ABOVE KNEE AMPUTATION

ARTHROSCOPY

KNEE JOINT Block 14 GNK 483

Anatomy Classification Bones Capsule Ligaments Synovial membrane Cruciate ligaments Menisci Nerve supply Blood supply Relationships Bursae Movements

Classification Synovial hinge joint Medially & laterally: femur & tibia (hinge and rotation) Intermediate: Femur & patella (gliding joint

Capsule Absent anteriorly Synovial membrane protrudes to form the bursa beneath the tendon of quadriceps femoris It is anteriorly reinforced by the tendon of quadriceps femoris, the patella and the patella retinacula

Capsule Inferiorly, the capsule is fixed to the margins of the tibia, except where the tendon of popliteus passes The capsule is reinforced on both sides by the expansions of vastus lateralis and medialis, as well as behind by the oblique popliteal ligament from the insertion of semimembranosus

Ligaments 5 extracapsular Patellar ligaments – quadriceps reflex L2,3,4 Lateral collateral ligament Medial collateral ligament Oblique popliteal ligament is an expansion from the insertion of semimembranosus Arcuate popliteal ligament Y-shaped ligament posterior that bridges the tendon of popliteus

Ligaments 4 intracapsular Synovial membrane Cruciate ligaments Menisci Tendon of popliteus

Synovial Membrane Infrapatellar fold is a reflexion from the posterior surface of the patella-forms a fold to the intercondylar fossa The synovial membrane from the posterior part of the capsule is reflected around the front of the cruciate ligaments-they are therefore intracapsular but extrasynovial

Cruciate Ligaments Extrasynovial Anterior Taut in extension Prevents post displacement of femur on tibia Prevents hyperextension of the knee

Cruciate Ligaments Extrasynovial Posterior Stronger Taut during flexion Prevents ant displacement of femur on tibia Prevents hyperflexion of the knee

Menisci - General Medial & lateral C-shaped Fibrous cartilage Upper surface concave Outer margins thicker, convex,attached to capsule Inner margins thinner, concave,free border Transverse ligament extends between the 2 ant parts of the menisci

Menisci Medial meniscus Semicircular (oval) Wider at back than in front Attached to medial collateral ligament Most commonly injured

Menisci Lateral meniscus Almost circular Even width front and back Separated from lateral collateral ligament via popliteal tendon

Nerve Supply Br of femoral n to vastus medialis Obturator n (the br passes with the femoral a thro the add hiatus to popliteus fossa Sciatic n

Blood Supply Genicular anatomosis formed by brrs of popliteal a Middle genicular a pierces the capsule & supplies cruciate lig’s, synovial mem, outer margins of menisci

Relations Anterior femoris quadriceps femoris & bursa Posterior popliteal fossa+contents, popliteal a+v, tibial+c.peroneal nn Lateral Biceps femoris, lateral collateral ligament, tendon of popliteus Medial Sartorius, gracilis,medial coll lig,semitendinosus

Bursae – Anterior (4) Suprapatellar Prepatellar Beneath quadriceps femoris Prepatellar Housemaids knee Superficial infrapatellar Betw skin & patellar ligament Clergyman’s knee Deep infrapatellar Betw patellar lig & tibia

Bursae – Posterior (2) Beneath popliteus Beneath semimembranosus

Bursae – Posterior (2) Others: Biceps femoris Lateral head of gastrocnemius Medial head of gastrocnemius Anserine bursa below insertion of: Sartorius Gracilis semitendinosus

Movements Flexion Extension Rotation hamstrings+sartorius,gracilis,gastroc Extension quadriceps femoris+medial rotation Rotation Passive: screw home mechanism Active: medially in a flexed knee (SarGrTen) laterally via Biceps femoris