Sports Injuries

1. Sports Injuries Mikey Bengzon, MD, MBAH 30 November 2010

2. 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.

6. Acute injuries Ankle sprain Muscle Strain Contusion rupture/dislocations Chronic injuries Tendinitis Stress Fractures Osgood Schlatter Disease Sever’s disease Sports Injuries

8. 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 - ?

9. 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)

10. Stress(?) Fracture Incomplete fracture Overuse -> Fatigue Force transfer from muscle to bone Rx: Rest vs IF

11. Osgood Schlatter Disease

12. Sever’s Disease • Inflammation of the growth plate • 8-13 year olds • Overuse injury in running sports • Rx. Rest, control of inflammation

13. Mallet finger

14. Rotator Cuff Tears Supraspinatus Infraspinatus Teres Minor Subscapularis

15. Yield/ Failure Toe Region Linear Region Stress Strain

16. 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

17. Yield/ Failure Toe Region Linear Region Stress Strain

18. 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 2 types of Skeletal muscles

19. 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

20. Tendons • Connects muscle to bone • Collagen are more parallel and larger compared to ligaments • Relatively avascular • 2 tendinous areas: • Musculotendinous • Osteotendinous

21. 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

22. 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

23. Strain • Pertains to muscles • Overexertion • Grade 1 strength maintained • Grade 2 – decrease strength • Grade 3 – loss of strength • Treatment – Similar to sprains

24. Yield/ Failure Toe Region Linear Region Stress Strain

25. Tendinitis akshdld

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

27. Ligaments vs. Tendons

29. Dislocations/Subluxations

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

31. 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

32. Ligaments • Soft connective tissue composed of densely packed collagen fibers • Mechanical properties depend on function and location • Fibroblasts • Extracellular matrix

33. 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

34. 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.

35. Crimping: • orientation of collagen in ligaments • Allows elongation of fibers before tensile stresses are experienced

36. 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

37. 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

38. 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

39. 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

40. Knee Injuries

42. Knee Injuries • Medial Collateral Ligament (MCL) strains • Anterior Cruciate Ligament (ACL) tears • Meniscal Tears

43. Examination of the Knee • Bone • Soft tissue • Ligaments

45. 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

49. ACL • Anterior Drawer’s test • Lachman’s test • Pivot Shift

50. KT 2000