Mikey Bengzon, MD, MBAH 30 November 2010 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 Chronic 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

Yield/ Failure Toe Region Linear Region Stress Strain

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

Yield/ Failure Toe Region Linear Region Stress Strain

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 Definiton

Yield/ Failure Toe Region Linear Region Stress Strain

Tendinitis akshdld

Lateral Epicondylitis Tennis elbow Tendinitis at the common extensor origin in the elbow Elbow and wrist extension

Ligaments vs. Tendons Ligaments Tendons % Collagen Less More % Ground Substance more less Organization More random Organized Orientation Weaving pattern Long axis direction

LIGAMENT TENDON COMPONENT Cellular Materials: Fibroblasts 20% Extracellular: Water 60-80% Solids 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

Mechanical Behavior of ligaments Yield/ Failure Toe Region Linear Region Stress Strain

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 Definition of sprain Types of sprain

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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Stages of Healing Inflammation Fibrosis regeneration Weeks

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 More info on RICE

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