Age / Sex : 62 / M

Ischiofemoral impingement syndrome

Discussion

Findings:

1.     Increased T2SI in left quadratus femoris muscle

2.     Decreased distance between left ischial tuberosity and femoral lesser tuberosity(narrowing of left ischiofemoral space)

Differential Diagnosis:
Quadratus femoris muscle injury/myositis

Diagnosis:  
Ischiofemoral impingement SD

Discussion:  

Ischiofemoral impingement is an uncommon source of hip, groin and/or posterior thigh pain that is usually seen in middle-aged to elderly women. Congenital or acquired narrowing of the ischiofemoral space results in compression or impingement of the quadratus femoris muscle, leading to edema, best demonstrated by MR. Fatty atrophy of the muscle may ensue. It is postulated that, with severe edema, irritation of the adjacent sciatic nerve may cause sciatica. MRI is required for diagnosis but not all patients with ischiofemoral narrowing or quadratus femoris muscle edema are symptomatic. Affected patients often have adjacent muscle or tendon abnormalities and these, as well as the hip joint, are generally well evaluated with MR.

P/E> Symptoms may be reproduced by a combination of hip extension, adduction and external rotation or with flexion and internal rotation.

MR> QFM edema, fatty atrophy, deformity in the LT/IT

ischiofemoral space cut-off for  IFI: ≤ 15 mm (sensitivity 77%, specificity 81%)

Differential diagnosis> QFM or adductor muscle tear and tendinitis, hamstring injury, snapping hip syndrome, piriformis syndrome and lumbar radiculopathy.

References:

1.     Singer AD et-al. Ischiofemoral impingement syndrome: a meta-analysis. Skeletal Radiol. 2015;44 (6): 831-7.

2.     Johnson KA. Impingement of the lesser trochanter on the ischial ramus after total hip arthroplasty. Report of three cases. J Bone Joint Surg Am 1977; 59:268-269.

3.     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.

4.     Torriani M, Souto SC, Thomas BJ, Ouellette H, Bredella MA: Ischiofemoral impingement syndrome: an entity with hip pain and abnormalities of the quadratus femoris muscle. AJR 2009; 193:186-190.

5.     Ali AM, Whitwell D, Ostlere SJ. Case report: imaging and surgical treatment of a snapping hip due to ischiofemoral impingement. Skeletal Radiol 2011; 40:653-656.

6.     http://radsource.us/ischiofemoral-impingement-syndrome/