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Pediatric and Adolescent Patellar Instability

Not Applicable
Conditions
Patellar Instability
Interventions
Procedure: Medial patellofemoral ligament reconstruction surgery
Other: Physical therapy and rehabilitation
Registration Number
NCT02333825
Lead Sponsor
Hospital for Special Surgery, New York
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.

Recruitment & Eligibility

Status
ENROLLING_BY_INVITATION
Sex
All
Target Recruitment
240
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.

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Surgical InterventionMedial patellofemoral ligament reconstruction surgeryThe surgical intervention to be studied in this arm is medial patellofemoral ligament reconstruction surgery using hamstring tendon. The tendon used will generally consist of autograft semitendinosus. If the hamstrings have been previously harvested or injured (i.e. in the setting of anterior cruciate ligament reconstruction or proximal tibial surgery), or if the patient/his or her family prefers to minimize donor site morbidity, allograft may be used.
Conservative treatmentPhysical therapy and rehabilitationThe intervention to be studied in this arm is a rehabilitation program directed by physical therapists. If patients in this arm are found to have a small loose body, a simple arthroscopy will be performed to remove the loose body, but no stabilization of the patellofemoral joint will be performed. The rehabilitation program will be compiled into a booklet and distributed for use by the physical therapist chosen by the patient.
Primary Outcome Measures
NameTimeMethod
Recurrence of patellar instability5 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 Outcome Measures
NameTimeMethod
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

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

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

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 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

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