hip. fractures zpelvic fx 2 0 mva - 15,300/yr in u.s. zproximal hip fx - 250,000/yr in u.s. z4.5/100...
Post on 21-Dec-2015
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Hip
Fractures
Pelvic fx 20 MVA - 15,300/yr in U.S.
Proximal hip fx - 250,000/yr in U.S.
4.5/100 in people > 70 y.o.
Mechanisms
Femoral neck fxTrauma 20 falls
Lateral Rotation of LE w/ fall backwards
Stress fx
Mechanisms
Impact 20 fall subsequent fx
Fracture precipitates fall
Hip fx occur in < 5% of falls
Inverse relationship between hip fx and BMI
Mechanisms
Mechanisms
Mechanisms
Understanding the Mechanisms
Bone qualityMuscular strengthSoft tissue characteristicsNeuromuscular coordinationRare
Lever-Arm Dysfunction
Bony lever arms are abnormal due to abnormal bone development
Cerebral Palsy
Lever-Arm Dysfunction
Normal bone growth dependent on:GeneticsAdequate nutritionAdequate dynamic forces Bone deforms according to the:Forces placed on itLack of forces placed on it
Angle of Inclination
Infancy – 1500
Adult - 1250
Coxa ValgaG. Medius
G. MediusG. Medius
Femoral Torsion
• Approximately 400 - 450 (anteverted) in newborn
•150 in the adult
Femoral Torsion
Anteversion
Retroversion
Femoral Anteversion
Why in CP?Delayed standingAbnormal external forces 20 tone ligamentous laxity45 - 650
Femoral Anteversion
Manifestations:Hip abductor weakness resulting
from moment arm out of planeAnterior pelvic tilt maintain
femoral head coverage knee extension moment Hip IR,
Knee flexion and valgus
Femoral Anteversion
Manifestations:Internal foot progression angle
rockersAbnormal patellafemoral mechanics
Dislocation
High forcesUsually associate with acetabular
and/or femoral fxDirect - trochanterIndirect - foot or flexed knee
(“dashboard dislocation”)
Dislocation
Anterior (10-20% of hip dislocations)Forcible abduction
Abduction w/ flexion & ERobturator-type anterior dislocationAbduction w/ extensionpubic- or iliac-type dislocation
Dislocation
Retroversion risk of dislocation
Congenital hip dislocation (hip dysplasia)
Osteoarthritis/DJD
Most common joint disorder20 inflammationsoftening of cartilage 20
proteoglycanthinning pitting, fissuring, ulcerationsubchondral bone necrosisosteophyte formation
Osteoarthritis/DJD
Gradedjoint space
narrowingosteophyte
formationsclerosisjoint deformity
Osteoarthritis/DJD
Strongly associated w/…OnsetMTPwrist and spinetoe IPs and 1st carpometacarpaltibiofemoralhip
Osteoarthritis/DJD
Development:predispositionjoint abnormalitymechanical loadinguse
Osteoarthritis/DJD
Primary - idiopathicSecondarytraumametabolic disorders
CPDD DISH
Osteoarthritis/DJD
BiomechanicalBiochemicalInflammatoryImmunological
Osteoarthritis/DJD
Biomechanicaltraumaoveruse - occupationobesity
Muscle Strain
Occurs duringforced lengthening/eccentric
- control- decelerate high velocity
movementscompromised muscle ability to
absorb energy
Muscle Strain
Muscle compromise:fatiguepredisposing factors
- muscle imbalance- inflexibility- insufficient warm-up
Hamstring Strain
Susceptibletwo-joint musclessprinters
- late swing- early stance- high proportion of FT
Hamstring Strain
Most commonproximalbiceps femoris long headmyotendinous junction
- actual interface (folding) more shearing than tensile - limited extensibility