- See: Anterior Capsulotomy
- Discussion:
- fibrous capsule encloses hip joint & greater part of neck of femur;
- it encloses the femoral head and most of its neck;
- capsule is attached anteriorly at the intertrochanteric line;
- posteriorly the lateral half of the femoral neck is extracapsular;
- reinforcing the capsular ligament are three ligaments:
- triangular iliofemoral ligament:
- strongest ligaments of hip capsule.
- anterior ligament which is attached above to ASIS & adjacent acetabular rim, and below to intertrochanteric line;
- medial iliofemoral ligament: resists anterior hip translation with hip extension and external rotation;
- lateral iliofemoral ligament: resists internal and external rotation with the hip in extension;
- pubofemoral ligament:
- attached to pubic portion of acetabular rim & superior ramus of pubis, & to inferior surface of neck of the femur;
- this ligament lies in the front of the hip joint;
- augments stability of the hip against external rotation in extension
- ischiofemoral ligament:
- attached to ischial wall of acetabulum & to neck of femur medial to base of greater trochanter;
- this ligament lies above and behind the joint.
- orientation of fibers of capsule & of three ligaments is such that they "wind up tightly" when femur is fully extended;
- has the effect in limiting hip internal rotation in both extension and flexion
- Hip Capsule in Femoral Neck Frx:
- displaced femoral neck frx may disrupt posterior part of hip capsule, however, capsule may remain intact w/ minimally displaced fractures;
- intracapsular hematoma may elevate pressure enough to occlude venous drainage system within capsule;
- this increased intracapsular pressure may have an adverse effect on the final clinical outcome, thru occlussion of local arterioles;
- extension & internal rotation of hip elevate intracapsular pressure due to effect on volume of capsule, and this position is avoided in pts w/ femoral neck frx;
- femoral neck frx may increase intracapsular pressure and capsular distention;
- this may decrease perfusion through the capsular vessels and contribute to development of osteonecrosis;
- immediate joint aspiration following femoral neck frx may reverse intracapsular pressure and AVN;
- anterior capsulotomy:
- may reduce danger of ischemia of femoral head;
- performed under direct vision, in line w/ femoral neck on anterior surface; which also allows an anatomical reduction under direct vision
- technique:
- straight lateral incision is made from the top of the trochanter to point 1 cm distal to the lesser trochanter;
- fascia lata is incised longitudinally & vastus lateralalis either split or lifted anteriorly;
- capsular attachements at trochanteric ridge/vastus tubercle can be exposed with anterior retraction and the capsule incised in line w/
neck of the femur and released proximally and distally from intertrochanteric ridge to produce a T shaped capsulotomy
- references:
- Intracapsular pressure and caput circulation in nondisplaced femoral neck fractures.
- Intracapsular pressure and hemarthrosis following femoral neck fracture.
- Intracapsular pressures in undisplaced fractures of the femoral neck.
- Capsular distension and intracapsular pressure in subcapital fractures of the femur.
- Intracapsular pressure and caput circulation in nondisplaced femoral neck fractures.
- Intraosseous pO2 in femoral neck fracture. Restoration of blood flow after aspiration of hemarthrosis in undisplaced fractures.
- Hip Joint Tamponade - an etiologic factor in the osteonecrosis of Legg Calve Perthes Disease.
Gershuni PH, Hargens AR, Greenberg EN, et al. Trans Orthop Rec Soc. Las Vegas, Feb 1981.
The function of the hip capsular ligaments: a quantitative report.
Fluoroscopically guided hip capsulotomy: effective or not? A cadaveric study
An Anatomic Arthroscopic Description of the Hip Capsular Ligaments for the Hip Arthroscopist