Early Controlled Loading on Conservative Treated Achilles Tendon Ruptures
Condition: Tendon Injuries; Soft Tissue Injuries; Achilles Tendon Rupture
MeSH terms: Wounds and Injuries; Rupture; Tendon Injuries; Soft Tissue Injuries
Study type: Interventional

Summary: 
      The purpose of this study is to measure the mechanical properties of the tendon after
      conservative treated Achilles tendon ruptures with or without early controlled loading. This
      is done in a randomized trial and the mechanical properties are measured using roentgen
      stereometric analysis (RSA).

      The hypothesis is that early weightbearing improves mechanical properties of conservative
      treated Achilles tendon ruptures without causing elongation of the tendon.
    

Detailed description: 
      Treatment of Achilles tendon ruptures includes surgical repair or immobilization in an
      orthosis, followed by prolonged rehabilitation. Improved rehabilitation regimens still
      display imperfect recovery, with deficits such as persistent end-range muscle weakness,
      tendon elongation and incomplete return to pre-injury activity level. The underlying
      mechanisms are unknown, but are likely to involve molecular and cellular aspects of the early
      healing processes. Animal experiments have shown that short episodes of vigorous loading
      during tendon healing create a stronger tendon, and lead to less elongation than continuous
      loading. Early controlled training has also been shown to improve the material properties of
      surgically repaired tendons. However, more and more clinics now turn away from surgery and
      towards conservative treatment, while studies on rehabilitation mainly concern sutured
      tendons. It is therefore also important to understand how to best rehabilitate conservatively
      treated patients. The aim is to investigate the effect of early controlled loading on
      conservatively treated Achilles tendon ruptures.

      The patients (age 18-60 years of age) are treated conservatively by receiving a removable
      foam walker boot at the emergency department. The patients are thereafter called by the
      principal investigator and are asked if they want to participate in the study. Patients who
      are interested in participating in the study receive oral and in written information about
      the study of the principal investigator of the study (Pernilla Eliasson).

      After 2 weeks, the rupture is localized by ultrasound and 4 tantalum beads are implanted
      percutaneously in the proximal and distal part of the tendon. These beads are used for
      measurements of the mechanical properties of the tendon by using RSA.

      The patients are thereafter randomized to early controlled loading or control.

      All patients wear the foam walker boot for 7 weeks. Full weight-bearing is allowed as
      tolerated from the beginning. Both groups perform motion exercises outside the boot with 20
      repetitions, 3 times per day as of 14 days after rupture.

      The patients in the early loading group are provided with a special training pedal where
      pedal resistance can be increased during the treatment period. The patients will use this
      pedal twice a day starting 2 weeks after rupture.

      After the initial 7 weeks, the patients are referred to physical therapists uninvolved in
      this research, but with the instruction to follow the regional rehabilitation guidelines for
      Achilles tendon ruptures.

      Mechanical properties of the tendon will be estimated by measuring tendon length,
      cross-sectional area (CSA) and stiffness at week 7, 19 and 52.

      The elastic modulus of the tendon at 19 weeks it the primary variable of this study.

      At week 7, both the elastic and plastic deformation will be measured. Tendon CSA will be
      evaluated using computer tomography (CT). Tendon elongation will be evaluated by RSA at week
      2, 7, 19 and 52. Calf muscle circumference, passive and active range of motion in the ankle
      joint and a heel-raise test will be performed at week 19 and 52.

      The overall function will be assessed by the Achilles Tendon Rupture Score at 19 and 52
      weeks.

      Complications and re-ruptures will be registered.
    

Intervention name(s): Early loading on a training pedal; Tendon strain exercises; Early weight bearing
Intervention type(s): Device; Other; Other
Intervention description(s): The patients will perform early loading by using a special training pedal for 5 weeks, starting 2 weeks after the rupture. The patients will remove the walker and train twice a day on this pedal.; The patients will perform tendon strain exercises 3 times each day from 2 weeks after the rupture.; The patients are allowed to bear weight as much as tolerated in the walker from day 1.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment
Keywords: Achilles; Tendon; Loading; Rehabilitation