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

This study has been completed.
Information provided by (Responsible Party):
Dominik Drnek, Orthopedic Clinic Gersthof Identifier:
First received: January 21, 2013
Last updated: January 30, 2013
Last verified: January 2013

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 Intervention
Device: Total knee arthroplasty (TKA) (Smith &Nephew®)

Study Type: Observational
Study Design: 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

Resource links provided by NLM:

Further study details as provided by Orthopedic Clinic Gersthof:

Primary Outcome Measures:
  • Alignment [ Time Frame: Postoperative x-ray (7-10 days after surgery) ] [ Designated as safety issue: No ]

    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:
  • Learning curve [ Time Frame: Intraoperative and early postoperative period (up to 14 days after surgery) ] [ Designated as safety issue: No ]
    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.

Enrollment: 73
Study Start Date: September 2011
Study Completion Date: October 2012
Primary Completion Date: October 2012 (Final data collection date for primary outcome measure)
Groups/Cohorts Assigned Interventions
Patients treated with Patient specific instruments in TKA 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.


Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
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
  Contacts and Locations
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, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01781598

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

No publications provided

Responsible Party: Dominik Drnek, Dr. med. univ., Orthopedic Clinic Gersthof Identifier: NCT01781598     History of Changes
Other Study ID Numbers: PMCBv1
Study First Received: January 21, 2013
Last Updated: January 30, 2013
Health Authority: Austria: for observational studies no authorities required

Keywords provided by Orthopedic Clinic Gersthof:
Total knee arthroplasty
Patient specific instruments
Patient matched cutting blocks
Learning curve
VISIONAIRE processed this record on November 25, 2014