MotionLoc Study, Femur Fractures

NCT ID: NCT01612208

Last Updated: 2014-05-23

Basic Information

• Recruitment Status: COMPLETED
• Total Enrollment: 2 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2011-04-30
• Study Completion Date: 2013-01-31

Brief Summary

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.

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.

Conditions

Fracture of the Distal Femur

Study Design

• Observational Model Type: COHORT
• Study Time Perspective: PROSPECTIVE

Study Groups

Distal femur fractures

(AO/OTA types 33-A and 33-C)

Periarticular Locking Plate (NCB, Zimmer)

Intervention Type: DEVICE

The proximal plate segment will be applied to the diaphysis using four 5.0 mm MotionLoc screws. The plate will not be compressed onto the femoral diaphysis to preserve periosteal perfusion and to enable controlled motion between the plate and the diaphysis. If desirable, temporary spacers of the NCB set may be used in the proximal plate segment to facilitate 1-2 mm plate elevation over the diaphysis. Only MotionLoc screws will be used for fixation of the NCB plate proximal to the fracture site.

MotionLoc Screw

Intervention Type: DEVICE

The NCB Polyaxial Locking Plate System is indicated for temporary internal fixation and stabilization of fractures and osteotomies of long bones. These MotionLoc screws have a reduced 3.4 mm diameter mid-shaft section to bypass the near cortex. By avoiding rigid constraint in the near cortex, the MotionLoc screw design increases the working length of the screw, allowing for elastic flexion of the screw shaft within a controlled motion envelope in the near cortex.

Interventions

Periarticular Locking Plate (NCB, Zimmer)

The proximal plate segment will be applied to the diaphysis using four 5.0 mm MotionLoc screws. The plate will not be compressed onto the femoral diaphysis to preserve periosteal perfusion and to enable controlled motion between the plate and the diaphysis. If desirable, temporary spacers of the NCB set may be used in the proximal plate segment to facilitate 1-2 mm plate elevation over the diaphysis. Only MotionLoc screws will be used for fixation of the NCB plate proximal to the fracture site.

Intervention Type: DEVICE

MotionLoc Screw

The NCB Polyaxial Locking Plate System is indicated for temporary internal fixation and stabilization of fractures and osteotomies of long bones. These MotionLoc screws have a reduced 3.4 mm diameter mid-shaft section to bypass the near cortex. By avoiding rigid constraint in the near cortex, the MotionLoc screw design increases the working length of the screw, allowing for elastic flexion of the screw shaft within a controlled motion envelope in the near cortex.

Intervention Type: DEVICE

Eligibility Criteria

Inclusion Criteria

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

Exclusion Criteria

• Pregnancy
• Patients who are enrolled in an investigational treatment trial.
• Patients who are not expected to survive the follow-up period.
• Considered an inappropriate participant by the study physician.
• Revision surgery.
• Patients currently incarcerated or awaiting incarceration.
• Severe spinal injury with neurological deficit resulting in paralysis.
• Fracture fixed more than 28 days after injury.
• Acute or chronic of systematic infections
• Patients with periprosthetic fractures.

• Minimum Eligible Age: 17 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Legacy Health System

OTHER

Sponsor Role: collaborator

University of Utah

OTHER

Sponsor Role: lead

Responsible Party

Eric Kubiak

M.D.

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Erik Kubiak

Role: PRINCIPAL_INVESTIGATOR

Orthopedic Surgery Operations

Other Identifiers

51842

Identifier Type: -

Identifier Source: org_study_id