1. Knee Conditions
Chapter 15

2. Anatomy Large synovial joint Two condylar articulations Gliding joint
Medial tibiofemoral joint
Lateral tibiofemoral joint
Gliding joint
Patellofemoral joint

3. Bones Femur Tibia Fibula Medial epicondyle Lateral epicondyle
Linea aspera
Tibia
Medial tibial plateau
Lateral tibial plateau
Fibula

4. Tibiofemoral Joint
Modified hinge joint allowing some lateral and rotational motions to occur as well.
Lateral epicondyle is larger than medial.
Because of size difference there is a screwing home mechanism to bring the knee into full extension.

5. Menisci Semilunar fibrocartilage (half moon shapes)
Attach to the superior plateaus of the tibia.
Absorption and dissipation of force
Lubrication
Medial meniscus is semicircular and attaches to the medial collateral ligament
Lateral meniscus is almost a complete circle and attaches to the posterior cruciate ligament

6. Bursae
Suprapatellar bursa, lies between the femur and quadriceps femoris tendon
Subpopliteal bursa, lies between the femur and the popliteal muscle
Semimembranosus bursa, lies between the medial head of the gastrocnemius and the semimembranosus tendon.
Prepatellar bursa, lies between the skin and the anterior surface of the patella

7. Bursae continued
Superficial infrapatellar bursa is located between the skin and the patellar tendon.
Deep infrapatellar bursa is located between the tibial tubercle and the infrapatellar tendon.

8. Ligaments
Anterior Cruciate Ligament (ACL), attaches anteriorly on the tibia, and to the posterior surface of the lateral femoral condyle.
Prevents:
Anterior translation of the tibia on a fixed femur
Posterior translation of the femur on a fixed tibia
Internal and external rotation of the tibia on the femur
Hyperextension of the tibia

9. Ligaments continued
Posterior Cruciate Ligament (PCL), attaches posteriorly to the tibia, and to the anterior surface of the lateral medial condyle of the femur.
Prevents:
Posterior displacement of the tibia on a fixed femur.

10. Ligaments continued
Medial collateral ligament (MCL) connects from the medial condyle of the femur to the medial tibia through the medial meniscus.
Prevents:
Medially directed shear forces (valgus)
Rotational forces

11. Ligaments continued
Lateral collateral ligament (LCL) connects from the lateral condyle of the femur to the head of the fibula.
Prevents:
Laterally directed shear forces (Varus)
External rotation of the tibia

12. Ligaments continued
Arcuate-popliteal complex composed of the semimembranosus tendon and the popliteal ligament connects the lateral condyle of the femur to the head of the fibula.
Prevents:
Anterior displacement of the tibia relative to the femur.
Hyperextension of the knee
Hyperflexion of the knee

13. Patellofemoral joint
Triangular bone (Patella) rests between the femoral condyle to form the patellofemoral joint.
Three distinct facets
Increases angle of pull on the patellar tendon
Glides between the femoral Trochlear groove

14. Patellofemoral joint cont.
Greatest compressive forces occur when the knee is in 30 deg. Of flexion.
Patellar positioning is maintained by:
Lateral retinaculum
Medial retinaculum
Medial patellofemoral ligament
Lateral patellofemoral ligament

15. Muscles of the Knee Rectus femoris (ext) Vastus lateralis (ext)
Vastus intermedius (ext)
Vastus medialis (ext)
Semitendinosis (flex)
Semimembranosus (flx)
Biceps femoris (flex)
Sartorius (flex)
Gracilis (flex)
Popliteus (flex)
Gastrocnemius (flex)
Plantaris (flex)

16. Nerves L4 L5 S1 S2 S3

17. Kinematics
Flexion primarily carried out by the hamstrings assisted by gastroc, popliteus, gracilis, and sartorius.
Secondary responsibility of these muscles is to rotate the tibia
Extension primarily carried out by the quadriceps group.

18. Contusions
Fat Pad Contusion
Peroneal Nerve Contusion

19. Bursitis Prepatellar Deep infrapatellar bursitis Pes anserine bursitis
Tibial collateral bursitis

20. Ligamentous Injuries Straight valgus Straight varus Straight anterior
Straight posterior
Anteromedial rotary
Anterolateral rotary
Posteromedial rotary
Posteroladeral rotary

21. Knee Dislocations

22. Meniscal Injuries
Longitudinal
Bucket-handle
Horizontal
Parrot-beak

23. Patellar and Related injuries
Patellofemoral stress syndrome
Chondromalacia Patellae
Patellar Instability and Dislocations
Patella Plica Syndrome
Patellar Tendinitis
Osgood-Schlatter Disease
Sinding-Larsen-Johansson’s Disease
Extensor Tendon Rupture

24. IT Band Friction Syndrome

25. Fractures Avulsion Epiphyseal and Apophyseal Tibial Tubercle
Distal Femoral Epiphyseal
Stress Fractures
Chondral and Osteochondral Fractures
Osteochondritis Dissecans
Patellar Fractures