Medial Patellofemoral Ligament Reconstruction in Children - a 2-8 Years Follow-up Study (MPFL)

The purpose of this project is to investigate the treatment outcome after MPFL reconstruction in children as a treatment for chronic patellar instability, where the superficial part of the quadriceps tendon is fixed to the femur with anchors.

The outcome will be compared with a healthy cohort matched on age and gender.

Study Overview

• Status: Not yet recruiting
• Conditions: Medial Patellofemoral Dislocation; Medial Patellofemoral Ligament Reconstruction
• Intervention / Treatment: Other: MPFL-reconstruction

Detailed Description

Lateral patella dislocation (PL) is defined as a total dislocation of the patella out of the trochlea.

In chronic patella instability, where the patella has been repeatedly dislocated, the treatment is most often surgical. The main ligamentous structure that stabilizes the patella against lateralization is the medial patello-femoral ligament (MPFL). The MPFL is a centimeter-thin ligamentous structure that runs from the upper medial patellar border to the medial femoral epicondyle. This ligament is torn in more than 90% of cases of PL and healing of the ligament is often insufficient, especially if there are predisposing factors in the knee joint such as dysplasia of the patello-femoral joint, high standing patella (patella alta) and hypermobility.

MPFL reconstruction (MPFL-r) can be performed with many different surgical techniques, but the basic principle is to use autologous tendon tissue to create a new MPFL by anchoring the new tendon tissue to the medial patellar border and the medial femoral epicondyle, while ensuring isometry of the reconstruction.

A number of different methods have been described for anchoring the new MPFL to the patella and femoral condyle.

The most commonly used type of graft for MPFL-r is the gracilis tendon, which is fixed with screws in the femur bone preceded by drilling a channel in the femoral condyle.

In non-grown patients, the growth zone of the distal femur is very close to the anatomical attachment of the MPFL. This poses a problem as a reaming that hits the growth zone carries a theoretical risk of compromising growth around the knee.

In addition, up to 50% of patients describe pain at 1 year after surgery if screw fixation is used in the medial femoral condyle.

A new MPFL-r method using a superficial portion of the quadriceps tendon fixed with an anchor provides a good 2-year result compared to gracilis tendon and screw fixation.

The effectiveness and long-term efficacy of MPFL surgery with the quadriceps tendon for children is not well described in the literature.

At the Department of Sports Traumatology in Aarhus, Denmark, the quadriceps technique has been used on non-adult patients since 2016.

In this study, the investigators want to include the 80 patients who have undergone this MPFL-r since 2016 with the quadriceps tendon technique and have a minimum of 2 years of follow-up. This patient group will compared to a healthy cohort matched on age and gender.

• Study Type: Observational
• Enrollment (Estimated): 160

Contacts and Locations

• Study Contact: Name: Torsten G Nielsen, MHSc; Phone Number: +4540491184; Email: torsne@rm.dk
• Study Contact Backup: Name: Martin Lind; Phone Number: +4530248244; Email: martinlind@dadlnet.dk

Study Locations

• Denmark
  • Aarhus N, Denmark, 8200
    • Division of Sports Trauma, Palle Juul-Jensens Boulevard 99

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

Patients who have undergone MPFL quadriceps surgery as children in the period 2016-2022 at Aarhus University Hospital and have more than 2 years of follow-up. The patients will be 14-23 years old at the time of referral.

Description

Inclusion Criteria - Intervention group:

• MPFL-reconstruction with Quadriceps tendon graft
• Open physis at surgery date
• Minimum 2 years Follow up

Exclusion Criteria - Intervention group:

• More surgeries in index knee
• MPFL-r in opposite knee
• MPFL revision in index knee

Inclusion Criteria - Healthy group:

• No knee problems

Exclusion Criteria - Healthy group

• None
• No knee problems

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
MPFL reconstruction with quadriceps graft; Children with medial patellofemoral reconstruction operated with epiphyses sparing quadriceps technique from 2016-2022.	Other: MPFL-reconstruction; Children with patella dislocations are operated from 2016-2022 with a quadriceps knee cap stabilization technique.
Healthy Cohort; A healthy cohort matched on age (+/- 2 years) and gender

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Kujala (Anterior Knee Pain Scale)	Patient reported outcome score, 0=worst and 100=best	24 month

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Donor site morbidity score, 0=worst and 100=best	Patient reported outcome score	24 month
Numerical Rating Scale (NRS-pain score)	Patient reported outcome score, 0=Best and 10=worst	24 month
Tegner (Activity Score)	Patient reported outcome score, 0=worst and 10=best	24 month
Knee pain	Palpatory pain in relation to graft fixation in femur on a four-point likert scale (0=no pain, 1=mild pain, 2=moderate pain, 4=severe pain)	24 month
One-legged single hop for distance	Physical performance test	24 month
One-legged triple hop for distance	Physical performance test	24 month
Side-to-side hop test	Physical performance test	24 month
Quadriceps Strength test	Physical performance test. Hand held dynamometry	24 month
Gluteus Medius Strength test	Physical performance test. Hand held dynamometry	24 month

Collaborators and Investigators

• Sponsor: Aarhus University Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): March 1, 2024
• Primary Completion (Estimated): December 31, 2024
• Study Completion (Estimated): June 1, 2025

Study Registration Dates

• First Submitted: February 6, 2024
• First Submitted That Met QC Criteria: February 13, 2024
• First Posted (Actual): February 14, 2024

Study Record Updates

• Last Update Posted (Actual): February 14, 2024
• Last Update Submitted That Met QC Criteria: February 13, 2024
• Last Verified: February 1, 2024

More Information

Terms related to this study

• Keywords: MPFL, Knee, Medial Patellofemoral Ligament, Surgery
• Additional Relevant MeSH Terms: Wounds and Injuries; Joint Diseases; Musculoskeletal Diseases; Joint Dislocations
• Other Study ID Numbers: Danish EC: 1-10-72-299-21

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