Orthopaedic Surgeon
Varus Ankle Arthritis
Varus ankle arthritis is where the cartilage wears out on the inside of the ankle faster than the outside and this causes the talus to tilt into “varus”- It is the same as bowlegged deformities at the knee.
This varus can be subtle at first but become more obvious as the wear and deformity increase and it can be associated with a visible “thrust” or instability with walking where the ankle visibly collapses out with each step. This makes the ankle unstable and painful.
Achieving Long-Term Stability and Pain Relief with
a suitable approach
The exact combination of procedures required for an individual patient is determined by the surgeon based on the individual patient's pathology.
Whatever combination of procedures is employed either as a one-stage or two-stage process the aim is to provide a well-aligned and stable mobile and pain-free ankle replacement thereby providing a long-term solution to the patient's pain instability and deformity.
Situations that can lead to varus ankle arthritis:
Instability
longstanding ankle instability from ligament injuries usually as a result of sport can lead to progressive asymmetrical wear that can lead to varus ankle arthritis.
Varus malalignment
Varus malalignment of the tibia above the ankle usually as a result of malunited fractures can lead
to uneven pressure on the joint that can lead to varus ankle arthritis.
Ankle fractures
Can cause ankle arthritis as a result of cartilage damage or incorrect healing
Cavovarus Foot Deformities
High arches can lead to an unstable foot and ankle that can lead to
progressive varus ankle arthritis
When a patient with varus ankle arthritis is being assessed for a total Ankle replacement any deformity above or below the ankle joint needs to be addressed either at the same time or in a staged manner depending on its severity and complexity.
Significant tibial deformity needs to be corrected before an ankle replacement can proceed. Cavovarus foot deformities can require staged correction depending on the flexibility and severity.
Procedures that may be required:
Closing Wedge Heel Shift
Correcting the hindfoot varus is critical to long-term success of an ankle replacement and this will often involve a closing wedge heel shift. This can be done percutaneously and is fixed by one of two screws. It can be necessary to do osteotomies at the front of the foot to balance the forefoot with the hindfoot.
Tarsal Tunnel Release
In associated with that we need to do a tarsal tunnel release- this is a release around the tibial nerve on the inside of the heel so that the heel correction doesn’t cause any pressure on the nerve. It also allows us to get a greater correction.
Achilles Lengthening
The Achilles can be tight and this may require lengthening to help achieve a mobile ankle joint.
Peroneus Longus to Brevis Transfer
With longstanding cavovarus deformities, the peroneal tendons can become weakened and painful from chronic overload so sometimes it is necessary to operate on these tendons and transfer one into the other to make one strong tendon.
Tibialis Posterior Tendon Transfer
In the more severe cases, a tendon transfer can become necessary to help restore soft tissue balance. The tibialis posterior is often strong in these cases and is a deforming force. Transferring it to the base of the 5th metatarsal can help restore the soft tissue balance and correct the deformity if it is flexible.
Lateral Ligament Reconstruction
This can be necessary as a result of chronic instability and reconstruction can assist in providing a stable ankle replacement.
Triple arthrodesis
In severe rigid deformities, fusion surgery is required to optimise the foot
position below the ankle joint- this is not an ankle fusion but a fusion of joints around the ankle so that the rigid deformities can be corrected. This is rarely required and is definitely a two-stage procedure if required.