An abduction pillow is a wedge-shaped foam device placed between the legs to keep the hips spread apart at a fixed angle after surgery. It’s most commonly used after hip replacement, though versions exist for shoulder recovery and pediatric hip conditions. The pillow prevents the legs from crossing or rotating inward, which protects a healing joint from dislocating during the vulnerable first weeks of recovery.
How an Abduction Pillow Works
The term “abduction” in medicine means moving a limb away from the body’s midline. An abduction pillow holds the legs in this spread position, typically at about 15 to 30 degrees apart, so the ball of the hip joint stays seated in its socket. After hip replacement surgery, the surrounding muscles and joint capsule are healing and can’t yet stabilize the joint on their own. Without something holding the legs apart, simply rolling over in bed or crossing your legs while sleeping could push the new joint out of position.
The pillow works as a physical barrier. It sits between the thighs or knees and attaches with adjustable foam straps that wrap around each leg. This keeps the device in place even when you shift during sleep. Some versions use hook-and-loop closures for easy adjustment, and universal designs accommodate a wide range of body sizes.
What It Looks Like
Most abduction pillows are triangular or trapezoidal foam wedges, wider at the top and narrower toward the knees. They come in several sizes. A small pillow is roughly 18 inches long and 12 inches wide, while a large one runs about 26 inches long and 18 inches wide, all standing about 6 inches tall. The foam is firm enough to prevent the legs from drifting together but soft enough to be tolerable for hours of wear. The core is typically open-cell foam, which means it’s lightweight and breathable but should not get soaked with water.
When Abduction Pillows Are Used
The most common use is after total hip replacement (arthroplasty) or partial hip replacement. Surgeons may prescribe one when the surgical approach requires “posterior precautions” or “global precautions,” meaning the patient needs to avoid certain leg positions that risk dislocation. Revision hip surgeries, where a previously placed implant is repaired or replaced, are especially likely to call for one because the surrounding tissue has been operated on more than once and is less stable.
In children, abduction devices serve a different purpose. Developmental dysplasia of the hip (DDH), a condition where the hip socket doesn’t fully cover the ball of the thighbone, is treated by holding an infant’s hips in a bent and spread position. For babies up to six months old, this encourages the socket to develop properly around the joint. Devices like the Pavlik harness are the most well-known option, but rigid abduction pillows and braces (such as the Mittelmeier abduction pillow) have also been used. Some clinicians have developed custom abduction braces specifically to make daily life easier for parents managing DDH treatment at home.
Abduction pillows and slings also appear in shoulder surgery recovery. After reverse total shoulder replacement, patients typically wear an abduction sling continuously for two to three weeks, then gradually discontinue it by the third week unless they’re healing from a fracture, which can extend use by an additional six weeks.
How Long You’ll Use One
For hip replacement, the pillow is generally used during the hospital stay and sometimes for several weeks at home, particularly while sleeping. The exact duration depends on your surgeon’s protocol and the type of surgery performed. Revision surgeries often require longer use than first-time replacements.
For shoulder procedures, the typical immobilization period is three to four weeks. Some protocols shorten this to two weeks of continuous sling wear followed by a gradual transition. Your surgical team will set the specific timeline based on how the healing progresses and whether the surgery involved a fracture repair.
Proper Positioning
When lying on your back, the pillow goes between your legs with the straps secured around each thigh. The goal is to keep your knees and ankles roughly hip-width apart or wider. If you sleep on your side, a pillow between the knees serves the same function by preventing the top leg from dropping across the bottom one. Some people also place pillows behind their back to keep from rolling into a position that could stress the joint. The straps should be snug enough to hold the wedge in place but not so tight they dig into the skin or restrict blood flow.
Do They Actually Prevent Dislocation?
This is where the evidence gets interesting. A study of nearly 2,500 hip replacement patients compared outcomes over two periods: one where 1,154 patients received abduction pillows and another where 1,296 patients did not. Only two dislocations occurred in the pillow group and one in the no-pillow group. The relative risk of dislocation was actually 2.25 times higher in the group that used the pillow, though the overall numbers were so small that the difference is hard to interpret as meaningful. The study concluded that removing abduction pillows from the standard protocol after primary hip replacement did not increase the risk of in-hospital dislocation regardless of surgical approach.
Post-surgical hip dislocation rates generally range from 0.5% to 10.6%, depending on factors like surgical technique, implant type, and patient anatomy. Despite the mixed evidence for routine use, many surgeons still prescribe abduction pillows for higher-risk cases, particularly revision surgeries and patients with neuromuscular conditions that make it harder to control leg position voluntarily.
Cleaning and Care
The foam core of an abduction pillow should never be submerged in water. Open-cell foam absorbs moisture and is difficult to dry completely, which can lead to mold or bacterial growth. Instead, wipe the foam surface with a damp cloth. The straps can usually be machine washed in warm water and dried on a low setting, but make sure they’re fully dry before reattaching them to the wedge. Covering the pillow with a towel or pillowcase during use helps keep it clean and reduces the frequency of deeper cleaning.