Pigmented Villonodular Synovitis (PVNS)

By admin Last updated Oct 21, 2023

Ovid: 5-Minute Sports Medicine Consult, The

Nancy White

Basics

Pigmented villonodular synovitis (PVNS) is a proliferative disorder of the synovium.
There are 2 forms described, localized and diffuse, which are likely both ends of a spectrum of the same disorder.
The synovial lesions are composed of lipid-laden macrophages, giant cells, and hemosiderin.
The knee is the most commonly involved joint.
PVNS also can involve the hip, ankle, shoulder, and elbow.

Epidemiology

Predominant age: Most commonly seen in 3rd and 4th decades; can be seen in patients as young as 10 yrs of age or as old as the 70s
Incidence: 1.8/1 million (general population)
Predominant gender: Male = Female

Risk Factors

Risk factors are unknown.

Genetics

No genetic component

Etiology

Etiology not fully understood; theories include the following:
- Trauma and recurrent local hemorrhage to affected joint
- Abnormal metabolic activity within the joint to cause inflammatory response (macrophages, giant cells, hemosiderin)
- Neoplastic process: Rare cases of malignant transformation have been reported.
Synovial lesions contain lipid-laden macrophages, giant cells, hemosiderin, and stromal and fibroblast proliferation.
There are 2 forms:
- Localized PVNS:
  - Lesions are pedunculated/lobular and localized to 1 area of synovium.
  - Knee is the most common joint involved.
- Diffuse PVNS:
  - Histology is similar to localized PVNS; however, involvement is noted throughout most or all of the involved joint, bursa, or affected tendon sheath.
  - Knee is the most commonly affected joint; however, can involve the hip, ankle, shoulder, elbow.
  - More common than localized PVNS
  - Higher recurrence rate following treatment than local form
  - More destructive course and consequently leads to more end-stage joint disease than localized PVNS

Diagnosis

History

Insidious onset with a history of associated trauma unusual
Symptoms are often vague and may be intermittent and are typically slowly progressive.
Swelling and stiffness out of proportion to pain
Monarticular involvement is the norm, with the knee the most commonly involved joint.
Localized PVNS symptoms most commonly involve locking/catching/instability; also can have pain/swelling.
Diffuse PVNS symptoms include insidious onset of pain, swelling, stiffness (often mistaken for early arthritis, meniscal or ligamentous injuries).

Physical Exam

Diagnostic Tests & Interpretation

Imaging

Plain radiographs:
- Often are normal
- May see periarticular erosions/subchondral cysts
- Reciprocal erosions on opposite sides of the joint, with a preserved joint space, are highly suggestive of PVNS.
CT scan:
- PVNS is a high-density soft tissue mass compared with skeletal muscle.
- Bone erosion and cysts may be seen.
- CT scan with contrast material displays the synovial changes.

P.469

Diagnostic Procedures/Surgery

Aspiration/joint fluid evaluation:

Differential Diagnosis

Osteoarthritis: Similar exam/radiographs, but PVNS does not have osteophytes.
Hemophilia: Similar exam/radiographs but without history of hemophilia
Synovial hemangioma: Similar exam/radiograph but age of presentation different (PVNS 3rd–4th decades, synovial hemangioma 1st–3rd decades)
Rheumatoid arthritis: Similar exam/radiographs but PVNS monarticular
Tuberculous arthritis: Similar exam but without periarticular osteoporosis/abscesses on radiographs/MRI
Lipoma arborescens: Similar exam and MRI findings, but lesions show low signal enhancement with contrast versus no enhancement

Treatment

Surgery is treatment of choice.
Localized PVNS: Arthroscopic partial synovectomy of lesion with margin of healthy synovium is recommended.
- Lesions in anterior compartment allow for surgeon to use standard arthroscopy approach.
- Lesions in posterior compartment require additional portals.
- Recurrence rate is low.
Diffuse PVNS: Arthroscopy is an option, but open arthrotomy is often selected.
- Extent of disease/location of lesions/surgeon's preference determine if arthroscopy or open arthrotomy is selected.
- Open arthrotomy is recommended when lesion is posterior to posterior collateral ligament, extraarticular, or located within a cyst.
- Complete synovectomy is treatment of choice.
Radiation may be combined with surgical techniques for extensive or recurrent disease.
Joint replacement also is considered for severe or recurrent disease where significant joint space narrowing is involved.

Ongoing Care

Follow-Up Recommendations

Patient Monitoring

Codes

ICD9