To fix a broken femur, surgeons insert a long metal rod down through the hollow center of the bone, threading it across the fracture site so the pieces are held in alignment while they heal. The rod, called an intramedullary nail, is made of surgical-grade titanium or stainless steel and stays inside the bone permanently in most cases. The procedure is performed under anesthesia and typically takes one to two hours. Here’s what happens at each stage.
Why a Rod Instead of a Plate or Cast
The femur is the longest, strongest bone in your body, and it sits deep under thick layers of muscle. A cast can’t hold a broken femur in position the way it can a broken wrist. Plates and screws bolted to the outside of the bone are sometimes used, but for most mid-shaft femur fractures, a rod down the center is the standard approach. It acts like an internal splint, sharing the load with the bone so you can start putting weight on the leg much sooner than you could with other methods.
Anesthesia and Positioning
Spinal anesthesia, which numbs you from the waist down, is the most common choice for this surgery. General anesthesia is also used depending on the situation. Getting into position for the spinal block can itself be painful because the broken bone ends shift when you move. To manage that, the surgical team often numbs the main nerve running to your thigh with a nerve block beforehand, which significantly reduces pain during positioning.
Once the anesthesia is working, you’re placed on a specialized traction table. This table applies a steady pull on your leg to separate the broken ends of the femur and bring them back into roughly the right alignment before the rod goes in. The surgeon checks the position using a portable X-ray machine (fluoroscopy) throughout the entire procedure.
Opening the Bone’s Canal
The rod enters from the top of the femur, near the hip. The surgeon makes a small incision above the greater trochanter, the bony bump you can feel at the outside of your hip. The exact entry point sits just medial to the tip of the trochanter, in a small depression called the piriformis fossa. Getting this spot right matters a lot. If the angle is off, the reaming tools can cut into the wrong part of the bone wall, weakening it or even causing a new fracture.
The surgeon uses an awl or drill to punch through the hard outer shell of the bone and into the soft, marrow-filled canal inside. A thin guide wire is then fed down through the canal, across the fracture, and into the lower fragment of the femur. Everything from this point forward follows that guide wire like a track, which is why its placement is confirmed on X-ray before moving on.
Reaming the Canal
The inside of your femur isn’t a uniform hollow tube. It narrows, widens, and curves along its length. To make room for the rod, the surgeon sends a series of flexible cutting tools (reamers) over the guide wire and through the canal. Each reamer is slightly wider than the last, gradually enlarging the channel to match the diameter of the rod that will be inserted. The reaming also creates a better surface for the rod to grip and stimulates bone healing by releasing marrow cells along the fracture.
Skipping the reaming step is sometimes done for open fractures where the bone has broken through the skin, but using a reamed technique generally leads to better healing rates. Not reaming has been identified as a risk factor for the bone failing to heal properly.
Inserting the Rod
The rod is attached to a long handle that lets the surgeon control its position and rotation. It slides over the guide wire and into the reamed canal. Ideally, the rod can be pushed in with steady pressure and twisting movements, but in practice some gentle hammering is often needed to seat it fully. The surgeon watches on fluoroscopy as the rod passes through the fracture site, making sure the broken ends stay aligned. The final position of the rod should be flush with the bone surface or just beneath it, so nothing protrudes into the surrounding tissue.
Locking the Rod in Place
A rod sitting loose inside the bone could spin or allow the bone to shorten as it heals. To prevent this, the surgeon drives screws through the bone and through holes in the rod at both ends. These are called locking screws. At the top of the femur, near the hip, the screws are placed using guides built into the insertion handle, which makes targeting the holes straightforward. At the bottom, near the knee, the surgeon uses X-ray guidance to line up small incisions with the screw holes in the rod. Once the screws are in at both ends, the rod is locked in position: it can’t rotate, slide, or telescope.
The incisions are small. The main one at the hip is typically just a few centimeters long, and each locking screw requires only a centimeter-sized cut. After the hardware is secured, the wounds are closed and bandaged.
What Recovery Looks Like
One of the biggest advantages of an intramedullary rod is that most patients can start putting weight on the leg almost immediately. Physical therapy usually begins within the first week. You progressively increase how much weight you bear as tolerated over the following weeks. In one study of patients with complex femur fractures treated with locked rods, 26 out of 28 were bearing full weight by six weeks after surgery.
Bone healing typically takes three to six months, though you’ll be walking with assistance long before the bone is fully consolidated. Follow-up X-rays track the progress of new bone forming across the fracture. The nonunion rate after femoral nailing ranges from 1% to 20%, with more complex fracture patterns carrying higher risk. Factors that increase the chance of delayed healing include fractures with large displaced bone fragments, fractures below the narrowest part of the canal, and broken locking screws.
Does the Rod Ever Come Out?
Most of the time, the rod and screws stay in your leg permanently. They don’t set off most metal detectors, and once the bone has healed around them, most people forget the hardware is there. Removal is occasionally done if the screws cause irritation, if there’s an infection, or if the hardware needs to be exchanged for a different implant. But for the majority of patients, a second surgery to take it out is not necessary.