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20/77 Treatment of recurrent patella dislocation




The aim of the HTA Programme is to ensure that high quality research information on the effectiveness, costs and broader impact of health technology is produced in the most efficient way for those who use, manage, provide care in or develop policy for the NHS. Topics for research are identified and prioritised to meet the needs of the NHS. Health technology assessment forms a substantial portfolio of work within the National Institute for Health Research and each year about fifty new studies are commissioned to help answer questions of direct importance to the NHS. The studies include both primary research and evidence synthesis.

Research question

What is the clinical and cost-effectiveness of surgery compared to conservative care for the treatment of recurrent patella dislocation?

  1. Interventions: (i) Surgical intervention e.g. medial patellofemoral ligament reconstruction and (ii) Conservative, non-surgical care. Techniques and treatments to be defined and justified by applicants.  
  2. Patient group: Patients with recurrent (at least two) lateral dislocations of the patella.  Applicants to define and justify. Consideration to be given to any previous treatments (e.g. a period of physiotherapy), the duration of patellar instability, and additional knee problems (e.g. trochlear dysplasia).  
    Applications are encouraged which include recruitment from geographic populations with high disease burden which have been historically underserved by research activity in this field.
  3. Setting: Secondary care.
  4. Comparator: The interventions will act as each other’s comparators. 
  5. Study design: A randomised controlled trial with an internal pilot phase to test the ability to recruit and randomise. Clear stop/go criteria should be provided to inform progression from pilot to full trial.
  6. Important outcomes: Functional outcomes, recurrent patella dislocation, subsequent surgery, pain, health-related quality of life.
    Other outcomes: Adverse events including surgical complications, work- or education-related outcomes, social activities, cost-effectiveness, patient acceptability.
    Where established Core Outcomes exist they should be included amongst the list of outcomes unless there is good reason to do otherwise. 
  7. Minimum duration of follow-up: Minimum follow-up of two years from randomisation but applicants should define and justify the most appropriate timing of the primary outcome measure.
    Longer-term follow up: If appropriate, researchers should consider obtaining consent from participants to allow potential future follow up through efficient means (such as routine data) as part of a separately funded study. 


The patella (kneecap) is a small bone located in the front of the knee joint at the point where the femur (thighbone) and tibia (shinbone) meet. When it is working well, the patella rests in a groove on top of the femur, moving backwards and forwards as the knee bends and straightens. A dislocation occurs when the patella disengages from this groove, often causing considerable soft tissue damage, pain and swelling. The patella may return to the correct position spontaneously or when manually reduced. Unfortunately, it is often the case that for many people primary, or first-time, dislocations will be followed by further, or recurrent, dislocations.

Both primary and recurrent dislocations are most common in young people and often mark the beginning of lifelong knee problems. Ongoing patellar instability can lead to cartilage damage, early degenerative changes and osteoarthritis causing chronic pain and disability; all of which have a detrimental effect on education, work and social life. 

In the UK, there is agreement in clinical practice that a primary patella dislocation should be treated conservatively with physiotherapy rather than surgery, unless there are additional complications. In contrast, when it comes to treating recurrent patella dislocations there is both a lack of robust evidence and clinical consensus about which intervention is best. The decision between the two possible treatments used to treat the condition in the NHS (surgery or non-operative care) is based on the opinion of the clinician and not on a robust evidence base. Systematic reviews have highlighted the evidence gap in how to treat recurrent patella dislocations and the importance of more research. The clinical community also highlight this treatment uncertainty and are very supportive of research. 

Applicants should be informed by a recently published feasibility study that assessed non-surgical treatment against surgery for recurrent patella dislocation and concluded that a definitive trial comparing both treatments is feasible in the UK. 

Repeated patella dislocations can have a considerable negative impact on a person’s quality of life. Considering that it is young people that are most commonly affected and that their lifelong wellbeing can be compromised, it is important that an optimal treatment approach is identified. The HTA Programme therefore wishes to commission a trial to compare the clinical and cost-effectiveness of two treatments currently in use in NHS practice. 

Additional commissioning brief background information

A background document is available that provides further information to support applicants for this call. It is intended to summarise what prompted the call and the existing evidence base, including relevant work from the HTA and wider NIHR research portfolio. It was researched and written on the basis of information from a search of relevant sources and databases, and in consultation with a number of experts in the field. If you would like a copy please email

Making an application

If you wish to submit a Stage 1 application for this call, the online application form can be found on the Funding opportunities page.  To select this call, use the filters on the right of the screen or search using the call name and/or number.

Your application must be submitted on-line no later than 1pm on the 31st March 2021. Applications will be considered by the HTA Funding Committee at its meeting in May 2021.

Guidance notes and supporting information for HTA Programme applications are available by clicking the links.

IMPORTANT: Shortlisted Stage 1 applicants will be given eight weeks to submit a Stage 2 application. The Stage 2 application will be considered at the Funding Committee in September 2021.

Applications received electronically after 1300 hours on the due date will not be considered.

For commissioned topics, the Programme strongly discourages the practice of the same co-applicant joining more than one competing team. There may be unusual circumstances where the same person could be included on more than on application eg a lead from a named charity or a unique national expert in a condition.

For such exceptions (i) each application needs to state the case as to why the same person is included (ii) the shared co-applicant should not divulge application details between teams and (iii) both teams should acknowledge in their application that they are aware that one of their co-applicants is part of a competing application and that study details have not been shared. 

Should you have any queries please contact us