Combined arthroscopic and open synovectomy for diffuse pigmented villonodular synovitis of the knee

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.

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.

One-Stage Synovectomies Result in Improved Short-Term Outcomes Compared to Two-Stage Synovectomies of Diffuse-Type Tenosynovial Giant Cell Tumor (D-TGCT) of the Knee: A Multicenter, Retrospective, Cohort Study

Diffuse-type tenosynovial giant cell tumors' (D-TGCTs) intra- and extra-articular expansion about the knee often necessitates an anterior and posterior surgical approach to facilitate an extensive synovectomy. There is no consensus on whether two-sided synovectomies should be performed in one or two stages. This retrospective study included 191 D-TGCT patients from nine sarcoma centers worldwide to compare the postoperative short-term outcomes between both treatments. Secondary outcomes were rates of radiological progression and subsequent treatments. Between 2000 and 2020, 117 patients underwent one-stage and 74 patients underwent two-stage synovectomies. The maximum range of motion achieved within one year postoperatively was similar (flexion 123-120°, p = 0.109; extension 0°, p = 0.093). Patients undergoing two-stage synovectomies stayed longer in the hospital (6 vs. 4 days, p < 0.0001). Complications occurred more often after two-stage synovectomies, although this was not statistically different (36% vs. 24%, p = 0.095). Patients treated with two-stage synovectomies exhibited more radiological progression and required subsequent treatments more often than patients treated with one-stage synovectomies (52% vs. 37%, p = 0.036) (54% vs. 34%, p = 0.007). In conclusion, D-TGCT of the knee requiring two-side synovectomies should be treated by one-stage synovectomies if feasible, since patients achieve a similar range of motion, do not have more complications, but stay for a shorter time in the hospital.

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.

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.

Image-guided, intensity-modulated radiotherapy for the treatment of diffuse-type tenosynovial giant cell tumor of the knee: Case report and review of the literature

RATIONALE

Tenosynovial giant cell tumor (TGCT) is a neoplastic, inflammatory disease with a benign but aggressive course that often presents as localized (TGCT-L) and diffuse (TGCT-D) forms based on the growth pattern and clinical behavior. For TGCT-L, simple excision of the diseased synovial tissue is the preferred treatment option, while for TGCT-D, adequate synovectomy is usually tricky but is essential. However, approximately 44% of TGCT-D cases will relapse after surgery alone. Thus, the optimal treatment strategy in patients with TGCT-D is evolving, and standalone surgical resection can no longer be regarded as the only treatment. The previous studies have shown that postoperative adjuvant radiotherapy can reduce recurrence in TGCT, especially in patients with incomplete synovectomy.

PATIENT CONCERNS

In the first case, a 54-year-old male presented with recurrent pain and swelling of the right knee with a protracted disease course (≥10 years). The other patient is a 64-year-old male who developed swelling, pain, abnormal bending, and limited movement of the left knee without obvious inducement.

DIAGNOSES

Clinical and imaging examinations can provide a definitive diagnosis, and pathology is the gold standard. TGCT-D was confirmed by postoperative pathology. After the operation, the patients underwent an MRI re-examination and showed that the lesions of the knee were not completely resected.

INTERVENTIONS

Arthroscopic synovectomy was performed on the patients, and postoperative pathology was confirmed as TGCT-D. Because of incomplete synovectomy, the 2 cases received image-guided, intensity-modulated radiotherapy (IG-IMRT) after the operation.

OUTCOMES

The follow-up time was 1 year, no evidence of disease progression was found in MRI. No obvious adverse effects associated with radiotherapy were detected during the follow-up period.

LESSONS

These cases and reviews illustrate the necessity of radiotherapy for TGCT-D and that IG-IMRT is a safe and effective method for treating TGCT-D of the knee.

Management of Tenosynovial Giant Cell Tumor: A Neoplastic and Inflammatory Disease

Background:

Patients with diffuse tenosynovial giant cell tumor (TGCT) face a high risk of recurrence, progression, and disability. This systematic review assesses the recent evidence of surgical, adjuvant, and systemic treatments for TGCT.

Methods:

We searched PubMed and Ovid with the terms “Giant cell tumor of tendon sheath” OR “pigmented villonodular synovitis” OR “tenosynovial giant cell” AND “treatment” OR “surgery.” Inclusion criteria: published 2013 to present; prospective or retrospective design; English language; > 20 patients with histopathological confirmed diagnosis of TGCT; and ≥ 1 efficacy and/or safety outcome from surgery, systemic drug therapy, or adjuvant ⁹⁰yttrium radiosynoviorthesis.

Results:

Of the 434 studies identified, 25 met the inclusion criteria. Of 11 studies in patients with disease in the knee, nine examined surgical treatment approaches, and two evaluated adjuvant ⁹⁰yttrium radiosynoviorthesis. Of 11 studies in patients with mixed sites of disease, six assessed surgical treatment approaches, and five evaluated systemic drug therapies. Three studies assessed surgery in patients with TGCT in the hand, hip, and ankle or foot.

Discussion:

The high rates of recurrence and risks associated with surgery emphasize the need for novel treatments in patients with symptomatic, advanced TGCT. Systemic therapy may be valuable as part of a multidisciplinary approach.

Incomplete resection increases the risk of local recurrence and negatively affects functional outcome in patients with tenosynovial giant cell tumor of the hindfoot

BACKGROUND

Diffuse tenosynovial giant cell tumors (TGCT) are more likely to occur in the hindfoot and tend to recur after surgical excision. We performed a pooled analysis of hindfoot TGCT cases to identify factors associated with local recurrence and functional outcomes.

METHODS

We retrospectively reviewed medical records of 33 patients diagnosed with TGCT (15, localized cases; 18 diffused cases) of the hindfoot between 1998 and 2017. Median follow-up was 32 months. Multivariable Cox proportional hazards regression analysis was conducted to estimate the hazard ratios for risk factors for local failure. Generalized linear regression models were used to assess whether resection status, tumor size, tumor type or bone involvement correlated with the Musculoskeletal Tumor Society (MSTS) score.

RESULTS

Local failure was reported in 30% (10/33) patients. Multivariable analysis showed that macroscopically incomplete resection was the only independent prognostic factor for poor local failure-free survival (P=.001). Incomplete resection significantly decreased MSTS score and negatively affected functional outcome (P=.047).

CONCLUSIONS

Incomplete resection increases the risk of local recurrence and negatively affects functional outcome in patients with TGCT of the hindfoot.

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.

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.

Surgical outcomes of patients with diffuse-type tenosynovial giant-cell tumours: an international, retrospective, cohort study

BACKGROUND

Diffuse-type tenosynovial giant-cell tumour is a rare, locally aggressive, and difficult-to-treat soft tissue tumour. Clinical and surgical outcomes depend on multiple factors, including preoperative diagnostic assessment, the localisation and extent of disease, and possibly the choice of treatment modalities by orthopaedic surgeons. We did a retrospective cohort study to characterise global surgical treatment protocols, and assess surgical outcomes, complications, and functional results in patients with diffuse-type tenosynovial giant-cell tumours.

METHODS

In this international, multicentre, retrospective cohort study, we included consecutive patients treated in 31 sarcoma reference centres between Jan 1, 1990, and Dec 31, 2017. Eligible patients were of any age and had histologically proven diffuse-type tenosynovial giant-cell tumour of large joints. Patient data were retrieved from the local databases of participating centres. Patients with localised-type tenosynovial giant-cell tumour were excluded. In the analysis, we only included patients with complete core criteria data regarding admission status, date of treatment, type of treatment at participating centre, and first local recurrence after treatment. We used a non-parametric method to estimate recurrence-free survival at 3, 5, and 10 years after initial surgical resection in a tertiary centre. We used a multivariate Cox regression model to estimate the effect of risk factors. We also present subgroup analyses of disease status at presentation (primary vs recurrent disease) and recurrence-free survival by surgery type (open surgery vs arthroscopic synovectomy), and prespecified risk factors were tested in a univariate and multivariable analyses, with an endpoint of first local recurrence after treatment in a tertiary centre.

FINDINGS

Data collection for these analyses occurred between January, 2016, and May, 2018. We received the records of 1192 patients, of which 966 (81%) were surgically treated and had complete information on core criteria. 445 patients were admitted with therapy-naive disease of the knee and were primarily treated in a tertiary centre. Since patients with wait and see treatment do not have a starting date of treatment, these patients were excluded in the calculation of median follow-up time for all patients. For this calculation we used time of surgery as a starting date. 758 (64%) of 1192 patients had knee involvement and 628 (54%) of 1163 patients with complete data on type of surgery had one-staged open synovectomy. At a median follow-up of 54 months (IQR 27-97), recurrent disease developed in 425 (44%) of all 966 surgically treated cases, and recurrence-free survival was 62% (95% CI 59-65) at 3 years, 55% (51-58) at 5 years, and 40% (35-45) at 10 years. Surgical complications were reported in 105 (12%) of 906 patients who had complete data on surgical complications. Pain improved after surgical treatment in 255 (59%) of 434 patients and swelling improved in 328 (72%) of 453 patients who had complete data.

INTERPRETATION

This study of patients with diffuse-type tenosynovial giant-cell tumour provides a comprehensive and up-to-date disease overview, assessing the clinical profile and management of the disease in multiple specialised referral centres. Surgical treatment of diffuse-type tenosynovial giant cell tumours is not a definitive treatment for every patient because it involves a high risk for local recurrent disease and a relatively high risk for postoperative complications. After surgical treatment in treatment-naive patients, risk factors for recurrent disease in individual patients were not identified in what we believe is the largest cohort to date.

FUNDING

Daiichi Sankyo.

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.

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.

Diffuse Pigmented Villonodular Synovitis as a Rare Cause of Graft Failure Following Anterior Cruciate Ligament Reconstruction

This case report describes a 42-year-old woman who was diagnosed with pigmented villonodular synovitis (PVNS) in the knee. The patient had received a bone-patella tendon-bone autograft reconstruction of her anterior cruciate ligament (ACL) 22 years prior to her diagnosis of PVNS. After a traumatic event that tore her ACL graft, she underwent a second surgery to repair the initial reconstruction. However, her pain and joint instability remained unresolved. When radiolucent lesions in her tibia and femur were identified through a radiographic image, the patient was referred to the authors' orthopedic oncology clinic. Additional imaging, including magnetic resonance imaging, revealed PVNS, and she was scheduled for debridement and a complete synovectomy of the knee. After surgery, the patient's pain decreased dramatically. She continues to maintain an active lifestyle despite a relatively minor decrease in range of motion. In this case, PVNS proved to be an unlikely complication after ACL reconstruction. The patient remains at risk for the development of degenerative arthritis. [Orthopedics. 2018; 41(1):e142-e144.].

Systematic Arthroscopic Treatment of Diffuse Pigmented Villonodular Synovitis in the Knee

Pigmented villonodular synovitis (PVNS) is a benign aggressive disease that presents in either a localized (LPVNS) or diffuse (DPVNS) form. Arthroscopic synovectomy is the standard operative treatment for LPVNS, and when used to treat DPVNS, it is usually combined with an open posterior procedure. The purpose of this Technical Note is to report the technique that we have refined to allow for arthroscopic synovectomy as the sole treatment for DPVNS. We describe our technique with the factors we have found to be important to ensure adequate arthroscopic synovectomy, while minimizing risks and complications. The combination of additional portals, the use of multiple different shavers and arthroscopes, and the use of a leg holder all maximize our ability to clear disease.

Diffuse pigmented villonodular synovitis in knee joint: diagnosis and treatment

Pigmented villonodular synovitis is a rare proliferative condition of the synovium. Although the condition can present in any joint, the knee is the most commonly affected site. Despite being a benign condition, pigmented villonodular synovitis is often aggressive, with marked extra-articular extension in some cases. Monoarticular involvement occurs in two forms: localized and diffuse. The latter is more common, with a high recurrence rate. There is no standard method of management of this lesion. Open surgery is a classical and effective method for treatment. Arthroscopic synovectomy, however, has gained popularity, and has several advantages over the open technique particularly in exclusively articular cases. The combined approach is suggested in cases with extra-articular involvement. Synovectomy through any approach may prevent secondary osteoarthritis and subsequent joint arthroplasty. Internal irradiation or external beam radiation as an adjuvant treatment to surgical synovectomy appears to decrease the rate of local recurrence in diffuse cases. The authors observed a great heterogeneity in reporting of functional results, and specific conclusions should not be drawn. Each patient should be managed in accordance with his/her particular condition.

Tenosynovial Giant Cell Tumor: Incidence, Prevalence, Patient Characteristics, and Recurrence. A Registry-based Cohort Study in Denmark

OBJECTIVE

Tenosynovial giant cell tumor (TGCT) is a rare benign proliferative and inflammatory disease arising from synovia of joints, bursae, or tendon sheaths. We aimed to estimate incidence rate and prevalence of TGCT in Denmark, to describe patient characteristics and treatment modalities among patients with TGCT, and to estimate risk of TGCT recurrence.

METHODS

Using registry data on pathology examinations and inpatient and outpatient hospital diagnoses, we identified adult patients with diagnoses of diffuse TGCT (D-TGCT) or localized TGCT (L-TGCT) between 1997 and 2012, followed through 2012. We described patients' characteristics, treatment modalities, and recurrence.

RESULTS

We identified 2087 patients with L-TGCT and 574 patients with D-TGCT. Their incidence rates per million person-years were 30.3 (95% CI 29.1-31.7) and 8.4 (95% CI 7.7-9.1), respectively. At the end of 2012, prevalence per 100,000 persons was 44.3 (95% CI 42.4-46.3) for L-TGCT and 11.5 (95% CI 10.6-12.6) for D-TGCT. Women made up 61% of the patients with L-TGCT and 51% of the patients with D-TGCT. Median age at diagnosis was 47 years. Ten-year risk of recurrence was 9.8% (95% CI 8.4-11.3%) after L-TGCT and 19.1% (95% CI 15.7-22.7%) after D-TGCT.

CONCLUSION

This study contributes evidence about epidemiology of TGCT based on routinely collected population-based data gathered in a setting of universal equal access to healthcare and complete followup.

Multifocal pigmented villonodular synovitis coexisting in both the knee joint and the patella: a case report and literature review

BACKGROUD

Pigmented villonodular synovitis (PVNS) is an uncommon entity of proliferative lesion of the synovium, presenting with different clinical signs and symptoms. PVNS rarely forms an osteolytic lesion in a bone. Here we report a unique case of PVNS with a nodular lesion in the left patella.

CASE PRESENTATION

A 37-year-old female was referred to our hospital with complaints of ongoing left knee pain and a painful and palpable mass in her left popliteal fossa. MRI demonstrated a nodular lesion in the left patella, diffuse affected synovial tissue in the left knee and an extra-articular mass in the left popliteal fossa. After a primary diagnosis of PVNS had been established, combined arthroscopic synovectomy and open resection were performed. The postoperative pathological diagnoses of the resected mass from the popliteal fossa, the affected synovial tissue and the lesion in the patella were consistent with PVNS. At 1-year follow-up, no evidence of recurrence was noted.

CONCLUSIONS

Based on brief literature review of PNVS, we presented a very rare case of PVNS with a nodular lesion in the left patella, diffuse affected synovial tissue in the left knee and an extra-articular mass in the left popliteal fossa.