ORIF of Intercondylar Distal Humerus Fracture
27 year old Japanese snow-boarder who landed on her extended arm, dislocating her elbow and fracturing her distal humerus. Her dislocation was partially reduced in Whistler, but her postreduction film showed that her medial column piece was flipped anteriorly and not articulating with the ulna. The lateral column piece was articulating with the radial head.
Posterior approach to the distal humerus. The patient lays prone with the elbow hanging over a bolster, and the Mayo stand is prepared so that the hand can hang in a sterile pouch. Sterile tourniquet is used to save tourniquet time. The incision is straight over the top – no curving. Sharp dissection down to the fascia, then strip the subcutaneous fat off the fascia both medially and laterally. Then fish out the ulnar nerve, which is best found a bit more proximally coming through the medial intermuscular septum along the medial head of triceps. It inclines posteriorly here to lie in the groove behind the medial epicondyle, then enters the forearm between the humeral and ulnar heads of the flexor carpi ulnaris, which is the first muscle it supplies in the forearm.
The nerve is picked up and dissected out proximally – you need to get enough slack on the nerve so that it can be moved around a bit. Then expose the proximal ulna/olecranon on both the medial and lateral sides – using a 15 blade to strip subperiosteally. You need to get all the way around both sides to be able to see the joint surface. Then prepare for the osteotomy. The 3.2 drill is used to drill through the olecranon – this drill MUST go STRAIGHT DOWN THE PIPE because the partially threaded cancellous screw that you put down to fix the osteotomy is a 6.5 mm screw and IT WILL NOT FIT if you don’t drill straight down the olecranon in both planes. Tap. Then draw out the Chevron on the dorsal cortex and use the micro-sagittal saw to get through the main part of the olecranon. The final part (including articular surface) is done by inserting an osteotome and cracking it off. Peel back triceps with the olecranon.
By peeling back triceps, you should get good exposure of the distal humerus. This was a nice, non-comminuted fracture. The first thing we did was to get the articular surface together. We took the medial column and drilled the 2.5mm drill from the fracture surface, perfectly in the middle of the piece and parallel to the trochlea, back out the medial epicondyle. We did in this “retrograde” kind of way because you can then ensure that the screw will go through the center of the piece. We then reduced the medial to lateral column and held it with reduction clamps. The channel in the medial piece was used as a drill guide to drill across into the lateral column and secured with a single partially threaded screw.
The distal humerus is then reduced back onto the shaft. Technically, you want bi-planar fixation, with the lateral plate lying posterolaterally, and the medial plate lying more along the medial crest. He uses DC plates rather than pelvic recon.