Pediatric and Adolescent Patellofemoral Instability

IRB Number: 2014-087

Institutional Review Board, Hospital for Special Surgery

January 20, 2016

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Principal Investigator

Beth E. Shubin Stein, MD


Sabrina Strickland, MD  
Jacqueline Munch, MD
Douglas Mintz, MD  
Beth Shubin Stein, MD
Joseph Nguyen  
Irene Kalbian  
Theresa Chiaia, PT
Daniel Green, MD  
Gabrielle Mayer


This is a multi-center, randomized controlled clinical trial, the purpose of which is to determine if skeletally immature patients 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. A total of 240 patients will be enrolled across the following 8 sites: The Hospital for Special Surgery, Texas Scottish Rite Children’s Hospital, San Diego Children’s Hospital, Boston Children’s Hospital, Mayo Clinic, Cincinnati Children’s Hospital, and Oregon Health and Science University. 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.  We 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.

Inclusion/Exclusion Criteria

Inclusion Criteria: 

Patients must be skeletally immature, meaning that they are still growing
Patients must be first-time dislocators, meaning have had only one episode of patellar instability, during which they dislocated their patella (kneecap)           
Ages 8-18

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.

Contact Information

Beth E. Shubin Stein, MD