How is it treated and managed?
Treatment of the disease depends on the clinical picture at presentation. Young patients under age 4 sometimes maintain a good range of movement without intervention and do well with conservative management. Children who lose range of movement are often treated surgically.
Maintaining independent mobility is one of the aims of treatment. Patients who lose range of movement are likely to have a period of immobility during the course of management when they are often kept in a hip spica cast for a period of 6-8 weeks. After removal of the cast there is a variable period of rehabilitation lasting from 3-6 months when mobility gradually improves in most but not all patients.
The goals of treatment are to -:
- reduce pain and maintain or restore hip mobility
- prevent deformity or restore normal spherical shape to the femoral head
Treatment used to achieve these goals will depend on the age of the child and the extent of disease. It will also depend on the preference and experience of the treating doctor. There is currently no agreed best or standard treatment for Perthes disease and various treatments have been, and are used including physiotherapy, bracing and surgical methods. More recent studies currently suggest that non-surgical treatment using physiotherapy or bracing is of little benefit. There is evidence that some patients will benefit from surgical treatment (femoral osteotomy /pelvic osteotomy) while others will not. Determination of whether surgical treatment is appropriate is best left to specialists in children’s orthopaedics.
- Physiotherapy and monitoring – many children will have conservative treatment consisting of physiotherapy and exercises done at home and regular clinical and x-ray monitoring of disease until healing occurs.
- Plaster cast or a brace – includes use of braces and short periods in plaster. The aim of the brace or plaster is to hold the femoral head in the best position for healing inside the hip socket, the hip socket acting as a mould around the femoral head.
- Surgical treatment – surgical operations on the hip are designed to ensure that the femoral head heals inside the socket of the hip joint and can include operations on the hip bone to ensure the femoral head sits more snugly in the socket whilst it heals, or operations on the pelvis to ensure the socket fits more snugly around the femoral head – or a combination of both. In this case the hip joint socket acts as a mould to the femoral head helping it to heal into the best possible shape to enable normal function in the long term.
Physiotherapy and monitoring
More than half of children will have this treatment. They are most likely to be children aged 5 and under at diagnosis or older children with very limited disease. These children are likely to have recurrent hip pain over the 2-4 year healing period but maintain most of their normal activities including walking for the majority of the time. Activities such as cycling and swimming are encouraged. During periods where the hip is very painful bed rest for a few days and painkillers may be advised. Prolonged bed rest or use of crutches is no longer advised. They may use crutches for a few days intermittently when weight bearing is painful. Although they will be able to walk the majority of the time they will sometimes be limited by hip pain and may for example sit out towards the end of PE and not be able to run about as much as other children because of hip pain or stiffness. Parents will be advised to give them painkillers such as ibuprofen and paracetamol to relieve pain and they may take one of these prophylactically (preventatively) prior to physical activity such as PE. The progress of their disease will be monitored by regular x-rays and observation. Physiotherapy continues as long as healing is progressing well. During this period daily physiotherapy exercise will need to be done at home to maintain mobility and muscle tone round the hip joint. In younger children the parent will need to help with and supervise these exercises. Older children may need prompting or reminding to do their physiotherapy exercises. These children may move on to have more active treatment such as surgery or bracing if healing does not progress as expected.
Plaster cast or a brace
This type of treatment is more likely to be used in children over 5 and those who have more severe disease. The aim of the treatment is to hold the femoral head inside the hip joint to encourage it to heal in a less flattened more functional rounded shape. The best position for the joint is ‘abduction’. In practice keeping one leg in abduction with a brace or cast is very difficult so both legs will often be braced to hold the legs apart and the hip joint in ‘abduction’. Whether a brace or serial plaster casts are used or a combination of both, treatment may last for 18-24 months. Because of the prolonged effect on mobility of bracing or serial plaster casts these treatments are used much less often in this country than they were even 10 years ago. There will be a period of daily physiotherapy and further monitoring once the cast or brace comes off.
Surgical treatment
Osteotomy
Surgery on the hip is used to improve the position of the femoral head in the socket of the hip joint. It is usually used when the assessment shows that results with conservative treatment are likely to be poor. Generally these will be children who have very limited movement of the hip, extensive disease on x-ray or who are 6years old or older who have relatively little time for skeletal remodelling after healing.
The position of the femoral head is changed using surgery so that it is more completely contained in the hip joint. There are many different types of operations that can be performed and more than one operation may be performed at the same time to improve the alignment.
Operations involve cutting the bone in two and plating and screwing or screwing the two pieces back at a different angle to improve alignment. This type of surgery where bones are cut is called an ‘osteotomy’. The metal plates or screws are used to hold the bone in place in the correct position whilst it heals. The screw and plates are called ‘metalwork’ and may need to be removed at a later date. The osteotomy may be performed on the femur - a femoral osteotomy or on the pelvis – a pelvic osteotomy. Or a combination of osteotomies may be done, e.g. triple osteotomy.
Recovery from these operations is similar and walking ability is almost always regained within 6 months of surgery. Recovery from surgery takes some months -:
- Recovery in hospital for up to one week.
- Up to 8 weeks in plaster after the operation – a hip spica may be used - the child will be unable to walk whilst this is in place.
- The child may not be in plaster whilst healing occurs but they are likely to be non-weight-bearing or partial weight bearing for a period after surgery, in either case they will be mobilising on crutches. An osteotomy is a deliberate break in a bone and takes time to heal like any other fracture.
Bony healing may take up to 12 weeks. Once this has occurred the child will be walking normally for short distances without crutches but they will still have Perthes Disease. They will need to continue with their physiotherapy exercises and will still have symptoms of hip pain from time to time. Mobility is usually good within a few months of weight bearing being allowed. Following surgery they will be closely monitored until healing of the femoral head has occurred. Further surgery or treatment may be required.
Arthrodiastasis
This is a surgical treatment using an external fixator. An external fixator is a metal frame that is used to support a joint. Metal pins are drilled in to bones above and below the joint and a very strong metal frame is constructed between the pins. The frame can hold the joint apart and this is effectively what the treatment is. The bones are not cut and there is no ‘fracture’ healing time. The metal frame holds the hip bone and the pelvis apart taking the weight that would normally go through the hip into the femoral head. By taking the weight from the femoral head it is hoped that this treatment will result in less femoral head collapse. The frame is fixed under an anaesthetic and worn for around 2 months, then it is removed and a small brace is worn for two months. The child is able to walk with these devices but may need crutches. Normal walking ability is regained within 6 months of the start of treatment in most cases.
Picture. This boy is weight bearing in an external fixator. His x-ray shows he has Perthes disease of the right hip and an external fixator in place.
Reproduced with the kind permission of Dr Nuno Craveiro Lopes. Hospital Garcia de Orta, Almada, Portugal.
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