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Enrolling by Invitation

NCT Number: NCT02333825

Pediatric and Adolescent Patellar Instability

This is a multi-center, randomized controlled clinical trial, the purpose of which is to determine if patients age 25 and younger who undergo medial patellofemoral ligament (MPFL) reconstruction have lower rates of recurrent instability compared to those treated non-operatively. The MPFL is a ligament that stabilizes the kneecap, and maintains its proper position in the groove on the femur (thighbone). Instability refers to a situation in which the kneecap moves out of place, or dislocates. When instability is recurrent, it occurs more than once in the same knee.

Enrolling by Invitation

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Key information

Conditions

Patellar Instability

Age range

8 year–25 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

About this study

A total of 240 patients will be enrolled across participating sites around the country. These sites currently include: The Hospital for Special Surgery, Oregon Health and Science University, Inova Sports Medicine, and Mayo Clinic. Patients are randomly assigned to one of two treatment groups. Patients assigned to the "stabilization" group will undergo surgery to reconstruct the MPFL using either a hamstring tendon that is your own or one obtained from a donor. Patients assigned to the "conservative" group will be treated with physical therapy, and possibly a simple knee arthroscopy if you are found to have a loose fragment on x-ray or MRI. All patients will be required to return for follow-up visits, which will continue over the course of 5 years. During these visits, patients will be examined, asked to answer questions about their surgery and general health, and have imaging (x-ray and MRI) performed on the knee. All patients enrolled in this study will undergo a standardized, intensive rehabilitation protocol. The investigators anticipate that all patients may benefit from extensive rehabilitation, including strengthening and return to sport training. The knowledge gained from this study may benefit others in the future.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Patients must be age 25 or younger
  • Patients must be first-time dislocators, meaning have had only one episode of patellar instability, during which they dislocated their patella (kneecap)

Exclusion criteria

  • Patients with more than one episode of patellofemoral instability
  • Patients who have had prior patellofemoral surgery on the knee of interest
  • Patients with large cartilage tears in the knee. These patients will undergo stabilization of the patellofemoral joint (MPFL reconstruction) as per standard of care, and will not be included in the study.

Treatment and study plan

Medial patellofemoral ligament reconstruction surgery

Procedure

Medial patellofemoral ligament reconstruction surgery using hamstring autograft

Other names: CPT code: 27427

Physical therapy and rehabilitation

Other

A standardized physical therapy and rehabilitation program to be administered and guided by rehab specialists

Primary outcomes

  1. Recurrence of patellar instability

    Time frame: 5 years

    The primary outcome is recurrent episode of patellar instability within 5 years following the primary patellofemoral dislocation event. A preliminary analysis will be performed at 2 years to examine for any early results of the study. Patellar instability will be defined as any patient-reported episode of subluxation or dislocation following the index event. Subluxation or dislocation will be defined as a feeling of dissociation of the patella from its trochlear groove. Subluxation will be noted if the patella spontaneously reduces into the groove, and dislocation will be noted if the patella requires any change in position or force (i.e. extending the knee or exerting a medially-directed force on the patella) in order to reduce into its trochlear groove. (Apprehension will not be classified as subluxation unless the patient specifically notes a sensation of departure of the patella from its trochlear groove at some point during the experience.)

Secondary outcomes

  1. Kujala Scoring Questionnaire

    Time frame: Preoperatively and at 1 year, 2 years, 3 years, 4 years, and 5 years after treatment.

    The Kujala Scoring Questionnaire is a validated patient reported outcome measure

  2. Knee Injury and Osteoarthritis Outcome Score (KOOS)

    Time frame: Preoperatively and at 1 year, 2 years, 3 years, 4 years, and 5 years after treatment.

    The KOOS is a validated patient reported outcome measure

  3. International Knee Documentation Committee (IKDC) Subjective Knee Evaluation

    Time frame: Preoperatively and at 1 year, 2 years, 3 years, 4 years, and 5 years after treatment.

    The IKDC Subjective Knee Evaluation is a validated patient reported outcome measure

  4. Hospital for Special Surgery Pediatric Functional Activity Brief Scale

    Time frame: Preoperatively and at 1 year, 2 years, 3 years, 4 years, and 5 years after treatment.

    The Hospital for Special Surgery Pediatric Functional Activity Brief Scale is a validated patient reported outcome measure

  5. Outerbridge grade of any cartilage lesions

    Time frame: MRI taken at initial exam, and for patients randomized to surgery only at 1 year and 5 years after surgery as well

    Outerbridge grade will be used to describe the severity of articular cartilage lesions at initial presentation and for surgical patients, 1 and 5 years after treatment as well

Sponsors and collaborators

Lead sponsor

Hospital for Special Surgery, New York

Other

Collaborators

  • Inova Medical Group
  • Mayo Clinic
  • Oregon Health and Science University

Registry information

Acronym: PAPI

Important dates

Study start
2015
Primary completion
2026
Study completion
2026
First posted
Jan 7, 2015
Registry last updated
Feb 13, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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