Frank J. Simeone MD, Presenter: Nothing to Disclose

Ambrose J. Huang MD, Abstract Co-Author: Nothing to Disclose

Maximilian Smith, Abstract Co-Author: Nothing to Disclose

Connie Y. Chang MD, Abstract Co-Author: Nothing to Disclose

Miriam Antoinette Bredella MD, Abstract Co-Author: Nothing to Disclose

Martin Torriani MD, Abstract Co-Author: Nothing to Disclose

Medial joint line pain in the knee is often secondary to meniscal tears or osteoarthritis. The purpose of this study is to describe a new cause of medial knee pain, characterized by edema between the gracilis/sartorius tendons and medial femoral condyle (MFC).

The study group comprised 31 patients with findings of edema between the sartorius/gracilis tendons and the posteromedial femoral condyle (mean age 36.6±8.5 years, 29 female, 1 male, BMI 22.9±3.3) and 27 age- and gender-matched controls. Cases were reviewed by two subspecialist radiologists with 2 and 17 years of experience for soft tissue findings, distance between gracilis tendon and medial femoral condyle, distance between sartorius tendon and MFC, knee flexion angle, position of gracilis tendon with respect to sartorius and presence or absence of related findings including Baker's cyst and pes anserine bursitis. Clinical notes were reviewed and history and physical exam data were recorded.  

Study patients with findings of edema demonstrated significantly lower BMI (P<0.05) and distance between the gracilis tendon and MFC (p<0.05) compared to controls. There was no significant difference between age, sartorius distance, knee flexion angle or other incidental findings in the knee. Study patients were often mistaken for medial meniscus tears clinically (70%). Ultrasound guided steroid and anesthetic injection of the MRI-identified area of edema between tendons and MFC resulted in immediate and up to 2 months of  pain relief  in 2 subjects.

MRI findings of focal soft tissue edema between the sartorius/gracilis tendons and medial femoral condyle represents a clinical syndrome of knee medial joint line pain. Subjects are more likely to be female, have lower BMI and closer position of the gracilis tendon relative to the MFC. 

This study describes a new cause of medial joint line pain with reproducible clinical and imaging findings which should be considered on the differential of medial sided pain.

Simeone, F, Huang, A, Smith, M, Chang, C, Bredella, M, Torriani, M, Edema between the Sartorius/Gracilis Tendons and Posteromedial Femoral Condyle: Description of a New Friction Syndrome in the Knee.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14011089.html