The Hip




Hip Checklists



Radiographic examination





  • Hip




    • AP pelvis



    • AP hip



    • Frog leg-view hip



    • Groin lateral hip




  • Femur




    • AP hip



    • AP femoral shaft and condyles



    • Lateral femoral shaft and condyles



    • Oblique femoral shaft





Common sites of injury in adults





  • Elderly – low-impact trauma (fall from standing height)




    • Femoral neck



    • Intertrochanteric



    • Greater trochanter



    • Pelvic fractures presenting as hip fractures




      • Pubic rami



      • Iliac wing





  • Adult – R/O pathologic fracture




    • Basicervical fractures



    • Lesser trochanteric avulsions



    • Transverse subtrochanteric fractures




  • Adult – high-impact trauma (MVC)




    • Posterior hip dislocation



    • Femoral neck



    • Subtrochanteric



    • Femoral shaft





Hip fractures rare in children and adolescents





  • Pelvic fractures about hip common




    • Pubic rami



    • Iliac wing




  • Occasional




    • Femoral neck



    • Posterior dislocation



    • Proximal femoral epiphyseal separation rare




      • Slipped capital femoral epiphysis (SCFE)






Injuries likely to be missed





  • Low-impact trauma – elderly




    • Fine, subtle fractures




      • Femoral neck



      • Intertrochanteric





  • High-impact trauma – all ages




    • Proximal injuries of the hip in association with femoral shaft fractures




      • Posterior dislocation of hip



      • Fracture of acetabulum



      • Fracture of femoral neck






Where else to look when you see something obvious
























Obvious Look for
Fracture of femoral shaft Posterior dislocation of hip
Fracture of acetabulum
Fracture of femoral neck
Fracture of distal femur (condyles)
Fracture of patella
Fracture of greater trochanter Intertrochanteric extension (MRI)



Where to look when you see nothing at all





  • Search for alternative diagnoses, fractures of




    • Iliac crest



    • Pubic rami



    • Acetabulum



    • Greater trochanter of proximal femur




  • Need to rule out obscure/not apparent femoral neck or intertrochanteric fracture




    • If questionable radiographic findings noted – CT often sufficient



    • If x-rays negative – MRI required






Hip – The Primer



Radiographic examination





  • Hip




    • AP pelvis



    • AP hip



    • Frog leg-view hip



    • Groin lateral hip




  • Femur




    • AP hip



    • AP femoral shaft and condyles



    • Lateral femoral shaft and condyles



    • Oblique femoral shaft




A radiographic examination of the traumatized hip should include the four standard views listed above. An AP of the pelvis ( Fig. 9-1 A ) is included to survey the surrounding bony pelvis for fractures (i.e., pubic rami and iliac wings), which can mimic hip fractures. The AP view of the hip ( Fig. 9-1 B ) should be obtained with the hip in internal rotation to place the femoral head and neck in profile. If the patient’s foot is in external rotation and he or she is unable to rotate the foot, the AP view should be taken as the patient lies, because with displaced fractures of the femoral neck the hip is typically held in external rotation. If this view shows no evidence of hip fracture, the toes should be brought together by wrapping the forefeet in a towel to place the hip in internal rotation, and a repeat AP view should be obtained. The frog leg-view ( Fig. 9-1 C ) is obtained with leg abducted and externally rotated, in effect, resulting in a modified lateral view of the proximal femur. The groin lateral ( Figs. 9-1 D and 9-1 E ) is an optional view of the femoral head and neck that better demonstrates posterior rotation of the femoral head in the presence of subcapital fractures.




FIGURE 9-1


Radiographic view of the traumatized hip: An AP of the pelvis ( A ) showing the surrounding bony pelvis for fractures that can mimic hip fractures; an AP view of the hip ( B ) in internal rotation to place the femoral head and neck in profile; the frog-leg view ( C ) with leg abducted and externally rotated results in a modified lateral view of the proximal femur. The groin lateral ( D, E ) is an optional view of the femoral head and neck that better demonstrates posterior rotation of the femoral head in the presence of subcapital fractures.


The AP view with slight internal rotation of the hip ( Fig. 9-2 A ) best profiles the head and neck junction, which facilitates identification of fractures of the femoral neck and intertrochanteric femur. With a displaced fracture of the femoral neck the distal fragment lies in external rotation, and the femur is drawn proximally ( Fig. 9-2 B ). External rotation of the hip on the AP view in the absence of a femoral neck fracture is, unfortunately, a common occurrence ( Fig. 9-2 C ). External rotation of the hip foreshortens the femoral neck, and the underlying greater trochanter obscures the femoral head and neck junction. Fractures of the femoral neck are difficult to identify on such views.




FIGURE 9-2


AP view showing slight internal rotation of the hip ( A ) best profiles the head and neck junction to identify femoral neck and intertrochanteric femur fractures. A displaced fracture of the femoral neck showing the distal fragment in external rotation with the femur drawn proximally ( B ). External rotation of the hip on the AP view without a femoral neck fracture is a common occurrence ( C ).


Subcapital fractures, particularly nondisplaced fractures, are obscured and readily overlooked ( Fig. 9-3 A ) with external rotation. A repeat PA view should be obtained with slight internal rotation of the femur ( Fig. 9-3 B ). Note that an impacted subcapital fracture is now visible. An even more striking example of difficulty in seeing fractures on the AP view with external rotation is shown in Fig. 9-4 . On the initial AP view with external rotation no fracture is seen or even suspected ( Fig. 9-4 A ). However, the repeat, properly positioned AP view clearly depicts a widely separated fracture of the greater tuberosity ( Fig. 9-4 B ) that is not apparent on the initial examination.




FIGURE 9-3


With external rotation, subcapital fractures, particularly nondisplaced, are obscured and can easily be overlooked ( A ). In a repeat PA view, there is a slight internal rotation of the femur with subcapital fracture now visible ( B ).



FIGURE 9-4


AP view example that demonstrates difficulty in seeing fractures with external rotation shown ( A ). On the initial AP view with external rotation no fracture is seen or even suspected. A properly positioned AP view depicts a widely separated fracture of the greater tuberosity ( B ) that is not apparent on the initial examination.



Common sites of injury in adults





  • Elderly – low-impact trauma (fall from standing height)




    • Femoral neck



    • Intertrochanteric



    • Greater trochanter



    • Pelvic fractures presenting as hip fractures




      • Pubic rami



      • Body of the pubis



      • Iliac wing





  • Adult – R/O pathologic fracture




    • Basicervical fractures



    • Lesser trochanteric avulsions



    • Transverse subtrochanteric fractures




  • Adult – high-impact trauma (MVC)




    • Posterior hip dislocation



    • Femoral neck



    • Femoral shaft




Pattern of search


A diagram of the hip ( Fig. 9-5 A ) pinpoints the common sites of fracture in adults as identified by red lines. Your pattern of search should include all sites: subcapital, intertrochanteric, and greater trochanteric.




FIGURE 9-5


A diagram of the hip ( A ) with redlines pinpointing the common sites of fracture in adults. Displaced subcapital fractures are held in external rotation, and the femoral shaft is drawn proximal, shortening the femur ( B ). The groin lateral view ( C ) shows the posterior rotation and displacement of the femoral head. A hemiarthroplasty is required for displaced fractures of the femoral neck that result in devascularization of the femoral head ( D ).


Fractures of the hip are most commonly encountered in the elderly in association with generalized osteoporosis. They occur in low-impact trauma, usually a fall from a standing height. The most common is a subcapital fracture of the femoral neck. Displaced subcapital fractures are held in external rotation, and the femoral shaft is drawn proximal, shortening the femur ( Fig. 9-5 B ). The groin lateral view ( Fig. 9-5 C ) shows the posterior rotation and displacement of the femoral head. Follow the anterior cortex of the femur to the fracture. Displaced fractures of the femoral neck result in devascularization of the femoral head, and therefore a hemiarthroplasty ( Fig. 9-5 D ) is required.


Subcapital fractures


Most subcapital fractures are impacted; two cases are shown ( Figs. 9-6 A and 9-6 B-E ). The head fragment is usually rolled posterolateral, valgus ( Figs. 9-6 A and 9-6 B ), or, less commonly, posteromedial, varus (see Fig. 9-7 ) and impacted on the femoral neck. Disruption of the medial cortex of the femoral neck ( Fig. 9-6 A ) is variable and often not apparent ( Fig. 9-6 B ). CT confirms the diagnosis in questionable cases ( Fig. 9-6 C , coronal reconstruction, and Fig. 9-6 D , axial). Impacted fractures are treated by screw fixation ( Fig. 9-6 E ) because the majority of the blood supply to the femoral head remains intact and therefore the head is viable.


Mar 23, 2019 | Posted by in MUSCULOSKELETAL IMAGING | Comments Off on The Hip
Premium Wordpress Themes by UFO Themes