• Reference Number: HEY827/2026
• Departments: Radiotherapy
• Last Updated: 28 February 2026

What is Heterotopic Ossification (HO)

It is the formation of bone outside of where it should be in the skeleton. Often, it forms in soft tissues close to the skeleton.  This can lead to swelling in the areas affected, pain and limitation of movement if close to a joint.

No one knows the exact cause of heterotopic ossification (HO), but there are a number of factors that increase the risk of it developing:

• Hip surgery or other joint surgery
• Long period of immobility
• Joint infection
• Trauma to muscle or soft tissue

About 1 in 3 patients who have a hip replacement or a severe fracture of the long bones of the leg will develop some heterotopic ossification, though in most, this will not cause symptoms.

Treatment

Treatment depends on the amount of extra bone formation and its location. It may involve physiotherapy, pain relief medication, anti-inflammatory drugs, surgery and occasionally radiotherapy.

Radiotherapy

Before you agree to any radiotherapy treatment, the need for this should have been discussed with you by your orthopaedic surgeon. As a next step, you will be seen by an oncologist/consultant therapeutic radiographer in the Queen’s Centre. Oncologists/consultant therapeutic radiographers specialise in the treatment of cancer and are therefore experts in the use of radiotherapy. Please do not think that because you have an appointment with an oncologist/consultant therapeutic radiographer, that this means you have cancer. The radiotherapy treatment will be explained, including the risks and side effects, and you will have the opportunity to ask questions. If you want to go ahead with the treatment, you will be asked to sign a consent form.

Who will explain the treatment to me?

Before you agree to any radiotherapy treatment, the need for this should have been discussed with you by your orthopaedic surgeon. As a next step, you will be seen by an oncologist/consultant therapeutic radiographer in the Queen’s Centre. Oncologists/consultant therapeutic radiographers specialise in the treatment of cancer and are therefore experts in the use of radiotherapy. Please do not think that because you have an appointment with an oncologist/consultant therapeutic radiographer, that this means you have cancer. The radiotherapy treatment will be explained, including the risks and side effects, and you will have the opportunity to ask questions. If you want to go ahead with the treatment, you will be asked to sign a consent form.

How is radiotherapy given?

Radiotherapy for HO is given a few hours before your surgery by a team of therapeutic radiographers, who are trained to plan and deliver radiotherapy treatment. Treatment is very similar to having an X-ray and will involve you lying still for a few minutes while the X-rays are delivered to the target area. Treatment will be given at the Queen’s Centre at Castle Hill Hospital because this is where the specialist radiotherapy machines are.

Before radiotherapy treatment, you will have a CT planning scan. You will be asked to remove any clothing from the area of interest and to lie comfortably (usually on your back). The information from this scan is used to produce your individual treatment plan.

The precise timing of your treatment depends on the time of your operation. When arrangements have been made for your surgery, you will be given an appointment for your radiotherapy treatment.

Side Effects

Side effects from a single dose of radiotherapy are usually mild. Side effects do depend on the area being treated and will be discussed with you in detail before any treatment. Common side effects can include:

• Tiredness
• Skin redness and itching
• delayed wound healing
• Joint swelling
• Loose bowel motions

If any of these side effects are experienced, they are likely to be mild and last less than one week. You will be advised on how to manage any side effects.

Long-term Risks

Any exposure to radiation may increase your risk of cancer in the future.  The risk is small, and modern radiotherapy techniques allow for accurate treatment, minimising the dose to the rest of the body.  If you are concerned about your risk of developing a cancer, please discuss your concerns with the oncologist/consultant therapeutic radiographer.

Radiation to the hip joint will also deliver a small dose of radiation to the testes and ovaries. For pre-menopausal women and men of any age, it is important to let the team treating you know if you have plans to have children in the future. The dose delivered should not affect the function of the testes or ovaries but caution may be required to avoid conception for a period after the radiotherapy. It is also important to let the team know if you are or think you might be pregnant at the time of your CT planning scan/radiotherapy treatment.

Please also let the treatment team know if you have ever had radiotherapy to your pelvic area before. This could have been many years ago and will probably have been for a cancer such as cancer of the cervix, bladder, uterus (womb) or prostate.

Radiotherapy Staff

Clinical Oncologist, Registrar, Consultant Therapeutic Radiographers

They are experts in radiotherapy and will be managing your treatment. They will take the responsibility for deciding what dose and how many treatments will be best for you; they will oversee the planning of your treatment. You may see them or a member of their team at your initial planning appointment, and you can see them during your treatment if you have any problems or queries.

Therapeutic Radiographers

Radiotherapy is delivered by male and female therapeutic radiographers who are specialist healthcare professionals trained to plan and deliver radiotherapy treatment and to use the specialist equipment. You will usually see the same team of radiographers, and they will assist you with any questions or problems or refer you to a more appropriate person.

Radiotherapy Support Team

The team consists of clinical nurse specialists and clinical support workers (CSW’s), who are based within the radiotherapy department where they provide specialised care, actively support, and advise patients before, during and after radiotherapy treatment.

 Physicists, Planning Dosimetrists and Machine Technicians

Medical physicists are specialist scientists who have a key role in the individual planning of your treatment, along with the planning technicians. They may also have an input into the arrangement of your treatment. They work together with the machine technicians to ensure that the machines are reliable and working accurately.

Students

At some point during your treatment, you may encounter student radiographers. Everything they do is supervised fully. If you would prefer our students not to be present during the planning and treatment, please let a member of staff know when you attend for your initial planning appointment.

Other members of staff

During your course of treatment, you may meet our receptionists, porters, volunteer workers. All are working together to provide you with a high-quality of healthcare.

Advice and Support Services

Please read the information leaflet. Share the information with your partner/family/carer if you wish. If you need the information in a different format/language, please speak to a member of staff.

Should you require further advice on the information contained in this leaflet, please do not hesitate to contact the Radiotherapy Information and Support Team on telephone number Tel: 01482 461206

Email: hyp-tr.radiotherapy.information@nhs.net

PALS (Patient Advice and Liaison Service)

Provide confidential advice and support, helping you resolve any concerns you have about the service you have received.

Tel:01482 623065 – Monday – Friday 8:30 am – 4:30 pm

Email: hyp-tr.pals.mailbox@nhs.net