What Is Femoral Retroversion? Symptoms and Treatment

Femoral retroversion is a structural variation in which the upper end of the thighbone (femur) twists backward relative to the knee more than it should. Where a normal adult femur angles forward by roughly 7 to 19 degrees, femoral retroversion means that angle drops below about 10 degrees or turns negative, pointing the femoral head and neck toward the back of the hip socket instead of sitting centered in it. The condition can cause out-toeing, groin or hip pain, and early joint wear, and it often goes unrecognized because its symptoms overlap with more familiar diagnoses. Treatment ranges from activity modification to surgical correction of the twist, depending on severity and how much it disrupts daily life.

How the Femur Is Supposed to Sit

To make sense of retroversion, it helps to picture what the femur normally does. If you laid the thighbone on a table, the ball at the top (the femoral head) would not point straight sideways. It angles forward. That forward twist is called femoral anteversion, and in most adults it falls between about 7 and 19 degrees. Anything above roughly 20 degrees is considered excessive anteversion, while a twist of less than 10 degrees is classified as femoral retroversion.¹ When the angle goes negative, the femoral head actually points somewhat behind the center of the socket.

This twist matters because the hip is a ball-and-socket joint, and the ball needs to sit in the socket in a way that distributes pressure evenly. A femur twisted too far backward pushes the ball against parts of the socket that weren’t designed to bear the heaviest loads, and it changes the range of motion available before bone hits bone.

What Causes It

Femoral retroversion can be something you’re born with or something that develops after an injury. The developmental form may trace back to the way the hip was positioned in the womb, where an external rotation contracture during fetal growth shapes how the femur ossifies. It can also show up as a posttraumatic torsional deformity after a femoral fracture that heals with the bone rotated out of its original alignment.²

Population data on how common retroversion is remain patchy. One study looking at people treated for femoral trauma found it in about 21% of white males in the United States, though broader prevalence figures across other demographics are not well established.² That number comes from a trauma population, so it likely overestimates rates in the general public. Still, retroversion is far from rare, and it is underdiagnosed partly because many clinicians look first for more common explanations of hip pain.

The Telltale Symptoms

The most visible sign is out-toeing: walking with the feet pointed outward rather than straight ahead. When the femur is twisted backward, the leg naturally wants to rotate externally, so the kneecap and foot follow suit. This is the mirror image of excessive anteversion, which tends to cause in-toeing (a pigeon-toed gait).³

Beyond the gait pattern, symptoms typically cluster around the hip and groin:

Anterior hip or groin pain: pain at the front of the hip, especially with activities that require hip flexion, like sitting for long periods, squatting, or climbing stairs.
Limited internal rotation: you can turn your leg outward easily but struggle to rotate it inward, which becomes obvious when a clinician measures your passive range of motion.
Catching or pinching: a sensation of something catching in the hip joint during certain movements, caused by bone-on-bone contact at the rim of the socket.
Activity-related flare-ups: pain that worsens with sports or exercise and eases with rest, leading many people to initially assume they have a muscle strain or labral tear.

Clinical research has found that people with femoral retroversion can begin experiencing pain before the age of 30, underscoring why early identification matters.² Pain that shows up in your twenties and gets blamed on overuse or a vague “hip impingement” label could actually be driven by an underlying bony twist that no amount of rest will fix.

How Retroversion Creates Impingement

The mechanical problem is straightforward once you picture the geometry. When you flex your hip, the femoral neck sweeps forward toward the rim of the acetabulum (the hip socket). In a normally anteverted femur, there’s enough clearance. In a retroverted femur, the neck is already oriented further back, so when you flex, it collides with the front rim of the socket sooner and harder than it should. Biomechanical modeling shows that femoral retroversion significantly increases peak joint pressure in the flexed position. The peak pressure shifts to the back-and-bottom portion of the joint, consistent with a pincer-type femoroacetabular impingement pattern.⁴

This means retroversion doesn’t just limit your range of motion. It actively increases the forces grinding through the hip cartilage every time you bend your hip. Over time, that extra pressure can damage the labrum (the cartilage ring lining the socket) and accelerate cartilage breakdown.

The Link to Early Osteoarthritis

Researchers have been building a case that femoral retroversion is a genuine risk factor for developing hip osteoarthritis at an unusually young age. Computational models show that as retroversion progresses, impingement occurs earlier in the flexion arc, meaning everyday movements start causing contact damage sooner. Clinical studies have found that up to 12% of patients with developmental dysplasia of the hip, particularly women, also have retroversion combined with acetabular retroversion, a pairing that raises the risk of anterior hip pain and joint degeneration.²

Among patients who eventually needed a total hip replacement, one study found retroversion in about 11% of males and 5% of females. That’s a meaningful share of people getting their hips replaced, and it raises the question of whether earlier detection and treatment of the twist could have delayed or prevented the need for a joint replacement altogether.²

Effects Beyond the Hip

The consequences of retroversion don’t stop at the hip joint. When the femur is twisted abnormally, it changes the alignment of the entire lower limb. The knee has to accommodate a leg that is externally rotated, which alters how the kneecap tracks in its groove and changes the loading pattern across the joint. Biomechanical modeling has shown that variations in femoral version affect both the patellofemoral joint load and the knee’s abduction/adduction moment, with these differences reaching statistical significance across version levels.⁵

In practical terms, if you have retroversion and also deal with chronic anterior knee pain or kneecap tracking problems, the root cause might be further up the chain than anyone has looked. Treating the knee in isolation without addressing the femoral twist can leave the underlying problem in place.

How It’s Diagnosed

Diagnosing retroversion involves two layers: a clinical exam in the office and imaging to measure the exact twist angle.

Clinical Examination

The most widely known bedside test is Craig’s test (also called the trochanteric prominence angle test). You lie face-down with your knee bent to 90 degrees. The examiner palpates the greater trochanter, the bony bump on the outside of your hip, while rotating your leg inward and outward. The position where the trochanter sticks out the most laterally indicates the version angle, and the examiner measures the angle of your lower leg relative to vertical at that point.

Research on clinical tests has found that the difference between internal and external rotation range of motion, measured with the hip in neutral, shows one of the higher correlations with femoral version measured on MRI.⁶ Craig’s test correlates reasonably well with imaging, but its reliability in practice is a real concern. One study assessing the trochanteric prominence angle test against MRI measurements found that agreement was only fair. Physical examination failed to match MRI values within a 10-degree margin more than half the time, and the test’s ability to identify grossly abnormal torsion was limited.⁷ So while a clinical exam can raise suspicion, it’s not reliable enough on its own to confirm the diagnosis or guide surgical planning.

Imaging

The gold standard for measuring femoral version is cross-sectional imaging, either CT or MRI, taken with a standardized protocol that captures both the hip and knee so the twist between the two can be calculated. Studies comparing CT and MRI have shown comparable results, and both are considered reliable by orthopedic surgeons.⁸ MRI has the advantage of not exposing you to radiation, which matters especially for younger patients who may need repeat scans over time. If your clinician suspects retroversion, getting proper imaging before making treatment decisions is critical, since a physical exam alone can miss the diagnosis or get the degree of twist wrong by a wide margin.

When the Socket Is Part of the Problem

Femoral retroversion doesn’t always exist in isolation. The hip is a two-sided equation: the ball and the socket. Some patients have retroversion of both the femur and the acetabulum, a combination that compounds the impingement problem. The McKibbin index, which adds the femoral and acetabular version angles together, is used to flag these combined deformities. Research on patients with femoroacetabular impingement has found that combined version abnormalities are common and that the frequency of aggravated versus compensated patterns differs across impingement subtypes.⁹

This matters for treatment because correcting only the femoral twist while leaving a retroverted acetabulum in place may not fully resolve the impingement. Surgeons evaluating a patient for possible osteotomy need the full version picture on both sides of the joint.

Non-Surgical Management

Conservative treatment is typically the first line, especially for mild retroversion or in younger patients who haven’t developed significant cartilage damage yet. The mainstays include:

Activity modification: avoiding deep squats, prolonged sitting in low chairs, and movements that force the hip into positions where impingement occurs.
Physical therapy: strengthening the hip abductors and external rotators to improve dynamic stability around the joint, even though therapy cannot change the bone’s twist angle.
Anti-inflammatory medication: nonsteroidal anti-inflammatory drugs for flare-ups, used as needed rather than continuously.
Gait and movement coaching: working with a therapist to optimize walking and movement patterns so the hip experiences less repetitive impingement during daily activities.

The honest limitation of conservative treatment is that it manages symptoms without addressing the structural cause. If the retroversion is significant and the patient remains active, the abnormal loading continues, and the joint may still degenerate over time. One case report of a patient with symptomatic retroversion noted that conservative treatment was not effective, ultimately leading to surgical correction.¹⁰ Conservative care buys time and can work well for lower-demand patients, but it’s not a permanent solution for everyone.

Surgical Treatment

When symptoms persist despite conservative management, surgical correction becomes the discussion. The primary operation is a femoral derotation osteotomy: the surgeon cuts the femur, rotates it to a more normal angle of anteversion, and fixes it in the new position with a plate and screws. The goal is to restore the geometric relationship between the femoral head and the socket so that impingement resolves and joint pressure distributes more normally.

The osteotomy can be performed at the proximal femur (near the hip) or more distally (toward the middle of the thighbone), and the choice depends on the specific anatomy, the degree of correction needed, and the surgeon’s experience. Both approaches have shown good clinical results with high patient satisfaction in the early follow-up period.¹¹

An important nuance: hip arthroscopy alone, the minimally invasive approach commonly used for labral tears and cam-type impingement, does not fix a version problem. The bone’s twist exists along the entire shaft of the femur, not at a single bump that can be shaved down through a scope. An editorial commentary in the arthroscopy literature has made this point clearly, noting that while some impingement pathologies respond to arthroscopy, those with excessive version require an osteotomy, either alone or combined with other procedures.¹² If you’ve had hip arthroscopy for impingement and your pain returned, an unaddressed version abnormality may be why.

Choosing Between Femoral and Acetabular Correction

When both the femur and the acetabulum are retroverted, surgeons face a choice: rotate the femur forward (anteverting proximal femoral osteotomy) or rotate the socket forward (anteverting periacetabular osteotomy). A matched study comparing the two approaches found that both can achieve good outcomes and short-term survivorship for combined retroversion, though hip function after either procedure may not reach the same level as patients who had arthroscopy without rotational abnormalities.¹³ The choice between the two often comes down to which side of the joint is more abnormal and what other structural issues coexist.

Surgical Outcomes and Risks

Outcome data for femoral derotation osteotomy are encouraging, though the literature is still relatively young. In one cohort of 61 patients (treated for either excessive retroversion or excessive anteversion), roughly 85% achieved a clinically meaningful improvement in their hip scores, about three-quarters reached a level considered a substantial clinical benefit, and 75% reached a state the researchers defined as acceptable symptom resolution.¹⁴ Patient satisfaction tends to be high. In another series focused on derotation osteotomy for impingement, satisfaction scores jumped from about 24% preoperatively to 84% postoperatively, and 80% of patients said they would undergo surgery again.¹⁵

The surgery is not without risks. In a study of 203 femoral rotational osteotomies in adolescent patients, the overall complication rate was about 7%, and nonunion, where the bone fails to heal at the cut site, occurred in roughly 5% of cases.¹⁶ Nonunion can require a second surgery with bone grafting. Other possible complications include infection, delayed union, and hardware-related issues. A large analysis of proximal femoral osteotomies in children with cerebral palsy, a different population but one that undergoes the same type of bone cuts, found a complication rate of about 13%, with heterotopic ossification (extra bone forming around the surgical site) being the most common issue, though most cases of it were asymptomatic and didn’t require treatment.¹⁷ Complication rates will differ between pediatric and adult populations, but these figures give a sense of the surgical landscape.

How Retroversion Affects Exercise and Sport

If you’ve been told you have retroversion and you’re an active person, you’ve probably noticed that certain movements feel restricted or painful. Deep squats are a common trouble spot because they demand significant hip flexion, which is exactly where impingement bites hardest. You may find that squatting with your feet turned out feels more natural than squatting with feet straight ahead, and that’s a direct reflection of how the femur sits in the socket.

There is a popular idea in fitness circles that everyone should adjust their squat stance to match their hip anatomy, sometimes accompanied by Craig’s test done in the gym. The evidence here is less dramatic than the online claims suggest. Research looking at adult hip version angles found they are normally distributed, and only a relatively small proportion of people have angles extreme enough to make a meaningful structural difference. For those individuals, there is no strong evidence that simply changing foot position during a squat improves performance or prevents injury. The more important takeaway is that if squatting or similar movements cause consistent hip pain, the problem may be bony rather than muscular, and a version assessment with proper imaging is worth pursuing.

Why It Gets Misdiagnosed

Femoral retroversion is frequently missed or mislabeled. The most common misdiagnosis is plain femoroacetabular impingement (FAI), particularly the cam or pincer type, treated with arthroscopy. And while retroversion does cause impingement, it does so through a different mechanism than a bony bump on the femoral head-neck junction (cam) or overgrowth of the acetabular rim (pincer). Shaving bone during arthroscopy doesn’t correct a rotational deformity that runs the length of the femur. Patients sometimes undergo one or even two arthroscopies before someone orders the right imaging and identifies the version problem.

Another source of confusion is tibial torsion, a twist in the shinbone that can also produce out-toeing. The gait pattern looks similar, but the origin is lower in the leg. A proper torsional assessment needs to evaluate the entire limb, from hip to ankle, to figure out where the twist actually lives. Isolated treatment of one level while the real abnormality is at another leads to predictable failure.

Labral tears are also a frequent companion diagnosis. They’re real, but in many cases they’re secondary to the impingement caused by retroversion. Repairing or debriding the labrum without addressing the underlying version abnormality is treating the symptom while ignoring the cause, and pain typically returns.

Who Should Be Evaluated

Clinicians should think about version abnormalities in anyone with persistent hip or groin pain who walks with noticeable out-toeing, who has markedly more external than internal rotation on exam, or whose symptoms haven’t responded to standard impingement treatment. Young adults with hip pain that started before age 30 deserve particular attention, given the association between retroversion and early-onset osteoarthritis. So do patients who have had arthroscopic hip surgery without lasting relief. Imaging with CT or MRI to measure version angles is the single most useful step and remains underutilized in many clinical settings. The measurement itself is straightforward once it’s ordered; the challenge is getting clinicians to think of it in the first place.