Either an ascending screw to support the medial calcar region or a compression screw for the compression of transverse or short oblique fractures can be inserted in the long nail (see Fig 2). The latter allows bicortical compression, which is an easy-to-handle feature improving rotational stability in transverse and short oblique fractures. The nail must be over-inserted by at least the same amount of interfragmentary travel that is anticipated, because, as compression is applied, the nail will back out at the insertion site. The instrumentation comprises color coding for easy assembly, while self-holding mechanisms facilitate handling of sleeves and screwdrivers. Flippable aiming arms for left and right nail instrumentation help to reduce inventory and costs.

The three distal locking screws, which are placed freehand, are located in two different planes to reduce implant toggling, and increase stability of the osteosynthesis. The locking planes are situated in anatomical anteroposterior and lateral oblique direction at 25 degrees to each other. Due to the three-dimensional distal locking features, which offer the option to insert ASLS screws, distal diaphyseal fractures can also be addressed with antegrade nailing.

In comparison to previous implants, the MultiLoc nail offers clear advantages for stable fixation, especially of complex fractures like combined proximal and diaphyseal fractures and proximal humeral fractures extending into the diaphysis. Based on surgeon opinions, the compression option could also be advantageous in the management of nonunions and situations with delayed fracture healing.

Case 1: AO 12C1 fracture following fall (Case provided by Stefaan Nijs, Leuven, Belgium)

A 54-year-old woman, and otherwise healthy patient, fell during her holidays and sustained an AO 12C1 fracture (Fig 1). There was no major soft tissue trauma. Other lesions: avulsion at the 5th metatarsal base, and concussion.

Surgery took place on day 9 after the accident. The patient left the hospital the day after surgery.

Case 2: Staircase fall (Case provided by Markus Wambacher, Innsbruck, Austria)

Following a fall downstairs, a 70-year-old woman sustained a head injury with intracerebral and subdural haematoma, as well as a complex fracture of the right humerus, representing a minimal displaced proximal and an oblique fracture in the distal part of the humerus (Fig 3).

After neurosurgical intervention, surgery of the humerus was planned 10 days after the index trauma. The patient was still at the neurological intensive care unit and a preoperative clinical examination of the patient, regarding radial nerve palsy, was not possible. Therefore, a surgical revision with exploration of the radial nerve and an osteosythesis of the humerus using a long MultiLoc Humeral Nail was indicated.

The patient was operated on in beach chair position. For the exploration of the radial nerve, a limited anterolateral approach was used. The nerve was mobilized and retracted laterally. An anterolateral approach to the proximal humerus was performed. The supraspinatus showed a small acute rupture without retraction. The supraspinatus tendon was split to get access to the insertion area on the humeral head. A 270 mm long MultiLock Humeral Nail of 8.5 mm diameter was inserted under visual and x-ray control to the desired endpoint. Reduction of both the proximal and the distal humerus fracture was anatomical. In the lateral view there was a small gap, and it was decided to apply compression after distal locking (Fig 4). Proximally, three MultiLoc screws were inserted and a 2 mm end cap was placed. Finally, the supraspinatus rupture was reconstructed with transosseous sutures and secured with an augmentation plate. The posterior greater tuberosity fracture was secured with Fiber Wire to the MultiLoc screws. Figure 5 illustrates the definitive fixation.

Postoperatively, no sling was used because the patient stayed in medically induced coma.