CONDITION
Coxofemoral Subluxation
Coxofemoral subluxation describes a partial displacement of the hip joint, where the head of the femur (thighbone) shifts out of its normal position within the acetabulum (hip socket) but remains in some contact with it. This can happen suddenly after trauma, or develop gradually in dogs or cats with underlying hip joint problems. The hip may slip in and out of place, or sit in a persistently abnormal position. Owners often notice a sudden onset of limping or difficulty bearing weight on one hind leg, particularly after a fall, collision, or awkward movement. In some cases, the leg may appear shorter or held at an unusual angle, and the animal may be reluctant to move or show discomfort when the hip is handled. Where the subluxation develops more slowly, signs may be subtler—intermittent lameness, stiffness after rest, or a change in gait that comes and goes. This page explores the signs that can accompany hip subluxation, what may be happening within and around the joint, how the condition is investigated through examination and imaging, and the range of approaches—from rest and physiotherapy to surgical stabilisation—that may be considered depending on the individual case.
Why this matters now
Coxofemoral subluxation can occur at any age, though the underlying causes often differ between life stages. In young animals, the condition may arise from congenital hip laxity or developmental problems such as hip dysplasia, where the joint has never formed a stable relationship. In adults and older animals, trauma—a fall, road traffic accident, or collision during play—is a more common trigger, particularly in cats. Certain breeds with a predisposition to hip dysplasia, including Labrador Retrievers, German Shepherds, and Rottweilers, may be at higher risk of subluxation developing on top of pre-existing joint instability.
The course of subluxation varies considerably depending on the initial cause and the degree of displacement. In some cases, particularly following acute trauma, the hip may remain in a persistently abnormal position, leading to ongoing lameness and discomfort that does not resolve with rest alone. In others, especially where underlying laxity is present, the joint may shift in and out of position intermittently, creating episodes of lameness that appear to improve and then return. Over weeks to months, chronic instability can lead to secondary changes within the joint, including cartilage wear, inflammation, and remodelling of the bone surfaces.
Signals & patterns
Early signals
Sudden hind limb lameness
An owner may notice their dog or cat begin limping on one back leg, often after a known incident such as a jump, fall, or rough play. The limb may be carried or only lightly touched to the ground, and the onset tends to be abrupt rather than gradual.
Leg held at an unusual angle
The affected limb may appear rotated outward or held in a position that looks different from the other side. This can be subtle or quite obvious, and may be accompanied by the appearance of one leg being shorter than the other when the animal is standing.
Reluctance to bear weight
The animal may shift weight away from the affected side, stand on three legs, or refuse to put the foot down fully. This reluctance is often most noticeable when rising from rest or when moving slowly.
Discomfort when hip is touched
Gentle handling or manipulation of the hip area may cause the animal to flinch, pull away, or vocalise. This sensitivity can be present even when the animal is resting quietly and not attempting to move.
Later signals
Intermittent or persistent lameness
Over time, lameness may become a recurring pattern, with the animal appearing better on some days and worse on others. In cases where the hip remains unstable, the lameness may settle into a consistent limp that does not fully resolve.
Muscle loss along the thigh
The muscles of the affected hind leg, particularly over the thigh and hip, may become visibly thinner compared to the opposite side. This atrophy develops as the animal uses the limb less and weight-bearing decreases over weeks to months.
Stiffness after rest
Animals with chronic hip instability may have difficulty rising after lying down, or walk stiffly for the first few steps before appearing to warm out of it. This pattern often worsens in cold or damp weather.
Click to read about the biological mechanisms
How this is usually investigated
Investigation typically begins with a detailed history of how the lameness started, whether there was a known injury, and how the signs have changed over time. The veterinary surgeon will observe the animal walking and standing, noting which leg is affected and how weight is distributed. Physical examination of the hip follows, often under sedation or anaesthesia to allow gentle manipulation of the joint without causing distress. Imaging is then used to confirm the diagnosis and assess the extent of displacement and any secondary changes within the joint.
Physical examination and manipulation
Radiography (X-rays)
Advanced imaging (CT or MRI)
Ortolani or Bardens test
Options & trade-offs
Management depends on the cause of the subluxation, the degree of displacement, the animal's age and activity level, and how well the hip tolerates being returned to a more normal position. In some cases, a combination of rest, controlled movement, and pain relief allows the joint to stabilise on its own, particularly if the displacement is mild and the soft tissues have not been severely damaged. In others, surgical intervention may be considered to restore alignment, remove damaged structures, or replace the joint entirely. The path chosen often reflects a balance between what the animal can tolerate, what the owner can manage at home, and what the joint itself is capable of achieving.
Conservative management with controlled activity
This involves restricting the animal's movement for several weeks to allow the joint capsule and surrounding soft tissues time to heal and form stabilising scar tissue. Pain relief, often in the form of non-steroidal anti-inflammatory drugs, is used to manage discomfort during this period. Physiotherapy, including controlled exercises and hydrotherapy, may be introduced gradually to maintain muscle mass and joint range of motion without destabilising the healing structures.
Trade-offs: Success depends on the degree of initial displacement and whether the femoral head can settle into a functional position. This approach tends to work less well in cases of severe subluxation or where the round ligament has ruptured completely. Strict rest can be difficult to enforce, particularly in young or active animals, and some degree of residual instability or altered gait may persist even after healing.
Closed reduction and immobilisation
Under anaesthesia, the femoral head is manipulated back into the acetabulum and the hip is stabilised, sometimes with a sling or hobbles that limit abduction and help maintain the joint in the correct position. The animal is then managed with strict rest while the soft tissues heal around the reduced joint.
Trade-offs: Reduction is not always possible if the subluxation has been present for some time or if significant soft tissue damage prevents the femoral head from staying in place. Re-subluxation can occur if the joint is not adequately stabilised or if the animal moves too much during the healing period. This approach may be less suitable for animals with pre-existing hip dysplasia, where underlying laxity makes long-term stability uncertain.
Surgical stabilisation or reconstruction
A range of surgical techniques can be used to restore or improve joint stability, including repairing or reconstructing the torn joint capsule, using artificial ligaments or sutures to hold the femoral head in place, or performing an osteotomy to alter the angle of the femur or pelvis and improve the fit of the joint. The choice of technique depends on the age of the animal, the anatomy of the hip, and the degree of secondary change already present.
Trade-offs: Surgery carries risks including infection, implant failure, and anaesthetic complications, and requires a period of postoperative rest and rehabilitation. Not all hips can be successfully stabilised, particularly if the cartilage is severely damaged or the bony anatomy is unfavourable. In some cases, the joint may remain painful or develop osteoarthritis despite surgical intervention.
Femoral head and neck excision
This procedure removes the femoral head and neck entirely, allowing a fibrous 'false joint' to form between the remaining femur and the pelvis. It eliminates the source of pain by removing the damaged bone-on-bone contact, and can be particularly useful in smaller dogs and cats where the forces across the hip are lower.
Trade-offs: The resulting false joint does not restore normal hip mechanics, and the limb may remain shorter or move with an altered gait. Muscle mass and strength tend to be reduced on the affected side, and the outcome is generally less predictable in larger, heavier dogs. Postoperative physiotherapy is important to encourage use of the limb and prevent muscle contracture.
Total hip replacement
The damaged hip joint is replaced with an artificial implant consisting of a metal or ceramic femoral head and a plastic or metal acetabular cup. This restores near-normal joint mechanics and can provide excellent pain relief and function, particularly in larger dogs where other surgical options may be less successful.
Trade-offs: Total hip replacement is a complex procedure requiring specialist training and equipment, and is not available at all referral centres. Complications can include implant loosening, dislocation of the prosthetic joint, and infection. The cost is higher than other surgical options, and long-term implant survival depends on factors including the animal's weight, activity level, and bone quality.
Common misconceptions
"If the dog is still walking on the leg, the hip cannot be seriously displaced."
Many animals continue to bear some weight on a subluxated hip, particularly if the displacement is partial or intermittent. The degree of lameness does not always correspond to the severity of the underlying joint damage. Some animals with significant instability may show only mild or fluctuating signs, while others may be reluctant to use the limb at all even when the displacement is relatively minor.
"Once the hip is put back into place, the problem is solved and the joint will return to normal."
Reducing the subluxation is only one part of the process. The soft tissues—joint capsule, ligaments, and surrounding muscles—have often been stretched or torn, and these structures take time to heal and may not regain their original strength or elasticity. Even after successful reduction, the joint may remain unstable or develop secondary changes such as cartilage wear and osteoarthritis, particularly if underlying hip dysplasia or other anatomical factors contributed to the initial displacement.
"Surgery is always necessary for a subluxated hip."
The need for surgery depends on the individual case, including the degree of displacement, the cause, and how the animal responds to initial management. Some hips stabilise with rest and controlled rehabilitation, particularly if the subluxation is mild and caught early. In other cases, surgical intervention may offer a better chance of restoring function and comfort, but the decision is made on the basis of the specific circumstances rather than a fixed rule.
Related conditions
Hip Luxation
Hip luxation represents the complete displacement of the femoral head from the acetabulum, whereas coxofemoral subluxation describes partial displacement with some retained contact. Subluxation can progress to full luxation if the joint becomes further destabilised, and the distinction between the two often depends on imaging and the degree of displacement at the time of examination.
Elbow Dysplasia in Dogs
Elbow dysplasia and coxofemoral subluxation both describe developmental or traumatic abnormalities of major limb joints that can lead to instability, abnormal movement, and progressive discomfort. Owners may observe similar patterns of lameness, reluctance to exercise, and stiffness, though the affected limb and specific mechanical disturbance differ.
Iliopsoas Strain
Iliopsoas strain can occur alongside hip subluxation, as the deep hip flexor muscles may be subjected to abnormal loads when the hip joint is unstable or malpositioned. Both conditions can present with hind limb lameness and reluctance to extend the hip fully, and differentiation often relies on palpation, gait analysis, and imaging.
Sacroiliac Disease in Dogs
Sacroiliac disease and coxofemoral subluxation can both arise from trauma to the pelvis and hind limbs, and in some cases injury to one region may accompany or predispose to problems in the other. The clinical picture may overlap, with hind limb lameness, pelvic asymmetry, and discomfort on manipulation, requiring careful examination and imaging to distinguish the source.
Syringomyelia (CM/SM)
Syringomyelia can cause gait abnormalities, weakness, and postural changes that may alter how weight is distributed across the hind limbs, potentially contributing to joint stress over time. While the primary problem lies within the spinal cord, the resulting movement patterns can sometimes be mistaken for primary limb or joint disease.
Hip subluxation can exist alongside other joint conditions, particularly hip dysplasia or osteoarthritis, and understanding how these relate to one another can help make sense of the signs and the range of approaches that may be discussed. Patterns of lameness and joint instability are explored in more detail within the Pain & Mobility pillar. For animals living with chronic hip conditions, conversations about long-term comfort, activity modification, and the role of physiotherapy can be useful as the picture becomes clearer over time.