Age / Sex : 61 / F

Chief complaint: right buttock pain with external rotation and abduction of the hip for 2 years

1) What is your impression?

Two weeks later, you can see the final diagnosis with a brief discussion of this case.

(Quiz는 quiz일 뿐이오니 답안은 한개만 보내주시기 바라오며, 복수의 답안을 보내주시는 분은 정답이 포함되어 있더라도 부득이 semi-correct answer로 처리토록 하겠습니다.)

Courtesy: 최상희(Sang-Hee Choi), 삼성서울병원(Samsung Medical center)

Ischiofemoral impingement syndrome

Discussion

Findings:

There is significant
narrowing of the right ischiofemoral distance compared with the contralateral
side (arrow), and the intervened quadratus femoris muscle shows abnormally high
signal intensity.

Diagnosis:
 

Ischiofemoral
impingement syndrome

Discussion:

Ischiofemoral
impingement is caused by the chronic osseous changes and narrowing of the space
between the lesser trochanter and ischium. With the hip in adduction, external
rotation, and extension, the lesser trochanter and ischial tuberosity are
normally about 2.0 cm apart, which allows the femur to rotate without
contacting the ischial tuberosity or proximal hamstring tendons. However, abnormal
relationship between the lesser trochanter and ischium may lead to injury of
intervening soft tissues, such as the quadratus femoris muscle or the iliopsoas
insertion and proximal hamstring tendons.

The etiologic factors include previous intertrochanteric
fractures, degenerative arthritis, anatomical variability of the ischium or the
femur and sessile osteochondroma.
Although there is no known sex­related anatomic variability of the lesser
trochanter, it is possible that women with prominence of this structure may be
predisposed to ischiofemoral impingement.

Ischiofemoral Impingement usually causes hip
pain and radiating pain to the lower extremity due to the proximity of the
edematous quadratus femoris muscle to the sciatic nerve. Also, it was reported
that a snapping sensation with motion of the hip could be related to this
syndrome.

The
radiological findings include abnormal signal of quadratus femoris
muscle, which suggests edema or hemorrhage, probably related to muscle strain or
tear as well as significantly narrower ischiofemoral and quadratus femoris
spaces.

Although the
ischiofemoral impingement requires further validation radiologically, it is
clear that, in a subset of patients with hip pain, we should include the
ischiofemoral impingement as a differential diagnosis with careful looking into
ischiofemoral spaces and intervened soft tissues.

References:

1.    
Martin
Torriani, Silvio C. L. Souto, Bijoy J. Thomas, Hugue Ouellette, Miriam A.
Bredella Ischiofemoral Impingement Syndrome: An Entity With Hip Pain and
Abnormalities of the Quadratus Femoris Muscle.  AJR 2009;193: 186-190

2.    
Patti JW,
Ouellette H, Bredella MA, Torriani M. Impingement of lesser trochanter on
ischium as a potential cause for hip pain.  Skeletal Radiol 2008;37:939–941

3.    
O’Brien SD,
Bui­Mansfield LT. MRI of quadratus femoris muscle tear: another cause of hip
pain.  AJR 2007; 189:1185–1189

4.    
Bredella MA,
Stoller DW. MR imaging of femoroacetabular impingement. Magn Reson Imaging.  Clin N Am 2005; 13:653–664