Deforming Force in Lower Limb Fracture Fix
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Transcript of Deforming Force in Lower Limb Fracture Fix
Deforming Force in Lower Limb Fracture
Presented by: Ahmad Tho Tuching
Supervisor :Dr. Jainal Arifin Sp.OT
DEPARTMENT OF ORTHOPEDIC AND TRAUMATOLOGY
FACULTY OF MEDICINE
HASANUDDIN UNIVERSITY
MAKASSAR
2012
DefinitionDeformation=a change in the shape or size of
an objectForce=An applied workDeforming Force=a change in the shape or
size of an object due to an applied force how that can make structural failure in lower
limb of the human.
Deforming force can be a result of tensile (pulling) forces, compressive (pushing) forces, shear, bending or torsion (twisting).
It can be as a result of applied Internal force or External Force
Internal Force:Related Atachment of Structures to the Bone. Ex: Muscle
External Force: Applied force outside of the body. (Mechanism of Trauma)
Lower Limb Fracture can involve structures as follow:
-Pelvis - Femoral Shaft -Calcaneus-Acetabulum - Distal Femur -Talus-Femoral Head - Patella -
Metatarsal-Femoral Neck - Tibial Plateau -
Phalanges-Intertrochanter - Tibial Fibula shaft-Subtrochanter - Ankle
Pelvic Structure Ilustration
Medial View
LateralView
PelvisA Unstable injury is defined as one that can’t with
stand normal physiologic forces without abnormal deformation
AP Force and Lateral ForceAP Force: External Rotated of hemipelvisLateral Force: Most Common Type and depend on
location of applied forceExternal rotation abduction force: This is common in
motorcycle accidents. Force application occurs through the femoral shafts
and head when the leg is externally rotated and abducted.
This tends to tear the hemipelvis from the sacrum
AcetabulumMainly caused high energy blunt traumaPattern determined by force vector and
position of femoral head at impactER and Abducted Hip causes anterior column
injuryIR causes Posterior Column InjuryHip Flexion: Posterior wall to inferior positionDecrease degree of the hip flexion tends to
involve superior portion of posterior wall
Femoral HeadMost femoral head fractures are secondary to MVA
with axial load transmission proximally through the femur.
If the thigh is neutral or adducted, a posterior hip dislocation with or without a femoral head fracture may result.
These fractures may be the result of avulsion by the ligamentum teres or cleavage by the posterior acetabular edge.
In anterior dislocations, impacted femoral head fractures may occur because of a direct blow from the acetabular margin.
Femoral NeckLow-energy trauma: In Elderly
Direct: A fall onto the greater trochanter (valgus impaction) or forced ER of the LE impinges an osteoporotic neck onto the posterior lip of the acetabulum (resulting in posterior comminution).
Indirect: Muscle forces overwhelm the strength of the femoral neck.
High-energy trauma: MVA or fall from significant Height
Cyclical loading-stress fractures: These are seen in athletes, military recruits, ballet dancers; patients with osteoporosis and osteopenia are at particular risk.
Intertrochanter the region between the greater and lesser trochanters of
the proximal femurDeforming muscle forces will usually produce shortening,
external rotation, and varus position at the fracture.Abductors tend to displace the greater trochanter
laterally and proximally.The iliopsoas displaces the lesser trochanter medially
and proximally.The hip flexors, extensors, and adductors pull the distal
fragment proximally.
SubtrochanterArea between the lesser trochanter and a
point 5 cm distal to the lesser trochanterAbduction by gluteusFlexion of hip by iliopsoasER by short eksternal rotatorsPulled the distal fragment into varus
and proximally bi adductorsOn PE is found Shortened and Rotated of LE
Femoral shaftOrthopaedic EmergencyThe femoral shaft is subjected to major muscular
deforming forcesAbductors (gluteus medius and minimus): abduct the
proximal femurIliopsoas: It flexes and externally rotates the proximal
fragmentAdductors: They span most shaft fractures and exert a
strong axial and varus load to the bone by traction on the distal fragment.
Gastrocnemius: flexes the distal fragment.Fascia lata: It acts as a tension band by resisting the
medial angulating forces of the adductors.
Deforming muscle forces on the femur; abductors (A), iliopsoas (B), adductors (C), and gastrocnemius origin (D). The medial angulating forces are resisted by the fascia lata (E). Potential sites of vascular injury after fracture are at the adductor hiatus and the perforating vessels of the profunda femoris.
Distal Femur The distal femur includes both the supracondylar and condylar regionsThe supracondylar area of the femur is the zone between the femoral condyles and the junction of the metaphysis with the femoral shaft.
Deforming forces from muscular attachments cause characteristic displacement patterns:
Gastrocnemius: This flexes the distal fragment, causing posterior displacement and angulation.
Quadriceps and hamstrings: They exert proximal traction, resulting in shortening of the lower extremity.
Patella The largest sesamoid bone in the bodyThe quadriceps tendon inserts on the superior pole and the
patellar ligament originates from the inferior pole of the patellaThe medial and lateral extensor retinacula are strong longitudinal
expansions of the quadriceps and insert directly onto the tibia.The most common MOI is secondary to forcible quadriceps
contraction while the knee is in a semiflexed position. The intrinsic strength of the patella is exceeded by the pull of the
musculotendinous and ligamentous structuresTransverse fracture Pattern
Possibility inferior pole CommunitionThe degree of displacement of the fragments suggests the degree
of retinacular disruption.Then Active knee extension is usually lost.
Tibial Plateau The tibial plateau is composed of the articular surfaces of the
medial and lateral tibial plateaus, on which are the cartilaginous menisci.
Medial articulate surface is stronger than lateral side Fractures of the tibial plateau are caused by a varus or valgus
force combined with axial loading (a pure valgus force is more likely to rupture the ligaments).
The momentary varus angulation may be severe enough to cause a rupture of the lateral collateral ligament and a traction injury of the peroneal nerve.
Schatzker Classification
Tibia Fibula Shaft Related to subcutaneous position, the tibia is more
commonly fracturedMOI:
A twisting force causes a spiral fracture of both leg bones at different levels; an angulatory force produces transverse or short oblique fractures, usually at the same level.
Indirect injury is usually low energy; with a spiral or long oblique fracture one of the bone fragments may pierce the skin from within.
Direct injury crushes or splits the skin over the fracture; this is usually a high-energy injury and the most common cause is a motorcycle accident.
AnkleThe ankle is a complex hinge joint composed
of articulations among the fibula, tibia, and talus in close association with a complex ligamentous system
CalcaneusMost Tarsal fracturesIntraartikular and ekstraartikular type
MetatarsalMOI
Direct: This most commonly occurs when a heavy object is dropped on the forefoot.
Twisting: This occurs with body torque when the toes are fixed, such as when a person catches the toes in a narrow opening with continued ambulation.
Avulsion: This occurs particularly at the base of the fifth metatarsal.
Stress fractures: These occur especially at the necks of the second and third metatarsals and the proximal fifth metatarsal.
PhalangesThe first and fifth digits are in especially
vulnerable positions for injuryA direct blow such as a heavy object dropped
onto the foot Transverse FractureA stubbing injury is the result of axial
loadingSpiral or Oblique Fracture
ReferencesAnonymous. Deformation (Engineering). 2012
[cited 2012 Sept 22]. Available from: http://www.wikipedia/Deformation_(engineering).htm
Koval KJ, Zuckerman JD. Handbook of Fractures. 3thed. Newyork: Lippincott Williams and Wilkins;2007.
Solomon L, Warwick D, Nayagam S. Apley’s System of Orthopaedics and Fractures. 9thed. London: Hodder Arnold;2010.
Thompson JC. Netter’s CONCISE ORTHOPAEDIC ANATOMY. 2nd ed. New York: Elsevier;2010.