Saturday, May 3, 2014

Management of anterior fracture-dislocations of the proximal humerus. Is Bankart repair necessary?

In cases of un-reconstructable proximal humerus fractures or 4 part proximal humerus fractures in the elderly prosthetic replacement is recommended. The fracture dislocations are often times associated with glenoid rim fracture which most of the time are less than 20% of the glenoid. Generally, biomechanical studies as well as clinical studies have shown that glenoid bone loss of more than 20% needs to be addressed either with fixation of the fractured glenoid or with bone augmentation of the glenoid. In the setting of a proximal humerus fracture dislocation it is uncommon to have more than 20% glenoid bone loss because most of the energy of trauma is absorbed by the fractured humerus. However, it is common to find during surgery small glenoid rim fractures. These fractures do not need to be addressed because they do not lead to instability. Fixation of the bony bankart lesion will lead to stiffness.

In younger patients (age <65) and with 2 or 3 part proximal humerus fracture with viable humeral heads every effort needs to be made for fixation of the fracture. The following case is a 62 year old nurse who presented after a fall with an anterior fracture dislocation of the shoulder. The humeral head was dislocated anteriorly and there was a small bony bankart lesion at the anterior inferior aspect of the humeral head. Disimpaction of the fractured humerus from the glenoid can be challenging and in this case was performed by a horizontal split of the subscapularis muscle belly, insertion of an elevator between the glenoid and the fracture humeral head to assist with the reduction maneuver. Open reduction and internal fixation was performed. At 2 years postoperatively the fracture is united, the patient had an active shoulder forward elevation of 120 degrees on the injured side and was pain free.

Further reading: http://www.bjj.boneandjoint.org.uk/content/88-B/4/502.full