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21/591 Surgical treatment of proximal ACL ruptures with ACL repair or ACL reconstruction commissioning brief



The aim of the HTA Programme is to ensure that high quality research information on the clinical effectiveness, cost-effectiveness and broader impact of healthcare treatments and tests is produced in the most efficient way for those who plan, provide or receive care from NHS and social care services. The commissioned workstream invites applications in response to calls for research on specific questions which have been identified and prioritised for their importance to the NHS, patients and social care.

Research question

What is the clinical and cost-effectiveness of anterior cruciate ligament (ACL) repair when compared to ACL reconstruction in patients with proximal ACL ruptures?

  1. Intervention: Acute ACL repair. Repair involves the reattachment of the damaged ligament from where it has been torn off. Repair technique to be defined and justified by the applicants.
  2. Patient group: Patients with acute ACL ruptures:
    1. Treated within 28 days of injury,
    2. Proximal tear pattern (where the ligament has been torn from the femoral attachment),
    3. Applicants to define and justify age range. 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, with patients recruited via an acute knee injury pathway.
  4. Comparator: Acute ACL reconstruction. Reconstruction involves removing the damaged ligament and using other patient tissue, such as the hamstring or patellar tendons, as a graft.
  5. Study design: A randomised controlled trial with an internal pilot phase to test key trial processes such as recruitment and adherence. Clear stop/go criteria should be provided to inform progression from pilot to full trial.
  6. Important outcomes: Patient reported outcome measures (PROMs) to be defined and justified by the applicants, return to daily activities, return to sport, re-rupture/further surgery, knee functionality (e.g., range of motion, strength), cost effectiveness, patient acceptability. Existing Core Outcomes should be included amongst the list of outcomes unless a good rationale is provided to do otherwise. Applicants are encouraged to report recruitment and findings disaggregated by sex (and other demographic factors where relevant). 
  7. Minimum duration of follow-up: Two years follow-up, with the possibility of an extended follow-up period if required (to be defined and justified by the applicants).
  8. Longer-term follow-up: If appropriate, researchers should consider obtaining consent to allow potential future follow-up through efficient means (such as routine data) as part of a separately funded study.


The anterior cruciate ligament (ACL) is a tough band of tissue at the knee joint that joins the thigh bone to the shin bone. It allows the knee to control movements of the lower leg and helps maintain knee stability. A proximal tear or rupture occurs when the ligament has been torn away from its femoral (thigh bone) attachment.

ACL reconstruction is currently the gold standard treatment for ACL ruptures. It involves surgery to rebuild the ACL using tendons from somewhere else in the body, for example the patellar tendon (kneecap), quadriceps tendon (front of thigh), or hamstring tendon (back of thigh). ACL repair is an alternative to ACL reconstruction. Repair involves the reattachment of the damaged ligament from where it has been torn off. It needs to be undertaken early for best healing to take place.

The British Association for Surgery of the Knee (BASK) and British Orthopaedic Sports Trauma and Arthroscopy Association (BOSTAA) 2020 guideline primarily focuses on the use of ACL reconstruction surgery, although the authors do note that ACL repair has recently begun to be used by surgeons for proximal tears in young patients and that this technique needs to be evaluated in adequately powered clinical trials.

Recent systematic reviews suggest that ACL repair could be a viable alternative to ACL reconstruction in patients with proximal ACL tears, and the Royal College of Surgeons has suggested this topic for prioritisation. Further research is needed to establish the clinical and cost-effectiveness of ACL repair to help guide UK clinical practice. The HTA Programme therefore wishes to commission the trial outlined above.

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 30 March 2022. Applications will be considered by the HTA Funding Committee at its meeting in May 2022.

Guidance notes and supporting information for HTA Programme applications are available.

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 2022.

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.

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