REIDER PART 225

Chapter 5_Pelvis> Hip, and Thigh 185

Figurę 5-36. I lip external rotation in tlexion.

motions avcragc about 45° of external rotation and 30° of internal rotation, although thc American Academy of Orthopaedic Surgeons handbook reports average internal rotation to be 45° in this position. If passive hip rotation is painful, pathology of the hip joint or femoral ncck should be suspected.

Rotation in flexion may also be assessed with thc patient in the seated position. Except for thc fact that the patient has been rotated 90" in space, the cxamina-tion in the seated position is identical to the procedurę just described for the supine position. The potential advantage of the seated position is that the patient s body weight tends to stabilize thc pclvis and prcvcnt pelvic rotation from supplcmcnting hip motion (Fig. 5-38).

It is important to notę that the presence of a pros-thetic hip is a contraindication to evaluating hip rotation

Figurę 5-37. Hip internal rotation in fiexion.

Figurę 5-38. Hip rotation in flexion, seated position.

or abduction-adduction in the flexed position. In the presence of a prosthesis, rotation is morę safely assessed with thc hip extcnded. Failure to heed this warning may rcsult in the dislocation of a prosthetic hip, especially in the early postoperative period.

PALPATION

Palpation for localized tenderness often hclps to pinpoint the cause of pain around thc hip and the pelvis. Often, the patient helps direct the examiner to thc appropriate area by indicating the spot where thc pain appears to be centered.

Anterior Aspect

llium. The ASIS is an easily identifiable landmark in most patients and a good place to start palpation (see Fig. 5-1). The ASIS, serving as the origin of the sartorius muscle, is a common site for one of the apophyseal avul-sion fractures that tend to occur in adolescents. Other sites include the iliac crest, thc AIIS, thc ischial tuberosity, and the lesser trochanter. Because these fractures are often minimally displaced and thus difficult to identify radiographically, the finding of localized tenderness over one of the typical apophyses may be the primary mcans of diagnosing an avulsion fracture about the hip.

Moving posteriorly from the ASIS, the examiners fingers are able to tracę the rest of the iliac crest. The anterior portion of the iliac crest is another common site of avulsion injury. This may present as an acute fracture or an ovcrusc injury of insidious onset, in which case the condition is usually called iliac apophysitis. Exquisite tenderness ovcr thc iliac crest following a direct blow sug-gests thc presence of a localized hematoma collocjuially known as a hip pointer, a common injury in football and other contact sports.