Isolated fusion of the talonavicular joint: A guide for patients

The talonavicular joint (TNJ) is an extremely important joint in the foot. It allows for most of the foot’s movement. The joint allows the foot to move in and outwards. It does not help with any up or down motion of the foot as this is carried out at the ankle joint.

The TNJ can be affected in arthritis and a flat foot deformity.

A previous fracture of the navicular or talus can often lead to osteoarthritis developing and, over time, this can produce pain and possibly a restriction in the foot’s motion.

Treatment

Treatment for this condition can be divided into conservative or surgical.

Conservative treatment

Insoles

Insoles can help support your arch and reduce excessive motion of your foot or, if your foot rolls in, the insole can help control this and stabilise

the TNJ. Often, over-the-counter insoles are not supportive enough and a referral to the biomechanical podiatrists would be needed.

Analgesics or painkillers

Analgesics, such as Ibuprofen, work well in controlling the pain associated with TNJ problems. However, you must read the drug label and be aware of why and when you should not take the medicine.

Steroid injections

Steroid injections into the TNJ can provide medium-term relief from pain. These injections are carried out under ultrasound or X-ray guidance.

The TNJ is unlike other joints of the foot and is saddle-shaped with a very small joint space; this can make the injection tricky but the benefits are appreciated.

Footwear

Much the same as an insole (a supportive shoe, for example) a running or walking trainer, can help stabilise the foot and reduce the pain.

Surgical treatment

Surgery for a painful TNJ involves fusing the joint. A fusion is carried out by removing the articular cartilage, which is the shiny material at the end of the bone on a joint of meat or chicken leg, down to the bone on the navicular and talus. The bony surfaces are brought together and held in place by screws and or plates (internal fixation).

The internal fixation is designed to hold the bones together while they heal. They are not designed to, and will not be able to, withstand the force of you walking around before the bone has healed.

Following the operation, cast immobilisation is required for eight to 12 weeks.

Once the TNJ has fused, you will lose 90 per cent of the in and outward movement of the foot, but the pain from the joint would have resolved.

A specific complication of this procedure is non-union of the bone, where the bones fail to knit together. Also, the blood supply to the talus can be adversely affected (avascular necrosis). If either of these conditions happen a period of extended cast immobilisation would be required and, possibly, further surgery.

Other specific complications include osteoarthritic changes to adjacent joints.

When one joint is fused, greater stress is placed on the adjacent joints. In the case of a TNJ fusion, patients might develop mild pain in the ankle or subtalar joint (the joint beneath the ankle joint to include the ankle bone -talus; and the heel bone – calcaneus). The joint along from the TNJ can also have an increased incidence of arthritis. The more joints that need to be fused increases the incidence of adjacent joints developing arthritis.

This information gives you an overview of the management of a fusion of the talonavicular joint. The procedure can be carried out in isolation, as is the case for arthritis, but can also be done in combination for the management of a flat foot deformity.

Recovery after your operation

Following this procedure you will be in a non-weight bearing cast for up to eight weeks.

Day of surgery to two weeks

• You will be in a plaster of Paris below knee cast. This cast is rather heavy but allows for foot swelling. This cast will be on for about two weeks.
• You should not walk on the foot which had surgery.
• You must rest with your feet up as much as possible. You should restrict walking to bathroom visits only, and when getting about you must use your crutches. The nursing team will show you how to use crutches and provide you with written information.
• If you experience pain, you should take the prescribed pain killers. Any pain is usually worse for the first two days.
• If you are still experiencing pain after three to four days that is not relieved by the pain killers, you should contact the department directly.
• If you have any concerns over your foot you should contact the department directly.
• The department is closed at weekends. Out-of-hours, you should contact your GP or go to your local accident and emergency (A&E) department.

Two weeks after surgery

• The plaster of Paris cast will be removed and replaced with a lightweight fibreglass cast, which stays on for a further eight to 10 weeks. You must continue to put no weight on the foot and use the crutches.

Between eight and ten weeks after surgery

• An X-ray will be taken to assess bony healing.
• If there is sufficient bony healing, the cast is removed.
• You will then be placed in a removable aircast boot and will be able to lightly put weight on your foot, using your crutches. This is known as partial weight-bearing.
• Partial weight-bearing is carried out for a further two to four weeks. No high-impact activities are allowed.

Twelve weeks after surgery

• You can begin to fully put weight on the foot and can gently start to return to normal activities. You should still avoid high-impact activities and remain in your running trainer.
• You can now return to driving; however you must feel able to perform an emergency stop without hesitation or pain. Please check with your insurance company about your cover.
• You may return to work, but this is dependent on the type of work and footwear needed for your job. For certain jobs, returning to work in less than 12 weeks can be an unrealistic expectation.
• Although the foot should now be comfortable and returning to normal, there will still be noticeable swelling, particularly towards the end of the day; this is normal.

Nine months after surgery

• The residual swelling should now be slight, although the healing process continues for 18 months.
• You should be getting the full benefit of the surgery.

Eighteen months after surgery

• All healing is now complete. Swelling should be completely resolved.

Frequent or serious occurring risks

All operations carry a small risk of complications. In foot surgery, complications are uncommon and most resolve without permanent disability or pain. Complications of this procedure can include:

• infection (two in 100)
• delayed or non-union of the bones*
• interruption of the blood supply to the talus – avascular necrosis*
• delayed healing of the skin (eight in 100)
• non-compliance of patients (four in 100)
• thick or sensitive scar formation (four in 100)
• loosening or movement of the screws or wires used to fix the bones (two in 100)
• blood clot deep vein thrombosis (DVT).

*There is a greater chance of delayed, non-union and avascular necrosis of the talonavicular joint. This is because of the way blood is supplied to the ankle bone. If a non-union happens and it is painful, further surgery may be needed to include a bone graft. Smoking can increase the risk of non union.

Complications following foot surgery are rare but can happen. If there is a complication, you will need to visit the hospital more frequently and there could be a significant impact on your recovery and return to work time. Foot surgery should be avoided if only for cosmetic gain.