The Influence of Coronally Knee Alignment on the Tibial Tuberosity Rotation

The Relationship of Radiological Lower Limb Alignment and Grade of the Knee Osteoarthritis With the Position of the Tibial Tuberosity

The primary aim of this study is to find a possible correlation between tibial tuberosity rotation and coronal leg alignment. If correlation exists, a more individual tibial component rotation might be proposed during a total knee arthroplasty.

Study Overview

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

Detailed Description

A malalignment of the tibial component is a possible source of pain after a total knee arthroplasty. Currently, an internal rotation of the tibial component of 18 degrees is considered as a golden standard. The value was obtained as an average rotation in the osteoarthritic knees scheduled for a total knee arthroplasty.

It is known that the femur internally rotates with the increasing valgus alignment. It would seem logical that also tibial rotation correlates with the coronal limb alignment (varus-valgus). The plan is to measure the native tibial rotation (angle between the transposed epicondylar line and the posterior cruciate-tibial tuberosity line). In order to get the necessary accuracy a CT of lower legs will be obtained in patients waiting for the knee replacement. If there is a correlation between the angles the adjustment of the tibial component rotation more to the patient's anatomy could be proposed.

A secondary outcome measure is the possible correlation between the proximal femoral anteversion and the tibial tuberosity rotation. The hypothesis is that the extensor mechanism follows the proximal femoral orientation. With increasing femoral anteversion (increases with valgus angle) the femoral part of the knee rotates internally. In order to keep the extensor mechanism in the direction of walking, a more lateralized position of the tibial tuberosity is expected.

• Study Type: Observational
• Enrollment (Actual): 200

Contacts and Locations

Study Locations

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

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Patients waiting for the knee arthroplasty will be asked to participate. Patients with pre-existing deformities will not be enrolled. Additionally, women in reproductive age will also not be enrolled to avoid unnecessary radiation risks.

Description

Inclusion Criteria:

• patients requiring knee arthroplasty

Exclusion Criteria:

• women in reproductive age, patients with leg deformities and previous hip/knee surgery

Study Plan

How is the study designed?

Design Details

• Observational Models: Case-Only
• Time Perspectives: Prospective

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Group; A CT scan of both legs will be made in patient scheduled for a primary knee arthroplasty. No other additional intervention will be made apart from those already routinely used for the operation.	Radiation: CT scan; CT of lower leg

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Correlation between coronal alignment and tibial tuberosity rotation	A hip-knee-ankle angle and a tibial rotation angle (angle between the transposed epicondylar line) will be calculated from the CT scan of the leg. A correlation between both angles will be analysed using the Spearmans's coefficient.	Before surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Correlation between femoral anteversion and tibial tuberosity position	A femoral anteversion angle (angle between femoral hip neck and posterior condylar knee line) and tibial tuberosity position (angle between posterior condylar line and posterior cruciate - tibial tuberosity line) will be measured and examined for correlation using a Spearman's coefficient.	Before surgery
Difference in tibial tuberosity position according to the osteoarthritis grade	Tibial tuberosity position will be compared according to the Kellgren-Lawrence grade with the ANOVA	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, 2021
• Primary Completion (Actual): December 15, 2023
• Study Completion (Actual): January 1, 2024

Study Registration Dates

• First Submitted: March 15, 2022
• First Submitted That Met QC Criteria: March 15, 2022
• First Posted (Actual): March 25, 2022

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: February 26, 2025
• Last Verified: March 1, 2023

More Information

Terms related to this study

• Keywords: knee arthroplasty; knee alignment; tibial component rotation
• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Arthritis; Joint Diseases; Rheumatic Diseases; Osteoarthritis; Osteoarthritis, Knee
• Other Study ID Numbers: Valdoltra - TT rotation

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