REIDER PART 229

Chapter 5_Pelvis, Hip, and Thigh 189

Sacrum and Coccyx. In the posterior midline, the firm prominence created by the sacral promontory is usually easily palpable. Tenderness of the sacrum may be caused by fracture, tumor, or infection. By following the sacrum distally into the natal crease, the examiner can identify and palpate the coccyx (Fig. 5-46). Owing to its location, the coccyx is a common site of pain, whether due to a fali on the buttocks or chronic irritation from prolonged sit-ting. Coccyodynia, or painful coccyx, may be caused by overuse, fracture, or disruption of one of the joints between the smali segments that constitute the coccyx.

If any uncertainty exists, a rectal examination can be helpful in confirming the coccyx as the site of pain. In this case, the patient is placed in the decubitus position and the upper hip flexcd. The examiner performs a rectal examination with the index finger. This allows the exam-iner to grasp the coccyx between the index finger, from within the rcctum, and the thumb, from the outside (Fig. 5-47). The coccyx may then be manipulated back and forth to see whether pain is elicited.

Ischium. The ischial tuberosity is located at the medial inferior margin of the gluteal prominence in the standing patient. However, palpation of the ischial tuberosity is most easily accomplished with the patient lying supine and the ipsilateral hip flexed 45° with the foot resting comfortably on the table (Fig. 5-48). Tenderness of the ischial tuberosity may indicate an avulsion fracture due to the hamstrings that originate there or from a direct fali onto the buttocks. Inflammation of the bursa, which occurs over the ischial tuberosity in individuals who habitually sit on hard surfaces, is sometimes known as weaver’s bottom.

Figurę 5-47. Simulated manipulation of the coccyx during rectal examinalion.

Piriformis. Knowledge of the location of major tendon insertions of the posterior aspect of the hip hclps the examiner differentiate among various sources of posterior hip pain. The piriformis tendon inserts into the piriformis fossa on the posterior superior aspect of the greater trochanter beneath the inferior border of the glu-teus medius muscle. The piriformis fossa is not palpable directly, but lies beneath the hook of the greater trochanter, which may be palpated with the patient lying with the leg maximally internally rotated (Fig. 5-49). In this position, the most prominent posterior structure on the greater trochanter is the hook of the trochanter. Tenderness to deep palpation at this site, combined with a positive piriformis test as described in the Manipulation section, suggests the presence of piriformis tendinitis. Gluteus Maximus. The gluteus maximus tendon may be palpated near the gluteal fold at the inferior aspect of the gluteus maximus. Tenderness at this location, combined with a painful response to Yeoman^ test, suggests a gluteus maximus tendinitis.

Figurę 5-48. Palpation of the ischial tuberosity.