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Hip ultrasound in adults
Last reviewed: 05.07.2025
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Pathological changes in the hip joint and surrounding soft tissues are not as numerous as in the knee and shoulder joints. MRI is the leading method for detecting pathology in this area. Ultrasound of the hip joints can be an additional method to clinical or X-ray examinations. It should be noted that ultrasound is more informative than MRI in detecting small effusions in the hip joint, even less than 1 ml. The hip region is the site of large vascular-nerve bundles, a zone of tumor metastasis and the spread of inflammatory processes from the abdominal cavity and small pelvis, as well as from the lower extremities. To examine this joint and surrounding soft tissues, depending on the constitution, a sensor in the range of 3.5-7 MHz with a linear or convex working surface is used.
Anatomy of the hip joint
The hip joint is formed by the articular surfaces of the head of the femur and the acetabulum of the pelvic bone. The acetabulum is attached to the edge of the acetabulum, increasing its depth. The joint capsule is attached to the edge of the acetabulum, covering the head of the femur, and is attached in front along the intertrochanteric line, and covers two-thirds of the neck of the femur behind.
For ease of examination, the hip region is conventionally divided into articular and periarticular. In turn, the periarticular region is divided into anterior, lateral, medial and posterior. Each of the above areas is assessed in two mutually perpendicular planes.
Ultrasound technique of hip joints in adults
Anterior approach.
The hip joint, soft tissues of the inguinal region and the femoral triangle area, and muscles are assessed from the anterior approach. The examination is performed in the supine position with straight legs. The sensor is installed longitudinally along the long axis of the thigh. An image of the iliac wing and the semicircle of the femoral head, which are bone landmarks, is obtained.
Between the ilium and the femoral head, a hyperechoic linear triangular structure is distinguished - the acetabular labrum. From this approach, the hypoechoic hyaline cartilage is clearly visible, as well as the synovial joint capsule of the hip joint, represented by fibers of several ligaments: iliofemoral, pubofemoral and ischiofemoral. Given the large size of the hip joint, it is recommended to use the capabilities of panoramic scanning. Visualization of the synovial capsule is enhanced by the presence of effusion in the joint cavity. The distance from the surface of the femoral neck to the joint capsule varies depending on the constitution from 4 to 9 mm (on average 6.4 mm).
Methodology for performing ultrasound examination of the hip joints
Ultrasound diagnostics of hip diseases
The main task of the ultrasound doctor is to conduct differential diagnostics between intra-articular and extra-articular pathology. Intra-articular pathological conditions include: effusion into the joint cavity, synovitis, deforming arthrosis, aseptic necrosis of the femoral head.
Joint effusion, synovitis.
The presence of effusion in the hip joint is diagnosed by ultrasound if the distance between the surface of the femoral neck and the joint capsule exceeds 9-10 mm. With synovitis, as a rule, thickening of the joint capsule is observed. Therefore, it is important to evaluate the symmetry of the thickness of the joint capsule with the healthy side. A difference of more than 1-2 mm indicates pathology of the synovial joint bag. Ultrasound is also used to detect fluid around a prosthetic hip joint or after osteosynthesis. With CT or MRI, metal prostheses often cause artifacts that interfere with the correct assessment of the presence of fluid in the cavity or around the joint.
Ultrasound signs of hip diseases
Ultrasound diagnostics of periarticular pathology
Muscle tears, muscle injuries, tendon and ligament tears.
Traumatic injuries to the hip area are less common than to the knee and shoulder joints. In car accidents, the rectus femoris is most often damaged. Athletes often have microtraumas to the rectus femoris. Symphysis pain in football players is often associated with a stretch or rupture of the adductor muscles attached to the pubic bones.
Hematomas of the thigh and gluteal region.
The subcutaneous fat layer on the thigh and buttocks is usually well defined. The tissue of this area contains few connective tissue partitions and is relatively weakly connected to the fascia, so blows to the thigh and buttocks relatively easily cause hematomas both in the thickness of the tissue and in the subfascial space.