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Benefits and risks

Benefits and risks

When NICE looked at the evidence, it decided that there is enough evidence on its efficacy but not enough about the risk of avascular necrosis (bone death). The 9 studies that NICE looked at involved a total of 378 patients.

Generally, they showed the following benefits:

  • less pain and other symptoms such as disability

  • improvement in activities of daily living and quality of life

  • equal leg lengths in 46% (22/48) of patients at 10 years

  • similar hip position and range of movements in the fixed hip as the other hip

  • better results in young people with unfused growth plates.

The studies showed that the risks of open reduction of a slipped capital femoral epiphysis included:

  • avascular necrosis (bone death) and joint cartilage damage in 1% to 14% of patients

  • avascular necrosis alone in 3% to 26% of patients

  • damage to the joint cartilage alone in 3% to 43% of patients

  • osteoarthritis of the hip in 40% of patients at an average follow‑up of 16 years

  • another operation, 6–8 weeks after surgery, in 8% of patients because of screws or wires breaking

  • permanent partial paralysis of the sciatic nerve in 1 patient

  • wound infections in 3% of hips

  • non‑healing of the top of the thigh bone in 9% of patients, who all needed more surgery to fix it

  • abnormal bone growth in 8% of patients.

NICE was also told about some other possible risks: stiffness and fracturing around screws and wires.

If you want to know more about the studies, see the guidance. Ask your health professional to explain anything you don't understand.

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