Distal femoral extension osteotomies and patella advancement surgery

Why is this surgery be needed?

Children and young people who have a movement disorder may have difficulty with standing and walking.

The way in which their muscles work can be affected, causing tightness, weakness, and reduced control. Over time due to an imbalance of forces some children and young people will begin to ‘sink’ when standing and walking and eventually loose the ability to straighten their knees.

Standing and walking in this position over a prolonged period can lead to other changes such as the kneecap sitting too high causing discomfort and tiring quickly as being in this position uses a lot of energy. All of these factors can lead to making standing transfers more difficult.

An operation can be done to straighten the knee and pull the kneecap into an improved position. These operations will be done together and are usually done on both legs at the same time. If necessary tight muscles will be lengthened during the operation. These could be across the hips, knees and or ankles.

When might this surgery be needed?

If your child’s independence is being affected due to not being able to straighten their knees this surgery might be able to help.

This surgery is usually offered when a child has stopped or nearly stopped growing. The aim of the surgery is to allow your child to continue to manage standing transfers into adulthood and hopefully reduce discomfort they may be experiencing. You should speak to your child’s surgeon if you have any questions.

What to consider when thinking about this operation?

After this operation, your child will find it difficult and uncomfortable to crawl. This is a big lifestyle change if your child currently crawls as their main method of indoor mobility.

The aim of this operation is to allow standing transfers into adulthood. It will not necessarily allow someone to walk, particularly if they have not walked before or for some time.

Recovery from this surgery can take up to 18 months to 2 years to see the full benefits. Your child must be motivated to work hard with their rehabilitation and you must be committed to supporting them.

It is important to consider what the aim of this surgery is for your child and discuss with your family, orthopaedic team and physiotherapist.

What happens during the operation?

This operation is done under a general anaesthetic meaning your child will be asleep.

Changing the position of the knee (distal femoral extension osteotomy)

A small wedge of bone is taken from the bottom of the thigh bone. This allows the leg to be fully straightened. The bones are held in their new position with metal plates and screws.

Changing the position of the kneecaps (patella advancement)

The kneecap is pulled down to its optimal position and fixed in place. The tendon needs to heal in its new position and caution should be taken on movement.

What happens after the operation?

You will come to a pre-assessment clinic where you will see your consultant and meet different members of the orthopaedic team. The team will go through each step of the operation and recovery process.

Your child will need to stay in hospital for around 7 days. The number of days will depend on multiple factors, including how comfortable they are after the operation and how they manage transferring out of bed. Your child will be given medication to help with pain and muscle spasms.

Therapy

After this operation it is important for your child’s bones and muscle to heal in their new position. The therapy team will see your child on the ward after their operation. They will go through exercises, positive positions, and things you can do to help your child get the most from their surgery. Exercises will need to be done a minimum of 3 times a day.

Your local physiotherapist will guide your child’s rehabilitation journey however it is your responsibility to make sure they complete the necessary exercises.

The therapy team at the hospital will speak to your child’s local physiotherapist requesting they see them after discharge and will pass on any important information.

Positioning

Immediately after the operation your child will have braces fitted to their legs to keep them straight. They will have to keep their legs straight for the first 2 weeks. After 2 weeks they will be able to gradually increase the amount of movement allowed at their knees over the following 6 weeks. Braces will be used to guide the movement.

Braces

Your child will be provided with 2 types of braces. One set of braces will help push their knees straight and keep them straight when they are resting. The second pair of braces will be used to help gradually increase the movement at the knees. These will be measured for at pre-assessment clinic and provided after the operation.

Standing, walking and transferring

Your child will not be able to put any weight through their legs after the operation until they have had an X-ray at around 6 to 8 weeks.

We will discuss what is going to be the safest way to transfer out of bed at pre assessment clinic. This will usually involve either slide transfers, shuffling from the bed out to the chair or hoisting. If you do not have the equipment at home currently to support your child after the operation, we will make arrangements at pre-assessment clinic to ensure you have everything you need.

When they are allowed to return to weight bearing and standing this will be a gradual process. We often recommend that they begin by accessing a standing frame as a starting point.

Washing and dressing

Your child will be able to have a shower whilst their wounds are healing but must not be submerged in water such as the bath until the wounds are healed and dry. It may be easier to carry out bed baths initially and what you are able to access will depend on your individual situation. The therapists will discuss the options with you. Your child’s legs will be positioned straight initially after the operation and it is helpful to bring loose fitting clothes and shorts, skirts or dresses.

What happens after leaving hospital?

An appointment will be arranged for you to come back to clinic at around 6 to 8 weeks. An X-ray will be taken to check the position of the knees, kneecaps and the healing process. You should have contact from your child’s usual therapists to help settle in back at home.

What happens next?

You will continue to be followed-up by your consultant and the orthopaedic team at Sheffield Children’s Hospital. You and your child will need to keep working hard with your local therapists.

What happens to the plates and screws?

The plates and screws do not need to be removed unless they were causing any problems.

Summary points

• It is a big operation that needs lots of rehabilitation to gain the benefits
• The aim is to facilitate standing transfers not necessarily improve walking