RecruitingInterventional

Operative or non-surgical treatment of Perthes’ disease

Perthes’ disease is a childhood condition where the blood supply to the hip joint temporarily stops. This weakens the ball of the hip, causing it to lose its round shape and flatten like soft ice cream. As the bone heals, it may harden out of shape, leading to pain and stiffness. Surgeons in the NHS currently use two different approaches. Some recommend surgery to cut and reposition the bone so the ball fits snugly in the socket while healing. Others recommend non-surgical care, using specialised physiotherapy, pain relief, and guided exercises to keep the hip moving safely. Because doctors are unsure which path gives children the best long-term mobility, this study (called OP Non-STOP) is comparing both options. Children aged 5 to 12 who are newly diagnosed can take part. The results will help families and NHS doctors choose the most effective treatment in future.

At a glance

Status

Recruiting

Sponsor

Alder Hey Children's NHS Foundation Trust

Enrolment target

216

Start

15 Nov 2024

Estimated completion

08 Mar 2027

Perthes’ disease

What is this study about?

The hip is a ball-and-socket joint, much like a scoop of ice cream resting inside a round ice cream scoop. In Perthes' disease, the blood supply to the ball part of the joint is temporarily cut off. Without enough blood, the bone weakens and can easily squash or flatten out of shape. Over time, the blood supply naturally returns and the bone hardens again, but it tends to stay in whatever shape it settled into while soft. If it does not stay round, it can cause limping, pain, and early arthritis.

At the moment, specialist NHS doctors disagree on the best way to help children heal. About half of surgeons believe an operation is best. This surgery cuts and resets the bone to tuck the ball deeply into the socket, helping it regrow smoothly. The other half believe an operation is not needed and recommend non-surgical care instead. This involves expert physiotherapy, tailored movement exercises, and advice on managing pain to keep the joint mobile and gently mould the soft bone naturally.

Because both methods are already widely used across the NHS, health professionals and families agree that testing them side-by-side is a top research priority. The OP Non-STOP trial compares both approaches directly to discover which one gives children the best hip movement, pain relief, and ability to enjoy everyday activities as they grow up.

Key takeaways

Compares surgery against specialised physiotherapy for Perthes’ disease in children.
Open to children aged 5 to 12 years with early-stage Perthes' disease.
Children are placed into one of the two standard NHS treatment groups at random.
Follow-up lasts for three years through routine hospital appointments and short online surveys.
Participation is entirely voluntary, and you can leave the study at any time.

Who may be eligible?

This trial is open to children aged between 5 and 12 years old who have recently been diagnosed with Perthes' disease. Their hospital X-rays must confirm that the condition is in its early stages (the initial, softening, or breaking down phase), which is when treatment can best protect the shape of the hip.

To take part, parents or guardians must give written consent, and children must also agree (give assent) to join.

Children cannot take part if they have already had surgery to reshape the affected hip or if they were previously enrolled in this trial. It is also not suitable for families who would find it difficult to attend follow-up visits or complete the study questionnaires.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

My child is aged between 5 and 12 years old.
My child has recently been diagnosed with Perthes’ disease.
X-rays show the condition is in its early stages.
My child has not had previous reshaping surgery on this hip.
We are able to attend routine NHS appointments and fill out short surveys over three years.

Answer every question to see your result.

What does participation involve?

If your child joins the study, a computer will place them into one of two treatment groups by chance (at random). One group receives non-surgical care, which includes one-to-one sessions with a specially trained physiotherapist, advice on managing pain without relying only on medication, and access to an app and website with guided exercises. The other group has an operation under general anaesthetic to realign the hip bone, followed by up to six weeks in a special plaster body cast (called a spica) and hospital physiotherapy. Metal plates or screws used during surgery are often removed in a second small operation later on.

Taking part lasts for three years (36 months). Your child will attend their usual NHS hospital check-ups and have standard X-rays. In addition, the research team will contact you eight times by text message or email to fill in short surveys about your child's recovery, pain, feelings, school attendance, and daily activities.

Potential risks and benefits

Both approaches are standard NHS treatments, but each comes with different pros and cons. Non-surgical care avoids the risks of surgery, hospital stays, and plaster casts, though the hip may still not heal into a smooth shape. Surgery directly positions the bone inside the socket, but it carries surgical risks such as infection, anaesthetic issues, nerve problems, and usually requires a second procedure to remove metal plates. Taking part helps doctors learn which option works best, but with either treatment, there is still a possibility that the hip may not regain its normal round shape. Joining the study is entirely voluntary, and you can withdraw your child at any time without their normal NHS care being affected.

Locations (40)

Alder Hey Children's Hospital
Approximate
Liverpool, England
The James Cook University Hospital
Approximate
Middlesbrough, England
Leeds Children's Hospital
Approximate
Leeds, England
Musgrove Park Hospital (taunton)
Approximate
Taunton, England
John Radcliffe Hospital
Approximate
Oxford, England
Peterborough City Hospital
Unverified
Peterborough, England
Royal Aberdeen Children's Hospital
Unverified
Aberdeen, Scotland
Royal Berkshire Hospital
Unverified
Reading, England
Royal Alexandra Children's Hospital
Unverified
Brighton, England
Royal National Orthopaedic Hospital
Unverified
Stanmore, England
The Royal Victoria Infirmary
Unverified
Newcastle upon Tyne, England
Sheffield Childrens Hospital
Unverified
Sheffield, England

Common questions

Can I choose whether my child has surgery or physiotherapy?

No. A computer allocates your child to one of the two groups at random. This is done to ensure the study results are completely fair and unbiased.

Are these new or experimental treatments?

No. Both surgery and active physiotherapy care are routine treatments already used every day by surgeons across the NHS.

What happens if my child is placed in the surgery group?

Your child will usually have the operation within four months under general anaesthetic. They may need a plaster cast for around six weeks and will receive follow-up physiotherapy.

What does the physiotherapy group involve?

Your child will have a personalised session with a trained physiotherapist, clear advice on movement and pain control, and access to an app and website for home exercises.

Can we change our minds after joining?

Yes. You can withdraw your child from the trial at any point without giving a reason, and their ongoing medical treatment will not be affected.

How to find out more

Daniel Perry

danperry@liverpool.ac.uk +44 (0)151 282 4661 Official trial record

Always speak to your GP or specialist before deciding to take part in a study.