochrondomatosis, hemophilic hemarthrosis and pigmented villonodular synovitis (PVNS) is provided. Based upon the published literature an indication of level of evidence of RSO is discussed. There is evidence that RSO is effective in persistent synovitis in patients with a variety of causes for synovitis, although the effectiveness seems to decrease over time. In these patients, RSO may not be used to its full potential in many parts of the world. Results in of RSO in hemophilia patients with hemarthrosis are favourable, however the evidence for the effectiveness of RSO in these patients is less firm and mainly based on case series. The evidence for the efficacy of RSO as adjuvant therapy in PVNS is, at best, of very low quality.

Pigmented Villonodular Synovitis of the Temporomandibular Joint: Case Report and Literature Review.

Pigmented villonodular synovitis is a benign soft-tissue lesion that can affect the synovium of joint spaces, bursae, or tendon sheaths. It is a rare condition and even rarer when it originates in the temporomandibular joint. The purpose of this study is to review the literature and report an additional case of pigmented villonodular synovitis arising from the temporomandibular joint and describe the surgical approach involving a Zimmer Biomet custom-fitted total joint prosthesis.

Clinical outcomes of patients with pigmented villonodular synovitis of the shoulder after arthroscopic synovectomy.

BACKGROUND: Shoulder pigmented villonodular synovitis (PVNS) is a severe clinical condition, while few studies have focused on this situation due to its rarity. This study was to investigate the efficacy of arthroscopic treatment of patients diagnosed with shoulder PVNS. METHODS: From Jan 1st, 2010 to Dec. 31st, 2019, 6 patients (5 females and 1 male) diagnosed with shoulder PVNS underwent arthroscopic synovectomy in our hospital and combined rotator cuff repair was performed in 3 of them. The outcomes of this study include Constant score, Visual Analogue Scale (VAS), University of California, Los Angeles (UCLA) score and American Shoulder and Elbow Surgeons (ASES) score. The data were retrieved from the patients' medical records. RESULTS: With a mean follow-up of 52.0 months (range, 28-92 months), the mean difference of Constant, VAS, UCLA and ASES scores were 27.83 ± 21.60, 2.83 ± 2.56, 11.67 ± 10.93 and 17.83 ± 25.35, respectively. Statistically significant improvements were detected in all the patient-reported outcomes except ASES score. One of the patients suffered from recurrence. Two patients suffered from mild complications after the surgeries while both of them achieved satisfactory recovery finally. CONCLUSION: Arthroscopic synovectomy in the setting of shoulder PVNS can improve patients' function. A concurrent rotator cuff repair is recommended if it is needed. The conclusion still needs testifying by further high-quality research with larger sample size.

Modified posterior approach of the knee in patients with diffuse pigmented Villonodular synovitis: case series of a single Institution's experience.

BACKGROUND: Diffuse pigmented villonodular synovitis (DPVNS) is a challenging tumor-like disorder that mainly occurs in the anterior aspect of the knee joint. The growth may sometimes extend to the posterior knee joint. Surgical excision is the mainstream treatment for DPVNS, and the posterior approach of tumor excision is adopted when the dominant tumor shows posterior extension. However, the optimal surgical approach over the posterior knee remains unknown. METHODS: Patients with DPVNS of the knee joint who received the posterior approach of synovectomy from 1995 to 2019 were retrospectively reviewed to describe the modified separate posterior (SP) approaches, and evaluate the treatment outcomes in a case series of DPVNS knees. The results of the SP approach was also compared with those of traditional direct posterior (DP) approach. Postoperative functional outcomes were evaluated using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) standardized questionnaire and clinician-completed Musculoskeletal Tumor Society (MSTS) functional rating system at outpatient department. RESULTS: A total of 20 DPVNS knees were included. Thirteen patients who received SP approaches were included in the SP group, while seven patients who received the DP approach were included in the DP group. The median follow-up times were 5.7 years (IQR, 2-8.8) in the SP group and 3 years (IQR, 2-5.3) in the DP group. Both groups showed satisfactory safety. The SP group presented higher postoperative mean WOMAC (91.23 ± 7.20) and mean MSTS (24.23 ± 2.68) than the DP group (mean WOMAC: 76.00 ± 16.57; mean MSTS: 22.43 ± 4.69). The Wilcoxon signed-rank test was use to compare preoperative and postoperative range of motion (ROM) for each group. The significant difference in SP group (p = 0.004) was found while p = 0.131 in DP group. CONCLUSIONS: The SP approach provides an effective approach with satisfactory outcomes for the surgical treatment of DPVNS knees.

Clinical outcomes of endoscopic synovectomy with adjuvant radiotherapy of pigmented villonodular synovitis of the hip: a case series of single center.

BACKGROUND: Though radiotherapy has been widely used for knee pigmented villonodular synovitis (PVNS), there is few literatures about radiotherapy for the treatment of PVNS hip. Thus, the purpose of this study was to analyze the clinical outcomes of endoscopic synovectomy with/without radiotherapy postoperatively of PVNS hip. METHODS: We performed a retrospective study of patients who underwent endoscopy in our hospital from November 2010 to January 2021. Inclusion criteria was patients with magnetic resonance image (MRI) signs, endoscopic findings and/or histological evidence of PVNS. Exclusion criteria was patients lost follow-up. All patients underwent synovectomy endoscopically and were divided into two groups depending on receiving postoperative radiotherapy or not. The primary outcome measurements were the recurrence of PVNS, receiving revision, and/or converting to total hip arthroplasty (THA). The secondary outcome measurements were the patient-reported outcome (PRO) collected at pre- and post-operation, which consist of Hip Outcome Score Activities of Daily Living (HOS-ADL), modified Harris Hip Score (mHHS), International Hip Outcome Tool-12 (IHOT-12), Non-arthritic Hip Scale (NAHS), and visual analog scale (VAS). RESULTS: In a case series of 16 patients (8 cases of male, 50%), 4 (25%) cases were localized type and 12 (75%) cases were diffuse type. The average follow-up was 44.8 ± 38.2 months (range,3 to 110). 8 (50%) cases (6 diffuse cases and 2 localized cases) received radiotherapy postoperatively, and the rest (6 diffuse cases and 2 localized cases) received endoscopic treatment alone. At the latest follow-up, 3 (18.75%) cases (2 diffuse cases and 1 localized case) who did not receive radiotherapy converted to arthroplasty. The preoperative HOS-ADL, mHHS, IHOT-12, NAHS, VAS scores of remaining 13 patients were 63.1 ± 19.1 (range,32.0 to 98.8), 54.8 ± 20.1 (range, 10.0 to 77.0), 50.9 ± 15.4 (range, 31.0 to 76.6),51.6 ± 15.9 (range, 20.0 to 84.4), 6.0 ± 1.4 (range,4.0 to 8.0) points, respectively. The latest HOS-ADL, mHHS, IHOT-12, NAHS, VAS scores of the 13 patients were 79.7 ± 10.8 (range, 58.0 to 97.6), 78.6 ± 9.1 (range,55.0 to 87.0), 74.7 ± 9.7 (range, 55.6 to 91.0), 78.9 ± 18.7 (range,20.0 to 92.5), 3.1 ± 1.2 (range,2.0 to 6.0) points respectively. CONCLUSION: Endoscopic synovectomy can achieve satisfactory PRO in PVNS hip patients. Besides, postoperative adjuvant radiotherapy can achieve higher hip survivability than synovectomy alone in this present study.

Tenosynovial giant cell tumor-diffuse type, treated with a novel colony-stimulating factor inhibitor, pexidartinib: initial experience with MRI findings in three patients.

Tenosynovial giant cell tumor-diffuse type (diffuse TSGCT) is a benign but locally aggressive proliferative disorder of the synovium. Treatment is usually surgical, although in cases of extensive disease complete synovectomy is not possible and local recurrence rates are high. Pexidartinib (trade name Turalio®), a colony-stimulating factor-1 (CSF-1) inhibitor, was shown in a recent phase III trial to effectively treat diffuse TSGCT and is FDA approved for the treatment of adult patients with symptomatic diffuse TSGCT associated with severe morbidity or functional limitations and not amenable to improvement with surgery. Pexidartinib is available only through a restricted program under a risk evaluation and mitigation strategy (REMS) because of the risk of hepatotoxicity. Magnetic resonance imaging (MRI) is the preferred imaging modality for the diagnosis and surveillance of TSGCT. Here we present three patients with diffuse TSGCT of the knee who underwent multiple MRIs over several years while on pexidartinib. We describe the disease burden and signal characteristics on MRI and correlate with the response reported in the patients' medical records. Given that the use of pexidartinib and other CSF inhibitors is likely to increase, musculoskeletal radiologists should be aware of this novel non-operative treatment and the MRI appearance of diffuse TSGCT during therapy.

Outcomes of arthroscopic management for pigmented villonodular synovitis of the hip.

INTRODUCTION: Early synovectomy is considered as the main treatment of pigmented villonodular synovitis (PVNS) of the hip in young patients with preserved cartilage. The purpose of the study is to evaluate outcomes of arthroscopic management for PVNS of the hip. METHODS: Patients who underwent primary hip arthroscopy for the treatment of histology-confirmed PVNS by the senior author between January 2012 and December 2016 were retrospectively reviewed. We excluded patients who had less than 1-year follow-up or had undergone primary surgeries with other surgeons and then received revision hip arthroscopic procedures by the senior author. The recurrence of PVNS and postoperative condition of affected hip were assessed by follow-up magnetic resonance imaging (MRI). Patient-reported outcomes of modified Harris hip score (mHHS) and 12-item International Hip Outcome Tool (iHOT-12) were collected at latest follow-up. RESULTS: Nine patients (2 males, 7 females) with a mean age of 24.3 ± 11.2 years (range 14-44 years) were included in this study. Localized PVNS was observed in four patients, and diffuse PVNS was observed in five patients. No patient presented with advanced osteochondral destruction. Five patients received single adjuvant radiosynoviorthesis. No patient had evidence of recurrence based on follow-up MRI. Patient-reported outcomes were obtained in eight patients at mean 55.8 ± 26.1 months (range 24-84 months) after the index surgery. The mean mHHS was 94.6 ± 4.9 (range 84.7-100) and the mean iHOT-12 was 93.3 ± 20.2 (range 50-120). No patient needed secondary surgery during the follow-up period. CONCLUSION: Arthroscopic subtotal synovectomy can offer favorable short to mid-term outcomes in the treatment of hip PVNS in case of no advanced osteochondral damage at presentation.

Tenosynovial giant cell tumor.

Tenosynovial Giant Cell Tumor (TGCT) is a group of typically benign lesions arising from the synovium of joints, bursae and tendon sheaths. Depending on their growth pattern and clinical course, they are divided into localized and diffuse types. It is predominantly caused by a mutation in the stromal cells of the synovial membrane leading to overexpression of the colony stimulating factor 1 that recruits CSF1R-expressing cells of the mononuclear phagocyte lineage into the tumor mass. The lesions contain mainly histiocyte-like and synovial cells accompanied by varying numbers of multinucleated giant cells, mononuclear cells, foam cells, inflammatory cells and hemosiderin deposits. The gold standard for detect- ing and monitoring the disease is MRI, where the characteristic hemosiderin accumulation can be best appreciated, but it is a histological examination that is most conclusive. The main treatment is surgical resection of all pathological tissue, but radio- and chemotherapy are also viable options for certain groups of patients.

Orthopedic management of a patient with pigmented villonodular synovitis.

ABSTRACT: Pigmented villonodular synovitis (PVNS), sometimes also called tenosynovial giant cell tumor, is a rare, slow-growing, benign soft-tissue disorder. PVNS most commonly affects the knee and is associated with painful hemarthrosis and joint swelling. The condition also can affect the hip, ankle, shoulder, or elbow. This article reviews practice guidelines for PVNS, diagnosis, and surgical and nonsurgical treatments.