Pelvic Ligaments Tests

Pelvic ligaments Tests are set of tests that is used to functional assessment of the pelvic ligaments: iliolumbar ligament, sacrospinous ligament, sacroiliac ligament and sacrotuberous ligament.

How it’s Performed?

• All Pelvic ligaments Tests is done with the patient is supine.
• To evaluate the iliolumbar ligament, the patient’s knee and hip are flexed and the examiner then adducts the leg to the contralateral hip. While executing this maneuver, the examiner presses on the knee to exert axial pressure on the femur.
• To evaluate the sacrospinous and sacroiliac ligaments, the patient’s knee and hip are maximally flexed and the examiner adducts the leg toward the contralateral shoulder. While executing this maneuver, the examiner presses on the knee to exert axial pressure on the femur.
• To evaluate the sacrotuberous ligament, the patient’s knee and hip are maximally flexed and the examiner moves the leg toward the ipsilateral shoulder.

What does a positive Pelvic ligaments Tests mean?

Stretching pain occurring within a few seconds suggests functional shortening and excessive stresses on the ligaments, although it can also occur in a hypermobile or motion-restricted sacroiliac joint.

Pelvic ligaments Tests is considered positive in these situations:

1. Pain that is caused by stretching the iliolumbar ligament is referred to the inguinal region (the differential diagnosis includes a hip disorder).
2. Pain caused by stretching the sacrospinous and sacroiliac ligaments is felt within the S1 dermatome from a point posterolateral to the hip as far as the knee.
3. Sacrotuberous ligament pain radiates into the posterior aspect of the thigh.

Related Anatomy

• The pelvis comprises three bones: The sacrum and each hemipelvis, also known as the innominate bones. The innominate bone is a fusion of three embryonic components: the ilium, the ischium, and the pubis.
• The fusion occurs at the triradiate cartilage where the acetabulum develops.
• These three bony structures are held together with strong ligaments.
• The articulations between each of the bony structures, the bilateral SI joints posteriorly and the symphysis pubis anteriorly, are all inherently unstable.
• The normal anatomic relationships are maintained secondarily to these strong supporting ligamentous structures. The SI joints are held together with anterior, intra-articular, and posterior sacroiliac ligaments.
• Additional stabilization of the posterior ring is provided by the sacrotuberous and sacrospinous ligaments.
• The posterior ring structures are responsible for the majority of pelvic ring stability, whereas the symphyseal ligaments, which hold the pubis together, account for only 15% of the stability to the entire ring. These ligaments are responsible for anterior stability.
• It is important to understand the structures that are affected with differing pelvic ring injuries such that appropriate treatment plans can be made.
• These ligaments not only support the bony pelvis but also the soft tissue structures contained within the pelvis. With disruption of the ligaments, and thus the pelvic ring integrity, there can be hemorrhage from both venous and arterial vessels.

When ligaments are injured, there is an alteration in the directional forces. If the symphysis is disrupted, but the posterior ligamentous complex is intact, the symphysis will close, that is, compressional forces prevail, hence the rationale for nonoperative management of an APC I injury. The diastasis has been noted to close down over time with mobilization.

When the anterior SI ligaments are disrupted in addition to the symphyseal injury, there continues to be tension on the symphysis resulting in further widening with weightbearing. Surgical intervention is then warranted.

Reference

• Clinical Tests for the Musculoskeletal System 3rd Edition.
• Rockwood and Green’s Fractures in Adults – 8th Edition book.