Patellofemoral instability (PFI) is a debilitating condition common in pediatric patients. One of the most common causes is an abnormal development of the trochlea. Despite its critical role, little is known about how the trochlea develops in children and when dysplastic (abnormally shallow or flat trochlea) changes occur.
Researchers at Children’s Hospital of Philadelphia (CHOP) recently published a landmark study exploring how trochlear morphology evolves in skeletally immature patients. Using consecutive MRI imaging over several years, they uncovered significant differences in trochlear development between children with and without PFI.
Research highlights
Led by orthopedic surgeons and a radiology research team including Brendan A. Williams, MD, J. Todd Lawrence, MD, PhD, and Jie Chen Nguyen, MD, MS, this study analyzed 128 pediatric patients including 98 with PFI and 30 without. The team reviewed the MRIs of each patient at two separate time points to evaluate a variety of measurements and assessments that quantify the severity of trochlear dysplasia.
Key findings:
- 1. Worsening dysplasia in patients with patellar instability:
- Children with PFI demonstrated increasing severity of trochlear dysplasia over time with more shallow or convex-shaped (less stable) trochlear grooves.
- Quantitative measures, such as sulcus angle, worsened over time, reflecting a shallower and more unstable trochlea.
- 2. Improvement in patients without patellar instability:
- Patients without PFI had more normally shaped trochlea that became less dysplastic as they grew. These patients had a deeper and more stable trochlea.
- 3. Implications for treatment:
- The findings suggest that interventions aimed at stabilizing the patella could prevent or slow the progression of dysplasia; however, more research is required on this topic.
Clinical relevance
Trochlear dysplasia is the strongest risk factor for recurrent patellar dislocations, which can lead to chronic knee pain, limited mobility and even the early development of arthritic changes of the knee. By showing that trochlear morphology can change during adolescence, this study emphasizes the importance of early and proactive management of PFI and may have implications for treatment guidelines for these patients.
“Understanding the relationship between patellar instability and trochlear development is critical to improving care for these young patients,” said Dr. Williams. “Our research highlights the potential to intervene during a crucial period of skeletal growth to optimize long-term outcomes.”
Looking ahead
The CHOP team’s findings add to a growing body of evidence that the patellofemoral joint is dynamic during childhood and adolescence. Future studies will explore whether early stabilization techniques, such as medial patellofemoral ligament (MPFL) reconstruction, can promote normal trochlear development and prevent recurrent instability.
Contact us
For more information about CHOP’s orthopedic research or to learn about treatment options for patellofemoral instability, visit CHOP’s Orthopedic Center and Sports Medicine and Performance Center. Together, we’re advancing the science of pediatric orthopedics to give children the best chance at a healthy, active future.
Featured in this article
Experts
Specialties & Programs
Patellofemoral instability (PFI) is a debilitating condition common in pediatric patients. One of the most common causes is an abnormal development of the trochlea. Despite its critical role, little is known about how the trochlea develops in children and when dysplastic (abnormally shallow or flat trochlea) changes occur.
Researchers at Children’s Hospital of Philadelphia (CHOP) recently published a landmark study exploring how trochlear morphology evolves in skeletally immature patients. Using consecutive MRI imaging over several years, they uncovered significant differences in trochlear development between children with and without PFI.
Research highlights
Led by orthopedic surgeons and a radiology research team including Brendan A. Williams, MD, J. Todd Lawrence, MD, PhD, and Jie Chen Nguyen, MD, MS, this study analyzed 128 pediatric patients including 98 with PFI and 30 without. The team reviewed the MRIs of each patient at two separate time points to evaluate a variety of measurements and assessments that quantify the severity of trochlear dysplasia.
Key findings:
- 1. Worsening dysplasia in patients with patellar instability:
- Children with PFI demonstrated increasing severity of trochlear dysplasia over time with more shallow or convex-shaped (less stable) trochlear grooves.
- Quantitative measures, such as sulcus angle, worsened over time, reflecting a shallower and more unstable trochlea.
- 2. Improvement in patients without patellar instability:
- Patients without PFI had more normally shaped trochlea that became less dysplastic as they grew. These patients had a deeper and more stable trochlea.
- 3. Implications for treatment:
- The findings suggest that interventions aimed at stabilizing the patella could prevent or slow the progression of dysplasia; however, more research is required on this topic.
Clinical relevance
Trochlear dysplasia is the strongest risk factor for recurrent patellar dislocations, which can lead to chronic knee pain, limited mobility and even the early development of arthritic changes of the knee. By showing that trochlear morphology can change during adolescence, this study emphasizes the importance of early and proactive management of PFI and may have implications for treatment guidelines for these patients.
“Understanding the relationship between patellar instability and trochlear development is critical to improving care for these young patients,” said Dr. Williams. “Our research highlights the potential to intervene during a crucial period of skeletal growth to optimize long-term outcomes.”
Looking ahead
The CHOP team’s findings add to a growing body of evidence that the patellofemoral joint is dynamic during childhood and adolescence. Future studies will explore whether early stabilization techniques, such as medial patellofemoral ligament (MPFL) reconstruction, can promote normal trochlear development and prevent recurrent instability.
Contact us
For more information about CHOP’s orthopedic research or to learn about treatment options for patellofemoral instability, visit CHOP’s Orthopedic Center and Sports Medicine and Performance Center. Together, we’re advancing the science of pediatric orthopedics to give children the best chance at a healthy, active future.
Recommended reading
A Return to Baseball
Months after knee surgery at CHOP, Sam hit two homeruns for his baseball team in one game.
Contact us
Orthopedic Center