Patient-specific Instruments as a Standard Procedure in Total Knee Arthroplasty

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01781598
Recruitment Status : Completed
First Posted : February 1, 2013
Last Update Posted : February 1, 2013
Information provided by (Responsible Party):
Dominik Drnek, Orthopedic Clinic Gersthof

Brief Summary:
Description of logistics, learning curve and radiological results in 70 patients treated with patient specific instrumentation in total knee arthroplasty as a standard procedure

Condition or disease Intervention/treatment
Alignment Device: Total knee arthroplasty (TKA) (Smith &Nephew®)

Detailed Description:

The Orthopaedic Clinic Gersthof is a teaching hospital, where the entire spectrum of joint replacements with emphasis on hips and knees is performed. Twenty surgeons perform TKAs at our institution, with approximately 400 TKAs implanted per year.

The PSI system of Smith &Nephew® (Patient-Matched Cutting Blocks [PMCB]; the VISIONAIRE® technology) is applied. The preoperative image modality is based on a long leg standing X-ray as well as an MRI of the knee. The Genesis II® Endoprosthesis (Smith & Nephew®) is used as the TKA implant.

This study is a observational monocentric prospective study.

Estimated enrollment: 70 Enrollment time: September 2011-October 2012 Primary outcome: Alignment

The postoperative X-rays (AP, lateral view, and long leg standing), taken 7-to-10 days after surgery are evaluated in terms of component position and restoration of the mechanical alignment. X-rays are routinely monitor-guided but not calibrated at our institution.

As a secondary outcome the learning curve is evaluated using the following parameters collected during surgery: the fit of the cutting blocks, changes of the implant size, bony recuts, soft tissue releases, and changes in inlay size. Gap balancing was subjectively judged by the operating surgeon. Operation time, number of blood transfusions, and early postoperative complications were recorded within the first 14 days after surgery.

Study Type : Observational
Actual Enrollment : 73 participants
Observational Model: Cohort
Time Perspective: Prospective
Official Title: Patient-specific Instruments as a Standard Procedure in Total Knee Arthroplasty: Logistics, Learning Curve, and Postoperative Radiological Results in 70 Patients
Study Start Date : September 2011
Actual Primary Completion Date : October 2012
Actual Study Completion Date : October 2012

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Knee Replacement
U.S. FDA Resources

Group/Cohort Intervention/treatment
Patients treated with Patient specific instruments in TKA Device: Total knee arthroplasty (TKA) (Smith &Nephew®)

Primary Outcome Measures :
  1. Alignment [ Time Frame: Postoperative x-ray (7-10 days after surgery) ]

    Alignment measured on monitor-guided x-rays:

    Mechanical Alignment: Hip-Knee-Ankle angle in degrees [°] Alignment of the tibial and femoral component in the sagittal and coronal plane [°]

Secondary Outcome Measures :
  1. Learning curve [ Time Frame: Intraoperative and early postoperative period (up to 14 days after surgery) ]
    In order to evaluate the learning curve associated with using VISIONAIRE® technology for TKA, the following parameters are registered during surgery: the fit of the cutting blocks[subjective grading by the surgeon], changes of the implant size[number of changes], bony recuts[number of recuts], soft tissue releases[number of releases, kind of release], and changes in inlay size [number of inlay changes]. Gap balancing is subjectively judged by the operating surgeon. Operation time[minutes], number of blood transfusions[units], and early postoperative complications associated with the treatment [kind and number] within the first 14 days after surgery are recorded.

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
Patients treated with GENESISII prothesis using VISIONAIRE are enrolled in the study

Inclusion Criteria:

  • Indication for TKA
  • Genesis II endoprosthesis
  • Operated using patient specific instruments (VISIONAIRE)

Exclusion Criteria:

  • contraindication for MRI
  • varus/ valgus deformity >15 degrees

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT01781598

Orthopedic Clinic Gersthof
Vienna, Austria, 1180
Sponsors and Collaborators
Orthopedic Clinic Gersthof

Responsible Party: Dominik Drnek, Dr. med. univ., Orthopedic Clinic Gersthof Identifier: NCT01781598     History of Changes
Other Study ID Numbers: PMCBv1
First Posted: February 1, 2013    Key Record Dates
Last Update Posted: February 1, 2013
Last Verified: January 2013

Keywords provided by Dominik Drnek, Orthopedic Clinic Gersthof:
Total knee arthroplasty
Patient specific instruments
Patient matched cutting blocks
Learning curve