Skip to content

Pediatric and Adolescent Patellar Instability

Pediatric and Adolescent Patellar Instability

Status
Enrolling by invitation
Phases
Unknown
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT02333825
Acronym
PAPI
Enrollment
240
Registered
2015-01-07
Start date
2015-12-01
Completion date
2026-12-01
Last updated
2026-02-13

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Patellar Instability

Brief summary

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.

Detailed description

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.

Interventions

PROCEDUREMedial patellofemoral ligament reconstruction surgery

Medial patellofemoral ligament reconstruction surgery using hamstring autograft

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

Sponsors

Hospital for Special Surgery, New York
Lead SponsorOTHER
Mayo Clinic
CollaboratorOTHER
Oregon Health and Science University
CollaboratorOTHER
Inova Medical Group
CollaboratorUNKNOWN

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT

Eligibility

Sex/Gender
ALL
Age
8 Years to 25 Years
Healthy volunteers
No

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.

Design outcomes

Primary

MeasureTime frameDescription
Recurrence of patellar instability5 yearsThe 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

MeasureTime frameDescription
Kujala Scoring QuestionnairePreoperatively 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
Knee Injury and Osteoarthritis Outcome Score (KOOS)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
International Knee Documentation Committee (IKDC) Subjective Knee EvaluationPreoperatively 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
Hospital for Special Surgery Pediatric Functional Activity Brief ScalePreoperatively 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
Outerbridge grade of any cartilage lesionsMRI taken at initial exam, and for patients randomized to surgery only at 1 year and 5 years after surgery as wellOuterbridge 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

Contacts

PRINCIPAL_INVESTIGATORBeth E Shubin Stein, MD

Hospital for Special Surgery, New York

STUDY_CHAIRJacqueline Munch, MD

Oregon Health and Science University Hospital

STUDY_CHAIRDiane Dahm, MD

Mayo Clinic

STUDY_CHAIRRobin V West, MD

Inova Sports Medicine

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 14, 2026