Achilles Tendon Rupture Patient Outcomes at 12 Months (ATR-12)

September 16, 2026 updated by: Raymond Healy, Liverpool University Hospitals NHS Foundation Trust

What Are the Isokinetic Strength Outcomes and Self-reported Functional Outcomes (ATRS) at 12 Months Following Non-surgical Management of Achilles Tendon Rupture Using the SMART Protocol?

Achilles tendon rupture is a common injury that can significantly impact strength, function, and quality of life. While non-surgical management using structured rehabilitation protocols such as the Swansea Morriston Achilles Rupture Treatment (SMART) protocol is increasingly adopted, there is limited evidence on long-term recovery outcomes, particularly beyond six months.

This study aims to evaluate recovery at 12-15 months following non-surgical management of Achilles tendon rupture in an NHS population. Participants will attend a single study visit during which plantarflexor muscle strength will be assessed using isokinetic dynamometry, and patient-reported outcomes will be collected using the Achilles Tendon Total Rupture Score (ATRS) and EQ-5D-5L questionnaire. Achilles Tendon Resting Angle (ATRA) will also be measured to provide an estimate of tendon elongation.

The primary objectives are to quantify plantarflexor strength recovery and self-reported functional outcomes. Secondary analyses will explore associations between strength, tendon elongation, quality of life, return to sport, and pre-injury symptoms.

This cross-sectional observational study will recruit adult patients managed non-surgically with the SMART protocol from Liverpool University Hospitals NHS Foundation Trust. Findings will provide clinically relevant data on long-term recovery following conservative treatment and may inform rehabilitation strategies and return-to-activity decision-making.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

This study is a cross-sectional observational investigation designed to evaluate objective and patient-reported recovery outcomes following non-surgical management of Achilles tendon rupture using the Swansea Morriston Achilles Rupture Treatment (SMART) rehabilitation protocol. The study is conducted within a National Health Service (NHS) setting at Liverpool University Hospitals NHS Foundation Trust.

Participants will be identified from an established clinical database of patients who have sustained an Achilles tendon rupture and completed non-operative rehabilitation. Eligible individuals will be invited to attend a single assessment session at 12-15 months post-injury. This time point has been selected to reflect longer-term recovery, as previous literature has predominantly focused on early and mid-term outcomes.

Study Procedures and Data Collection During the study visit, participants will undergo a comprehensive assessment including objective, clinical, and patient-reported measures. Isokinetic dynamometry will be used to quantify plantarflexor muscle performance under controlled conditions. Testing will be standardised, including participant positioning, joint alignment, range of motion, and angular velocities. Outcome variables will include peak torque and torque relative to body mass, allowing both within-participant and between-participant comparisons.

Achilles tendon structural characteristics will be assessed indirectly using the Achilles Tendon Resting Angle (ATRA), a clinically applicable proxy for tendon elongation. Measurements will be taken bilaterally using a standardised protocol with repeated trials to improve reliability, and side-to-side differences will be calculated.

Participants will also complete validated patient-reported outcome measures to capture functional status and general health. Additional contextual variables, including return-to-sport status and pre-injury Achilles symptoms, will be recorded to enable exploratory subgroup analyses.

Data Management and Quality Assurance All study data will be recorded using a structured case report form and stored within a secure, NHS-hosted electronic data capture system (REDCap). Data will be pseudonymised at the point of entry, with each participant assigned a unique study identifier. Identifiable information will be stored separately from research data and accessible only to authorised study personnel.

Data quality will be maintained through predefined validation rules within the data capture system, including range checks and logical consistency checks across related variables. Regular data monitoring will be conducted by the research team to ensure completeness and accuracy. Source data verification may be undertaken by comparing selected data fields against original clinical records where necessary.

A data dictionary will be maintained to define all study variables, including measurement units, coding structures, and allowable ranges. Standard Operating Procedures (SOPs) will guide all aspects of study conduct, including participant identification, data collection, data entry, and data storage, ensuring consistency across sites.

Sample Size Justification The sample size has been determined based on statistical considerations for detecting meaningful differences in strength between limbs as well as associations between objective and patient-reported outcomes. Allowance has been made for incomplete data to ensure adequate statistical power for primary analyses.

Statistical Analysis Plan Data analysis will be conducted using established statistical software. Continuous variables will be assessed for normality and summarised using appropriate descriptive statistics. Associations between variables will be explored using correlation analyses, with parametric or non-parametric methods applied as appropriate. Comparative analyses may be performed for exploratory subgroup comparisons (e.g., return to sport categories or presence of pre-injury symptoms).

All analyses will be interpreted within the context of an observational study design, and findings will be considered hypothesis-generating.

Handling of Missing Data Missing data will be assessed to determine patterns and potential sources (e.g., non-response, incomplete testing). Where feasible, analyses will be conducted using available data without imputation. The extent and impact of missing data will be reported transparently, and sensitivity analyses may be undertaken if appropriate.

Study Oversight and Governance The study is conducted in accordance with Good Clinical Practice (GCP), the Declaration of Helsinki, and NHS research governance frameworks. All study personnel are trained in study procedures to ensure standardisation. Data handling complies with the UK General Data Protection Regulation (GDPR) and Data Protection Act 2018.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
115

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • United Kingdom
    • Merseyside
      • Liverpool, Merseyside, United Kingdom, L14 3LB
      • Liverpool, Merseyside, United Kingdom, L9 7 AL

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Adults who previously sustained an Achilles tendon rupture and were treated non-surgically using the SMART rehabilitation protocol within Liverpool University Hospitals NHS Foundation Trust. Eligible participants are identified from an existing clinical database and represent patients 12-15 months post-injury who completed standard physiotherapy rehabilitation. All participants are drawn from routine NHS orthopaedic and physiotherapy services at Aintree and Broadgreen Hospitals.

Description

Inclusion Criteria:

Aged 18 years or older at the time of recruitment

  • Have a confirmed diagnosis of Achilles tendon rupture, diagnosed clinically and recorded within the NHS clinical database
  • Have been managed non-surgically using the SMART (Swansea Morriston Achilles Rupture Treatment) rehabilitation protocol
  • Be between 12 and 15 months post-injury at the time of study assessment
  • Be able and willing to provide written informed consent to participate in the study

Exclusion Criteria:

  • Unable to provide informed consent
  • Have previously undergone surgical repair of the Achilles tendon or experienced a re-rupture
  • Have a neuromuscular or neurological condition that could affect lower limb strength or function
  • Did not follow the SMART rehabilitation protocol for non-surgical management
  • Have a history of Achilles tendinopathy or rupture in the contralateral (uninjured) limb
  • Are unable to tolerate isokinetic strength testing due to pain, discomfort, or other medical reasons

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Non-Surgically Managed Achilles Tendon Rupture Cohort
Adults who sustained an Achilles tendon rupture and were managed non-surgically using the SMART rehabilitation protocol within Liverpool University Hospitals NHS Foundation Trust. All participants are 12-15 months post-injury at the time of assessment.
Other: Non-Surgical Management Using the SMART Protocol
Participants previously received standard non-surgical treatment for Achilles tendon rupture following the SMART (Swansea Morriston Achilles Rupture Treatment) functional rehabilitation protocol as part of routine NHS care. No interventions are assigned as part of this study; all data are collected at a single follow-up visit.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Isokinetic plantarflexor strength - Peak Torque
Time Frame: 12-15 months post-injury (single study visit)

Peak plantarflexion torque will be measured using isokinetic dynamometry. Peak torque (Newton metres [Nm]) represents the maximum force generated by the plantarflexor muscles during a maximal voluntary contraction.

Unit of Measure: Newton metres (Nm)

Minimum value: 0 Nm

Maximum value: No fixed maximum value

Higher values indicate: Greater plantarflexor muscle strength (better outcome)
12-15 months post-injury (single study visit)
Isokinetic Plantarflexion Strength Normalised to Body Weight
Time Frame: 12-15 months post injury

Peak plantarflexion torque normalised to body weight, measured using isokinetic dynamometry. Results are expressed as Newton metres per kilogram (Nm/kg) to facilitate comparison of plantarflexor muscle strength between individuals of different body sizes.

Unit of Measure: Newton metres per kilogram (Nm/kg)

Minimum Value: 0 Nm/kg

Maximum Value: No fixed maximum value

Higher values indicate: Greater plantarflexor muscle strength relative to body weight (better outcome)
12-15 months post injury
Isokinetic Plantarflexion Strength Limb Symmetry Index (LSI)
Time Frame: 12-15 months post injury

Limb Symmetry Index (LSI) for isokinetic plantarflexion strength. LSI is calculated as the peak torque of the injured limb divided by the peak torque of the uninjured limb and expressed as a percentage. An LSI of 100% indicates equal strength between limbs, while values below 100% indicate a strength deficit in the injured limb.

Unit of Measure: Percent (%)

Minimum Value: 0%

Maximum Value: No fixed maximum value

Higher values indicate: Greater symmetry between injured and uninjured limbs and therefore a better outcome.
12-15 months post injury
Achilles Tendon Total Rupture Score
Time Frame: 12-15 months post-injury (single study visit)

The Achilles Tendon Total Rupture Score (ATRS) is a validated patient-reported outcome measure assessing symptoms, physical activity, and functional limitations following Achilles tendon rupture. Scores range from 0 to 100, with higher scores indicating better perceived recovery and fewer symptoms.

Time Frame: 12-15 months post-injury (single study visit)

Unit of Measure: Points

Minimum Value: 0

Maximum Value: 100

Higher scores indicate: Better outcome (fewer symptoms and greater function)

Lower scores indicate: Worse outcome (more symptoms and greater functional limitation)
12-15 months post-injury (single study visit)

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Correlation Between Achilles Tendon Total Rupture Score and Peak Plantarflexion Torque
Time Frame: 12-15 months post injury

Correlation between subjective recovery measured by the Achilles Tendon Total Rupture Score (ATRS) and objective plantarflexor muscle strength measured as peak plantarflexion torque during isokinetic dynamometry.

Unit of Measure: Correlation coefficient (r)

Minimum Value: -1

Maximum Value: 1

Interpretation: Values closer to ±1 indicate a stronger relationship between ATRS and peak plantarflexion torque. Values closer to 0 indicate a weaker relationship.
12-15 months post injury
Correlation Between Achilles Tendon Total Rupture Score and Plantarflexion Strength Limb Symmetry Index
Time Frame: 12-15 months post injury

Correlation between subjective recovery measured by the Achilles Tendon Total Rupture Score (ATRS) and objective plantarflexion strength symmetry measured using the Limb Symmetry Index (LSI).

Time Frame: 12-15 months post-injury (single study visit)

Unit of Measure: Correlation coefficient (r)

Minimum Value: -1

Maximum Value: 1

Interpretation: Values closer to ±1 indicate a stronger relationship between ATRS and Limb Symmetry Index. Values closer to 0 indicate a weaker relationship.
12-15 months post injury
Health-related quality of life - EuroQol Five-Dimension Five-Level Questionnaire (EQ-5D-5L) Summed Dimension Score
Time Frame: 12-15 months post injury

Health-related quality of life will be assessed using the EuroQol 5-Dimension, 5-Level (EQ-5D-5L) Questionnaire.

The EuroQol Five-Dimension Five-Level Questionnaire (EQ-5D-5L) is a patient-reported measure of health-related quality of life consisting of five dimensions: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. Each dimension is rated on a five-level scale from no problems to extreme problems.

Minimum value: 5 Maximum value: 25 Direction of scale: Lower scores indicate a better outcome (fewer health problems); higher scores indicate a worse outcome (more severe health problems).
12-15 months post injury
Health related quality of life - EuroQol Visual Analogue Scale
Time Frame: 12-15 months post injury

The EuroQol Visual Analogue Scale (EQ VAS) is a self-reported measure of overall health status. Participants rate their current health on a vertical visual analogue scale ranging from 0 ("the worst health you can imagine") to 100 ("the best health you can imagine").

Minimum value: 0 Maximum value: 100 Higher scores indicate: Better self-rated health status Lower scores indicate: Worse self-rated health status
12-15 months post injury
Achilles Tendon Resting Angle (ATRA)
Time Frame: 12-15 months post injury

The Achilles Tendon Resting Angle (ATRA) is a goniometric measure used as an indirect assessment of Achilles tendon elongation. Side-to-side difference in ATRA between the injured and uninjured limbs will be measured in degrees. ATRA does not have fixed minimum or maximum possible values. Higher values indicate less tendon elongation (better outcome), while lower values indicate greater tendon elongation (worse outcome).

Time Frame: 12-15 months post-injury (single study visit)

Unit of Measure: Degrees (°)

Minimum Value: No fixed minimum value

Maximum Value: No fixed maximum value

Higher values indicate: Less tendon elongation (better outcome)

Lower values indicate: Greater tendon elongation (worse outcome)
12-15 months post injury
Return to sport/activity status
Time Frame: 12-15 months post injury

Return to sport/activity status assessed at follow-up. Participants will be categorised according to their highest level of return to pre-injury sport or physical activity:

Return to same level and frequency Return to same level at reduced frequency Return to a lower level No return to sport/activity

Time Frame: 12-15 months post-injury (single study visit)

Unit of Measure: Category

Minimum Value: No return to sport/activity

Maximum Value: Return to same level and frequency

Higher categories indicate: Greater return to pre-injury sport/activity participation (better outcome)
12-15 months post injury
Presence of Pre-Injury Achilles Tendon Symptoms
Time Frame: 12-15 months post injury

Description: Presence of Achilles tendon pain or symptoms prior to tendon rupture, assessed by participant self-report. Participants will be classified according to whether Achilles tendon symptoms were present before the rupture.

Time Frame: Assessed at 12-15 months post-injury (single study visit; recall of pre-injury symptoms)

Unit of Measure: Category

Categories:

No pre-injury Achilles symptoms Pre-injury Achilles symptoms present

Interpretation: Presence of pre-injury symptoms may indicate preceding Achilles tendon pathology.
12-15 months post injury

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Liverpool University Hospitals NHS Foundation Trust

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Chair: Jeff Morton, BSc. (Hons) Physiotherapy, Liverpool University Hospitals NHS Foundation Trust

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
September 8, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
June 1, 2028

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
January 1, 2029

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
January 25, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 2, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
February 6, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 17, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 16, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
September 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • JRO-0663 (Other Identifier: LIVERPOOL HEALTH PARTNERS JOINT RESEARCH OFFICE)
  • IRAS ID: 357432 (Other Identifier: Health Research Authority)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual participant data will not be shared. Only aggregated, anonymised results will be published. This is consistent with participant consent and NHS data governance requirements

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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