Radiostereometric Analysis of Fracture Healing in Distal Femur Fractures

NCT ID: NCT01593176

Last Updated: 2015-05-06

Basic Information

• Recruitment Status: UNKNOWN
• Total Enrollment: 30 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2012-05-31
• Study Completion Date: 2015-06-30

Brief Summary

The investigators are doing this research study to look at how distal femoral fractures (knee bone break) heal. In this study, the investigators will use Radiostereometric Analysis (RSA) to look at how the pieces of femur bone move as the bone heals. RSA is a special x-ray that uses radiographs to measure very small movements in the bone over time. The question that will be answered by this study is whether RSA can be used as a tool to monitor fracture healing.

Detailed Description

Determining when a fracture has united can be very difficult. Plain radiographs are easy to obtain but are notoriously inaccurate for determining union. CT scans are more helpful, but are more costly and inconvenient. Artifacts from the metal implants often mask the visibility of the bone structure. In addition, the accuracy of CT scans for determining non-unions is not known. CT scanning will identify a nonunion when a clear persistent fracture line separates the fragments. Unfortunately, the scans often reveal some areas where bone has bridged the fracture, and other areas where the fracture line remains. Ultimately, no one knows the amount of bridging necessary to stop motion between the fragments. Often the best indication of fracture healing is the resolution of pain. However, patients' pain tolerance varies greatly. It is clear that our specialty needs better techniques to determine fracture union. This is particularly important since the market is introducing many new drugs that purport increased rate of fracture healing. If there are no standards to evaluate fracture healing, there is no way to determine drug efficacy.

Radiostereometric analysis (RSA) is a highly accurate, precise, safe and objective technique that uses radiographs to measure very small displacements and relative motion over time. It has been used successfully for some time to evaluate small changes in the position of prosthetic joints. There is some indication that this technique can also be used to evaluate healing by determining when motion between the fragments stops. A limited number of phantom model RSA in-vitro studies have proven useful for measuring the rigidity of different types of osteosyntheses methods. However, RSA has so far only been applied in a few in-vivo studies to evaluate fracture healing.

Osteosynthesis of distal femur fractures is challenging. Fractures are reduced through a large skin incision and often patients face non-union or union in a varus or valgus deformity after a long convalescence. That said, increased fracture fixation is now achievable through the newly invented locked angle screw plate system. The Synthes product, Less Invasive Stabilization System (LISS) plate is one example of this new system. The exact time of fracture healing, however, remains uncertain. No RSA in-vivo studies have been published among patients with distal femur fractures - but one RSA in-vitro study on 18 phantom distal femurs demonstrates RSA to be a relatively simple way to collect and analyze the relative motion between fragments fixed with the LISS.8 Given this, it should be possible to evaluate fragment motion in distal femur fractures stabilized using the LISS plate in order to evaluate healing.

At the time of surgery, sets of up to 9 RSA beads will be implanted on sides of the main fractures lines with the use of the inserter instrument and the image intensifier. In AO/OTA type 33A fractures, two sets will be implanted - one in the femoral shaft and one in the distal femoral epiphysis. In AO/OTA type 33C fractures with an extra fracture line through the epiphysis, three sets will be implanted - one in the femoral shaft, one in the main lateral condyle segment and one in the main medial condyle segment. No beads will be planted in comminuted bone fragments. Patients will be evaluated during outpatient follow-up visits standard for this fracture (2 weeks, 6 weeks, 3 months, 6 months and 1 year after surgery.)

The purpose of this study is to use RSA to evaluate fracture healing in distal femoral fractures osteosynthezed using the LISS.

Conditions

Distal Femur Fractures

Study Design

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

Study Groups

Distal Femur Fracture, LISS Plate

Patients presenting with a distal femur fracture requiring surgical fixation with a Less Invasive Stabilization System (LISS) plate will have placement of RSA beads for analysis.

Placement of RSA beads

Intervention Type: PROCEDURE

At the time of surgery sets of up to 9 RSA beads will be implanted on sides of the main fractures lines with the use of the inserter instrument and the image intensifier. In AO/OTA type 33A fractures two sets will be implanted - one in the femoral shaft and one in the distal femoral epiphysis. In AO/OTA type 33C fractures with an extra fracture line through the epiphysis, three sets will be implanted - one in the femoral shaft, one in the main lateral condyle segment and one in the main medial condyle segment. No beads will be planted in comminuted bone fragments. The fracture will then be plated with a LISS plate as it normally would.

Interventions

Placement of RSA beads

At the time of surgery sets of up to 9 RSA beads will be implanted on sides of the main fractures lines with the use of the inserter instrument and the image intensifier. In AO/OTA type 33A fractures two sets will be implanted - one in the femoral shaft and one in the distal femoral epiphysis. In AO/OTA type 33C fractures with an extra fracture line through the epiphysis, three sets will be implanted - one in the femoral shaft, one in the main lateral condyle segment and one in the main medial condyle segment. No beads will be planted in comminuted bone fragments. The fracture will then be plated with a LISS plate as it normally would.

Intervention Type: PROCEDURE

Other Intervention Names

RSA Biomedical Tantulum Markers; Synthes Less Invasive Stabilization System Fixation Plate

Eligibility Criteria

Inclusion Criteria

• Male or female subjects aged 18 and older
• Isolated distal femur fracture requiring surgical stabilization with a LISS plate
• Subjects who are able to return to MGH for follow-up during the year following their injury.

Exclusion Criteria

• Subjects with expected limited life span less than a year.
• Subjects who were non ambulatory prior to their injury
• Female subjects who are pregnant
• Subjects who are treated with an orthopaedic implant other than the LISS
• Subjects with bone structure illnesses.
• Pathologic fractures secondary to neoplasm
• Subject with a severe open distal femur fracture with vascular damage
• Subjects who are unable to attend post-operative outpatient appointments at the MGH

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Massachusetts General Hospital

OTHER

Sponsor Role: lead

Responsible Party

Mark Steven Vrahas

Chief, Orthopaedic Trauma Service

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Mark S Vrahas, MD

Role: PRINCIPAL_INVESTIGATOR

Massachusetts General Hospital

Charles Bragdon, Ph.D

Role: PRINCIPAL_INVESTIGATOR

Massachusetts General Hospital

Michael J Weaver, MD

Role: PRINCIPAL_INVESTIGATOR

Brigham and Women's Hospital

Locations

Massachusetts General Hospital

Boston, Massachusetts, United States

Site Status: RECRUITING

Brigham & Women's Hospital

Boston, Massachusetts, United States

Site Status: RECRUITING

Countries

United States

Central Contacts

Mark S Vrahas, MD

Role: CONTACT

mvrahas@partners.org

617-726-2943

Jordan H Morgan, BS

Role: CONTACT

jhmorgan@partners.org

617-643-3653

Facility Contacts

Mark S Vrahas, MD

Role: primary

mvrahas@partners.org

617-726-2943

Michael J Weaver, MD

Role: primary

mjweaver@partners.org

617-525-8088

Other Identifiers

2011P001012

Identifier Type: -

Identifier Source: org_study_id