This 28-year-old recreational football player presented following a twisting injury. He described feeling a popping sensation followed by near immediate pain and swelling. He was unable to weight-bear, had a large effusion and had laxity with Lachman’s test.
X-ray imaging showed an avulsion fracture of the tibial spine with an associated effusion. An MRI, and a CT scan, was then obtained. This imaging confirmed an avulsion fracture of the tibial spine with no other associated injuries. The MRI showed 6 mm separation and proximal displacement of a 2 x 1 cm bony fragment incorporating the medial tibial spine. The distal ACL was thickened and oedematous but intact. The CT imaging was more reassuring showing minimal displacement of the medial tibial spine. A repeat CT scan conducted two months later did not show any further displacement.
After a discussion regarding the treatment options this player was managed non-surgically. This decision was made for a variety of logistical, rather than medical, reasons. He was managed in an extension brace for two weeks followed by a brace allowing 20-90 degrees of flexion for a further three weeks. At five month follow up the player had a normal Lachman’s test and had returned to recreational football.
ACL avulsion fractures are relatively uncommon in adults (being more commonly seen in children). This may be due to the relative weakness of incompletely ossified bone (relative to the strength of the ligament) or due to the increased elasticity of the ligament in children. They are generally caused by injuries involving knee hyperextension. In most cases surgical stabilisation of the avulsion is advisable – however undisplaced fractures can do well with non-surgical treatment. A period of up to four weeks of immobilisation is generally needed. Prolonged immobilisation is not advisable as this frequently leads to stiffness.
This case highlights to value of CT imaging for the assessment of fracture characteristics. Compared with MRI (or x-rays) CT gives far better detail about bony injuries and can help with treatment planning.
FIFA does not bear any responsibility for the accuracy and completeness of any information provided in the “Radiology Review” features and cannot be held liable with regard to the information provided or any acts or omissions occurring on the basis of this information.