Where is the coccyx located

At the bottom of the lumbar spine below the waist, there is a bone called the coccyx. It is shaped like an inverted triangle and supports the vertical position of the entire lumbar spine. Moreover, there are many nerves distributed around the coccyx, and this part is relatively fragile. If you do not pay attention to your sitting and standing posture, it is easy to cause a coccyx fracture. Therefore, if you want to maintain the health of the coccyx, you must do more physical exercises, such as running, high jumping, playing ball, etc. The following will give you a detailed introduction to where the coccyx is.

The coccyx is slightly triangular in shape and is formed by the fusion of 3 to 5 coccygeal vertebrae. The fusion is usually completed at the age of 30 to 40 years old. The coccygeal angle that extends upward from the base is the superior articular process of the first coccygeal vertebra, which is articulated with the sacral angle. On the outside of the coccygeal angle, there is a pair of sharp processes extending outward on each side, which are the transverse processes of the coccygeal vertebrae. The transverse process of the second coccygeal vertebra is very small. The 3rd and 4th coccygeal vertebrae degenerate into small nodular bone blocks.

Overview

The coccyx has no vertebral arch and therefore no vertebral canal. The coccyx has a pointed lower end and a base at the upper end. Its oval articular surface forms a joint with the tip of the sacrum, with a fibrocartilage disc in between. The depression at the posterior and superior part of the coccyx where it is connected to the sacrum is called the sacrococcygeal space. There is a coccygeal angle on each side of the posterior part of the articular surface, which is equivalent to the vertebral arch and superior articular process of the coccyx.

The rear edge of the base of the coccyx is higher than the front edge and faces forward and downward. Its front is slightly concave and smooth, while the back is protruding and rough. The shape of the coccyx can vary greatly. It can be asymmetrical on both sides, and its curvature can be forward-bending or tilted to one side.

Development history and functions

Bony fusion may occur at the sacrococcygeal joint. In humans, it is a degenerate bone and has little impact after removal. When sitting, the coccyx does not bear the weight, but the ischial tuberosity bears the weight. The coccyx can fuse with the sacrum to form one bone in later life, which is more common in women. The coccyx can change the shape of the pelvic outlet. If the coccyx cannot move, it may fracture during childbirth.

Related diseases and treatments

1. Coccyx fracture is relatively common, mostly caused by direct violence. A small number of people will experience local persistent pain after a coccyx fracture.

2. Methods

2.1 Manual reduction treatment: Instruct the patient to empty the stool, perform a cleansing enema, and take the knee-chest position. The operator wears gloves, and after dilating the anus, he inserts the index and middle fingers together into the anus, presses the posterior wall of the rectum with the two fingertips, and slowly and evenly applies force to lift the distal end of the coccyx fracture posteriorly and upward to reposition it. Be careful not to use force to avoid damaging the rectum. Avoid sitting for 3 weeks after reduction. Patients who failed manual reduction underwent surgical treatment.

2.2 Surgical treatment: Empty the stool and perform a cleansing enema before surgery. The patient was placed in the right lateral position with the hip and knee flexed 90° each, and the surgical field was disinfected with 1:5000 Sanisol. The operator wears gloves, stuffs a treatment towel between the two legs in front of the anus, places a hole towel on the sacrum and coccyx, and performs anal reduction under local infiltration anesthesia with 1% lidocaine. Touch the coccyx with your index finger and push it gently backwards, then push up with your right thumb to reset it. After reduction, disinfection is performed again. The operator uses the left index thumb to maintain the position and holds a 2-2.5 mm Kirschner wire in the right hand, which is inserted into the skin 3-4 cm behind the anus to the coccyx. The assistant wears gloves, tightens the Kirschner wire with a hand drill, and gently drills from the distal end of the fracture to the proximal end, and drills vertically into the sacrum 2 to 2.5 cm through the sacrococcygeal joint (avoid violent operation to prevent the Kirschner wire from slipping and drilling through the posterior wall of the rectum). Then the assistant loosens the hand drill, and the operator shakes the Kirschner wire and uses the left index finger to feel that the coccyx has no movement. After confirming that it is firmly fixed, the needle tail is bent, 0.5 cm is cut off, and it is rotated to one side of the coccyx and buried under the skin. After disinfection again, the needle eye is pressed with an alcohol cotton ball and a skin care film or a Band-Aid is applied. Antibiotics were used appropriately after surgery, and the Kirschner wires were removed after 4 weeks.