CASE 13647 Published on 26.05.2016

Larsen syndrome


Musculoskeletal system

Case Type

Clinical Cases


Jayanth H. Keshavamurthy, Supriya Gupta, Clarence Joe.

1120 15th street,
BA-1411 30912 Augusta,
United States of America;

25 years, female

Area of Interest Extremities ; Imaging Technique Digital radiography
Clinical History
25-year-old female patient with chronic knee pain had radiographs of the knee joints obtained.
Imaging Findings
There is chronic anterior and superior dislocation of the tibia with respect to femur, left knee joint worse than right. There is genu recurvatum.
A. Background
Larsen syndrome is associated with unusually large range of joint movement (hyper-mobility). It predominantly affects large joints, foot deformities like club foot, cervical spine dysplasia, scoliosis, short stature, craniofacial anomalies like cleft palate, hearing loss, accessory carpal bones and flat, square shaped tips of fingers (pseudo clubbing).

B. Clinical Perspective

Larsen syndrome is a rare genetic disorder. The classic form of Larsen syndrome is caused by mutations of the FL-NB gene and has autosomal dominant inheritance. The estimated incidence is 1 in 100, 000 people. [1] There is a lethal and non-lethal from. The lethal form is associated with pulmonary hypoplasia.

These patients may die of early complications secondary to dislocation of the cervical spine, tracheomalacia, heart disease, and severe respiratory infection. [4] Surgical repair has high failure rates due to abnormal connective tissue. So conservative treatment for clubfoot, knee and hip dislocations are suggested. [1, 2]

C. Imaging Perspective

Congenital connective tissue disorders, among them Ehlers-Danlos syndrome, osteogenesis imperfecta, Marfan syndrome, Loeys-Dietz syndrome and Larsen syndrome, are all characterized by generalized joint hyper-mobility. [3]

Antenatal ultrasound may help in diagnosing the features of multiple congenital joint dislocations, and facial abnormalities. One can do amniocentesis and genetic testing prenatally.

D. Outcome

The definitive diagnostic confirmation of Larsen syndrome is obtained from molecular genetic testing. Termination of pregnancy can be offered thereafter before viability.
Differential Diagnosis List
Larsen syndrome
Ehlers-Danlos syndrome
Osteogenesis imperfecta
Marfan syndrome
Loeys-Dietz syndrome
Final Diagnosis
Larsen syndrome
Case information
DOI: 10.1594/EURORAD/CASE.13647
ISSN: 1563-4086