Anatomical Concepts (UK)
Masters of Rehabilitation Engineering

VVAS Knee Orthosis

Custom Knee Orthosis

Anterior View of the V-VAS

Anterior View of the V-VAS

Lateral View of the V-VAS

Lateral View of the V-VAS

The V-VAS Orthosis for severe Osteoarthritis of the Knee

Whilst there are various options for treating severe, single compartment, osteoarthritis (OA) of the knee, these severe forms can be very difficult to treat successfully whether by medication, surgery or orthotically.

When patients have co-morbidities that prevent pain-relieving surgery the V-VAS (Varum Valgum Adjustable Stress) orthosis has proved to be a particularly successful conservative orthotic approach in hundreds of cases.

The V-VAS is a custom fit orthosis made with a special technique and components. An intial, standing, plaster cast is taken of the patient whilst some careful manual correction is applied to the joint with a special technique. The resulting cast is used as the model around which the V-VAS orthosis is manufactured. The resulting orthosis is extremely light and comfortable to wear but the real secret of it’s success is it’s structural joint design that allows the amount of offloading provided to the damaged joint to be carefully adjusted and controlled.

V-Vas KO Medial view.JPG

Most orthotic designs on the market cannot offload a severe OA knee case without using very high forces on the surrounding tissue which result in discomfort - and almost certainly the result is rejection of the brace.

The V-VAS uses a “Dynamic Closed Frame” that allows some unique features including easy adjustment whilst being worn by the user. The patented joint design efficiently allows the damaged joint compartment to the “off-loaded” producing pain relief and a return to activity.

Instead of using a narrow frame as seen on most designs, it uses a total contact cuff on the thigh and tibia along with an adjustable, self aligning, polycentric joint system to create four points of pressure instead of three. There is no need for a condylar pad. This results in increased comfort.

Sample Case (Mr MD - 47years OLD)


  • 1985 left knee arthroscopy & open medial menisectomy

  • 1995 repeat arthroscopy shows complete loss of medial chondral surface

  • 2005 right knee arthroscopy - bone on bone contact. Both knees moderate PFJ and lateral compartment chondral loss.


  • Bilateral clinical varus > 20 degrees

  • Both knees lack 5 degrees full extension

  • Moderate effusion right knee only

  • Severe pain and swelling right knee

Clinical Observations

  • Too young for joint replacement

  • Too severe for chondral resurfacing

  • Too advanced for high tibial osteotomy

  • May be suitable for Benjamin’s double osteotomy

Interpretation of Outcomes

  • Brace initially used 2 - 4 hours per day

  • Now used during whole working day

  • Excellent reduction in pain and swelling of right knee

  • Weight-bearing Xray

  • No brace 11 deg Varus

  • With brace 4 deg Varus


Mr MD in V-VAS orthosis

Indications for the V-VAS Orthosis

  • Mild to severe Genu Varum or Valgum

  • Non-operative Tibial Plateau fixations

  • Failed Tibial Plateau Reconstructions

  • Osteochondral Defects

  • Post total-knee arthroplasty

  • Tibial and/or Femoral spacers

At present we are looking to establish a training programme to roll out the V-VAS beyond our current Scottish Central Belt area.

If you would like to learn more please contact us.

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