Sciatic nerve neuropathy (piriformis syndrome)

The bones used to sit

Ischial tuberosity

(or
process of the ischium
,
tuber ischiadicum
), also known colloquially as
the sit bones
or
SITZ bones
, [1] or as a pair of the
sit bones
[2] is a large swelling posterior to the superior ramus of the ischium. It marks the lateral border of the pelvic outlet.

In a sitting position, the load often falls on the ischial tuberosity. [3] The gluteus maximus provides coverage in an upright position, but leaves it free in a sitting position. [4] The distance between a cyclist's ischial tuberosities is one of the factors influencing the choice of a bicycle saddle.

Divisions[edit]

The tuberosity is divided into two parts: the lower rough, somewhat triangular part and the upper smooth quadrangular part.

• The lower part
  is divided by a prominent longitudinal ridge, running from the base to the apex, into two parts: The outer one gives attachment to the adductor magnus muscle
• Internal to sacrotuberous ligament

Publications in the media

Pelvic fractures account for 4–7% of all fractures. Classification • Marginal fracture: fractures of the iliac spines, ischial tuberosities, coccyx, transverse fracture of the sacrum below the sacroiliac joint, ilium • Fracture of the pelvic ring without breaking its continuity •• Unilateral or bilateral fracture of the same branch of the pubic bone •• Unilateral or bilateral fracture of the ischium •• Fracture of one branch of the pubis on one side and the ischium on the other • Injuries with disruption of the continuity of the pelvic ring •• Vertical fracture of the sacrum or fracture of the lateral mass of the sacrum •• Rupture of the sacroiliac joint •• Vertical fracture ilium •• Fracture of both branches of the pubic bone on one or both sides •• Fracture of the pubis and ischium on one or both sides (butterfly type fracture) •• Rupture of the symphysis • Damage with simultaneous disruption of the continuity of the anterior and posterior half rings (Malgenia type ). and posterior on the other •• Dislocation of the innominate bone - rupture of the sacroiliac joint and symphysis •• Combination of rupture of the symphysis with a fracture of the posterior semi-ring or combination of rupture of the sacroiliac joint with a fracture of the anterior semi-ring of the pelvis • Fracture of the acetabulum •• Fracture of the edge of the acetabulum; may be accompanied by posterosuperior hip dislocation •• Fracture of the floor of the acetabulum; may be accompanied by a central dislocation of the hip - a displacement of its head inward towards the pelvic cavity.

Fracture of the marginal pelvic bones • Causes: direct trauma, short-term compression of the pelvis, sudden muscle contraction. • Detachment of the anterosuperior spine •• Clinical picture: pain, swelling, displacement of the fragment downwards and outwards, which creates the impression of a shortened limb; Lozinski's symptom of reverse movement - the appearance of sharp pain when flexing the hip while taking a step forward (moving the leg back causes less pain); the patient walks backwards •• Treatment: pain relief, the leg is placed on a Beler splint in a position of slight abduction for 3 weeks. Sometimes osteosynthesis is used. • Duvernay's fracture is a fracture of the ilium and the upper part of the acetabulum •• Clinical picture: pain in the area of ​​the iliac wing, aggravated by tension of the abdominal muscles and percussion, limitation of movements in the hip joint. When the wing is displaced upward, a shortening of the distance from the xiphoid process to the anterosuperior spine is detected •• Treatment: pain relief - intrapelvic blockade according to Shkolnikov-Selivanov, Beler splint, exercise therapy, physiotherapy; if there is significant displacement, the patient is placed in a hammock with compression of the lateral surfaces of the pelvis for 4 weeks. • Transverse fracture of the sacrum and coccyx •• Clinical picture : pain, aggravated in a sitting position, pressing on the distal part of the sacrum during rectal examination, difficulty in defecation, swelling in the area of ​​the sacrum (coccyx), pathological mobility of the distal fragment of the coccyx (sacrum). If the sacral nerves are damaged, urinary incontinence and anesthesia of the buttock area develop •• Treatment: pain relief, the patient is placed in bed on a backboard (a wide cushion is placed under the lower back so that the sacrum does not touch the bed) or in a hammock (the hammock is placed under the back from the angle of the shoulder blades to fracture area so that the distal fragment of the sacrum does not touch the bed) for 3–5 weeks, belladonna suppositories, warm enemas, physiotherapy; if pain persists, presacral blockades and physical therapy are repeated; if conservative treatment is ineffective, the fragment is removed.

Fracture of the pelvic ring • Fracture of the pelvic ring without breaking its continuity •• Causes : direct trauma, compression of the pelvis in the anteroposterior direction (fracture of the ischium) or load on the greater trochanter (fracture of the pubis) •• Clinical picture : pain in the pubic area (with a fracture pubic bones) or in the perineum (with a fracture of the ischial bones), aggravated by palpation, leg movements, compression of the pelvis from the sides; sometimes - a symptom of a stuck heel •• Treatment: anesthesia, the patient is placed on a hard bed with a shield; for a unilateral fracture - a Beler splint in the position of abduction of the leg; for bilateral fractures - the “frog” position. Bed rest - 4-5 weeks. • Fracture of the pelvic bones with disruption of the continuity of the pelvic ring •• Frequency : up to 50% of all pelvic injuries •• Complications : shock, damage to the pelvic organs (rectum, bladder, urethra) •• Causes: indirect injury - anteroposterior or lateral compression of the pelvis , fall from a height, birth injury (rupture of the symphysis) •• Damage to the anterior semi-ring of the pelvis ••• Clinical picture: pain in the pelvis and perineum, aggravated by leg movement, anteroposterior and lateral compression, an attempt to separate the iliac bones; Volkovich's symptom - with a fracture of the upper branch of the pubic and ischial bones, the patient is in a frog position; with a fracture near the symphysis and its rupture, the thighs are brought together and slightly bent, an attempt to separate them causes sharp pain; stuck heel symptom; when the symphysis is torn, the space between the bones is sometimes palpable ••• X-ray examination. It must be remembered that the width of the symphysis pubis at 18 years of age is 6 mm, later it decreases to 2 mm ••• Treatment: fractures without displacement - Volkovich position for 5-6 weeks, from the end of 1 week - exercise therapy, physiotherapy; fracture of the pubic and ischial bones on both sides (butterfly-type fracture) with displacement - Volkovich position; when the X-shaped fragment is displaced upward, additional pillows are placed under the back to bring together the attachment points of the rectus abdominis muscles; if ineffective, skeletal traction with a load of 4–5 kg; symphysis rupture - treatment on a hammock with cross traction; osteosynthesis is used when conservative treatment is unsuccessful; in the postoperative period - treatment on a hammock with cross traction for 6 weeks •• Damage to the posterior semi-ring ••• Clinical picture: the patient lies on the healthy side, active movements of the leg on the injured side are limited, painful, pain increases with palpation; if the sacroiliac joint is ruptured, the posteriorly displaced edge of the ilium is palpated ••• Treatment: the patient is placed on a backboard in a hammock without cross traction for 8–9 weeks; for displaced fractures - skeletal traction; if it is impossible to reposition a rupture of the sacroiliac joint with displacement, arthrodesis of the sacroiliac joint is used •• Malgenya fracture - simultaneous disruption of the continuity of the anterior and posterior half rings ••• Causes: compression of the pelvis, fall from a height ••• Clinical picture: pain, dysfunction of the lower limbs, bruises in the area of ​​the scrotum, perineum and inguinal ligament, asymmetry of the pelvis, upward displacement of one of its halves by 2–3 cm - a decrease in the distance from the xiphoid process to the anterosuperior spine; with lateral compression or an attempt to separate the halves of the pelvis, pathological mobility is revealed ••• Treatment. Antishock therapy - intrapelvic anesthesia, compensation of blood loss; for a non-displaced fracture - treatment on a hammock, skeletal traction with a load of 4-5 kg ​​on each leg for 8 weeks; when half of the pelvis is displaced upward and inward on the side of displacement, the load of skeletal traction is increased to 10–14 kg, traction is carried out in the abduction position for 8–10 weeks; the hammock is used only after reposition; in case of a bilateral vertical fracture with upward and inward displacement - skeletal traction with a load of 10–14 kg for both legs in the abduction position for 8–10 weeks; in case of symphysis rupture - treatment on a hammock with cross traction after reposition for 10–12 weeks.

Fracture of the acetabulum • Causes : lateral compression of the pelvis in the area of ​​the greater trochanters, load on the greater trochanter • Clinical picture: pain in the hip joint and dysfunction (pain intensifies with axial load and tapping on the thigh); with combined dislocation, the apex of the greater trochanter is above the Roser–Nelaton line, the limb is adducted, slightly bent and internally rotated; with central dislocation of the hip, the greater trochanter falls • Treatment •• Anesthesia: intrapelvic blockade according to Shkolnikov-Selivanov •• Fracture without displacement - skeletal traction with a load of up to 5-7 kg, if closed reduction is unsuccessful - osteosynthesis of the broken edge of the acetabulum •• For fractures of the acetabular floor depressions accompanied by central dislocation of the hip, skeletal traction along the axis of the hip and beyond the greater trochanter or subtrochanteric region, transosseous compression-distraction osteosynthesis; if closed reduction is ineffective, open reduction of the central dislocation of the hip and osteosynthesis of fragments of the acetabulum.

ICD-10 • S32 Fracture of the lumbosacral spine and pelvic bones

Additional images[edit]

• The muscles of the gluteal and posterior thighs with the ischial tuberosity are highlighted in red.
• Right femur. External surface.
• Right femur. Inner surface.
• Plan of ossification of the pelvic bone.
• Diameter of the lower pelvic opening (female).
• Right hip joint in front.
• External obturator.
• Anterior view of the pelvis with the ischial tuberosity indicated at the bottom of the image.

Causes of pain in the ischial tuberosity

The most common reason that the ischial tuberosities hurt is a bruise from a fall on the buttocks. Signs that they have suffered include the following symptoms:

1. It hurts to swing your leg.
2. Bend painfully to the floor from a standing position;
3. Pain when running with long strides, but jogging does not cause discomfort.
4. Pain after sitting for a long time on a hard surface.
5. Hematoma in the area of ​​the bruise.

Due to the fact that the ischial tuberosities are located in a difficult-to-reach place, the bruise is treated with the following procedures:

1. For a large hematoma, for a faster treatment result, a puncture is performed under ultrasound guidance to remove blood clots.
2. To prevent infection, a course of antibacterial drugs is prescribed.
3. Limit the load on the bruised leg.

If for some reason the patient does not agree to undergo a puncture, then this procedure can be dispensed with, but in this case the hematoma will take longer to resolve.

Notes[edit]

1. MD, John R. Schultz (October 28, 2021). "Sit Bone Pain (also known as Sitz Bone)". Centeno-Schultz Clinic
   . Retrieved April 12, 2021.
2. Window Sills, Franklin (2004). Craniosacral biodynamics: the primary midline and body organization (revised, illustrated ed.). Berkeley, CA: North Atlantic Books. p. 99. ISBN 1-55643-390-5.
3. Goossens (2005), pp. 895-982
4. Platzer (2004), page 236

Discussion

Analysis of clinical data for 2 years suggests that before the advent of CT in the routine practice of examining patients, some pelvic fractures in elderly patients remained undetected and were treated with conservative methods. In all cases, when treating elderly patients, early activation is necessary to prevent hypostatic complications, combat pain and senile dementia. However, today, after establishing the correct diagnosis, the question remains open about the need to fix fractures using known methods of internal or external fixation. One of the main problems is the choice between the risks of surgical treatment and its benefits in the form of stabilization of the pelvic ring and the possibilities of early activation. Obviously, the main obstacle to early activation in elderly patients is pain. In addition, it is quite difficult to assess the intensity of pain in patients after various types of treatment due to the lack of objectivity of such a parameter as pain.

Russian authors report that minimally invasive fixation, activation and early rehabilitation can significantly reduce the number of complications and mortality [30]. According to A. Höch et al. [11], in 18% of cases in the surgical treatment group complications occurred, however, despite this, the 2-year survival rate was 82%, while in the conservative treatment group there were encouraging results (8% complications) and a disappointing survival rate of only 61%. . According to N. Kanakaris et al. [8], in most cases, preference is given to a conservative method of treatment, since the majority of fractures are considered mechanically stable and there are a limited number of fixation techniques in conditions of porous bone and aggravated somatic status of patients. In addition, the situation is aggravated by the insufficient number of qualified surgeons. A. Hoch et al. [13] revealed that the choice of treatment method is based on the patient’s age, regardless of the type of fracture: thus, surgical treatment is mainly carried out in the group of patients under 80 years of age, while older patients are treated with conservative therapy. For type C fractures, surgical interventions were performed in 50% of cases, which exceeds the rates of previous studies [31].

M. Rollmann et al. [17] believe that type B fractures with stable hemodynamics, the possibility of early activation and adequate pain relief must be treated conservatively, and type C fractures have the highest mortality rate and require surgical intervention.

This work shows the need for further study of the problem by conducting ethically and organizationally possible randomized scientific studies using conservative and surgical methods and subsequent comparison of results.

Links[edit]

This article incorporates public domain text from page 235 of the 20th edition

"Grey's Anatomy"
(1918)

• Goossens, R., Teeuw, R., & Snyders, S. (2005). "Sensitivity to changes in pressure on the ischial tuberosity." Ergonomics
  .
  48
  (7):895–902. DOI: 10.1080/00140130500123647. PMID 16076744. S2CID 854065.
• Platzer, Werner (2004). Color Atlas of Human Anatomy, Vol.
  1: Musculoskeletal system (5th ed.). Time. ISBN 3-13-533305-1.

Diagnostics

For an experienced specialist, determining the presence of damage to the sciatic nerve is not difficult by the presence of characteristic pain, the addition of neurological disorders or movement disorders. But finding the reasons that triggered this may take some time.

To do this, the doctor must conduct a general examination and interview the patient. This allows you to assess the condition of the spine, the functionality of the nervous system, muscle tone, conduct specific tests and detect local changes in the skin. Having formed a general impression of the nature of the existing pathological changes, and sometimes having a preliminary diagnosis, the doctor refers the patient for a comprehensive examination. It allows you to obtain objective data about the condition of the patient’s body, diagnose the slightest pathological changes in the spine and other organs, and formulate a prognosis.

Therefore, patients are usually prescribed:

• radiography of the spine, pelvis and legs in two projections - allows you to assess the condition of bone structures, detect signs of osteochondrosis and its complications, displacement of the vertebrae relative to each other, which will be the reason for further examination with other instrumental methods;
• CT is a more advanced method for studying the condition of bones, allowing one to visualize the slightest changes in them, the presence of tumors of various natures;
• MRI is the most informative method for diagnosing diseases of soft tissues and cartilage, which, in fact, are intervertebral discs; with its help, even the smallest protrusions and hernias, vascular tumors, aneurysms, spinal stenosis and a number of other common spinal diseases are detected;
• electromyography – used to assess the quality of nerve impulses to muscles and the intensity of their contraction;
• Ultrasound is used to diagnose gynecological, urological and a number of other diseases of internal organs, which can cause the development of an inflammatory process.

Often, instrumental diagnostic methods are complemented by laboratory tests. Depending on what diseases the doctor suspects, the patient may be prescribed a general blood and urine test, biochemical blood test, etc.