Blocking screw augmentation in intramedullary nailing for displaced surgical neck fractures of the proximal humerus

A displaced surgical neck fracture can be a good indication for antegrade intramedullary nailing. However, nail insertion may result in malreduction and translational displacement of the humeral head fragment because of muscle traction and size discrepancies between the diameters of the medullary canal and the intramedullary nail. We used blocking screw augmentation in 20 fractures with residual medial displacement of the distal fragment after nail insertion to anatomically reduce displacement of the fracture and to maintain the reduced position before bone union. A blocking screw was placed percutaneously at the lateral side of the canal. Next, a straight intramedullary nail was reinserted medial to the blocking screw. Finally, the nail was locked both proximally and distally. All cases showed bone union without fixation failure at the time of the final follow-up. Blocking screw augmentation with intramedullary nailing is feasible for the treatment of humeral surgical neck fractures and is thought to be helpful for fracture reduction during surgery and stable fixation after surgery.

Repair of proximal humerus fracture nonunions using a standardized treatment algorithm: a case series

BACKGROUND

Nonunion of fractures about the proximal humerus represents a rare and complex problem. The purpose of this study was to evaluate the clinical and functional outcomes following proximal humerus fracture (PHF) nonunion repair using a plate and screw construct with a direct comparison to those experienced following operative fixation of acute PHF using a plate and screw construct.

METHODS

Two separate patient cohorts were included in this study. The first consisted of 16 patients diagnosed with a non-united PHF who underwent operative nonunion repair treated with a standard algorithmic approach. The comparison group consisted of 173 patients who achieved union following initial open reduction and internal fixation of an acute PHF treated with a proximal humerus locking plate construct. All patients had at least 12 months of postoperative follow-up. Outcomes were assessed for both groups using American Shoulder and Elbow Surgeons (ASES) scores, visual analog scale (VAS) pain scores, and postoperative shoulder range of motion (ROM). Statistical analyses were used to compare these outcome measures between the two cohorts.

RESULTS

The nonunion repair cohort consisted of eleven surgical neck nonunions and five nonunions of both the surgical neck and greater tuberosity. Ten patients had undergone surgical treatment for their original fracture, while six were initially treated non-operatively. All patients had Boileau type 3 sequelae of their proximal humerus fracture. Union was achieved in all patients at a mean of 5.4 months following nonunion repair. Complications included hardware failure requiring revision in two patients (12.5%) and avascular necrosis requiring conversion to anatomic total shoulder arthroplasty following union in one patient (6.3%). The nonunion repair and acute fracture cohorts did not differ with respect to mean ASES scores, VAS pain scores, or active shoulder ROM at any postoperative time point.

CONCLUSION

Surgical repair of PHF nonunion is a viable treatment strategy that can lead to consistent bony healing with outcomes comparable to those of patients who achieve fracture union following initial surgical repair of an acute proximal humerus fracture. Surgeons should be cognizant of mechanical considerations that may lead to early failure.