Plating of Distal Femur Fractures by Far Cortical Locking Using MotionLoc Screws

This study has been completed.
Sponsor:
Collaborators:
Slocum Center for Orthopaedics, Eugene, OR
University of Utah
Financial support provided by Zimmer Inc., Warsaw, IN
Information provided by (Responsible Party):
Michael Bottlang, PhD, Legacy Biomechanics Laboratory
ClinicalTrials.gov Identifier:
NCT01667887
First received: August 15, 2012
Last updated: January 28, 2013
Last verified: January 2013
  Purpose

The objective of this study is to document callus formation and healing of fractures stabilized with locking plates utilizing modern MotionLoc screws that provide controlled axial micro-motion to actively promote fracture healing.


Condition
Fracture of Distal Femur

Study Type: Observational
Study Design: Observational Model: Cohort
Time Perspective: Prospective
Official Title: MotionLoc Study: Healing of Distal Femur Fractures Stabilized With a Flexible Plating Construct Using MotionLoc Screws

Resource links provided by NLM:


Further study details as provided by Legacy Biomechanics Laboratory:

Primary Outcome Measures:
  • Fracture Healing [ Time Frame: 6, 12, and 24 weeks post surgery ] [ Designated as safety issue: No ]
    Fracture healing is defined clinically by the ability of pain-free weight bearing, and radiographically by callus formation and bridging.


Secondary Outcome Measures:
  • Periosteal Callus Size [ Time Frame: 6, 12, 24 weeks post surgery ] [ Designated as safety issue: No ]
    Periosteal callus size is assessed at the anterior, posterior, and medial aspects on radiographs using a validated computational algorithm.

  • Bridging Callus from CT [ Time Frame: 12 weeks post surgery ] [ Designated as safety issue: No ]
    Cross-sectional image analysis, supported by 3-D rendering, to detect bony bridging at the anterior, posterior, and lateral aspects of the femur.

  • Fixation Failure [ Time Frame: 24 weeks post surgery ] [ Designated as safety issue: No ]
    Assessed in terms of loss of alignment at 12 and 24 weeks post surgery

  • Hardware failure [ Time Frame: 6, 12, 24 weeks post surgery ] [ Designated as safety issue: No ]
    Breakage of screw or plate


Estimated Enrollment: 33
Study Start Date: April 2011
Study Completion Date: January 2013
Primary Completion Date: May 2012 (Final data collection date for primary outcome measure)
Groups/Cohorts
Femur Fractures
Patients with Distal Femur Fractures

Detailed Description:

Rigid locked plating constructs can suppress fracture healing, particularly at the near cortex adjacent to the plate where interfragmentary motion is minimal. Dynamic fixation with Far Cortical Locking (FCL) screws reduces construct stiffness and induces axial interfragmentary motion to stimulate symmetric callus formation and healing. Two versions of FCL screws are commercially available, but the clinical durability of this novel concept has not been documented to date. This prospective observational study documented our early clinical experience with MotionLoc® FCL screws for stabilization of distal femur fractures to assess their durability and potential complications.

Thirty-two consecutive patients with 33 distal femur fractures (AO/OTA types 33-A and 33-C) were prospectively enrolled at three trauma centers. Fractures were stabilized by plate osteosynthesis with MotionLoc® FCL screws without supplemental bone graft or bone morphogenic proteins. Thirty patients with 31 fractures were available for follow-up until union or revision. Follow-up visits at 6, 12, and 24 weeks comprised functional and radiographic assessment of implant fixation and fracture healing, including computed tomography scans at week 12. The primary endpoint was fracture healing in absence of complications and revision.

There was no incidence of implant breakage or diaphyseal fixation failure. Thirty of 31 fractures healed within 15.6 ± 6.2 weeks, as evident by bridging callus and pain-free load bearing. There were two revisions, one at 5 days post surgery to correct a mal-rotation, and one at 6 months post surgery to revise a non-union. Periosteal callus distribution at week 6 was symmetrical, with similar amounts of callus at the medial cortex (35%) anterior cortex (30%) and posterior cortex (35%). In 23 fractures (74%), callus formation extended to the lateral cortex under the plate.

Absence of hardware and fixation failure suggests that dynamic plating of distal femur fractures with FCL screws provides safe and effective fixation. Moreover, the amount and symmetric distribution of periosteal callus suggests that dynamic fixation with FCL screws may promote increased fracture healing over standard locked plating. However, this hypothesis on the stimulatory effect of dynamic fixation on fracture healing requires investigation in a future randomized control trial.

  Eligibility

Ages Eligible for Study:   17 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Sampling Method:   Probability Sample
Study Population

Distal femur fractures (AO/OTA Type 33A and 33C)

Criteria

Inclusion Criteria:

  1. Patients with distal femur fracture (AO/OTA Type 33A and 33C)
  2. Patients 17 years of age and over.
  3. Patients able to be operated on by selected surgeons at the participating centers.

Exclusion Criteria:

  1. Pregnancy
  2. Patients who are enrolled in an investigational treatment trial.
  3. Patients who are not expected to survive the follow-up period.
  4. Considered an inappropriate participant by the study physician.
  5. Revision surgery
  6. Patients currently incarcerated or awaiting incarceration.
  7. Severe spinal injury with neurological deficit resulting in paralysis.
  8. Fracture fixed more then 28 days after injury.
  9. Acute or chronic local or systemic infections
  10. Periprosthetic fractures
  Contacts and Locations
Please refer to this study by its ClinicalTrials.gov identifier: NCT01667887

Locations
United States, Oregon
Legacy Health System
Portland, Oregon, United States, 97232
Sponsors and Collaborators
Legacy Biomechanics Laboratory
Slocum Center for Orthopaedics, Eugene, OR
University of Utah
Financial support provided by Zimmer Inc., Warsaw, IN
Investigators
Principal Investigator: Michael Bottlang, PhD Legacy Biomechanics Laboratory
Study Chair: Steven Madey, MD Legacy Health System
  More Information

Additional Information:
No publications provided

Responsible Party: Michael Bottlang, PhD, Director, Legacy Biomechanics Laboratory, Legacy Biomechanics Laboratory
ClinicalTrials.gov Identifier: NCT01667887     History of Changes
Other Study ID Numbers: MotionLoc Screw
Study First Received: August 15, 2012
Last Updated: January 28, 2013
Health Authority: United States: Legacy IRB

Keywords provided by Legacy Biomechanics Laboratory:
Far Cortical Locking
Distal Femur Fracture
Locking Plate
MotionLoc
Fracture Fixation

Additional relevant MeSH terms:
Femoral Fractures
Fractures, Bone
Wounds and Injuries
Leg Injuries

ClinicalTrials.gov processed this record on April 17, 2014