Information about pelvic bone fractures. Evaluation and treatment.
General information about pelvic bone fractures
The pelvic bones transfer the weight of the body from the spine to the lower extremities. The human pelvis is formed by three pairs of fused bones and the sacrum, which is located behind. There are five joints in the pelvis. In front of them is the pubic symphysis, which is formed by a cartilaginous plate between the cavity formed by the pubic bones, measuring 5 mm. There are two acetabular sockets and two sacroiliac joints in the pelvic region. The line that unites the edges of the pelvic bones and is located on the inner surface of the pelvic bones divides the pelvis into two regions (large pelvis and small pelvis).
The pelvic cavity in women contains the urethra, rectum, vagina and uterus; in men the prostate gland is located. In the pelvis, the iliac arteries divide into two branches to form the external and internal iliac arteries.
In the region of the greater sciatic awn we can observe such structures as: the sciatic nerve; the superior and inferior gluteal nerves; the internal genital nerve; the posterior saphenous femoral nerve; the nerve innervating the quadriceps muscle; the nerve innervating the external obturator muscle; the superior and inferior gluteal arteries and the internal genital vessels; the sternalis muscle. The ligaments that hold the pelvic bones together are the strongest ligaments of the human body. Of these ligaments, the following ligaments stabilize rotation: the symphysis ligament, the sacrospinal ligament, the anterior sacroiliac ligament, and the posterior short sacroiliac ligament. Vertical stabilization is supported by the interosseous sacroiliac ligament, posterior long sacroiliac ligament, iliopsoas ligament, lateral lumbosacral ligament, and sacrotuberous ligaments.
Patient Assessment and Diagnosis of Pelvic Bone Fractures
The history collection is very important to quickly establish the diagnosis, the type and form of the fracture, its direction, the severity of the fracture and the degree of stress, and to investigate additional complications that may arise. During the physical examination of the patient, the presence of hematomas in the pelvic region, external asymmetry, and abnormal rotational deformity in the pelvic cavity and externally are clarified. The presence of blood in the urethra, vagina, or rectum may indicate the occurrence of an injury. Palpation clarifies the presence of hypersensitivity and crepitations.
By performing rotary movements (outward and inward) in the area of the wings of the iliac bones, the presence of rotational instability is determined. The presence of vertical instability is determined by performing clear pushing and pulling movements while the assistant holds the patient’s leg. All these complex manipulations must be performed once and very carefully, so as not to cause the formed hematoma to collapse and cause new bleeding. In order not to overlook a concealed open fracture of the pelvic bones, as well as the accompanying injuries, it is necessary to conduct a finger examination of the rectum and vagina (in women) for each patient. During the examination of the patient, the Morel-Lavalle type injury (separation of the dense fascia from the femoral trochanter) must not be missed, because this injury has a very high risk of infectious complications.
Radiological examinations performed for pelvic bone fractures
When evaluating the severity of a pelvic bone fracture, X-rays should be performed not only in the anterior and posterior projections, but also in the entrance and exit regions of the pelvis. With radiography, 90% of pelvic fractures can be diagnosed in the anterior and posterior projections, and 94% of bone fractures are diagnosed by examining the entry and exit regions. Computed tomography assesses structures such as: posterior lesions in the acetabulum region that can’t be detected by X-rays; the spinal canal and exit sites of the spinal nerves; mild anterior, posterior and rotational displacement; and fracture transition (extension) to the acetabulum region.
Young-Burgess classification of pelvic bone fractures
According to the Young-Burgess classification, lateral rotation is the result of a compression injury due to forced rotation of the bones. Compared to other fractures, this type of fracture is more stable and the risk of vascular-nervous bundle damage is lower. When radiographs are taken in the projection of the pelvic inlet, a fracture line is observed on the anterior surface of the pelvis, which is pathognomonic (wide). In the posterior aspect of the pelvis, internal rotation of half of the pelvis can be observed. During examination of the patient, compression of the wings of the iliac bones in the direction of internal rotation may be applied.
Type I fractures are characterized by compression of the sacrum.
Type II fractures are characterized by the occurrence of fractures in the area of the iliac wings as a result of forced internal rotation. Special type of this fracture includes semilunar fracture.
Type III fractures include Type I and II fractures along with open book fractures.
Lateral compression injury type III (Lateral compression III). In this type of injury, the left side of the pelvis turns over and overlaps the right side.
The indications for surgical treatment of pelvic bone fractures include unstable hemodynamics, mechanical instability, and open pelvic bone fractures. Short-term external fixation may be given to patients with concomitant trauma to reduce the degree of pain and facilitate the intervention.
During an emergency intervention for patients with unstable hemodynamics, a bandage is applied to the pelvis, thereby reducing the rate of bleeding. To date, the “gold standard” is considered to be the use of external fixators, which achieve fracture stabilization, prevent blood clots, and at the same time reduce the volume of the pelvic cavity. The use of external fixators has been demonstrated to reduce the mortality rate of patients in the emergency department with systolic pressure below 100 mm Hg from 41% to 21% of cases.
Anterior fixation is performed by incisions (iliac-lingual and Pfannenstiel). The most common incision is the Pfannenstiel incision, in which, after bladder catheterization, a horizontal incision of 6-8 cm is made 1-2 cm above the level of the pubic symphysis.