Influence of Knee Alignment and Pelvis Rotation on Accuracy of Radiograph Measurements Before Total Knee Arthroplasty

The Influence of Lower Extremity and Pelvic Alignment on Accuracy of Hip-Knee-Ankle Radiograph Measurements Before Total Knee Arthroplasty

The aim of this study is to determine the accuracy of long leg standing X-rays with respect to coronal alignment of the knee.

Study Overview

• Status: Completed
• Conditions: Knee Osteoarthritis
• Intervention / Treatment: Radiation: CT scan

Detailed Description

Long leg standing x-ray is a routine examination to measure the femoral valgus angle before a total knee arthroplasty. Newer studies have shown that coronal leg alignment influences the rotation of the distal femoral part. This rotation might influence the measurements obtained with a long leg standing x-ray.

The primary purpose of this study is to determine whether there is a significant difference between 2D measurements taken on the x-ray and 3D measurements obtained with a CT scan.

• Study Type: Observational
• Enrollment (Actual): 112

Contacts and Locations

Study Locations

• Slovenia
  • Ankaran, Slovenia, 6820
    • Orthopaedic Hospital Valdoltra

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 50 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

All patients that require primary knee replacement will be enrolled in the study. Patients with prevoius surgery that might had already changed the leg aligment (hip/knee artroplasty, osteotomy) or patients with previous leg deformity are not eligible for the enrolment. Women in reproductive age are also not eligible.

Description

Inclusion Criteria:

Knee osteoarthritis scheduled for knee arthroplasty

Exclusion Criteria:

• previous leg deformities or surgery that changes alignment

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Group; All patients scheduled for a total knee arthroplasty without any previous lower limb deformities or previous hip/knee surgery will be enrolled. A long leg standing x-ray and a CT scan of the lower limb will be obtained for every patient.	Radiation: CT scan; CT of the lower limb

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The angle difference between an x-ray and a CT scan	The femoral valgus angle, femoral mechanical angle, tibial mechanical angle and hip knee ankle angle are measured separately on the x-ray and on the CT scan. The difference in individual angle is the calculated.	Before surgery

Collaborators and Investigators

• Sponsor: Valdoltra Orthopedic Hospital
• Investigators: Principal Investigator: Andrej Strahovnik, Valdoltra Orthopaedic Hospital

Study record dates

Study Major Dates

• Study Start (Actual): December 1, 2022
• Primary Completion (Actual): December 25, 2024
• Study Completion (Actual): December 25, 2024

Study Registration Dates

• First Submitted: March 3, 2022
• First Submitted That Met QC Criteria: March 3, 2022
• First Posted (Actual): March 14, 2022

Study Record Updates

• Last Update Posted (Actual): March 30, 2025
• Last Update Submitted That Met QC Criteria: March 25, 2025
• Last Verified: December 1, 2024

More Information

Terms related to this study

• Keywords: total knee arthroplasty; knee aligment; coronal alignment of the lower limb; x-ray accuracy
• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Arthritis; Joint Diseases; Rheumatic Diseases; Osteoarthritis; Osteoarthritis, Knee
• Other Study ID Numbers: Valdoltra - x-ray accuracy

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No