Magnetic Resonance Imaging Findings After Acute Patellar Dislocation in Children.

Area of Science:

• Pediatric Orthopedics
• Sports Medicine
• Knee Injuries

Background:

• Acute patellar dislocation (APD) is a frequent knee injury in children.
• Medial patellofemoral ligament (MPFL) injury patterns differ between pediatric and adult populations.

Purpose of the Study:

• To characterize MPFL injury patterns in pediatric APD.
• To evaluate if adult-predisposing factors for APD are relevant in children.

Main Methods:

• Retrospective review of MRI scans for 36 children with APD.
• Documentation of MPFL injury, tear location, and associated factors like trochlear dysplasia, patella alta, TTTG distance, and LPR thickness.

Main Results:

• Only 16 of 36 children sustained an MPFL tear.
• MPFL tears occurred at the origin, insertion, or both, with no midsubstance tears.
• Significant correlation found between MPFL rupture and LPR thickness >3mm or TTTG distance >19mm.

Conclusions:

• MPFL tears are not universal in pediatric APD and exhibit variable locations.
• Thickened LPR and increased TTTG distance are predisposing factors for MPFL tears in children.