Knee Surg Relat Res.  2016 Mar;28(1):75-78. 10.5792/ksrr.2016.28.1.75.

Magnetic Resonance Imaging Findings in Small Patella Syndrome

• Kim HS
• Yoo JH
• Park NH
• Chang JH
• Ban YS
• Song SH

• KMID: 2223088
• DOI: http://doi.org/10.5792/ksrr.2016.28.1.75

Abstract

Small patella syndrome (SPS) is characterized by aplasia or hypoplasia of the patella and pelvic girdle abnormalities, including bilateral absence or delayed ossification of the ischiopubic junction and infra-acetabular axe-cut notches. Here, we report a case of SPS in a 26-year-old female. Magnetic resonance image (MRI) showed a small patella with thick eccentric non-ossified patellar cartilage and femoral trochlear dysplasia with hypoplastic patellar undersurface. To our knowledge, this is the first report of MRI findings in SPS. MRI findings could be clinically relevant because elongation of the medial patellofemoral ligament and trochlear dysplasia with eccentric non-ossified patellar cartilage might lead to patellofemoral maltracking with an osteochondral lesion or acute dislocation or an extensor mechanism injury. Though the patient presented in this case report only had a gastrocnemius injury at the origin site, physicians should carefully examine abnormalities with MRI when an SPS patient has a trauma to the knee.

Keyword

Small patella syndrome; Magnetic resonance imaging

MeSH Terms

Adult
Cartilage
Dislocations
Female
Humans
Knee
Ligaments
Magnetic Resonance Imaging*
Patella*