1. Knee Injuries Idan Ilsar, MD Arthroscopy and Sport Injury Unit
Department of Orthopaedic Surgery
Hadassah – Hebrew University Medical Center

2. Today’s Menu Meniscal tears Anterior Cruciate Ligament (ACL) tears
Stress fractures

3. Meniscal injuries Prevalence …… (under-reported)
Surgical incidence is 60-70/100,000/y

4. Meniscal anatomy

5. Meniscal anatomy

6. Meniscal fibers orientation
Most of the collagen fibers aligned longitudinally
Some fibers aligned radially - to hold the longitudinal fibers together
These longitudinally oriented fibers allow for dissipation of compressive forces via hoop stresses

7. Meniscus In the past: “vestigial remnants of a muscle within the knee”
Meniscal tear
“Cut it out”

8. Meniscus - functions In the present: Load sharers Shock absorber
Secondary knee stabilizers
Proprioception
Joint lubrication
Nutrition of articular cartilage

9. Tears of medial meniscus > lateral meniscus
Meniscal motion in ROM
Tears of medial meniscus > lateral meniscus
LM>MM

10. Meniscal blood supply Peripheral 20-30% of MM Peripheral 10-25% of LM
Periphery
White
Red
Peripheral 20-30% of MM
Peripheral 10-25% of LM

11. Meniscal tears

12. Patient’s history (traumatic)
Twisting injury
Swelling – after several hours-days (synovitis)
Pain
Limp
Locking

13. Physical examination Swelling Intra-articular fluid
Joint-line tenderness
Locked knee
(Quadriceps atrophy if prolonged)

14. McMurry Test

15. Apley’s Test

16. Imaging
X-Ray
Ultrasound CT
Bone scan SPECT
MRI

17. Knee x-ray
AP (standing)
Tunnel
Lat

18. Standing vs. Prone Rt Knee, 41y male

19. X- ray Knee alignment Osteoarthritis Osteonecrosis (AVN)
Chondrocalcinosis
LBs
(fracture)

20. Ultrasound Effusion Baker’s cyst Meniscal excursion But:
Operator – dependent
Can’t visualize interior aspects

21. CT scan
Fractures
Dislocations

22. MRI

23. Treatment Analgesics NSAIDS Rest, Ice, Compression, Elevation
Elastic bandage
Physical therapy

24. Arthroscopy

25. Outside-In repair

26. Suture meniscus

28. PHLM tear

29. PHMM tear

30. Future Options

31. Meniscus implant

32. ACL tear

33. ACL Anatomy ACL = two-bundle ligament small anteromedial
large posterolateral

34. ACL Mechanics
The anteromedial band is tight in flexion, providing the primary restraint, whereas the posterolateral portion of this ligament is tight in extension.

35. ACL History and PE Incidence: 30 cases /100 000 people/ year
Noncontact deceleration, jumping, or cutting action
Valgus-external rotation
(hyperextension)
A “pop” is frequently heard or felt
Rapid swelling = hemarthrosis

36. Physical examination
Test LACHMAN
Anterior drawer
PIVOT SHIFT

37. X-Ray SEGOND fracture avulsion fracture of the lateral capsule
pathognomonic of ACL tear

38. MRI Normal ACL

39. MRI ACL Tear

40. Treatment Non operative
If a nonoperative approach is chosen, it should include an aggressive rehabilitation program and counseling about activity level
Early Rehab:
Reduce swelling
ROM
Quad/Hamstrings

41. Treatment Non operative
The use of a functional knee brace is controversial and has not been shown to reduce the incidence of re-injury significantly if a patient returns to high-level sports

42. Treatment
Operative
Primary repair was advocated by some authors in the 1950s
Although the short-term results were encouraging, long-term retrospective and prospective reviews showed that as many as 40% to 50% failed within 5 years.

43. Treatment : Operative ACL Reconstruction Extraarticular Intraarticular
Autografts :
Patellar tendon
Hamstring ligament double loop
Allograft

44. ACL reconstruction
Normal ACL
Complete ACL tear=
“empty notch”

45. ACL reconstruction surgery

46. Stress fracture

47. Overload injury Stress fracture
Etiology:
More load
More repeats
Combination
The emphasis is CHANGE

48. X Ray

49. Bone Scan

50. Pathophysiology
Wolff’s Law: change in external stress leads to change in shape and strength of bone
bone re-models in response to stress
ABRUPT Increase in duration, intensity, frequency without adequate rest (re-modeling)
Stress fracture: imbalance between bone resorption and formation
Microfracture -> continued load -> stress fracture

51. Anatomic Location Tibia - 39.5% Metatarsals - 21.6% Fibula - 12.2%
Navicular - 8.0%
Femur - 6.4%
Pelvis - 1.9%

52. Tibial stress fracture
Local tenderness over middle – distal 1/3rd
No swelling/redness

53. Treatment

54. IDF study
Recruits
Shoes, insoles, Biphosphonates – no reduction of SF incidence
Good night sleep, length of marches – 60% reduction
FINESTONE, A., and C. MILGROM. How Stress Fracture Incidence Was Lowered in the Israeli Army: A 25-yr Struggle. Med. Sci. Sports Exerc (11S):S623-S629

55. Treatment
"Rest"

56. “Rest” = relative rest Stationary cycling Elyptical Swimming
Avoid running/jumping

57. Return to sports
סרגל מאמצים

58. “Cousin” of stress fractures
Shin Splints
Medial tibial stress syndrome (MTSS) / tibial periostitis
Runners, flat feet
Tibia
Diffuse tenderness
“Cousin” of stress fractures
Similar treatment

59. Thank you for listening