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

Completed

• Conditions: Alignment
• Interventions: Device: Total knee arthroplasty (TKA) (Smith &Nephew®)

• Registration Number: NCT01781598
• Lead Sponsor: 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

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 Timeline

• Study Start: 2011-09
• Primary Completion: 2012-10
• Study Completion: 2012-10
• Status Verified: 2013-01
• Study First Submitted: 2013-01-21
• Study First Submitted QC: 2013-01-30
• Last Update Submitted: 2013-01-30
• Study First Posted: 2013-02-01
• Last Update Posted: 2013-02-01

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 73

Inclusion Criteria

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

Exclusion Criteria

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

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
Patients treated with Patient specific instruments in TKA	Total knee arthroplasty (TKA) (Smith &Nephew®)	-

Primary Outcome Measures

Name	Time	Method
Alignment	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

Name	Time	Method
Learning curve	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.

Trial Locations

Locations (1)

Orthopedic Clinic Gersthof; 🇦🇹 Vienna, Austria