Ultrasonographic Guided Treatment of Acute Achilles Tendon Rupture. Evaluation of Two Novel Ultrasonographic Measurements
Condition: Achilles Tendon; Rupture; Ultrasound
MeSH terms: Rupture
Study type: Observational

Summary: 
      With this project the investigators wish to:

        1. Test the reproducibility of Amlang's ultrasound classification by examining the intra-
           and inter-rater reliability.

        2. Investigate whether Amlang's ultrasound classification is able to predict which patients
           are likely to develop complications when treated non-operatively.

        3. Investigate whether Barfod's length measurement is able to predict which patients are
           likely to develop complications when treated non-operatively.
    

Detailed description: 
      Study objectives

      To validate Amlang's ultrasound classification and investigate whether the treatment of acute
      Achilles tendon ruptures (ATR) can be guided by:

        1. Amlang's ultrasound classification of ATR

        2. Barfod's ultrasound measurement to determine the elongation of the Achilles tendon
           following a rupture Backgrund A larger group of patients end up with a poor outcome
           after treatment for ATR. ATR is a frequent and potentially debilitating injury that
           typically affects young active adults (11 to 37 per 100,000)1 2 3. Consequently, there
           are great socioeconomic benefits in optimizing treatment and shortening time of
           recovery.

      There is currently no consensus regarding the best treatment of ATR. Traditionally the
      operative treatment has been considered superior, however recent studies show that
      non-operative treatment is a safe treatment which leads to good results 4 5 6. For this
      reason a transition towards greater use of non-operative treatment is seen in many orthopedic
      departments 7.

      Patients who end up with a poor result after treatment for ATR typically suffer from
      rerupture of the tendon or an elongation of the tendon. There is a 5-10 percent risk of
      rerupture 4 5 6. It is unknown how many patients heal with an elongation of the Achilles
      tendon. Correct length of the Achilles tendon is essential for the subsequent function of the
      tendon.

      In order to shorten time of recovery and optimize the treatment-outcome, it is desirable to
      identify patients at risk of re-rupture or elongation as early as possible as early surgery
      might help these patients.

      Amlang et al. have developed an ultrasonographic classification system to be used in the
      acute phase of rupture 8. The aim is to predict whether the patient will benefit from
      operative or non-operative treatment. The classification system appears well considered;
      however, the classification needs validation and to be correlated to outcome.

      Barfod et al. have developed a method for measuring the prolongation of the Achilles tendon
      in the acute phase following a rupture. The length measurement has been validated using
      healthy subjects. Data are analyzed and publication is expected autumn 2013. It has not been
      tested whether the measurement works on torn Achilles tendons and whether there is a
      correlation between the measurement and outcome.

      With this project the investigators wish to:

        1. Teste the reproducibility of Amlang's ultrasound classification by examining the intra-
           and inter-rater reliability.

        2. Investigate whether Amlang's ultrasound classification is able to predict which patients
           are likely to develop complications when treated non-operatively.

        3. Investigate whether Barfod's length measurement is able to predict which patients are
           likely to develop complications when treated non-operatively.

      Study Design Type of study The study is carried out as a prospective cohort study. Time
      schedule The recruitment of patients will begin 1 of November 2013. It is expected that the
      study will be completed after 4-5 years; the recruitment itself is expected to span 2 years,
      provided that an average of 6 patients is included per month.

      Discontinuation Each patient can choose to withdraw from the trial at any time. A patient may
      also be withdrawn from the trial at any time based on the investigators' discretion.

      Method Amlang's ultrasound classification and Barfod's length measurement are determined as
      described below. For the initial 30 patients Amlang's ultrasound classification will be
      determined using two independent ultrasound-operators in order to test the inter-observer
      consistency.

      Ultrasound - Set up The patient is in the prone position with the knees slightly flexed (10
      -20 degrees). A triangular foam pad is placed below (anterior to) the ankle joints, so that
      the feet are resting limply. By moving the pad up (cranial) and down (caudal) the angle of
      the relaxed ankle joints is adjusted to 20 degrees plantar flexion. The angle is measured
      using a goniometer (the longitudinal axis of the fibula is at 110 degrees with the posterior
      part of the lateral border of the foot). The calf muscles are relaxed.

      Amlang's ultrasound classification Amlang's ultrasound classification is conducted by
      determining the cross-sectional area of the widest point of the tendon below (distal to) the
      rupture (area-widest) and of the narrowest point at the rupture site (area-smallest). The
      ratio between "area-smallest" and "area-widest" is interpreted as a measure for the magnitude
      of overlap between the tendon ends. A ratio above 70 percent is considered as a total
      adaption of the tendon ends. A ratio of 30 to 70 percent is considered as a partial adaption
      of the tendon ends. And a ratio of less than 30 percent is considered as a lack of adaption
      of the tendon ends.

      Barfod's length measurement Barfod's length measurement is conducted using a simple method
      that does not require expensive equipment or advanced instruments. A needle is placed between
      the skin and the ultrasonographic probe. The shadow of the needle then projects the internal
      structures to the skin surface and the distance between calcaneus and the medial head of the
      gastrocnemius muscle can then be measured.

      Study Design Type of study The study is carried out as a prospective cohort study. Time
      schedule The recruitment of patients will begin 1 of November 2013. It is expected that the
      study will be completed after 4-5 years; the recruitment itself is expected to span 2 years,
      provided that an average of 6 patients is included per month.

      Discontinuation Each patient can choose to withdraw from the trial at any time. A patient may
      also be withdrawn from the trial at any time based on the investigators' discretion.

      Method Amlang's ultrasound classification and Barfod's length measurement are determined as
      described below. For the initial 30 patients Amlang's ultrasound classification will be
      determined using two independent ultrasound-operators in order to test the inter-observer
      consistency.

      Ultrasound - Set up The patient is in the prone position with the knees slightly flexed (10
      -20 degrees). A triangular foam pad is placed below (anterior to) the ankle joints, so that
      the feet are resting limply. By moving the pad up (cranial) and down (caudal) the angle of
      the relaxed ankle joints is adjusted to 20 degrees plantar flexion. The angle is measured
      using a goniometer (the longitudinal axis of the fibula is at 110 degrees with the posterior
      part of the lateral border of the foot). The calf muscles are relaxed.

      Amlang's ultrasound classification Amlang's ultrasound classification is conducted by
      determining the cross-sectional area of the widest point of the tendon below (distal to) the
      rupture (area-widest) and of the narrowest point at the rupture site (area-smallest). The
      ratio between "area-smallest" and "area-widest" is interpreted as a measure for the magnitude
      of overlap between the tendon ends. A ratio above 70 percent is considered as a total
      adaption of the tendon ends. A ratio of 30 to 70 percent is considered as a partial adaption
      of the tendon ends. And a ratio of less than 30 percent is considered as a lack of adaption
      of the tendon ends.

      Barfod's length measurement Barfod's length measurement is conducted using a simple method
      that does not require expensive equipment or advanced instruments. A needle is placed between
      the skin and the ultrasonographic probe. The shadow of the needle then projects the internal
      structures to the skin surface and the distance between calcaneus and the medial head of the
      gastrocnemius muscle can then be measured.

      Statistics The groups will be described descriptively regarding demographic parameters as
      well as primary and secondary endpoints. The correlation between Amlang's ultrasound
      classification and the primary and secondary endpoints will be examined using a regression
      analysis. The correlation between Barfod's length measurement and the primary and secondary
      endpoints will be examined in the same way.

      The research group The study is carried out as collaboration between the research unit,
      Clinical Orthopaedic Research Hvidovre (www.corh.dk) and the Department of Physical- and
      Occupational Therapy, both at Copenhagen University Hospital Hvidovre.
    

Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        130 patients who are treated for acute Achilles tendon rupture at Copenhagen University
        Hospital Hvidovre. Patients who fulfil the inclusion criteria but do not wish to
        participate are treated according the standard regimen (non-operatively without early
        controlled movement of the ankle joint).