Diagnosis

Turf Toe

Case Discussion

“Turf toe” is a traumatic hyperextension injury of the hallux (i.e., great toe). It typically results from an axial load placed on the heel of a plantarflexed foot, resulting in hyperextension of the 1st metatarsophalangeal joint. This causes injury to the plantar capsuloligamentous complex ranging from a sprain to complete rupture, and, if left untreated, may result in hallux valgus or varus, FHL tendon tear, and degenerative joint disease.

Turf toe injuries can be divided into 3 separate grades based on severity:

– Grade 1: stretch or minor tearing of the capsuloligamentous structures

– Grade 2: partial tearing of the capsuloligamentous structures with intact articular surface.  Attempts should be made to grade the percent of tear based on how much plantar plate can be seen transversely or from side to side when possible.

– Grade 3: complete rupture of the capsuloligamentous structures with damage to the articular cartilage, edema, and possible sesamoid fracture

MRI is recommended for patients with abnormalities seen on radiography, as well as those with grade II and III injuries. MRI findings of turf toe injuries can include increased signal intensity in and around the plantar capsuloligamentous complex on both T1- and T2-weighted images, discontinuity of the plantar capsuloligamentous complex, proximal retraction and/or fracture of the sesamoids, and synovitis within the flexor tendon sheath and metatarsophalangeal joint. Sagittal sequencing best depicts tears of the medial and lateral sesamoid phalangeal ligaments, short-axis sequencing best depicts tears of the metatarsosesamoid ligament, and long axis sequencing best reveals tears of the medial collateral ligament.

Key Images

Turf toe in a 30-year-old man sustaining an injury to the right great toe while playing football 1 day prior.

A. Sagittal T2* ADAGE 3D image of the right great toe shows hyperintense signal  edema and discontinuity of the plantar plate in the region of the medial or tibial sesamoid phalangeal ligament (yellow arrow). Incidental note is made of the partial thickness tear of the distal flexor hallucis longus tendon just proximal to the interphalangeal joint on the same slice (blue arrow). The tibial sesamoid is slightly proximally subluxed (red arrow). 
B. Sagittal T2* ADAGE 3D image shows massive edema and completely absent lateral plantar plate (yellow arrow) and lateral/fibular sesamoid phalangeal ligament, with associated proximal migration of the sesamoid (red arrow). 
C. Coronal (short axis) PD FSE fat saturated image shows abnormal high signal consistent with full thickness tearing of the tibial/medial (red arrow) and fibular/lateral (yellow arrow) sesamoid phalangeal ligaments. The adjacent abductor hallucis tendon is thickened/sprained (Ab). There is incidental mild interstitial tearing of the adjacent flexor hallucis longus muscle (blue arrow) and a confluent high signal area consistent with microtrabecular fracture of the second metatarsal head (green arrow).
D. Coronal (short axis) PD FSE fat saturated image shows low grade edema consistent with a strain of the flexor hallucis brevis lateral head (yellow arrow), medial head (blue arrow) and abductor hallucis oblique head (AdO – red arrow). The adductor hallucis transverse head (AdT) is normal in appearance. 
E. Axial (long axis) STIR image shows a linear hyperintense fluid signal area, consistent with complete tear of the lateral/fibular sesamoid phalangeal ligament (yellow arrows) and high signal consistent with tearing of the medial/tibial sesamoid phalangeal ligament (red arrow).  
F. Coronal (short axis) PD FSE fat saturated image shows co-existing thickening, hyperintensity and fibre waviness, consistent with interstitial partial thickness tearing of the lateral/fibular collateral ligament of the big toe (yellow arrow).

References

  1. Anderson J. Turf toe injuries of the hallux metatarsophalangeal joint. Techniques in Foot & Ankle Surgery 2002; 1(2):102-111
  2. Linklater J. Imaging of sport injuries in the foot. American Journal of Roentgenology 2012; 199:200-508