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Completed

NCT Number: NCT01124305

Knee Arthroplasty Performed With Conventional and Customized Instrumentation

The main purpose of this study is to determine whether the surgical time required for primary total knee arthroplasty is significantly less when performed with Customized Patient Instrumentation (CPI) than with conventional instrumentation. Each case will be recorded by video camera, in order to time the length of surgery and each surgical step. The number of surgical trays required for each case will be recorded. As an additional endpoint, the investigators will measure limb and component alignment on x-rays to determine if these two methods achieve equivalent alignment results. The thickness of bone cuts will be compared to the surgical plan and to each other.

The primary hypothesis is that the use of customized patient instrumentation will reduce the operative time required for total knee arthroplasty.

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Key information

Conditions

Knee Arthritis

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 4

Primary location

Anderson Orthopaedic Research Institute

Alexandria, Virginia, 22306, United States

About this study

Patient-specific instrumentation (PSI) has been developed for total knee arthroplasty (TKA) with several potential advantages over traditional instrumentation (TI). Shortened surgical time, fewer surgical instruments, and improved alignment are some of these proposed advantages. We sought to examine these assertions.

52 patients (26 per group) were enrolled in a prospective, randomized trial comparing CT-based PSI with TI. No difference was seen in average patient age (68 years) or BMI (31) between groups (p=0.84 and p=0.89), although there were more males in the PSI group (14 vs 7, p=0.002). A single surgeon and consistent staff performed the surgeries with the same knee prostheses, and all cases were videotaped to measure the length of surgery and each individual step. Any additional bone cuts, size changes, or ligament releases made to achieve correct alignment and balance were documented. The number of instrument trays opened for each case was recorded. Postoperative long alignment and lateral radiographs were taken to measure the coronal and sagittal plane component alignment and mechanical axis in each patient.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Patient requires unilateral primary total knee arthroplasty

Exclusion criteria

  • Body mass index greater than 41
  • Previous ipsilateral hip or ankle replacement
  • Knee flexion contracture greater than 20 degrees

Treatment and study plan

Customized Patient Instrumentation

Device

Custom cutting guides based on computed tomography (CT) images of the patient's leg are used to make the bone cuts and select the implant size.

Traditional Instrumentation

Device

Traditional surgical instruments will be used to make bone cuts and size the components in this control group.

Primary outcomes

  1. Length of Surgery

    Time frame: 1 day

    Time elapsed from skin incision to wound closure (in seconds)

Secondary outcomes

  1. Length of Each Surgical Step (in Seconds)

    Time frame: 1 day

    surgical exposure, tibial alignment and resection, femoral distal cut, extension gap balancing, sizing the femur, 4 finishing femoral cuts, posterior releases, patellar resection, trial components, tibial tray preparation, cleanup/ prep for cement, cementing femur, cementing tibia, cementing patella, and closure

  2. Number of Instrument Trays Required

    Time frame: 1 day

  3. Limb Alignment (Mechanical Axis)

    Time frame: 4 months

    Alignment is measured on 4 month postoperative radiograph in degrees. The goal is a mechanical axis between and femur and tibia of 0 degrees. Varus alignment ("bow-legged") is shown as a negative number in degrees away from 0. Valgus alignment ("Knock-kneed") is expressed as a positive number in degrees away from 0.

Sponsors and collaborators

Lead sponsor

Anderson Orthopaedic Research Institute

Other

Registry information

Official study title

A Prospective, Randomized Evaluation of Total Knee Arthroplasty Performed With Conventional and Customized Patient Instrumentation

Acronym: CPI

Important dates

Study start
2010
Primary completion
2012
Study completion
2012
First posted
May 17, 2010
Registry last updated
Dec 18, 2013

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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