Campbell's Concepts: Intramedullary Nailing of Humeral Shaft Fractures
Possible indications: Segmental or highly comminuted fractures, pathologic fractures, compromised soft-tissue cover, and some fractures in selected polytrauma patients.
When nailing is indicated, a locked nail inserted antegrade is preferred.
Avoid iatrogenic radial nerve injury during reduction, reaming, nail insertion and locking. For example, in a comminuted fracture, the reamer is gently "pushed" past the comminuted zone, both going in and coming out.
A limited open exposure that spares the soft tissues can be added to the nailing to help reduce and hold the fracture.
As well as length and alignment, correct rotation must be restored during closed nailing.
Flexible humeral nails had theoretical advantages that were offset by more complications, such as axillary nerve injury. Self-locking expandable nails avoid some of the difficulty of interlocking, but large studies have not shown them to be clinically superior.
Surgical Technique (Technique 62.8)
Planning and Positioning
Study the preoperative radiographs carefully to make sure the diaphysis is wide enough for a nail. If the canal is too narrow, plate fixation is indicated.
Place the patient on a radiolucent table with the thorax raised 30–40° on a bump.
Position the C-arm across the table from the surgeon. Rolling it back gives an adequate AP view; rolling it forward gives an adequate lateral view of the shoulder and humerus.
Entry Point
Make a diagonal incision starting at the anterolateral acromial corner. Split the deltoid along its fibers through the anterior–middle third raphe.
To protect the axillary nerve, do not split the deltoid more than 5 cm distal to the acromion.
Insert the first guidewire:
Lateral view: Central, collinear with the medullary canal.
About 1 cm posterior to the biceps tendon.
A more medial entry point at the articular margin helps avoid varus malposition and avoids cutting the rotator cuff at its tendinous insertion.
Advance the wire under AP and lateral fluoroscopy.
Under direct vision, incise the rotator cuff in line with its fibers. Place full-thickness sutures to retract the cuff and protect it from the reamer.
Advance the proximal reamer carefully.
Reduction and Reaming
Reduce the fracture with the reduction device and pass the bead-tipped guidewire.
Ream sequentially to the planned diameter, usually 1.0–1.5 mm larger than the nail.
Middle-third fractures: A small incision at the fracture site lets you check by hand that the radial nerve is not trapped in the fracture before reduction and reaming.
Nail Insertion and Locking
Insert the nail down the canal without distracting the fracture. Make sure the nail is below the articular surface of the humeral head.
Insert the proximal locking bolts through the outrigger. Spread the soft tissues carefully to avoid the axillary nerve.
Assess humeral rotation:
Obtain a true AP view of the proximal humerus with the C-arm rolled back 30°.
Then rotate the distal fragment until a true AP view of the distal humerus is seen with the C-arm at 0° (neutral).
This gives approximately 30° of humeral head retroversion.
With rotation held, insert the distal locking screws anterior to posterior, to avoid the radial nerve.
Make a 4–5 cm anterior incision and split the biceps and brachialis bluntly, to avoid injuring the brachial artery.
Repair the rotator cuff with full-thickness sutures.
Confirm reduction and screw lengths on AP and lateral fluoroscopy.
Postoperative Care
Start an early rehabilitation program with active-assisted range-of-motion exercises.
Humeral Shaft Fracture With Radial Nerve Palsy
The radial nerve is the nerve most often injured with humeral shaft fractures, because it spirals across the back of the midshaft and is relatively fixed in the distal arm where it pierces the lateral intermuscular septum. It is involved in about 12% of humeral shaft fractures.
Mechanisms:
Closed fractures: Usually a stretch injury at maximal displacement. Less often entrapment between the fragments, and rarely laceration on a sharp bone edge.
Ballistic injuries: Classically thought to cause contusion from the shock wave, but Carney et al. reported a 40% rate of complete laceration.
Sharp penetrating open injuries: More likely to cause transection.
Recovery: Neurapraxic injuries recover at high rates. Entezari et al. reported 91% spontaneous recovery (72% full, 19% partial), with a median of 7–9 weeks.
Management (closed fracture):
Treat the fracture in the usual way, and splint the wrist and fingers to prevent contracture while waiting for recovery.
At about 1 mm/day of regeneration, brachioradialis and ECRL activity should appear at around 3–4 months.
For a dense palsy, electrodiagnostic testing may be warranted at 6 and 12 weeks.
Exploration is reserved for cases with no clinical recovery at 3–4 months and electrodiagnostic confirmation of no recovery. The optimal time for secondary exploration is 4–5 months, which allows time for recovery to show and still leaves time for regeneration before irreversible neuromuscular junction loss at 12 months.
Open fracture with radial nerve palsy: Explore the nerve at the time of irrigation and debridement.
Palsy when fracture surgery is indicated anyway: Explore the nerve at the time of fixation. If it is intact, careful neurolysis at the index operation may improve recovery.
In closed fractures, high-resolution ultrasound, combined with electrodiagnostic testing, can identify entrapped or lacerated nerves and may refine the indications for exploration.
Reference
Cosgrove CT. Fractures of the shoulder, arm, and forearm. In: Azar FM, Sawyer JR, Throckmorton TW, eds. Campbell's Operative Orthopaedics. 15th ed. Philadelphia: Elsevier; 2026. Chapter 62, Technique 62.8.