Prolifermented Villo-Nodular Synovitis
- benign inflammatory process that arises in synovial tissues
- contains significant amounts of hemosiderin
Age: 20 - 50
Sex: M > F
A. Diffuse
- throughout joint synovium
- more difficult to treat / excise fully
B. Localised
- just one area of synovium
- i.e. suprapatella / medial or lateral gutter
Major joints
- knee, hip, shoulder, and ankle
- has been observed in all joints
Usually mono-articular
- occasionally multiple joints
In aggressive cases, PVS may involve adjacent bone
The cause is unknown
Theories
1. Recurrent hemarthrosis
- cavity of the involved joint is recurringly filled with old unclotted blood
- hemosiderin is a prominent gross and histological finding
- may lead to
2. Inflammatory process
- marked synovitis
- no virus, bacteria or other inflammatory stimulant has been demonstrated
3. ? Neoplasm
- there are scattered reports of distant metastases to the lungs and other organs leading to death
The process is intermittently progressive
- over a period of several months or years
- diffuse synovial involvement
Progressive destruction of the articular cartilage and subchondral bone
- results in severe degenerative arthritis
Extensive soft-tissue extension occurs
- may produce peripheral neuropathy by neurovascular bundle involvement
In aggressive cases, PVNS may involve adjacent bone
- pathologic fracture secondary to subchondral bone invasion is occasionally seen
- especially in the femoral neck
Intermittent joint effusion
Modest discomfort
Antecedent trauma
- often recounted but difficult to relate to the development of PVNS
Blood tinged / xanthochromic
- in absence of trauma
- highly suspicious of PVNS
Soft tissue swelling
Arthritic changes
Bone destruction
- invasion of adjacent metaphyseal cancellous bone
- may be suggestive of neoplasm
Increased uptake +++
Characteristic T2
- heterogenous picture
- high intensity signal from vascular component
- low intensity signal from hemosiderin
Hemosiderin has low signal intensity on TI and T2
Assess involvement of knee areas
- suprapatella
- medial and lateral gutters
- posterior compartments
- femoral notch
Nodular
Diffuse
Haemophilia
Lipoma arborescens
Synovial chondromatosis
Complete synovectomy
- dissecting the synovium and intermediate layers
- preserve deep fibrous layers and ligaments
- need to remove all affected synovium for best results
- meticulous surgical technique required
Options
Open
- posterior recess difficult to access
- or if extracapsular
Arthroscopic
- often need posterior cannulas / portals
- takes up to 2 hours
Kim et al Clin Orthop Research 2000
- 11 patients with localised PVNS of the knee treated arthroscopically
- no recurrences at 2 - 4 years
Chin et al JBJS Am 2002
- treatment of recurrent PVNS in 40 patients
- repeat surgery with post op radiation synovectomy or DXRT if residual disease
- best outcomes with complete surgical excision of all disease