Lower Extremity Hip Joint z z z z z Introduction Acetabulum Acetabulum z Head of the femur with acetabulum of innominate Ball in socket Better union than shoulder Acetabular labrum similar to glenoid labrum Acetabulum is not a complete circle open inferiorly This opening is closed by the transverse ligament Head of femur attached to inside of acetabulum by ligamentum teres AKA Head ligament Acetabulum Transverse Ligament 1 Femur Anterior Femur Posterior Hip Joint Hip Joint Hip z z z Anterior Capsule Strong but loose joint capsule running from above the acetabulum and labrum down to the intertrochanteric line Suction exists in joint owing to atmospheric differences this increases joint stability Approximately 70 of head of femur in contact with acetabulum at max contact 2 Posterior Capsule Anterior Capsule Head Ligament Acetabular Labrum Y Ligament Hip z z z z Iliofemoral ligament AKA the Y ligament or the Y ligament of Bigelo AIIS inferiorly to the intertrochanteric line Triangular in shape Supports hip anteriorly resists extension internal rotation and some external rotation 3 Hip Joint Ligaments Y Hip z z z Pubofemoral Runs from the superior pubic ramus and the acetabular rim to just above lesser trochanter Resists ABD with some resistance to external rotation Pubofemoral Pubofemoral Hip z z z z Ischiofemoral Ischiofemoral From the ischium to the posterior neck of the femur is directed upwards and laterally Resists ADD and internal rotation ALL three loose during flexion the freest motion 4 Hip z My Friends Nerve Supply Superior gluteal Inferior gluteal and Femoral z Blood Supply Medial circumflex artery Lateral circumflex artery z Bursae Iliopectineal Blood Supply to Hip Iliopectineal Bursae Blood Supply Hip Angles z z Femur is held away from the hip joint and the pelvis via the femoral neck Forms an angle called the angle of inclination z In the frontal plane angle approximately 125 degrees the range from about 90 degrees to 135 degrees Determines The effectiveness of hip ABD muscles The length of the limb The forces acting on the hip joint and femoral neck 5 Hip Angles z If greater than 125 degrees called coxa valgus z Angle of Inclination Increase lengthened limb length increase load on femoral head decrease stress on femoral neck decrease effectivness of hip ABD If less than 125 degrees called coxa cara Decrease shortened limb decrease load on femoral head increase stress on femoral neck increase effectiveness of hip ABD Angle of Inclination Coxa Valga L v Coxa Vara Hip Angles z z z Anterversion Angle of femoral neck in the transverse plane is termed anterversion Neck is rotated 12 14 degrees with respect to femur Increases the MA of the gluteus maximus making it a more effective hip external rotator Excessive beyond 14 degrees to the anterior side means that the head of femur is uncovered tends to dislocate unstable hip Decrease less than 12 degrees is called Retroversion angle reversed and moved posteriorly 6 Anterversion Normal Retroversion Anterversion Excessive Hip ROM z z z z z Lumbo Sacral Plexus z z z z 70 140 degrees of flexion 90 with knees extended 125 140 with knees flexed 4 15 degrees of hyperextension beyond anatomical position Hyperextension is limited by anterior capsule strong hip flexors iliofemoral ligament ABD about 30 50 ADD about 25 from anatomical position Lumbar Plexus Schematic Two distinctly different plexi that are connected and serve the entire Hip and LE Lumbar from T12 L1 L2 L3 L4 Sacral from L4 L5 S1 S2 S3 and S4 Ventral rami anterior and posterior divisions and terminal nerves 7 Sacral Plexus Schematic Lumbar Division Ventral Rami from T12 to L5 z z z z z z z z Lumbar Division More Important Stuff Subcostal T12 Iliohypogastric T12 L1 Ilioinguinal L1 Genitofemoral L1 L2 Lateral Femoral Cutaneous Post Divisions L2 L3 Femoral Posterior Division L2 L3 L4 Obturator Anterior Division L2 L3 L4 Sacral Trunk L4 L5 Lumbar Plexus in Situ Sacral Division Ventral Rami from L4 to S4 z Posterior Division Nerves Superior Gluteal L4 L5 S1 Inferior Gluteal L5 S1 S2 Common Peroneal L4 L5 S1 S2 z Anterior Division z Both Divisions Tibial L5 S1 S2 S3 Posterior Femoral Cutaneous S1 S2 S3 8 Both Sacral Plexus in Situ Sacral Plexus Small Nerves from Sacral Plexus z z z z Small Nerves Branch to Quadratus Femoris and Inferior Gemellus L4 L5 S1 ant div Branch to Obturator Internus and Superior Gemellus L5 S1 S2 Nerve to Piriformis S1 S2 post div Pudenal Nerve S3 S4 Coccygeal Plexus 9 Femoral Nerve Obturator Nerve Sciatic Nerve Femoral Nerve Obturator Nerve Sciatic Nerve 10 Tibial Nerve Common Peroneal Nerve Common Peroneal Nerve Tibial Nerve Foot Tibial Nerve Foot 11