Clustered localized pigmented villonodular synovitis

The effect of surgical synovectomy and radiotherapy on the rate of recurrence of pigmented villonodular synovitis of the knee

Pigmented villonodular synovitis (PVNS) is a rare proliferative process of the synovium which most commonly affects the knee and occurs in either a localised (LPVNS) or a diffuse form (DPVNS). The effect of different methods of surgical synovectomy and adjuvant radiotherapy on the rate of recurrence is unclear. We conducted a systematic review and identified 35 observational studies in English which reported the use of surgical synovectomy to treat PVNS of the knee.

A meta-analysis included 630 patients, 137 (21.8%) of whom had a recurrence after synovectomy. For patients with DPVNS, low-quality evidence found that the rate of recurrence was reduced by both open synovectomy (odds ration (OR) = 0.47; 95% CI 0.25 to 0.90; p = 0.024) and combined open and arthroscopic synovectomy (OR = 0.19, 95% CI = 0.06 to 0.58; p = 0.003) compared with arthroscopic surgery. Very low-quality evidence found that the rate of recurrence of DPVNS was reduced by peri-operative radiotherapy (OR = 0.31, 95% CI 0.14 to 0.70; p = 0.01). Very low-quality evidence suggested that the rate of recurrence of LPVNS was not related to the surgical approach.

This meta-analysis suggests that open synovectomy or synovectomy combined with peri-operative radiotherapy for DPVNS is associated with a reduced rate of recurrence. Large long-term prospective multicentre observational studies, with a focus on both rate of recurrence and function, are required to confirm these findings.

Cite this article: Bone Joint J 2015;97-B:550–7.

Arthroscopic treatment of localized pigmented villonodular synovitis of the knee

PURPOSE

The purpose of this study was to review the outcome of the arthroscopic treatment of localized pigmented villonodular synovitis of the knee and to determine the recurrence rate with clinical and magnetic resonance imaging evaluation at midterm follow-up.

METHODS

Thirty consecutive patients diagnosed with localized pigmented villonodular synovitis of the knee were treated arthroscopically between 1990 and 2008. Clinical assessment was made with the use of Lysholm Knee Scale, and radiologic assessment was done by plain radiographs and magnetic resonance imaging of the knee. Recurrence rate of the disease was also estimated.

RESULTS

The average follow-up was 75 months (range 12-144). The median age of the patients was 46 years (range 23-71). Symptoms were discomfort of the knee (100%), swelling (90%), locking (50%), pain (10%) and palpable mass (15%). A history of knee trauma was present in 10% of the patients. The nodules were localized in the gutters (45%), suprapatellar pouch (26%), patellar fat pad (13%), posterior compartment of the knee (13%) and in the femoral notch (9%). The median Lysholm Knee Score was 56.5 (range 53-60) and 85.5 (83-88) preoperatively and at final follow-up, respectively. No postoperative complications occurred.

CONCLUSIONS

Arthroscopy is a safe and effective procedure for the treatment of localized pigmented villonodular synovitis of the knee. Magnetic resonance imaging is essential to diagnose this pathologic condition and to define accurately its localization and treatment strategy.

Long-term follow-up of surgically treated localized pigmented villonodular synovitis of the knee

PURPOSE

The purpose of this study was to review a single institution's large consecutive series of localized pigmented villonodular synovitis (PVNS) of the knee.

METHODS

Cases for review were identified by a search of our institution's pathology records for definitive diagnoses of monoarticular localized PVNS (LPVNS) of the knee between 1970 and 1996. Patients' presenting symptoms and examination were recorded, as were the preoperative diagnosis and documentation of the PVNS nodule's location in the knee at surgery. Eighty-four patients were diagnosed with localized PVNS of the knee during the study period. Twenty-nine of these cases were incidental findings associated with planned total knee replacement and were excluded from the study. Of the remaining 55 patients constituting the study subgroup, 26 have been reviewed in detail.

RESULTS

There were 15 males and 11 females, and the mean age at presentation was 36.7 years. Patients presented for evaluation at an average of 15 months after the onset of symptoms. Pain was the most common complaint, reported by 24 of the 26. Locking and giving way were reported by 10 and 5 patients, respectively. On examination, 13 patients had an effusion, 11 had joint line tenderness, and 10 had a palpable mass. The most common preoperative diagnosis was a meniscus tear (10 of the 26), followed by PVNS (4), "mass" (4), and anterior cruciate ligament injury (3). At surgery, the nodule of PVNS was found most frequently in the suprapatellar pouch (6 cases), followed by the femoral notch (4), lateral synovium/gutter (4), popliteal fossa (3), lateral compartment (3), and medial compartment (2). Fourteen of the procedures performed were open, and 12 were performed by arthroscopy. Ten of the 26 patients participated in a long-term follow-up via the Lysholm Knee Scoring Scale questionnaire (average, 65.8 months postoperatively; average score, 95.4/100). Of these 10, 7 returned for follow-up clinical examinations (6 excellent results and 1 good). All 10 patients were operated on arthroscopically, and none required repeat surgery.

CONCLUSIONS

This review represents the largest series of localized PVNS of the knee to date. Echoing the findings of other PVNS studies, patients presented, on average, in their fourth decade. The common preoperative diagnosis of a meniscal tear is not surprising given the frequent presentation of a painful and, typically, locking knee with joint line tenderness and effusion. Interestingly, what is perhaps the most diagnostic finding on examination, a palpable mass, was present in only 1 of the 6 patients who had PVNS in the most common location, the suprapatellar pouch. With the ease and utility of modern arthroscopy, however, PVNS is an easily treatable condition that can be diagnosed at the time of surgery.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.