Novel Method for Diagnosing Lateral Patellar Compression Syndrome Using X-ray: a Retrospective Case-Control Study

This study evaluates whether the patellar axial radiograph of lateral patellar curvature angle （LPCA）with knee flexion at 30 ° can be used as a new diagnostic surrogate of lateral patellar compression syndrome（LPCS）. We believe that the new index LPCA has high sensitivity and specificity in initial diagnosis of LPCS using axial patellar radiograph with knee flexion at 30 ° , and has high application value.

Study Overview

• Status: Completed
• Conditions: Lateral Patellar Compression Syndrome
• Intervention / Treatment: Other: no intervention

Detailed Description

Background: A well-established reference is lacking for diagnosing lateral patellar compression syndrome (LPCS), and this diagnosis currently depends on clinicians' subjective judgment and several examination results. X-rays are primarily used to diagnose LPCS, but they have low detection rates of patellar tilt using the congruence angle (CA) and patellar tilting angle (PTA).

Purpose: To investigate whether patellar axial radiography of the lateral patellar curvature angle (LPCA) of knee in 30° flexion can diagnose LPCS.

Methods: We enrolled 87 patients between 2016 and 2019 and divided them as per diagnosis into three groups of 29 each: LPCS, patellar dislocation (PD, control), and meniscus tear (MT, negative control) groups. A senior radiologist and the chief physician of sports medicine examined their patellar axial radiographs of the knee in 30° flexion using a computer imaging system, measuring LPCA, PTA, and CA. Univariate analysis of variance and Kruskal-Wallis H test were used to compare measurement data with normal distribution and non-normal distribution, respectively. Bonferroni correction was used to analyze different indicators for different groups. The area under the curve (AUC) was calculated to verify the value of LPCA in initial diagnosis of LPCS.

• Study Type: Observational
• Enrollment (Actual): 87

Contacts and Locations

Study Locations

• China
  • Beijing
    • Beijing, Beijing, China, 100191
      • Peking University Third Hospital

Participation Criteria

Eligibility Criteria

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

• Sampling Method: Non-Probability Sample

Study Population

We enrolled 87 patients between 2016 and 2019 and divided them as per diagnosis into three groups of 29 each: LPCS, patellar dislocation (PD, control), and meniscus tear (MT, negative control) groups.

Description

Inclusion Criteria:

• Patients were diagnosed as LPCS ，MT and PD respectively

Exclusion Criteria:

• patients with ligament injury, malunion of patella fracture, free bodies in the joint, surgical contraindications, and with both knees affected.

Study Plan

How is the study designed?

Design Details

• Observational Models: Case-Control
• Time Perspectives: Retrospective

Number of groups / cohorts

3

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Lateral patellar compression syndrome; Patients diagnosed with lateral patellar compression syndrome between February 2016 and April 2019	Other: no intervention; This is an observation study,with no intervention
patellar dislocation; Patients diagnosed with patellar dislocation between February 2016 and April 2019	Other: no intervention; This is an observation study,with no intervention
meniscus tear; Patients diagnosed with meniscus tear between February 2016 and April 2019	Other: no intervention; This is an observation study,with no intervention

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
lateral patellar curvature angle	lateral patellar curvature angle in three groups was compared	between 2016 and 2019

Collaborators and Investigators

• Sponsor: Peking University Third Hospital
• Investigators: Study Chair: Yang Yu-ping, Peking University Third Hospital

Study record dates

Study Major Dates

• Study Start (Actual): March 22, 2020
• Primary Completion (Actual): April 22, 2020
• Study Completion (Actual): May 22, 2020

Study Registration Dates

• First Submitted: June 29, 2020
• First Submitted That Met QC Criteria: June 30, 2020
• First Posted (Actual): July 1, 2020

Study Record Updates

• Last Update Posted (Actual): July 1, 2020
• Last Update Submitted That Met QC Criteria: June 30, 2020
• Last Verified: June 1, 2020

More Information

Terms related to this study

• Keywords: Lateral patellar compression syndrome; Lateral patellar curvature angle; Patellar axial radiographs; The area under the curve
• Additional Relevant MeSH Terms: Pathologic Processes; Disease; Syndrome
• Other Study ID Numbers: M2019464

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