Irreducible anteromedial radial head fracture-dislocation: value of pre-operative magnetic resonance imaging

Abstract

We describe a case of an anteromedial fracture-dislocation of the radial head in an adult patient, which was initially irreducible using closed means, and remained challenging to reduce despite open surgery. Further advanced CT/MRI revealed entrapment of the radial head due to the interposition of the brachialis tendon posteriorly, thereby preventing sustained reduction. While three other cases of irreducible anteromedial radial head dislocation due to the brachialis tendon have been reported in the English surgical literature, none of the imaging findings have been described in the radiological literature. Only one other case published in a surgical journal briefly demonstrated pre-operative MRI imaging. We would like to share the value of pre-operative MRI in this rare presentation, which would be helpful in diagnosing not only cases with interposition of the brachialis tendon, but potentially other types of soft tissue interposition which also limit closed reduction. To the best of the authors’ knowledge, this would be the first report on the imaging findings in a radiological journal. Awareness of this phenomenon would assist radiologists in the diagnosis and management of this rare condition.

Irreducible anteromedial radial head dislocation without fracture caused by transposed biceps tendon in an adult: A case report and literature review

“…Through 3D-CT images, we found an extremely pronated radius and movement of the bicipital tuberosity posterior to the elbow joint, which was not observed in other causes of anteromedial dislocation of the radial head, probably due to the special “umbilical cord wrapping” phenomenon of the biceps tendon around the radial neck. 9 , 13 , 18 , 20 , 21 …”

“…10 , 11 , 12 , 16 MRI is of great value in diagnosing this type of disease. 5 , 7 , 17 , 18 , 19 Unfortunately, none of the reported cases of IARHD caused by biceps tendon have been examined with MRI preoperatively. 10 , 11 , 12 , 13 , 14 , 15 , 16 All reported IARHD caused by biceps tendon have been performed using either a lateral elbow approach or a mid-dorsal approach.…”

A Hidden “Suspender” in Irreducible Isolated Anteromedial Radial Head Dislocations – A Case Report and Review

“…Isolated anterior radial head dislocations or fracture dislocations are rare [ 4 , 5 , 6 , 7 , 8 , 9 , 10 ]. The direction of radial head dislocation, anterolateral, or anteromedial could give an idea about the possible impediments and success of closed reduction maneuvers.…”

“…Tarallo et al described a “sling effect” due to “spring preloading,” where the forearm elastically springs from supination to neutral rotation in presence of a biceps tendon loop. Besides, a pre-operative non-contrast magnetic resonance imaging (MRI) can be valuable in detecting the musculotendinous sling and injuries to collateral ligaments commonly encountered with such an injury [ 5 ].…”

“…Almost all the cases reported in the literature had a hyperextension force vector. The majority of these cases (7/11) had an associated radial head fracture [ 1 , 4 , 5 , 7 , 8 , 9 , 10 ] and half of them had a medial epicondyle fracture [ 3 ] or medial collateral ligament (MCL) tear [ 4 , 5 , 8 , 13 ] suggesting a possible valgus injury. We hypothesize a probable sequence of events leading to posterolateral subluxation of the superficial brachialis tendon suspending the radial head.…”