Patellar Stability After MPFL Reconstruction With Fascia Lata Allograft: Conventional CT vs Under Weight-bearing CT

May 29, 2023 updated by: Istituto Ortopedico Rizzoli

Assessment of Patellar Stability in Patients Who Underwent Reconstruction of the Medium Patello-femoral Ligament With Fascia Lata Allograft: Comparison Between Conventional CT and Under Weight-bearing CT

The objective of the present study is to compare the stability and alignment of the patella in patients with previous recurrent dislocation treated with medial patellar femoral ligament reconstruction with fascia lata allograft, 5 years after surgery by conventional CT and by CT under weight-bearing.

Conventional CT will be performed with the patient supine, the knee fully extended and with the muscles of the thigh and leg completely relaxed. On the same day, the patient will undergo a CT scan of the knee under weight-bearing with the Cone Beam Computed Tomography (CBCT) scanner system.

The CT images will be viewed through the PACS system by two independently expert radiologists who will measure the tilt, congruence angles and the TT-TG with the methodical notes described in the literature.

The use of a CT under weight-bearing allows for the first time to evaluate in a realistic way the stability and tracking of the patella, with the knee flexed and therefore with the activation of the quadriceps muscle.

Study Overview

Status

Active, not recruiting

Conditions

Intervention / Treatment

Detailed Description

Patellofemoral disorders make up about 20% of all knee pathologies and are often a source of diagnostic and therapeutic doubts for the orthopedic surgeon. The incidence of patella dislocation is estimated to be 5.8 cases per 100,000 people, with values that become five times higher in patients aged between 10 and 17 years. Conservative treatment is preferable in the first case of acute dislocation, however the recurrence of this episode occurs in a percentage equal to 15 - 44% in these subjects.

Many surgical interventions have been described to correct the various factors that predispose to patellofemoral instability, with variable success rates (72% with the Hauser technique and 93% with the Roux-Goldthwait technique, 73% with that of Fielding and 78% with that of Trillat after a long follow-up.

The medial patello-femoral ligament (MPFL) is one of the main stabilizers of the patella in its movement on the femur; numerous studies have recently shown that this ligament is damaged in almost all cases, thus recognizing the role of the structure that most limits the patella in its lateral dislocation to the MPFL. Following these studies, the reconstruction of the MPFL as an elective treatment for relapsing patella dislocation has been recently proposed with countless surgical techniques that use various types of grafts: autologous tendons (the first in 1990 by Suganuma et al), tendons from donor (allograft) and synthetic ligaments.

Our team recently developed a minimally invasive MPFL reconstruction technique using an allograft tendon of the fascia lata with the aim of stabilizing the patella and limiting the patellofemoral arthritic degeneration in the medium to long term.

The imaging evaluation of instability and correct alignment of the patella, both in the pre-operative and in the post-surgery, is normally performed using magnetic resonance imaging or conventional CT. The CT offers the advantage of being able to make a very accurate morphological evaluation and therefore to be able to calculate with great precision the degrees of the tilt angle of the patella, the subluxation and the distance between the tibial tuberosity and the center of the trochlear sulcus (TT-TG ). The big limit of this method is that the patient is acquired supine, with the knee extended and with the muscles of the leg relaxed while it is well known how the knee flexion and the contraction of the quadriceps muscle possible in load, significantly affect the tracking of the patella on the trochlea. In literature, numerous studies show that the acquisition of the lying patient removes these determining factors (Callaghan; Draper; Tanaka) by altering the assessment of instability and malalignment. In a recent study by Marzo et al. it has been shown that in subjects suffering from instability of the patella, the evaluation under weight-bearing and with knee flexed by CT (CBCT Carestream) shows lower tilt angles, congruence and TT-TG than the evaluation in load and therefore the evaluation under load of the patellar alignment is more adequate to evaluate with precision these parameters.

The objective of the present study is to compare the stability and alignment of the patella in patients with previous relapsing dislocation treated with reconstruction surgery by means of a medial patellar ligament with lata band allograft 5 years after surgery by conventional CT and by CT under weight-bearing.

The assessments are carried out in a group of 20 patients with previous recurrent patella dislocation who underwent reconstruction surgery between 2012 and 2013 via a medial patello-femoral ligament with fascia lata allograft at the Orthopedic and Traumatologic Clinic 2nd of the Rizzoli Orthopedic Institute. The patients will be contacted by phone and a follow-up visit will be scheduled which is normally carried out 5 years after the operation to evaluate the stability of the patella and therefore the patient's clinical condition. The patient will undergo a clinical examination and radiological control with conventional CT at the Rizzoli Orthopedic Institute. Conventional CT will be performed with the patient supine, the knee fully extended and with the muscles of the thigh and leg completely relaxed. On the same day, the patient will undergo a CT scan of the knee under weight-bearing with the Cone Beam Computed Tomography (CBCT) scanner system.The CT images will be viewed through the PACS system by two independently expert radiologists who will measure the tilt, congruence angles and the TT-TG with the methodical notes described in the literature.

The use of a CT under weight-bearing allows for the first time to evaluate in a realistic way the stability and tracking of the patella, with the knee flexed and therefore with the activation of the quadriceps muscle.

Study Type

Interventional

Enrollment (Estimated)

20

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • Italy
      • Bologna, Italy, 40136
        • IRCCS Istituto Ortopedico Rizzoli

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Who is able to provide informed consent and who agrees to sign the Informed Consent Form approved by the Ethics Committee (EC).
  • Subject who underwent reconstruction of the MPFL using a minimally invasive technique using a fascia fascia allograft, performed at the Rizzoli Orthopedic Institute between 2012 and 2013 by the team of Prof. Zaffagnini.

Exclusion Criteria:

  • patients with severe morphostructural deformities or other pathologies affecting the knee and lower limb
  • patients with serious systemic vascular and neurological pathologies
  • patients unable to perform a CT scan under weight-bearing
  • State of pregnancy.
  • Obese or with body mass index BMI> 30 kg / m2.
  • Association of Trocleoplasty (intervention that produces degenerative changes of the joint in high percentage)

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Diagnostic
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: MPFL reconstructed
20 patients with previous recurrent patella dislocation who underwent MPFL reconstruction surgery with fascia lata allograft between 2012 and 2013
Diagnostic test: CT scan of the knee under weight-bearing with the Cone Beam Computed Tomography (CBCT) scanner system.
The patient will be evaluated under weight-bearing, with knee flexed at 30 ° and therefore with contracted thigh muscles. The measurement and maintenance of the 30 ° of flexion will be controlled by a goniometer applied laterally to the knee and fixed by means of an elastic band.
Diagnostic test: Conventional CT scan
The patient will be evaluated in supine position, with the muscles relaxed and the knee in full extension by conventional CT scan

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Patellar Tilt Angle
Time Frame: 24 months
The tilt angle is defined as the angle subtended by a line joining the medial and lateral edges of the patella and the horizontal plane on the axial plane, measured both by conventional CT scan with the knee extended and by CT scan under weight bearing conditions with the knee flexed at 30°.
24 months
Patellar Congruence Angle
Time Frame: 24 months
Angle made by a line parallel to the posterior condyles and the line joining the edges of the patella on the axial plane, measured under weight-bearing with knee flexed at 30° and supine with knee extended.
24 months
Tibial tuberosity-trochlear groove distance
Time Frame: 24 months
Radiographic parameter measured by CT scan both under weight-bearing with knee flexed at 30° and supine with knee extended.
24 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Istituto Ortopedico Rizzoli

Investigators

  • Principal Investigator: Giada Lullini, MD, IRCCS Istituto Ortopedico Rizzoli

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

February 26, 2019

Primary Completion (Actual)

May 26, 2023

Study Completion (Estimated)

February 26, 2024

Study Registration Dates

First Submitted

January 20, 2020

First Submitted That Met QC Criteria

January 24, 2020

First Posted (Actual)

January 27, 2020

Study Record Updates

Last Update Posted (Actual)

May 31, 2023

Last Update Submitted That Met QC Criteria

May 29, 2023

Last Verified

May 1, 2023

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • CBCT-MPFL

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

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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