Review Question - QID 216813

This patient sustained a comminuted proximal humerus fracture. Of the variables listed, <8mm of calcar length attached to the articular segment is a predictor of humeral head ischemia.

Fractures of the proximal humerus are now the third most common fracture in patients >60 years of age. Adequate perfusion can be maintained to the humeral head through the posteromedial calcar following trauma. Hertel's criteria have established that the most accurate predictor of ischemia was whether the length of the metaphyseal head extension for the calcar segment was <8mm. If posttraumatic osteonecrosis does develop following head preservation treatment, conversion to an anatomic shoulder arthroplasty can provide good success in motion and function, particularly when the tuberosities heal in a relatively anatomic position.

Moineau et al. evaluated the prognostic factors and limitations of anatomic unconstrained shoulder arthroplasty, performed without tuberosity osteotomy, for the treatment of secondary glenohumeral arthritis following posttraumatic cephalic collapse or necrosis of the humeral head, defined as type-1 fracture sequelae. They reported that the outcomes of anatomic shoulder arthroplasty for the treatment of type-1 fracture sequelae are good and predictable when the deformation of the proximal humerus is acceptable (ie. when no greater tuberosity osteotomy is necessary). They concluded that the results were negatively affected by proximal humeral varus deformity and by fatty infiltration of the rotator cuff on imaging studies; in such cases, reverse shoulder arthroplasty may be more appropriate, especially in elderly patients.

Hertel et al. evaluated the predictors of fracture-induced humeral head ischemia. They reported on several factors including fracture morphology, calcar length, and integrity of the medial hinge. They concluded that the most relevant predictors of ischemia were the length of the dorsomedial metaphyseal extension (<8mm), the integrity of the medial hinge, and the basic fracture type determined with the binary description system.

Südkamp et al. performed a prospective, multicenter, observational study to evaluate the functional outcome and the complication rate after open reduction and internal fixation of proximal humeral fractures with the use of a locking proximal humeral plate. They reported that 40% of complications were related to incorrect surgical techniques and were present at the end of the operative procedure. They concluded that the most common complication was screw penetration, noted in 14% of patients.

Illustration A highlights the vascular anatomy of the proximal humerus. Illustration B depicts the differences in posteromedial calcar lengths in proximal humerus fractures. Illustration C highlights the difference between an intact and disrupted medial hinge.

Incorrect Answers:
Answer 1-3,5: Predictors of humeral head ischemia (Hertel criteria) include <8 mm of calcar length attached to articular segment, disrupted medial hinge, increasing fracture complexity, displacement >10mm, and angulation >45°.