<clinical_study>
  <!-- This xml conforms to an XML Schema at:
    https://clinicaltrials.gov/ct2/html/images/info/public.xsd -->
  <required_header>
    <download_date>ClinicalTrials.gov processed this data on September 20, 2023</download_date>
    <link_text>Link to the current ClinicalTrials.gov record.</link_text>
    <url>https://clinicaltrials.gov/ct2/show/NCT03282578</url>
  </required_header>
  <id_info>
    <org_study_id>MH 2017.165</org_study_id>
    <nct_id>NCT03282578</nct_id>
  </id_info>
  <brief_title>Sternalock Versus Wires for Sternal Closure Study</brief_title>
  <official_title>Prospective Randomised Sternal Closure Study Sternalock 360 Plates vs Conventional Stainless Steel Wires</official_title>
  <sponsors>
    <lead_sponsor>
      <agency>University of Melbourne</agency>
      <agency_class>Other</agency_class>
    </lead_sponsor>
    <collaborator>
      <agency>Zimmer Biomet</agency>
      <agency_class>Industry</agency_class>
    </collaborator>
  </sponsors>
  <source>University of Melbourne</source>
  <oversight_info>
    <has_dmc>No</has_dmc>
    <is_fda_regulated_drug>No</is_fda_regulated_drug>
    <is_fda_regulated_device>No</is_fda_regulated_device>
  </oversight_info>
  <brief_summary>
    <textblock>
      Design:&#xD;
&#xD;
      Investigator Initiated Prospective Randomised Trial&#xD;
&#xD;
      Study Centre's:&#xD;
&#xD;
      Melbourne Private Hospital Royal Melbourne Hospital&#xD;
&#xD;
      Study Hypothesis:&#xD;
&#xD;
      Use of the SternaLock 360 will reduce the incidence of sternal motion &gt; 2mm by absolute&#xD;
      difference of 40% at 6 weeks of surgery compared to stainless steel wiring.&#xD;
&#xD;
      Use of the SternaLock 360 will improve bone healing and quality of recovery after surgery&#xD;
      compared to stainless steel wiring&#xD;
&#xD;
      Study Objective:&#xD;
&#xD;
      To determine if the SternaLock 360 system reduces sternal instability, increases bone&#xD;
      healing, and improves quality of recovery compared to stainless steel wiring of the sternum,&#xD;
      after cardiac surgery involving median sternotomy&#xD;
&#xD;
      Inclusion Criteria:&#xD;
&#xD;
      Age ≥ 18 year old Elective cardiac surgery Primary cardiac surgical procedure No evidence of&#xD;
      infection at time of surgery Sufficient English language to complete the Postoperative&#xD;
      Quality of Recovery Survey&#xD;
&#xD;
      Exclusion Criteria:&#xD;
&#xD;
      Previous sternotomy (redo) Clinical sternal deformity Home locality preventing follow-up&#xD;
      (e.g. remote regional, interstate or overseas patient)&#xD;
&#xD;
      Number of Planned Subjects:&#xD;
&#xD;
      50&#xD;
    </textblock>
  </brief_summary>
  <detailed_description>
    <textblock>
      Introduction/Background Information Since the inception of cardiac surgery in the early&#xD;
      1960s, division of the sternum has provided the superior access to cardiac structures.&#xD;
      Cardiac surgery may involve treatment of the coronary arteries, valves or major vessels such&#xD;
      as the ascending aorta. In children, correction of congenital malformations is also&#xD;
      performed.&#xD;
&#xD;
      The conventional bone fixation during the 1960s was the placement of stainless steel wires&#xD;
      around or through the sternum, predominantly as single wires which were tensioned by&#xD;
      twisting. In the 1980s, it became fashionable for some cardiac surgeons to pass the wire&#xD;
      twice around the bone (as would be the case repairing a fence on a farm), so-called &quot;figure&#xD;
      of 8&quot; configuration and tensioning again occurring by twisting the wires. There have been no&#xD;
      adequate studies investigating which of these two techniques may be superior.&#xD;
&#xD;
      In simple terms, bone healing is promoted by&#xD;
&#xD;
        -  Minimising movement of the bone edges at the fracture site and&#xD;
&#xD;
        -  Improved alignment of the bone edges&#xD;
&#xD;
      The sternum is a connecting bone that moves in multiple planes to transfer load and position&#xD;
      the limbs in space during every day functional tasks and respond to the demands of&#xD;
      respiration. The healing of the sternum is in the context of many efforts by the treating&#xD;
      physicians and physiotherapists to encourage activities that might cause distracting forces&#xD;
      at the sternal fracture site. Additionally, simple everyday activities by the patient such as&#xD;
      coughing, deep breathing, sneezing, transferring in and out of bed, turning over in bed and&#xD;
      driving all lead to substantial distracting forces acting on the sternal fracture site1.&#xD;
      External fixation is not encouraged because the patient needs to have significant chest wall&#xD;
      movement in order to breathe and clear sputum as part of the recovery from surgery.&#xD;
&#xD;
      Also, ultrasound data suggests an additional mechanism by which sternal healing is&#xD;
      compromised with conventional sternal wiring techniques. The shape of the sternum is complex&#xD;
      1. The upper part is called the manubrium to which the clavicles and first rib join, and is&#xD;
      generally quite thick with a reasonably robust and cortex and strong marrow. By contrast, the&#xD;
      body of the sternum which forms the majority of the sternum is thinner and the marrow is&#xD;
      frequently less robust than for the manubrium. In both areas, the cortical bone is present&#xD;
      superficially (anterior) and deep (posterior) with the marrow between. When sternal wires are&#xD;
      used, and the two halves of the sternum brought together and tensioned by twisting the wires,&#xD;
      best efforts made to ensure that the cortical bone edges on either side are opposed or well&#xD;
      aligned (that is, that in the anterior and posterior direction that the two bone edges from&#xD;
      either side of well opposed). Generally, this is quite well achieved, but not always. Yet,&#xD;
      even with ultrasound studies performed 1 or 2 days after surgery, the alignment between the&#xD;
      anterior cortical bone edge on either side is lost as detected by the cortical bone of one&#xD;
      side overriding the cortical bone of the other side.&#xD;
&#xD;
      The implications of this ultrasound finding are twofold&#xD;
&#xD;
        1. Irrespective of the perfect alignment of the two sides of the sternal fracture at the&#xD;
           time of surgery under general anaesthetic, coughing and deep breathing usually leads to&#xD;
           distraction forces that results in one side of the divided sternum overriding the other&#xD;
           side, typically by a couple of millimetres or so. This must be because there is less&#xD;
           bone to bone force when the cortical bone edge is being forced against soft tissue or&#xD;
           against the marrow than it would be if it were forced against the cortical bone of the&#xD;
           other side. This is important because any distracting force caused by coughing or deep&#xD;
           breathing or indeed any other activity should logically, result in the two halves of the&#xD;
           sternal bone adopting a position of least force.&#xD;
&#xD;
        2. What this means is that the two halves of the sternum in combination (and after over&#xD;
           riding has occurred) are now less wide than they had been at the time that the sternal&#xD;
           wire was tensioned at the end of the surgical procedure, by the distance of the sternal&#xD;
           override detected by the ultrasound.&#xD;
&#xD;
      Consequences of poor sternal healing: Patients may feel movement of the sternum and that may&#xD;
      limit their activity. However, chronic sternal instability is associated with pain 2, which&#xD;
      may in turn affect other aspects of daily living, require long term medications and&#xD;
      predispose to depression.&#xD;
&#xD;
      SternaLock 360 system The SternaLock 360 system is a band and plating system designed to&#xD;
      improve sternal stability. 3 bands surround the sternum to oppose the bones (like wires), but&#xD;
      an additional 3 plate system prevents anterior posterior displacement and provides a rigid&#xD;
      fixation. CT scan follow up shows improved bone healing at 3 months after surgery compared to&#xD;
      conventional wires, but the CT scan is a poor measurement of dynamic movement. Quality of&#xD;
      recovery and functional status has not been adequately studied.&#xD;
&#xD;
      The unique design of the SternaLock 360 system, is that it combines a&#xD;
&#xD;
        1. Compressive force to the two sternal halves forcing them together (similar to the&#xD;
           principal of the sternal wires), thus counteracting lateral distracting forces.&#xD;
&#xD;
        2. Additionally, by the placement of metal plates that cross the fracture and are fixed on&#xD;
           either side by screws, predominantly the plates acts to prevent anterior/posterior&#xD;
           distracting forces; longitudinal translation and thus better maintain the cortical bone&#xD;
           to cortical bone apposition between the two sides.&#xD;
&#xD;
      Pilot Data Our research group is experienced in assessing sternal motion with ultrasound 4.&#xD;
      We have conducted sternal ultrasound measurements of sternal motion after surgery as part of&#xD;
      clinical follow up.&#xD;
&#xD;
      Over all the SternaLock 360 results in a far greater rigid fixation as noted at the time of&#xD;
      surgical implantation. Subsequent pilot ultrasound studies performed during dynamic&#xD;
      distracting forces (such as coughing) reveal reduced or absent movement at the fracture site&#xD;
      and better preservation of fracture alignment. Ultrasounds have been performed at varying&#xD;
      intervals from Day 1 post-operative to 6 weeks post-operative, and ultrasounds of sternal&#xD;
      wire fixation have been performed at varying intervals after 10 months post-operative. Our&#xD;
      observations are that fewer than 10% of patients who have received the SternaLock 360 have&#xD;
      had motion &gt;2 mm, whereas patients with conventional wiring have motion &gt; 2 mm in more than&#xD;
      50%.&#xD;
&#xD;
      Evidence Gap The SternaLock 360 is an effective system for closing the sternum. There are few&#xD;
      comparative data investigating bone healing with CT scans, but the CT alone is a poor&#xD;
      indicator of sternal instability. There is no long term comparative data on sternal micro&#xD;
      motion, or quality of recovery outcomes to identify whether the SternaLock 360 system will&#xD;
      improve patient centred outcomes over and above improved bone healing.&#xD;
&#xD;
      Study Objectives Hypothesis Use of the SternaLock 360 will reduce the incidence of sternal&#xD;
      motion &gt; 2mm by absolute difference of 40% at 6 weeks of surgery compared to stainless steel&#xD;
      wiring.&#xD;
&#xD;
      Use of the SternaLock 360 will improve bone healing and quality of recovery after surgery&#xD;
      compared to stainless steel wiring.&#xD;
&#xD;
      Study Aims To determine if the SternaLock 360 system reduces sternal instability, increases&#xD;
      bone healing, and improves quality of recovery compared to stainless steel wiring of the&#xD;
      sternum, after cardiac surgery involving median sternotomy.&#xD;
&#xD;
      Randomisation The randomization sequence will be produced using a computer generated&#xD;
      randomization sequence, in unequal blocks. Concealment will be by placing the card containing&#xD;
      the allocation information in double opaque sealed envelopes, and concealment will be&#xD;
      maintained until after recruitment and the patients is admitted to the operating theatre. The&#xD;
      treating surgical team will then open the envelopes to reveal the allocation after (1)&#xD;
      weaning from cardiopulmonary bypass and (2) final confirmation from the treating surgeon that&#xD;
      the patient is suitable to be randomised.&#xD;
&#xD;
      Statistical Methods Participants who are scheduled for cardiac surgery will be screened and&#xD;
      recruited from the cardiac surgery operation lists, surgeon's clinics and pre-operative ward.&#xD;
&#xD;
      The initial contact will be made in person during the first contact session prior to surgery.&#xD;
      In-patients scheduled for cardiac surgery will be screened on the ward.&#xD;
&#xD;
      Medical histories will be reviewed and screened for participant suitability and eligibility.&#xD;
      Once the patient's medical history has been reviewed and the patient's eligibility has been&#xD;
      confirmed, the patient is then approached by the research staff member and the process of&#xD;
      informed consent will proceed.&#xD;
&#xD;
      Power Calculation and Study Size Sample size estimates are based on the primary outcome of&#xD;
      sternal motion &gt; 2 mm at any location at 6 weeks after surgery. From pilot data, fewer than&#xD;
      10% of patients who have received the SternaLock 360 have had motion &gt;2 mm, whereas patients&#xD;
      with conventional wiring have motion &gt; 2 mm in more than 50%. Based on a Fischer's Exact&#xD;
      test, Alpha of 0.05, power of 80% and two-tailed design, 25 participants are required in each&#xD;
      group to detect a difference of 50% to 10% between groups, favoring the SternaLock 360&#xD;
      system. The sample size will increase to 26 in each group to account for an estimated 5%&#xD;
      dropout rate. The total number will be 52 participants.&#xD;
&#xD;
      Statistical Methods To Be Undertaken The primary endpoint will be assessed using the Chi&#xD;
      Squared test on the incidence of sternal motion &gt; 2 mm at 6 weeks after surgery.&#xD;
&#xD;
      Postoperative Quality of Recovery Variables of &quot;recovery&quot; are dichotomized to &quot;recovered&quot; or&#xD;
      &quot;not recovered&quot; based on whether they have returned to their baseline (preoperative) values&#xD;
      or a better result than their preoperative values; at each of the time points when&#xD;
      measurements are performed. A tolerance factor is included in the scoring of cognitive&#xD;
      recovery to allow for performance variability 6. The secondary outcomes of recovery over&#xD;
      time, analysis will be performed using the a general linear mixed model to investigate group&#xD;
      differences over time.&#xD;
&#xD;
      Continuous data will be analyzed using independent samples t test, or repeated measures&#xD;
      analysis of variance (RM ANOVA). A P[Symbol]0.05 will define statistical significance.&#xD;
&#xD;
      References&#xD;
&#xD;
        1. El-Ansary D, Waddington G, Adams R: Trunk stabilisation exercises reduce sternal&#xD;
           separation in chronic sternal instability after cardiac surgery: a randomised cross-over&#xD;
           trialAust J Physiother 2007; 53: 255-60&#xD;
&#xD;
        2. El-Ansary D, Waddington G, Adams R: Relationship between pain and upper limb movement in&#xD;
           patients with chronic sternal instability following cardiac surgery. Physiother Theory&#xD;
           Pract 2007; 23: 273-80&#xD;
&#xD;
        3. Nishimura T, Kurihara C, Sakano Y, Kyo S: Sternalock plating system for elderly&#xD;
           post-sternotomy patients. J Artif Organs 2014; 17: 288-90&#xD;
&#xD;
        4. El-Ansary D, Waddington G, Adams R: Measurement of non-physiological movement in sternal&#xD;
           instability by ultrasound. Ann Thorac Surg 2007; 83: 1513-6&#xD;
&#xD;
        5. Royse CF, Newman S, Chung F, Stygall J, McKay RE, Boldt J, Servin FS, Hurtado I,&#xD;
           Hannallah R, Yu B, Wilkinson DJ: Development and feasibility of a scale to assess&#xD;
           postoperative recovery: the post-operative quality recovery scale. Anesthesiology 2010;&#xD;
           113: 892-905&#xD;
&#xD;
        6. Royse CF, Newman S, Williams Z, Wilkinson DJ: A human volunteer study to identify&#xD;
           variability in performance in the cognitive domain of the postoperative quality of&#xD;
           recovery scale. Anesthesiology 2013; 119: 576-81&#xD;
    </textblock>
  </detailed_description>
  <overall_status>Completed</overall_status>
  <start_date type="Actual">October 5, 2017</start_date>
  <completion_date type="Actual">November 25, 2018</completion_date>
  <primary_completion_date type="Actual">November 25, 2018</primary_completion_date>
  <phase>N/A</phase>
  <study_type>Interventional</study_type>
  <has_expanded_access>No</has_expanded_access>
  <study_design_info>
    <allocation>Randomized</allocation>
    <intervention_model>Parallel Assignment</intervention_model>
    <primary_purpose>Treatment</primary_purpose>
    <masking>None (Open Label)</masking>
  </study_design_info>
  <primary_outcome>
    <measure>Sternal motion</measure>
    <time_frame>6 weeks after surgery</time_frame>
    <description>Sternal edge movement with coughing that is &gt;2 mm in any location as measured by ultrasound (US)</description>
  </primary_outcome>
  <secondary_outcome>
    <measure>Sternal override</measure>
    <time_frame>1 day to 3 months</time_frame>
    <description>Anterior/posterior displacement of the sternal edges</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Sternal motion</measure>
    <time_frame>1 day to 3 months</time_frame>
    <description>Sternal edge movement at rest and coughing that is &gt;2 mm in any location as measured by ultrasound (US)</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Lung ultrasound</measure>
    <time_frame>1 day to 3 months</time_frame>
    <description>Lung ultrasound examination for pathology</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Sternal wound infection</measure>
    <time_frame>1 day to 3 months</time_frame>
    <description>Any deep or superficial wound infection</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>MACCE</measure>
    <time_frame>1 day to 3 months</time_frame>
    <description>Major adverse cerebral and cardiac events</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Sternal pain</measure>
    <time_frame>1 day to 3 months</time_frame>
    <description>Visual analogue pain score</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>PostopQRS</measure>
    <time_frame>1 day to 3 months</time_frame>
    <description>Postoperative Quality of recovery scale - a multidimensional scale to measure quality of recovery after surgery</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>FDQ</measure>
    <time_frame>1 day to 3 months</time_frame>
    <description>Functional difficulty questionaire</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Sternal closure time</measure>
    <time_frame>1 day to 3 months</time_frame>
    <description>Time from commencement of passage of first wire or SternaLock band to time of completion of all wire tensioning or screw fixation in plates</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Penetration of the posterior cortical bone by screws</measure>
    <time_frame>6-10 days after surgery</time_frame>
    <description>Penetration of the posterior cortical bone by screws assessed by chest X-Ray</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Degree of bone healing</measure>
    <time_frame>3 months</time_frame>
    <description>Degree of bone healing by CT scan at 3 months after surgery</description>
  </secondary_outcome>
  <number_of_arms>2</number_of_arms>
  <enrollment type="Actual">50</enrollment>
  <condition>Cardiac Surgery</condition>
  <condition>Sternal Closure</condition>
  <arm_group>
    <arm_group_label>Sternalock 360 sternal plating system</arm_group_label>
    <arm_group_type>Active Comparator</arm_group_type>
    <description>use of the SternaLock 360 system to close the sternum: 3 plates with 3 bands and measured screw length to engage but not penetrate the posterior sternal cortex, used to close the sternum</description>
  </arm_group>
  <arm_group>
    <arm_group_label>Sternal wires</arm_group_label>
    <arm_group_type>Active Comparator</arm_group_type>
    <description>Stainless steel sternal wires applied in a &quot;figure of 8&quot; configuration to close the sternum</description>
  </arm_group>
  <intervention>
    <intervention_type>Device</intervention_type>
    <intervention_name>Sternalock 360 sternal plating system</intervention_name>
    <description>The SternaLock 360 system is a band and plating system designed to improve sternal stability. 3 bands surround the sternum to oppose the bones (like wires), but an additional 3 plate system prevents anterior posterior displacement and provides a rigid fixation.</description>
    <arm_group_label>Sternalock 360 sternal plating system</arm_group_label>
  </intervention>
  <intervention>
    <intervention_type>Device</intervention_type>
    <intervention_name>Sternal Wires</intervention_name>
    <description>Stainless steel wires are applied in a &quot;figure of 8&quot; configuration to close the sternum</description>
    <arm_group_label>Sternal wires</arm_group_label>
  </intervention>
  <eligibility>
    <criteria>
      <textblock>
        Inclusion Criteria:&#xD;
&#xD;
          -  Age ≥ 18 year old Elective cardiac surgery Primary cardiac surgical procedure No&#xD;
             evidence of infection at time of surgery Sufficient English language to complete the&#xD;
             Postoperative Quality of Recovery Survey&#xD;
&#xD;
        Exclusion Criteria:&#xD;
&#xD;
          -  Previous sternotomy (redo) Clinical sternal deformity Home locality preventing&#xD;
             follow-up (e.g. remote regional, interstate or overseas patient)&#xD;
      </textblock>
    </criteria>
    <gender>All</gender>
    <minimum_age>18 Years</minimum_age>
    <maximum_age>N/A</maximum_age>
    <healthy_volunteers>No</healthy_volunteers>
  </eligibility>
  <overall_official>
    <last_name>Alistair Royse, MD</last_name>
    <role>Principal Investigator</role>
    <affiliation>Melbourne Health</affiliation>
  </overall_official>
  <location>
    <facility>
      <name>Melbourne Private Hospital</name>
      <address>
        <city>Melbourne</city>
        <state>Victoria</state>
        <zip>3050</zip>
        <country>Australia</country>
      </address>
    </facility>
  </location>
  <location_countries>
    <country>Australia</country>
  </location_countries>
  <verification_date>April 2019</verification_date>
  <study_first_submitted>September 12, 2017</study_first_submitted>
  <study_first_submitted_qc>September 12, 2017</study_first_submitted_qc>
  <study_first_posted type="Actual">September 14, 2017</study_first_posted>
  <last_update_submitted>April 15, 2019</last_update_submitted>
  <last_update_submitted_qc>April 15, 2019</last_update_submitted_qc>
  <last_update_posted type="Actual">April 17, 2019</last_update_posted>
  <responsible_party>
    <responsible_party_type>Principal Investigator</responsible_party_type>
    <investigator_affiliation>University of Melbourne</investigator_affiliation>
    <investigator_full_name>Colin Royse</investigator_full_name>
    <investigator_title>Co-PI</investigator_title>
  </responsible_party>
  <keyword>sternum</keyword>
  <keyword>bone healing</keyword>
  <keyword>recovery</keyword>
  <patient_data>
    <sharing_ipd>No</sharing_ipd>
  </patient_data>
  <!-- Results have not yet been posted for this study                                          -->
</clinical_study>


download date: ClinicalTrials.gov processed this data on September 20, 2023
link text: Link to the current ClinicalTrials.gov record.
url: https://clinicaltrials.gov/ct2/show/NCT03282578
org study id: MH 2017.165
nct id: NCT03282578
lead sponsor: 
collaborator: 
has dmc: No
is fda regulated drug: No
is fda regulated device: No
Design:

      Investigator Initiated Prospective Randomised Trial

      Study Centre's:

      Melbourne Private Hospital Royal Melbourne Hospital

      Study Hypothesis:

      Use of the SternaLock 360 will reduce the incidence of sternal motion > 2mm by absolute
      difference of 40% at 6 weeks of surgery compared to stainless steel wiring.

      Use of the SternaLock 360 will improve bone healing and quality of recovery after surgery
      compared to stainless steel wiring

      Study Objective:

      To determine if the SternaLock 360 system reduces sternal instability, increases bone
      healing, and improves quality of recovery compared to stainless steel wiring of the sternum,
      after cardiac surgery involving median sternotomy

      Inclusion Criteria:

      Age ≥ 18 year old Elective cardiac surgery Primary cardiac surgical procedure No evidence of
      infection at time of surgery Sufficient English language to complete the Postoperative
      Quality of Recovery Survey

      Exclusion Criteria:

      Previous sternotomy (redo) Clinical sternal deformity Home locality preventing follow-up
      (e.g. remote regional, interstate or overseas patient)

      Number of Planned Subjects:

      50
Introduction/Background Information Since the inception of cardiac surgery in the early
      1960s, division of the sternum has provided the superior access to cardiac structures.
      Cardiac surgery may involve treatment of the coronary arteries, valves or major vessels such
      as the ascending aorta. In children, correction of congenital malformations is also
      performed.

      The conventional bone fixation during the 1960s was the placement of stainless steel wires
      around or through the sternum, predominantly as single wires which were tensioned by
      twisting. In the 1980s, it became fashionable for some cardiac surgeons to pass the wire
      twice around the bone (as would be the case repairing a fence on a farm), so-called "figure
      of 8" configuration and tensioning again occurring by twisting the wires. There have been no
      adequate studies investigating which of these two techniques may be superior.

      In simple terms, bone healing is promoted by

        -  Minimising movement of the bone edges at the fracture site and

        -  Improved alignment of the bone edges

      The sternum is a connecting bone that moves in multiple planes to transfer load and position
      the limbs in space during every day functional tasks and respond to the demands of
      respiration. The healing of the sternum is in the context of many efforts by the treating
      physicians and physiotherapists to encourage activities that might cause distracting forces
      at the sternal fracture site. Additionally, simple everyday activities by the patient such as
      coughing, deep breathing, sneezing, transferring in and out of bed, turning over in bed and
      driving all lead to substantial distracting forces acting on the sternal fracture site1.
      External fixation is not encouraged because the patient needs to have significant chest wall
      movement in order to breathe and clear sputum as part of the recovery from surgery.

      Also, ultrasound data suggests an additional mechanism by which sternal healing is
      compromised with conventional sternal wiring techniques. The shape of the sternum is complex
      1. The upper part is called the manubrium to which the clavicles and first rib join, and is
      generally quite thick with a reasonably robust and cortex and strong marrow. By contrast, the
      body of the sternum which forms the majority of the sternum is thinner and the marrow is
      frequently less robust than for the manubrium. In both areas, the cortical bone is present
      superficially (anterior) and deep (posterior) with the marrow between. When sternal wires are
      used, and the two halves of the sternum brought together and tensioned by twisting the wires,
      best efforts made to ensure that the cortical bone edges on either side are opposed or well
      aligned (that is, that in the anterior and posterior direction that the two bone edges from
      either side of well opposed). Generally, this is quite well achieved, but not always. Yet,
      even with ultrasound studies performed 1 or 2 days after surgery, the alignment between the
      anterior cortical bone edge on either side is lost as detected by the cortical bone of one
      side overriding the cortical bone of the other side.

      The implications of this ultrasound finding are twofold

        1. Irrespective of the perfect alignment of the two sides of the sternal fracture at the
           time of surgery under general anaesthetic, coughing and deep breathing usually leads to
           distraction forces that results in one side of the divided sternum overriding the other
           side, typically by a couple of millimetres or so. This must be because there is less
           bone to bone force when the cortical bone edge is being forced against soft tissue or
           against the marrow than it would be if it were forced against the cortical bone of the
           other side. This is important because any distracting force caused by coughing or deep
           breathing or indeed any other activity should logically, result in the two halves of the
           sternal bone adopting a position of least force.

        2. What this means is that the two halves of the sternum in combination (and after over
           riding has occurred) are now less wide than they had been at the time that the sternal
           wire was tensioned at the end of the surgical procedure, by the distance of the sternal
           override detected by the ultrasound.

      Consequences of poor sternal healing: Patients may feel movement of the sternum and that may
      limit their activity. However, chronic sternal instability is associated with pain 2, which
      may in turn affect other aspects of daily living, require long term medications and
      predispose to depression.

      SternaLock 360 system The SternaLock 360 system is a band and plating system designed to
      improve sternal stability. 3 bands surround the sternum to oppose the bones (like wires), but
      an additional 3 plate system prevents anterior posterior displacement and provides a rigid
      fixation. CT scan follow up shows improved bone healing at 3 months after surgery compared to
      conventional wires, but the CT scan is a poor measurement of dynamic movement. Quality of
      recovery and functional status has not been adequately studied.

      The unique design of the SternaLock 360 system, is that it combines a

        1. Compressive force to the two sternal halves forcing them together (similar to the
           principal of the sternal wires), thus counteracting lateral distracting forces.

        2. Additionally, by the placement of metal plates that cross the fracture and are fixed on
           either side by screws, predominantly the plates acts to prevent anterior/posterior
           distracting forces; longitudinal translation and thus better maintain the cortical bone
           to cortical bone apposition between the two sides.

      Pilot Data Our research group is experienced in assessing sternal motion with ultrasound 4.
      We have conducted sternal ultrasound measurements of sternal motion after surgery as part of
      clinical follow up.

      Over all the SternaLock 360 results in a far greater rigid fixation as noted at the time of
      surgical implantation. Subsequent pilot ultrasound studies performed during dynamic
      distracting forces (such as coughing) reveal reduced or absent movement at the fracture site
      and better preservation of fracture alignment. Ultrasounds have been performed at varying
      intervals from Day 1 post-operative to 6 weeks post-operative, and ultrasounds of sternal
      wire fixation have been performed at varying intervals after 10 months post-operative. Our
      observations are that fewer than 10% of patients who have received the SternaLock 360 have
      had motion >2 mm, whereas patients with conventional wiring have motion > 2 mm in more than
      50%.

      Evidence Gap The SternaLock 360 is an effective system for closing the sternum. There are few
      comparative data investigating bone healing with CT scans, but the CT alone is a poor
      indicator of sternal instability. There is no long term comparative data on sternal micro
      motion, or quality of recovery outcomes to identify whether the SternaLock 360 system will
      improve patient centred outcomes over and above improved bone healing.

      Study Objectives Hypothesis Use of the SternaLock 360 will reduce the incidence of sternal
      motion > 2mm by absolute difference of 40% at 6 weeks of surgery compared to stainless steel
      wiring.

      Use of the SternaLock 360 will improve bone healing and quality of recovery after surgery
      compared to stainless steel wiring.

      Study Aims To determine if the SternaLock 360 system reduces sternal instability, increases
      bone healing, and improves quality of recovery compared to stainless steel wiring of the
      sternum, after cardiac surgery involving median sternotomy.

      Randomisation The randomization sequence will be produced using a computer generated
      randomization sequence, in unequal blocks. Concealment will be by placing the card containing
      the allocation information in double opaque sealed envelopes, and concealment will be
      maintained until after recruitment and the patients is admitted to the operating theatre. The
      treating surgical team will then open the envelopes to reveal the allocation after (1)
      weaning from cardiopulmonary bypass and (2) final confirmation from the treating surgeon that
      the patient is suitable to be randomised.

      Statistical Methods Participants who are scheduled for cardiac surgery will be screened and
      recruited from the cardiac surgery operation lists, surgeon's clinics and pre-operative ward.

      The initial contact will be made in person during the first contact session prior to surgery.
      In-patients scheduled for cardiac surgery will be screened on the ward.

      Medical histories will be reviewed and screened for participant suitability and eligibility.
      Once the patient's medical history has been reviewed and the patient's eligibility has been
      confirmed, the patient is then approached by the research staff member and the process of
      informed consent will proceed.

      Power Calculation and Study Size Sample size estimates are based on the primary outcome of
      sternal motion > 2 mm at any location at 6 weeks after surgery. From pilot data, fewer than
      10% of patients who have received the SternaLock 360 have had motion >2 mm, whereas patients
      with conventional wiring have motion > 2 mm in more than 50%. Based on a Fischer's Exact
      test, Alpha of 0.05, power of 80% and two-tailed design, 25 participants are required in each
      group to detect a difference of 50% to 10% between groups, favoring the SternaLock 360
      system. The sample size will increase to 26 in each group to account for an estimated 5%
      dropout rate. The total number will be 52 participants.

      Statistical Methods To Be Undertaken The primary endpoint will be assessed using the Chi
      Squared test on the incidence of sternal motion > 2 mm at 6 weeks after surgery.

      Postoperative Quality of Recovery Variables of "recovery" are dichotomized to "recovered" or
      "not recovered" based on whether they have returned to their baseline (preoperative) values
      or a better result than their preoperative values; at each of the time points when
      measurements are performed. A tolerance factor is included in the scoring of cognitive
      recovery to allow for performance variability 6. The secondary outcomes of recovery over
      time, analysis will be performed using the a general linear mixed model to investigate group
      differences over time.

      Continuous data will be analyzed using independent samples t test, or repeated measures
      analysis of variance (RM ANOVA). A P[Symbol]0.05 will define statistical significance.

      References

        1. El-Ansary D, Waddington G, Adams R: Trunk stabilisation exercises reduce sternal
           separation in chronic sternal instability after cardiac surgery: a randomised cross-over
           trialAust J Physiother 2007; 53: 255-60

        2. El-Ansary D, Waddington G, Adams R: Relationship between pain and upper limb movement in
           patients with chronic sternal instability following cardiac surgery. Physiother Theory
           Pract 2007; 23: 273-80

        3. Nishimura T, Kurihara C, Sakano Y, Kyo S: Sternalock plating system for elderly
           post-sternotomy patients. J Artif Organs 2014; 17: 288-90

        4. El-Ansary D, Waddington G, Adams R: Measurement of non-physiological movement in sternal
           instability by ultrasound. Ann Thorac Surg 2007; 83: 1513-6

        5. Royse CF, Newman S, Chung F, Stygall J, McKay RE, Boldt J, Servin FS, Hurtado I,
           Hannallah R, Yu B, Wilkinson DJ: Development and feasibility of a scale to assess
           postoperative recovery: the post-operative quality recovery scale. Anesthesiology 2010;
           113: 892-905

        6. Royse CF, Newman S, Williams Z, Wilkinson DJ: A human volunteer study to identify
           variability in performance in the cognitive domain of the postoperative quality of
           recovery scale. Anesthesiology 2013; 119: 576-81
allocation: Randomized
intervention model: Parallel Assignment
primary purpose: Treatment
masking: None (Open Label)
measure: Sternal motion
time frame: 6 weeks after surgery
description: Sternal edge movement with coughing that is >2 mm in any location as measured by ultrasound (US)
measure: Sternal override
time frame: 1 day to 3 months
description: Anterior/posterior displacement of the sternal edges
measure: Sternal motion
time frame: 1 day to 3 months
description: Sternal edge movement at rest and coughing that is >2 mm in any location as measured by ultrasound (US)
measure: Lung ultrasound
time frame: 1 day to 3 months
description: Lung ultrasound examination for pathology
measure: Sternal wound infection
time frame: 1 day to 3 months
description: Any deep or superficial wound infection
measure: MACCE
time frame: 1 day to 3 months
description: Major adverse cerebral and cardiac events
measure: Sternal pain
time frame: 1 day to 3 months
description: Visual analogue pain score
measure: PostopQRS
time frame: 1 day to 3 months
description: Postoperative Quality of recovery scale - a multidimensional scale to measure quality of recovery after surgery
measure: FDQ
time frame: 1 day to 3 months
description: Functional difficulty questionaire
measure: Sternal closure time
time frame: 1 day to 3 months
description: Time from commencement of passage of first wire or SternaLock band to time of completion of all wire tensioning or screw fixation in plates
measure: Penetration of the posterior cortical bone by screws
time frame: 6-10 days after surgery
description: Penetration of the posterior cortical bone by screws assessed by chest X-Ray
measure: Degree of bone healing
time frame: 3 months
description: Degree of bone healing by CT scan at 3 months after surgery
arm group label: Sternalock 360 sternal plating system
arm group type: Active Comparator
description: use of the SternaLock 360 system to close the sternum: 3 plates with 3 bands and measured screw length to engage but not penetrate the posterior sternal cortex, used to close the sternum
arm group label: Sternal wires
arm group type: Active Comparator
description: Stainless steel sternal wires applied in a "figure of 8" configuration to close the sternum
intervention type: Device
intervention name: Sternalock 360 sternal plating system
description: The SternaLock 360 system is a band and plating system designed to improve sternal stability. 3 bands surround the sternum to oppose the bones (like wires), but an additional 3 plate system prevents anterior posterior displacement and provides a rigid fixation.
arm group label: Sternalock 360 sternal plating system
intervention type: Device
intervention name: Sternal Wires
description: Stainless steel wires are applied in a "figure of 8" configuration to close the sternum
arm group label: Sternal wires
criteria: 
gender: All
minimum age: 18 Years
maximum age: N/A
healthy volunteers: No
last name: Alistair Royse, MD
role: Principal Investigator
affiliation: Melbourne Health
facility: 
country: Australia
responsible party type: Principal Investigator
investigator affiliation: University of Melbourne
investigator full name: Colin Royse
investigator title: Co-PI
sharing ipd: No