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Sports Injuries
Mikey Bengzon, MD, MBAH
30 November 2010
Specific Learning Objectives:
• Enumerate and define common acute and chronic orthopedic Sports injuries.
• Describe the anatomy and physiology of musculoskeletal structures.
• Review the ligamentous anatomy of the knee.• Analyze the pathology of Orthopedic sports
injuries.• Enumerate the methods of treatment of
Orthopedic sports injuries.
Sports Injuries
Acute injuries• Ankle sprain• Muscle Strain• Contusion• rupture/dislocations
Chronic injuries• Tendinitis• Stress Fractures• Osgood Schlatter
Disease• Sever’s disease
Orthopedic Sports Injuries
• S - Onset: Acute vs. Chronic;– MOI: Direct vs. Failure
• O - Location: Long bone vs. Periarticular; Structure: Osseous vs. Soft tissue
• A – Osseous or non osseous, Location
• P - ?
Contusion
• Blunt injuries• Intra: Within the
compartment; more painful; swelling lasts longer; no obvious hematoma
• Inter muscular: less painful; swelling resolves sooner; obvious hematoma
• Grade 1 – 3 (tightness)
Stress(?) Fracture
• Incomplete fracture• Overuse -> Fatigue• Force transfer from
muscle to bone• Rx: Rest vs IF
Osgood Schlatter Disease
Sever’s Disease
• Inflammation of the growth plate
• 8-13 year olds• Overuse injury in
running sports• Rx. Rest, control of
inflammation
Mallet finger
Rotator Cuff Tears
Supraspinatus
Infraspinatus
Teres Minor
Subscapularis
Toe RegionLinear Region
Yield/ Failure
Strain
Stress
Types of Muscle Contraction
• Concentric – Joint moves with a load and the muscle shortens (biceps contract)
• Eccentric – results in muscle lengthening while controlling a load during joint motion (biceps in elbow extension)
• Isometric – fixed load with no joint motion (quadriceps sets)
• Isokinetic – variable load with constant velocity (exercise bike)
• Isotonic contraction - tension rises and the skeletal muscle shortens
Toe RegionLinear Region
Yield/ Failure
Strain
Stress
2 types of Skeletal muscles
• Type I – Slow twitch, more for endurance and aerobic bc of the presence of mitochondria and myoglobulin
• Type II – fast twitch, for rapid generation of power but anaerobic so less able to sustain prolonged contraction – Type IIA vs Type IIB
Factors affecting muscle properties
• Strength training – High force, low repetition: leads to an increase in muscle strength; increase muscle fiber size leads to an increase in contractile proteins
• Endurance training – (low tension, high repetition): Increases capillary density & mitochondria concentration resulting in VO2 max and improved fatigue resistance– MHR = 220 – Age– Increase VO2 max, HR must increase to 65-85% of
MHR
Tendons
• Connects muscle to bone
• Collagen are more parallel and larger compared to ligaments
• Relatively avascular• 2 tendinous areas:
– Musculotendinous– Osteotendinous
Functions of Tendons
• Length of tendon allows muscle belly to be at a distance from the joint
• Transmits force between muscle and bone– Tensile stresses are high
• Conservation of muscular energy during locomotion/ energy storage capacity– Satisfies kinematical and damping
requirements
Mechanical Properties of Tendons
• Greater cross - sectional area– Larger loads can be applied prior to failure– Increased tissue strength– Increased stiffness
• Longer tissue fibers– Greater fiber elongation before failure– Decreased tissue stiffness– Unaltered tissue strength
Strain
• Pertains to muscles• Overexertion• Grade 1 strength
maintained• Grade 2 – decrease
strength• Grade 3 – loss of
strength• Treatment – Similar to
sprains
Toe RegionLinear Region
Yield/ Failure
Strain
Stress
Tendinitis
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Lateral Epicondylitis
• Tennis elbow• Tendinitis at the
common extensor origin in the elbow
• Elbow and wrist extension
Ligaments Tendons
% Collagen Less More
% Ground Substance
more less
Organization More random Organized
Orientation Weaving pattern
Long axis direction
Ligaments vs. Tendons
COMPONENT LIGAMENT TENDON
Cellular Materials:
Fibroblasts 20% 20%
Extracellular:
Water 60-80% 60-80%
Solids 20-40% 20-40%
Collagen 70-80% Slightly higher
Type I 90% 95-99%
Type III 10% 1-5%
Ground substance 20-30% Slightly less
Elastin Up to 2X Collagen Scarce
Dislocations/Subluxations
Toe RegionLinear Region
Yield/ Failure
Strain
Stress
Mechanical Behavior of ligaments
Sprain
• Pertains to ligaments• Ankle, knee & finger• Children vs adults• Grade 1- fxn
maintained• Grade 2 – partial
weight bearing• Grade 3 – unstable• Treatment: depends
on severity
Ligaments
• Soft connective tissue composed of densely packed collagen fibers
• Mechanical properties depend on function and location
• Fibroblasts• Extracellular matrix
Ligaments
• Functions:– Holds skeleton together– Transmit load bone to bone– Provides stability at joints– Limits freedom of movement
• Prevents excessive motion by being a static restraint• Occasionally acts as a positional bend/strain sensor• Mediate motions bw opposing fibrocartilage surfaces
Ligaments
• No molecular bonds between fascicles– Free to slide relative to
each other
• Parallel or Branching/interwoven– Collateral vs Cruciates
• Smaller diameter than tendons
Simon, SR. Orthopaedic Basic Science. Ohio: American Academy of Orthopaedic Surgeons; 1994.
Crimping: – orientation of collagen in ligaments– Allows elongation of fibers before tensile stresses are
experienced
Viscoelastic Response
• Viscous – resists strain; Elastic – returns to original state• Dependent on
– Magnitude of load – Duration of load– Prior loading
• Affected by movement of water– Resistance to compressive forces due to water trapped in
proteoglycans– Contributes to sustained or cyclic responses to stress
• Types of responses– Creep – Stress relaxation– Hysteresis
http://www.tendinosis.org/injury.htm
Creep • Time dependent elongation when subjected to a constant stress– Tendons: in an isometric
contraction, the tendon will lengthen slightly and more muscle fibers will be recruited in order to maintain the position of the limb
– Ligaments: Joints will loosen with time, decreasing the possibility of injury
• Ex. Maintaining posterior pressure of the knee in extension
http://www.orthoteers.co.uk/Nrujp~ij33lm/Orthconntiss.htm
http://ttb.eng.wayne.edu/~grimm/ME518/L5A3.html
Stress - Relaxation• Time dependent
decrease in applied stress required to maintain a constant elongation– Tendons: in an isotonic
contraction, the stress will decrease with time
– Ligaments: joints will loosen with time decreasing the possibility of injury
• Ex. Biceps curls x 2 reps
http://www.orthoteers.co.uk/Nrujp~ij33lm/Orthconntiss.htm http://ttb.eng.wayne.edu/~grimm/ME518/L5A3.html
Hysteresis
• Energy lost within the tissue between loading and unloading– Response of tissue
becomes more repeatable
– Subsequent use of the same force results in greater deformation
Knee Injuries
Knee Injuries
• Medial Collateral Ligament (MCL) strains
• Anterior Cruciate Ligament (ACL) tears
• Meniscal Tears
Examination of the Knee
• Bone
• Soft tissue
• Ligaments
Anterior Cruciate Ligament
• Located between the femur & tibia at the center of the knee– Origin: Medial Surface of the Lateral Femoral
condyle– Insertion: anterior tibial plateau– Intracapsular; extrasynovial
• 2 bundles: AM & PL*• + Lachman’s & Anterior drawer’s test
ACL
• Anterior Drawer’s test
• Lachman’s test
• Pivot Shift
KT 2000
ACL MRI
Posterior Cruciate ligament
• Origin: Medial Femoral Condyle• Insertion: Posterior Cortical
surface of the tibia in the sagittal midline
• Covered by synovium (intimately associated with the posterior capsule)
• Blood supply from the middle geniculate artery
• + sag sign, Posterior drawer’s test
Medial Collateral Ligament
• Primary stabilizer to valgus
• Origin: MFC at the adductor tubercle
• Insertion: Medial aspect of the proximal tibia
• Superficial and Deep layer
• + Valgus Stress test
Lateral Collateral Ligament
• Origin: Lateral Femoral condyle
• Insertion: fibular head
• Resists Varus stress
Meniscal tear
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Inflammation
regeneration
Fibrosis
Weeks
Stages of Healing
R.I.C.E.
• REST – avoid painful movements but use as tolerated
• Ice – 20 minutes at a time x 24-48 hours
• Compression
• Elevation
• Address main pathology
Issues in Treatment
• Temperature: – Negative Effects of Ice, Dr. Ho, University of Hawaii –
Decreases blood flow and metabolism– 1980 AOS & AJSM – nerve palsies
• Motion – immobilization affects overall health of the joint (scar tissue, cartilage necrosis, ligament weaknening)
• Medications– NSAIDS: inhibit fibroblastic growth processes
Post Surgery
• Range of Motion
• Strengthening
• Endurance