Hip Morphology in MPS-1H Patients: An MRI-based Study

Area of Science:

• Orthopedics
• Medical Imaging
• Genetics

Background:

• Hip dysplasia is a common complication in mucopolysaccharidosis type-1H (MPS-1H).
• The precise hip morphology in MPS-1H patients remains incompletely understood.
• No prior studies have utilized magnetic resonance imaging (MRI) to investigate hip morphology in MPS-1H.

Purpose of the Study:

• To enhance the understanding of hip dysplasia pathology in MPS-1H patients.
• To describe the hip morphology using MRI, plain radiographs, and arthrograms.

Main Methods:

• A retrospective chart review of 18 MPS-1H patients was conducted.
• Analysis included 36 hip plain radiographs and 18 hip MRI scans.
• Six hip arthrograms were also reviewed.

Main Results:

• Plain radiographs showed a mean acetabular index (AI) of 36.2 degrees and a mean migration percentage of 59.0%.
• MRI confirmed the mean AI (39.1 degrees) and revealed increased cartilaginous (22.4 degrees) and labral (13.5 degrees) AI.
• Radiographs and MRI indicated negative center-edge angles, with MRI yielding more negative values (-19.6 degrees).

Conclusions:

• This study presents the first MRI-based description of hip morphology in MPS-1H patients.
• Cartilaginous hip coverage is increased in MPS-1H patients compared to healthy children.
• MRI and arthrograms are recommended for accurate assessment, especially when considering surgery, as radiography alone may be misleading.