CASE 6377 Published on 15.05.2008

Sinding-Larsen and Johansson Syndrome: MRI findings


Musculoskeletal system

Case Type

Clinical Cases


P Kankanalu


14 years, male

Clinical History
14-year-old presented with pain in anterior knee over 5 months time without any history of direct trauma.
Imaging Findings
14-year-old presented with pain in anterior knee over 5 months time without any history of direct trauma. Pain is worse during sporting activities. On examination patient is tender over inferior part of patella and over patellar ligament. MRI scan was done to confirm the clinical diagnosis and to rule out other knee pathologies.
Sinding-Larsen and Johansson syndrome was described independently by Norwegian physician Christian Magnus Falsen Sinding-Larsen and Swedish surgeon Sven Christian Johansson. It is a type of osteochondrosis at the proximal attachment of patellar ligament, which is common in adolescents especially those who participate in jumping activities. The aetiology appears to be traction tendinitis with de novo calcification in the proximal attachment of patellar tendon [1]. This may be caused by repetitive microtrauma to the tendon at the insertion to lower pole of patella. Clinically, patients present with pain, swelling and tenderness over inferior pole of patella precipitated by overstretching or trauma. Although it’s mainly a clinical diagnosis, imaging modalities help in diagnosis. Plain x-ray imaging may show osseous fragmented appearance of lower pole of patella [1]. MRI findings include fragmentation of lower pole of patella, marrow oedema within the fragments, thickening of patellar tendon at its insertion and oedema of Hoffa’s fat pad. Although ultrasound imaging is also effective and can be used for periodic follow-up during the course of this condition, the advantage of MRI is that it allows ruling out other intra-articular derangements [2-4]. As it is self-limiting condition, treatment involves conservative methods. The condition can last from three to twelve months [1]. Restricting activities such as jumping, kneeling, squatting, stair climbing and running should be avoided during the course of this condition. In severe cases brief period of immobilisation of affected knee joint may be beneficial. In the end the fragmented lower pole of patella may get incorporated into patella.
Differential Diagnosis List
Sinding-Larsen and Johansson Syndrome
Final Diagnosis
Sinding-Larsen and Johansson Syndrome
Case information
DOI: 10.1594/EURORAD/CASE.6377
ISSN: 1563-4086