The Hip: Preservation, Replacement and Revision

Forces acting on the Hip Joint

- Discussion:
    - broad range of forces acts upon the hip joint;
    - muscles that cross hip joint generate most of the load that it bears;
    - femoral neck fracture:
           - distance between the head and shaft of the femur determines the moment arm tending to produce varus;
           - shorter moment arm, & thus less deforming force, follows valgus reduction;
    - gait:
           - standing:
                  - wt of body equally distributed to lower limbs, so that weight on each femoral head is half of the body weight above hips;
                  - in one-legged stance, as in walking, head of femur serves as fulcrum;
                         - the standing hip must support the wt of the patient's head, upper extremities, torso, as well as the contralateral, non supporting, limb;
                  - in order to maintain the pelvis level to the ground, the gluteus medius & minimus must pull pelvis downward lateral to the fulcrum.
                         - upward opposing force is that of fulcrum, head of femur, force that is sum of the two downward forces;
                  - cane obviates decrease need for hip abductors on affected side to contract;
                  - may relieve upto 60% of the load on hip in stances phase;
                  - unsupported gait may result in 4 to 7 times body wt across hip where as supported gait (w/ a walker or a cane) may produce loads across the hip of 2-3 times body wt;
    - supine:
           - joint reaction forces during supine straight leg raising > 3 times body wt;
           - getting on & off bed pan is equal to four times body wt

Hip joint loading during walking and running, measured in two patients.

Telemeterized in vivo hip joint force data: a report on two patients after total hip surgery.

Telemetric Force Measurements across the Hip after Total Arthroplasty.

Medial-displacement intertrochanteric osteotomy in the treatment of osteoarthritis of the hip. A long-term follow-up study.

Hip Motion Measurements for Selected Activities of Daily Living.

The Effect of Cane Use on Hip Contact Force.

Mechanics of the normal and osteoarthritic hip. A new perspective.

The role of femoral neck anteversion in the development of osteoarthritis in dysplastic hips

Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Thursday, December 11, 2014 1:25 pm