Standardization and Reproducibility Regarding Scanning Procedures and Measurements of Weight-bearing Cone Beam CT in the Lower Extremity

Cone Beam CT (CBCT) of the knee is gaining interest, especially regarding patients suffering from patellofemoral instability. With this study we wish to investigate the day-to-day, test-retest reliability of weight bearing (WB) and non-weight bearing (NWB) CBCT of the knee in healthy participants and patients suffering from trochlear dysplasia. The participants and patients will be scanned in the following positions: 0° WB, 0° NWB, 20° WB, 20° NWB on two separate days. The trochlear dysplasia patients will furthermore be scanned 6 months postoperatively.

The aim is to develop af protocol on how to both position patients during weight bearing scannings as well as a protocol on how to prepare the cross sectional images before measurements.

Study Overview

• Status: Recruiting
• Conditions: Musculoskeletal Diseases
• Intervention / Treatment: Diagnostic test: Weight bearing CT

Detailed Description

We expect that scans performed with CBCT will show a clear change in the TT-TG distance when comparing scans performed in two different degrees of flexion of the knee. We expect a discrete change in the TT-TG distance between non-weight bearing and weight-bearing state of the same degree of flexion. We expect that other radiological targets for assessing patellofemoral instability, e.g. in trochlear dysplasia patients will change between the different scan situations. In addition, we expect that the TT-TG distance measurement method has a high reproducibility of intra- and in-terobserver variation as well as over time with repeated scans. The reproducibility is expected to be at least as good or above existing 2D measurement methods on conventional scans. In patients with trochlear dysplasia, a greater TT-TG distance is expected than in healthy controls. In addition, differences in TT-TG distance between flexion/extension as well as between non-weight bearing and weight bearing condition are expected to be greater than in healthy controls. In addi-tion, we expect to be able to detect a correlation between controlled changes in the position of the foot which will lead to passive changes in the TT-TG distance.

The purpose of the study is:

• To investigate changes in TT-TG distance in CBCT scans of the knee joint, in healthy con-trols as well as in trochlear dysplasia patients, in two predefined degrees of flexion (0 ° i.e. fully stretched position; 20 ° flexion), in respectively weight-bearing loaded and unloaded position
• To investigate the day-to-day reliability of the measured TT-TG distance, knee flexion angle and other radiological measurements regarding patellofemoral instability, at two separate CBCT scan sessions in patients with trochlear dysplasia compared with healthy controls
• To investigate changes in the TT-TG distance in trochlear dysplasia patients before and after surgery in terms of evaluation of the patellofemoral instability

• Study Type: Observational
• Enrollment (Anticipated): 40

Contacts and Locations

• Study Contact: Name: Signe Brinch, MD; Phone Number: 28299718; Email: signe.brinch@regionh.dk
• Study Contact Backup: Name: Philip Hansen, MD, PhD; Phone Number: 21232666; Email: philip.hansen.02@regionh.dk

Study Locations

• Denmark
  • Copenhagen, Denmark, 2000
    • Recruiting
    • Dept. of Radiology, Bispebjerg-Frederiksberg Hospital
    • Contact: Philip Hansen, MD, PhD; Phone Number: 21232666; Email: philip.hansen.02@regionh.dk
    • Contact: Signe Brinch, MD; Phone Number: 28299718; Email: signebrinch@gmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 39 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Healthy participants recruited amongst employees in the ER, Bispebjerg-Frederiksberg Hospital Trochlear dysplasia patients selected from the sports surgery unit, Bispebjerg-Frederiksberg Hospital

Description

Inclusion Criteria:

Substudy 1 Healthy Male or female aged 18-39 years Must be able to stand on one leg for 30 seconds

Substudy 2 Diagnosed with trochlear dysplasia, in addition healthy Male or female aged 18-39 years Patients scheduled to either a trochlear plastic surgery + MPFL reconstruction or Elmslie-Trillat + MPFL reconstruction + trochlear plastic surgery Must be able to stand on one leg for 30 seconds

Exclusion Criteria:

Substudy 1 Current knee injury and / or knee pain. Known rheumatoid and / or connective tissue disease. Previous treatment requiring knee injury and / or knee surgery. Pregnancy

Substudy 2 Known rheumatoid and / or connective tissue disease Previous treatment requiring knee injury and / or knee surgery. Patients who need distalization Pregnancy

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Other

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Healthy; Weight bearing CT in fully extended and flexed (20 degrees) position, loaded and unloaded, respectively.	Diagnostic test: Weight bearing CT; Weight bearing CT in loaded and unloaded positions
Trochlear dysplasia; Weight bearing CT in fully extended and flexed (20 degrees) position, loaded and unloaded, respectively.	Diagnostic test: Weight bearing CT; Weight bearing CT in loaded and unloaded positions

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Measurement of patellofemoral indices	Intra and interrater reliability and day to day repeatability	1 year

Collaborators and Investigators

• Sponsor: Bispebjerg Hospital
• Investigators: Principal Investigator: Signe Brinch, MD, Bispebjerg Frederiksberg Hospital

Study record dates

Study Major Dates

• Study Start (Actual): September 1, 2021
• Primary Completion (Anticipated): May 15, 2023
• Study Completion (Anticipated): September 15, 2023

Study Registration Dates

• First Submitted: June 21, 2022
• First Submitted That Met QC Criteria: June 21, 2022
• First Posted (Actual): June 27, 2022

Study Record Updates

• Last Update Posted (Actual): June 27, 2022
• Last Update Submitted That Met QC Criteria: June 21, 2022
• Last Verified: June 1, 2022

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Musculoskeletal Diseases
• Other Study ID Numbers: H-20068116

Drug and device information, study documents

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