Limb Reconstruction

+ Limb Malalignment

Malalignment of the lower limb can be present since childhood or can be acquired due to a fracture which has healed in a mal-aligned position. Degenerative (wear and tear) changes in the knee joint can also contribute to the deformity.

Deformities include abnormal angulation when viewed from the front or the side, abnormal rotation in the axis of the bone (torsion), and a discrepancy in length of the bone. Malalignment can lead to problems with function, or result in an uneven distribution of load through the joints.

LIMB REALIGNMENT FOLLOWING TRAUMA

Limb malalignment after severe lower limb trauma is often multiplanar (made up of a combination of angulation in different planes, rotation, length discrepancy and translation). Minor deformity is amenable to non-operative treatment with physiotherapy, activity modification and the use of specialist footwear including heel raises. If there is malalignment causing problems which are refractory to non-operative management then surgery may be indicated.

KNEE REALIGNMENT

Sometimes in individuals who are bow-legged, as a consequence of uneven load distribution, there may be arthritis affecting the inner (medial) side of the knee joint whilst the outer (lateral) side has much lower loads passing through it and the cartilage is unaffected. Wear on the cartilage in the medial compartment can exacerbate bow-legged (varus) malalignment and result in further loading of the inner (medial) side. The converse is true in some individuals who have knock-knees (valgus deformity).

By realigning the knee joint the body weight is shifted away from the damaged side, onto the healthy side. This relieves the pain that is due to arthritis in the knee by offloading the damaged side and can delay the need for knee replacement in young active individuals.

Osteotomy can also help with symptoms of instability: By altering the slope of the tibia it is possible to reduce the dependence of the knee on the anterior or posterior cruciate ligament.

+ Complex deformity correction

WHAT IS THIS PROCEDURE?

After a major injury the broken bones sometimes heal in a less-than-perfect position. This can lead to deformity of the leg, for example a shortened leg (leg length discrepancy). Sometimes this does not lead to symptoms but sometimes it can be difficult to walk normally, or there can be joint pain.

Often as well as the break in the bone, there is significant damage to the skin, muscle and other soft tissues. Attempting to perform an osteotomy (cut in the bone) and plate fixation in such cases could result in inadequate correction of alignment, stretching of the nerves, wound breakdown and deep infection. In this situation, the deformity can be corrected by performing an osteotomy (cut in the bone) and using a frame to externally fix the fracture. The external fixation consists of a combination of pins going into the bone and tight wires which pass through the bone, typically attached to a series of rings around the outside of the leg. The rings are then held in position by rods running between them to make a rigid frame on the outside of the leg. If the amount of deformity is too large to correct in one go, then the rods can be adjusted to gradually correct the deformity, giving time for the nerves, muscles and other soft tissues to elongate. Often the frame will need to stay on for 4-6 months whilst the deformity is corrected gradually.

WHO SHOULD CONSIDER THIS OPERATION?

This operation may be of benefit if you malalignment of the lower limb and experience symptoms which are refractory to non-operative management. Good bone healing is important for this operation to be successful so if you smoke you are strongly advised to quit.

PREOPERATIVE PREPARATION AND EVALUATION

A full history and examination is required along with investigations to make the diagnosis and identify any other complications such as infection or nonunion (where the fracture has not healed). Full leg length, weight bearing X-rays allow the overall limb alignment to be assessed. CT or MRI scanning is a useful adjunct to physical examination if there is a rotational component to the deformity.

WHAT HAPPENS IN THE POST-OPERATIVE PERIOD?

After surgery you will be taught how to care for your leg whilst it is in the frame, including how to keep the pin-sites (where the wires or pins enter through the skin) clean. Full weight bearing is encouraged wherever possible to stimulate bone healing. If deformity correction is to take place gradually over several months, either you or a member of your family may be required to make gradual adjustments to the frame. If this is the case, written instructions will be provided. It is very common to have some inflammation around the pin sites and sometimes a course of antibiotics is required if the skin becomes infected. When the time comes for the frame to be removed, this is usually done as a day-case procedure under general anaesthetic.

+ Problem fractures

WHAT IS THIS PROCEDURE?

Lower limb fractures often require surgery in order to restore the alignment of the bones, promote healing and allow mobilisation. Sometimes ‘internal fixation’ (using a plate and/or screws or nail down the middle of the bone) is a good option but in some cases it is not ideal. For example if there is a severe injury to the skin and muscles around the fracture site there is a risk that a plate and screws would get infected. In this case ‘external fixation’ also known as a ‘frame’ might be recommended.

WHO SHOULD CONSIDER THIS OPERATION?

This procedure may be recommended as a first line treatment if the fracture you have sustained is more amenable to fixation with a frame than by other methods. This can include fractures with multiple fragments of bone as well as those with a severe soft tissue injury. Frame fixation can also be used where other methods have failed, for example in a fracture that has previously been plated but has not healed or has an infection.

WHAT HAPPENS IN THE POST-OPERATIVE PERIOD?

+ Ankle distraction arthroplasty

WHAT IS DISTRACTION ANKLE ARTHROPLASTY?

Distraction ankle arthroplasty is a treatment option for ankle arthritis. A cage is put on the leg in order to stretch the ankle apart. By stretching the ankle apart by even a small amount, the cartilage cells of the ankle are rested and may start to form the critical type of cartilage required to correctly lubricate the joint.

It has been proven both in the laboratory and with patients that when the joint is stretched and weight is applied to the leg at the same time that the cartilage improves. This has a lot to do with the biology of the cartilage cells.

HOW IS A DISTRACTION ANKLE ARTHROPLASTY PERFORMED?

Prior to performing a distraction ankle arthroplasty, the ankle joint first needs to be cleaned out with a minor surgery called arthroscopy where small loose fragments, bone spurs and inflamed tissue inside the ankle are removed.

Either during the arthroscopy or a few weeks later, the cage (called an external fixator) is applied to the leg. This circular cage or a set of rings on the foot and leg allows the ankle to be stretched apart. The ankle is stretched only about 5mm (less than a quarter of an inch). The fixator device is left on the ankle for about 10 weeks.

During the time that the external fixator is on the ankle, the patient is encouraged to walk on the leg as much as possible to stimulate the cartilage. Initially, this is painful, but by about one week is tolerated quite well. Once the fixator is removed, physical therapy and exercises are very important to try to regain as much movement of the ankle as possible.

The ankle remains quite uncomfortable for about six months, but by one year, 80% of patients notice a significant improvement in pain in the ankle.

WHO SHOULD RECEIVE A DISTRACTION ANKLE ARTHROPLASTY?

The ideal patient for a distraction ankle arthroplasty is someone with:

Advanced ankle arthritis
Good alignment of the foot under the leg
Not much deformity of the ankle
A total ankle replacement most likely would be recommended for patients over the age of 50.

WHEN IS THE DISTRACTION ARTHROPLASTY THE BEST OPTION?

A distraction ankle arthroplasty is a one of the best treatment options when a fusion of the ankle joint in a younger patient is trying to be avoided.

+ Bone infection

Osteomyelitis is painful infection of the bone that can affect anyone. It's more common after a recent fracture, especially if you needed pins in your bone, if you have an artificial hip, or if you've had surgery or osteomyelitis before. A severely weakened immune system, diabetes or close contact with tuberculosis can also make it more likely.

If you have osteomyelitis, you are likely to experience pain, swelling, redness or a warm feeling around an area of bone. You usually feel it in the long bones of your legs. This may be combined with a high temperature or fever, although less so in young children. You should be especially aware of these symptoms if you've had osteomyelitis before.

If you have osteomyelitis, your consultant will prescribe you antibiotics, usually for at least six weeks. If the infection is severe, you may have to stay in hospital to have antibiotics intravenously, which is when they are given directly into your vein. In some cases, you may need surgery. This could be to remove bone damaged by the infection, to prevent possible deformity or to relieve pressure on the spinal cord.

+ Limb Lengthening

Following trauma, bones can heal in a shortened and deformed position (mal-union). Sometimes the bone can even remain unhealed (non-union). Limb lengthening procedures address all of these issues. We have been able to successfully correct large deformities and equalize limbs with discrepancies of several inches. A segment of bone can be missing after a bone tumor, bone infection or severe fracture. We can transport new bone to fill in this defect.