Assessment Of The Ischiofemoral Space And The Correlated Factors Using Ultrasonography

Reduction in the ischiofemoral space will extrude the muscle inside it, ading to ischiofemoral impingment, which is an uncommon cause of hip and )uttock pain. Assessing the ischiofemoral accurately, and evaluating the correlated factors are important in diagnosis and treatment of ischiofemoral mpingment.Part 1 Study of the dimensions of ischiofemoral space relative to femur positionObjective:To measure the dimensions of ischiofemoral space in iifferent femoral position in normal hip joint and to investigated the possibility of using ultrasonography in measuring the dimensions of schiofemoral space.Methods:1 Measurement of the dimensions of ischiofemoral space in different emoral positions in cadaver specimens. Ten adult formalin-fixed cadaver pecimens (six male and four female) in scientific research were collected om the department of anatomy of Hebei Medical University. The cadaver pecimens that lay in prone position were given an opography posterior to hip oint.The lesser trochanter of femur and ischial tuberosity were exposed. The ower limbs were set in three different positions with the trans-articular external fixator, three different femur positions involved neutral position, 15° posterior extension and 30°osterior extension. The narrowest distances between the lesser trochanter of femur and ischial tuberosity were measured )y sliding caliper and then analyzed statistically.2 Measurement of the dimensions of ischiofemoral space in different emoral positions using ultrasonography.23 male and 12 female subjects with no hip pain and no history of hip disorders or surgery were recruited in the >tudy. Ultrasound was used to measure the ischiofemoral space in bilateral luteal regions of each volunteer. The volunteers underwent imaging in a rone position. The ischiofemoral space was defined as the narrowest distance etween the medial cortex of the lesser trochanter and the lateral cortex of the schial tuberosity. The ischiofemoral space was measured in three different emur positions involved neutral position,15°osterior extension and 0° posterior extension. The dimensions of ischiofemoral sapce in different emoral position and different sex were analysed statically.Results:1 Measurement in cadaver specimens showed that the dimensions of IFS vere 2.10±0.43cm,1.81±0.40cm,1.66±0.38cm respectively in neutral osition,15°osterior extension and 30°osterior extension in left side, and vere 2.01±0.48cm,1.78±0.43cm,1.60±0.46cm respectively in right side. Fhere was no statistically significant difference in the dimensions of IFS etween the left side and the right side in each hip position(P>0.05). IFS was arrower in 15± posterior extension than neutral position(P<0.05), and was arrower in 30° posterior extension than 15° posterior extension (P<0.05)2 In ultrasound examination, the lesser trochanter of femur and ischial uberosity were easily identified in all subjects. The dimensions of IFS were 48±0.57cm,2.24±0.52cm,1.97±0.52cm respectively in neutral position,15° osterior extension and 30° posterior extension in left side, and were 39±0.51cm,2.18±0.52cm,2.00±0.54cm respectively in right side. There vas no statistically significant difference in the dimensions of IFS between the ft side and the right side in each hip position(P>0.05). IFS was narrower in 5° posterior extension than neutral position(P<0.05), and was narrower in 50° posterior extension than 15° posterior extension (P<0.05).The schiofemoral space was narrower in female than that in male (P<0.05):The FS was 2.62±0.44cm in male and 1.93±0.25cm in female in neutral position, .39±0.51cm in male and 1.77±0.20cm in female in 15° posterior extension, .16±0.60cm in male and 1.67±0.17cm in female in 30° posterior extension.Either in male or female, IFS was narrower in 15° posterior extension than neutral position(P<0.05), and was narrower in 30° posterior extension than 15° posterior extension (P<0.05)Conclusions:The ischiofemoral space is narrower in hip posterior extension position. The ischiofemoral space is narrower in female than that in male. Ultrasonography may be used to measure the dimension of ischiofemoral space, and may be a preliminary screening method to ischiofemoral impingement diagnosis.Part 2 The impact of morphology of ischium to the dimension of ischiofemoral spaceObjective:To evaluate the impact of morphology of ischium to the dimension of ischiofemoral space, and to evaluate the significance of assessing the morphology of ischium to keeping the appropriate ischiofemoral space.Methods:1 Measurement of angulations between the body of ischium and vertical axis.100 pelycograms (58 male and 42 female) were collected. Inclusion age was above 18 years old. Main inclusion criteria of the pelycograms which we collected are as follows:there should be no fracture, no congenital deformities or no unusual bony change in body of ischium. Apex of coccyx lies oppositely to the upper margin of pubic symphysis, both obturator foramen are symmetrical and similar. Angulations between the body of ischium and sagittal axis were measured on the pelycograms by Image Processing Software Photoshop. The angulations between left side and right side was analyzed, and so was the angulations between male and female.2 Measurement of the dimensions of ischiofemoral space.23 male and 2 female subjects with no hip pain and no history of hip disorders or surgery ere recruited in the study. Ultrasound was used to measure the ischiofemoral pace in bilateral gluteal regions of each volunteer. The volunteers underwent maging in a prone position. The ischiofemoral space was measured with hip n neutral position. Correlation was analyzed between the angulations between the body of ischium and vertical axis and the dimensions of ischiofemoral space.Results:The angulations between the body of ischium and vertical axis vas 23.19°±5.92°in the left side and 22.03°±4.38°in the right side.There was o statistically significant differences between the left side and the right >ide(P>0.05). The angulations between the body of ischium and vertical axis vas 25.03°±4.56°in male 19.23°±5.72°in femal. The angulations between the ody of ischium and vertical axis were smaller in female than in hale(t=-3.52,P=0.001).2.The correlation of the angulations between the body f ischium and vertical axis and the dimensions of ischiofemoral space. The iimension of ischiofemoral space measured using ultrasonography was 39±0.51cm in 35 volunteers. The angulation between the body of ischium nd vertical axis was 20.36°±5.56°. The angulations between the body of schium and vertical axis were correlated with the dimensions of schiofemoral space. The dimension of ischiofemoral space measured using iltrasonography was 2.62±0.44cm in male. The angulation between the body of ischium and vertical axis was 22.07°±4.60° in male. The angulations between the body of ischium and vertical axis were correlated with the iimensions of ischiofemoral space in male. The dimension of ischiofemoral space measured using ultrasonography was 1.93±0.25cm in female. The angulation between the body of ischium and vertical axis was 17.08°±6.00° The angulations between the body of ischium and vertical axis were correlated vith the dimensions of ischiofemoral space in female.Conclusion:The angulations between the body of ischium and vertical xis were smaller in female than in male;The angulations between the body of schium and vertical axis was correlated with the dimension of ischiofemoral space. The patients undergoing the hip surgery with small angulation should e paid more attention in keeping the approriate ischiofemoral space.Part 3 The impact of femoral offset to ischiofemoral space in femoral head necrosisObject:To assess the dimension of ischiofemoral space in the femoral head necrosis patients with femoral head collapse, and to assess the relationship between ischiofemoral space and femur offset.Methods:Eight male and two female with femoral head necrosis were recruited. All the patients were diagnosed unilateral femoral head necrosis stage Ⅲ or Ⅳ. The offside hip joints were normal. The patients with femoral neck fraction were excluded. Ultrasonography was used to measured the dimension of ischiofemoral space in three different femur positions involved neutral position,15°osterior extension and 30°osterior extension. Pelycograms were collected to measure the distance from the center of rotation of the femoral head to a line dissecting the long axis of the femur, the offset. Compare the dimension of ischiofemoral and offset in different position and between the affected side and the offside. The correlation of the dimensions of ischiofemoral and offset was analyzed.Results:The dimensions of ischiofemoral space were 2.35±0.31cm, 1.91±0.56cm,1.77±0.63cm respectively in neutral position,15°osterior extension and 30°osterior extension in offside and 1.81±0.42cm 1.35±0.51cm,0.10±0.07cm respectively in affected side. There were statistically significant differences between affected side and the offside(neutral position t=3.493，P=0.043; 15° posterior extension t=6.385， P=0.008; 30° posterior extension t=3.145 ， P=0.041).The offset was 39.27±2.05cm in the offside and 29.68±1.10cm in the affected side t=15.142, P=0.001).The dimension of ischiofemoral space was correlated with the offset (r=0.694,P=0.044)Conclusion:Femoral head necrosis with collapse will induce a reduction of ischiofemoral space and offset. There was correlation between the dimension of ischiofemoral space and the offset. Reconstruction of the offset could be effective method to avoid ischiofemoral impingement.