Total Knee Arthroplasty - Accelerated Recovery Without Tourniquet
Condition: Arthropathy of Knee Joint
MeSH terms: Joint Diseases
Study type: Interventional

Summary: 
      Introduction:

      Approximately 7000 total knee replacements (TKAs) are done every year. More than 90% of these
      knee replacements are performed with the use of bone cement. Traditionally, a tourniquet has
      been, used to reduce the bleeding during surgery, enabling surgeons to perform delicate
      dissections in a bloodless operative field.

      A tourniquet can be defined as a constricting or compressing device used to control
      temporarily venous and arterial circulation to an extremity. Pressure is applied
      circumferentially on the skin and underlying tissues of a limb. This pressure is transferred
      to the walls of vessels, causing them to become occluded.

      It is well known that applying a tourniquet for more than 1 to 2 hours is associated with a
      number of disadvantages, for instance, severe pain and muscle effects during the first
      postoperative day, thereby slowing rehabilitation.

      Other side effects related to tourniquet use, include pulmonary embolus caused by venous
      thrombosis and arterial thrombosis as a result of the dislodgement of an arterial plaque.
      Furthermore, tourniquet-induced hypertension with general anaesthesia, muscle injury, a wide
      spectrum of neurologic injuries, and tissue changes (Oedema compartment syndrome,
      post-tourniquet syndrome) have been reported. An important fact is that bleeding affects the
      quality of binding between bone and cement and thereby fixation of the knee prosthesis? Since
      the introduction of modern cementing techniques, no previous clinical studies have
      investigated the advantages or disadvantages of tourniquet use in knee replacement surgery.

      Aims/hypothesis of the study:

        1. To investigate the advantages and disadvantages of tourniquet use, including whether not
           using a tourniquet reduces pain, facilitates mobilisation and recovery, and shortens
           length of stay.

        2. To study whether use of a tourniquet affects leg muscles during and after surgery, as
           measured by with use of microdialysis to quantify level of ischemia .

        3. To determine whether prosthesis fixation, measured by RSA, is affected by tourniquet
           use. Because third generation cements secure prosthesis fixation, the investigators do
           not expect to find any clinically significant migration (less than 2 mm) 2 years after
           surgery.

      Perspectives:

      The investigators hope that the results of our study will improve rehabilitation regimes so
      that patients will experience less pain after surgery and thus achieve more rapid
      mobilisation and return to their daily lives.
    

Detailed description: 
      Design

      Patients being able to participate in this study all have to fulfill the given inclusion
      criteria:

        -  Patients with symptomatic and radiographic verified knee symptoms, selected for primary
           unilateral total knee joint replacement (TKA)

        -  Age 50 and above (not older than 85)

        -  BMI < 35 and height >160 cm

        -  No severe cardiovascular conditions

        -  No previously knee surgery done in the same knee

        -  Oral and written acceptance

      A group concerning 2 x 30 patients will be randomized into two groups. Either an intervention
      group, with absence of tourniquet or a control group with tourniquet. Which group they will
      belong to, is blinded to patient and surgeon until they reach operation room. The operation
      will be performed as usual, but with exception of two additional procedures. During operation
      small spheric tantalum pellets are placed around the prosthesis. Furthermore patients are
      prepared for microdialysis, which contain placement of 3 catheters: one in each thigh and one
      subcutaneously in the abdomen.

      Microdialysis is a unique technique to monitor the chemistry of the extracellular space in
      living tissue. It is primarily used for In Vivo determinations of endogenous metabolites,
      thus serving as an indicator for ischemia.

      RSA is precision radiology where the small pellets are visual on x-ray. Using computer a 3D
      image is created and the pellets serve as markers. These markers will be measured every 6
      months showing whether a possible migration of the prosthesis is occurring and thereby
      indicating a loosening.

      Out-patient treatment Patients will among other things be followed by clinical functional
      scores, registration of analgetica use, conventional X-ray and RSA In the long run the
      perspective is that surgery concerning knee replacements will be conducted without the use of
      tourniquet and thereby reducing the pain of the patients without compromising the end result
      of the operation, namely the fixation of the prosthesis.

      Permissions approved by the Regional Committee on Biomedical Research Ethics, Region of
      Northern Jutland and Danish Data Protection Agency.
    

Intervention name(s): Total Knee Arthroplasty
Intervention type(s): Procedure
Intervention description(s): Surgery for OA knee pains
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Prothesis fixation; Bloodlessness