Humeral Shaft Fracture : Wheeless' Textbook of Orthopaedics

- See: Humeral Frx - Main Menu
- Condylar Fractures
- Non Union of Humeral Fractures
- Pediatric Humeral Shaft Fracture
- Synthes Humeral Shaft Products

- Discussion:
- mechanism:
- bending force produces transverse frx of the shaft;
- torsion force will result in a spiral fracture;
          - combination of bending and torsion produce oblique frx w/ or w/o a butterfly fragment;
- compression forces will frx either proximal or distal ends of humerus;
- types of humeral shaft frx:
- transverse humeral fractures
- distal third frx
- short oblique fractures:
- displaced frx thru distal shaft are difficult to reduce & are difficult to maintain in reduced position;
- these fractures may be associated w/ delayed healing;
- long spiral fractures:
- spiral, comminuted, and oblique fractures have the advantage of generous fracture surface areas and tend to heal rapidly;
- if displaced with a gap which does not close when rotational alignment is restored, there may be muscle interposition;
- if left with good alignment, but with a significant gap between the frx frag, these frx go on to atrophic nonunion;
          - associated fractures:
                 - A review of outcomes in 18 patients with floating elbow.
                 - Functional outcomes of "floating elbow" injuries in adult patients.
                 - Management of concomitant ipsilateral fractures of the humerus and forearm.
                 - Skeletal management of humeral shaft fractures associated with forearm fractures.

- Exam:
- need to rule out radial nerve palsy (see discussion), noting function of the ECRL/ECRB, EDC, ECU, EIP, and EPL;
             - do not assume that every extension deficit reflects a radial nerve palsy (vs brachial plexus injury);
      - references:
             - Humeral shaft fracture with brachial artery injury.
             - Management of fractures of the humerus in patients who have an injury of the ipsilateral brachial plexus.

- Acceptable Reduction: (forces displacing the fracture)
- axial malalignment:
- upper arm will accommodate 10-20 deg of anterior angulation & 10-30 deg of varus;
- this amount of angulation would be considered acceptable for patients w/ low to moderate functional demands;
- overriding fracture:
- bayonet position w/ upto 1 inch of shortening is acceptable;
- over-riding displacement is influenced to a degree by muscle contraction, which may have led to hanging cast principle;
- note displacing forces:
- frx just distal to insertion of deltoid muscle are prone to abduction of proximal fragment & also require special attention;

- Non Operative Treatment of Humeral Shaft Frx:
- note that these injuries are often very painful and that good initial immobilization is required;
- long arm splint needs to be applied from shoulder to wrist to fully immobilize the extremity;
- although rate of union is generally high with non operative treatment, incidence of mild malunion is high;
- in the study by Sarmiento A, et al (2000), the researchers were able to follow 620 patients with humeral shaft fractures that
                     were treated with cast bracing;
- 465 (75 %) of the fractures were closed, and 155 (25 percent) were open;
- non-union: 9 patients (6 %) who had an open frx vs 7 (less than 2 %) who had a closed fracture had a nonunion after bracing;
- 87 % of 565 patients for whom AP xrays were available, frx healed in less than 16 deg of varus angulation, and in
      81 % of the 546 for whom lateral radiographs were available, it healed in less than 16 deg of anterior angulation;
- at the time of brace removal, 98 % of the patients had limitation of shoulder motion of 25 degrees or less;
            - Functional bracing for the treatment of fractures of the humeral diaphysis.
- cast bracing:
- can be used for most closed humeral shaft frx;
- in most cases, cast braces are applied at 10-12 days following injury;
- forces displacing the fracture:
- hanging casts: may produce frx distraction & may increase risk of nonunion;
- reference:
- Tips of the trade #41. Modified coaptation splint for humeral shaft fractures.
            - Outcome of nonoperative vs operative treatment of humeral shaft fractures: a retrospective study of 213 patients.