Fracture of Tuberosity Occurring During Revision or Primary Arthroplasty
When periprosthetic tuberosity fractures occur intraoperatively, they must be identified, and the fracture fragments must be controlled and well-fixed to the final construct. At our institution, we will switch to a fracture-type stemmed reverse humeral prosthetic. Three large structural sutures (we use Arthrex FiberTape) are placed in the posterior rotator cuff (infraspinatus and teres minor) at the tendon-osseous junction in a simple configuration. A fourth suture is placed in the anterior supraspinatus to use as a traction stitch to assist with reduction. Prior to placing the final stem, an anterior to posterior 2.0 mm drill hole is placed just lateral to the biceps groove and inferior to the surgical neck. Using a Hewson suture passer, FiberTape and FiberWire sutures are placed through the humerus to serve as vertical limb fixation sutures. The stem and humeral component are then impacted. The prosthesis is reduced, and then the tuberosity is reduced to the prosthesis and fixed with the three sutures. The vertical limb two sutures are then passed anterior to posterior for one and posterior to anterior for the other, creating a “figure-of-eight” tension band fixation laterally with the vertical limb sutures. These are tightly tied with the arm positioned in shoulder abduction. This abduction position is critical, because when the arm is then lowered, the sutures become even tighter and compress the greater tuberosity fragment, further securing it. We will use our typical shoulder immobilizer for 4 weeks following this and avoid any pendulum range of motion exercises.
Midshaft Fracture Requiring Revision to Long-Stemmed Component
In fractures that occur in the midshaft and require revision to a long-stemmed component, there can be challenges with maintaining an adequate fracture reduction while placing the long-stemmed implant. For these fractures at our institution, we position the patient supine and elevate the radiolucent portion of the bed 30°. The C-arm is positioned to come in from the head of the patient. We utilize a deltopectoral approach and extend it into an anterolateral approach to the humerus. In these situations, we prefer to get a provisional reduction and stability at the fracture site prior to placing the long stem. Often times this stability can be achieved with tibial cortical strut allografts, which can be utilized as “bone plates” and affixed with cortical screws to the proximal and distal fracture fragments. In addition to stabilizing the fracture, this technique can help by providing additional bone stock in poor quality bone or bone loss situations. Another technique involves bridge plating the fracture with unicortical locking fixation. This can be performed with either large fragment 4.5 mm plates or orthogonal small fragment 3.5 mm plates. Following final long-stemmed placement, stem skiving cortical screws may be employed within the plate to increase the rigidity of the final construct.
Supracondylar Fracture Occurring Distal to a Well-fixed Stem
For supracondylar or distal humerus shaft fractures occurring below a well-fixed stem, we will typically position the patient lateral with a beanbag and the arm over a post to perform a posterior paratricipital or triceps splitting approach. We prefer the added rigidity of parallel plating for these fractures, especially if there is intra-articular extension into the distal humerus. The limitation of this approach is that it does not allow for any revision of the prosthesis, if it turns out to not be well-fixed.
Case examples from Dr Mighell/Dr Frankle (Monahos, Shiela Schumacker)