Anatomy of the Lower Limb PDF

O’donoghue’s pursuit of unhappiness ! Anatomy of the Lower Limb Morgan Titmus This lecture will…. Briefly consider the function of the lower limb. Describe the regions of the lower limb. Identify the bones and type of arti...

O’donoghue’s pursuit of unhappiness ! Anatomy of the Lower Limb Morgan Titmus This lecture will…. Briefly consider the function of the lower limb. Describe the regions of the lower limb. Identify the bones and type of articulations within the lower limb with consideration of the possible movements at each articulation. Distinguish the various muscular compartments found in the thigh and leg. Identify the major muscle groups contained within each compartment and their actions. Discuss the nerve innervations of each muscle group. Consider the blood supply and venous drainage of the lower limb. 1  Introduction Divided into 6 regions – Gluteal – Femoral – Knee – Leg – Ankle – Foot Introduction Divided into 6 regions – Gluteal Between trunk and the free lower limb Buttocks (post.) and hip (lat.) Bone - Hip (os coxae) – Femoral (Thigh) Between gluteal/inguinal and proximal knee Bone - Femur 2  Introduction Divided into 6 regions – Knee Distal femur (condyles) Patella Proximal tibia Post. known as popliteal – Leg Distal to knee & ankle Bones – most of Tibia & fibular Introduction Divided into 6 regions – Ankle Talocural Distal leg Medial/lateral malleoli of (tib. and fib.) – Foot Most distal part Bones – Tasal, Metatarsal, phalanges 3  Femur Sits obliquely in thigh when standing knees are next to each other, directly under trunk Transmits body wt. hip to tibia The Femur 4  Distal femur While the shaft slopes outwards towards the hip, the distal surfaces of the femoral condyles both sit in an approximately horizontal plane Inte ossa rcon f dyla r From McMinn and Hutchings, 1977 lateral medial femoral femoral anterior view condyle condyle posterior view The medial and lateral condylar surfaces have lateral margins complex curvatures which articulate with the menisci and tibia condyles While the distal surfaces of the femoral condyles both sit in an approximately horizontal plane, the shaft slopes outwards towards the hip Intercondylar tubercles of Gerdy’s tubercle Proximal tibia intercondylar eminence Tibial plateau Medial Lateral condyle condyle Tibial tuberosity Soleal line Fibular facet anterior view posterior view proximal tibia From McMinn and Hutchings, 1977 5  The principal tibial condyles bony landmarks of the leg head of fibula Tibia transmits wt tibial tuberosity from femur to foot. tibia fibula tibial shaft shaft Fibular anchored to fibula tibia by fibrous ct Tibiofibular syndesmosis Interosseus membrane Prox tib/fib is synovial planar Distal tib/fib is syndesmosis medial malleolus lateral malleolus anterior posterior Knee (patella) A sesamoid bone found embedded in the quadriceps tendon/patellar ligament Role? 6  medial lateral The medial and lateral Position of the patella when patellar surfaces of the knee is extended femur have different slopes, which are matched by the asymmetrical shape of the patella. Position of the patella when knee is flexed From McMinn and Hutchings, 1977 Movements of the knee The knee is a biaxial synovial joint Movements occuring include: Flexion/Extension Rotation Movt in sagittal plane Movt in horizontal plane Axis runs lateral to medial Axis runs down sup. to inf. 7  Ankle (Talocural) Formed by the distal end of tibia and fibula and the superior part of Talus Synovial, hinge joint – dorsiflexion – plantarflexion Ankle The medial and lateral malleoli cradle the talus as it moves Allows dorsiflexion and plantarflexion as the talus rocks in the cradle Strongest in dorsiflexion – why? Strong ligaments stop the tibia and fibula from spreading apart. 8  Foot Tarsal bones (7) Calcaneus Talus Metatarsals (5) Phalanges Cuboid Navicular 3rd 2nd – Numbered 1 - 5 1st Cuneiform – Proximal Metatarsals – Middle – Distal Phalanges – 1 has only prox and distal Extensive ligament attachment limits movt. The tarsal joints and tarsometatarsal joints are synovial, gliding joints. Subtalar allows most movement – Inversion and eversion Metatarsophalangeal and interphalangeal allow some flex/ext and abd/add. 9  Ankle: Ligaments Lateral collateral ligament The comprises: small lateral ligaments (arrows) Anterior talofibular similarly restrict ligament movement to plantar and dorsiflexion, but Calcaneofibular they are relatively weak, and are ligament frequently strained or broken by rolling the Posterior talofibular foot into inversion ligament Netter Presenter Image Copyright 2005. Icon Learning Systems. All rights reserved Ankle: Ligaments – Anterior talofibular Lateral ligament avulsion 10  Ankle: Ligaments – Calcaneofibular Ankle: Ligaments – Posterior talofibular Muhle C et al. Radiographics 1999;19:673-683 ©1999 by Radiological Society of North America 11  Ankle: Deltoid ligament – resists eversion Knee: The stabilisers 12  Knee stability depends on - surrounding muscles - connecting ligaments - menisci With the patella removed the menisci, collateral ligaments and cruciate ligaments can be seen. Grantʼs Atlas There are external ligaments; patellar, fibular collateral (LCL), tibial collateral (MCL), oblique popliteal, arcuate popliteal LCL New ligament?! MCL MCL role? LCL role? Netter Presenter Image Copyright 2005. Icon Learning Systems. All rights reserved 13  * The anterior cruciate ligament (ACL*) is so named because ? Netter Presenter Image Copyright 2005. Icon Learning Systems. All rights reserved Knee: Anterior cruciate ligament - biomechanics Prevents posterior Limits tibial rotation translation of the Argued to be the femur on tibia primary stabilising Prevents anterior structure of the knee translation of the tibia on the femur Prevents knee hyperextension 14  Rotation of the femur laterally/externally on a fixed tibia will ʻwind upʼ the cruciates. This is the most common reason for ACL rupture Netter Presenter Image Copyright 2005. Icon Learning Systems. All rights reserved 15  The PCL prevents the femur sliding forwards off the tibia or tibia sliding backwards and prevents hyperflexion of knee * Similarly, the posterior cruciate ligament (PCL*) is so named because ? Netter Presenter Image Copyright 2005. Icon Learning Systems. All rights reserved 16  Knee: Posterior cruciate ligament - biomechanics Strongest ligament of the knee The collateral ligaments Primary restraint to ab- and prevent posterior tibial adduction, and sideways slide of the femur. translation PCL Stabilises the flexed knee (esp. at 90 degrees) Netter Presenter Image Copyright 2005. Icon Learning Systems. All rights reserved A view down onto the tibial plateau, anterior showing the crescent shaped menisci. Note the larger medial meniscus and and The anterior pcl acl tibial surface posterior cruciate ligaments are so named medial because they are seen lateral Menisci are thicker at their margins from the anterior or and taper to a point so posterior in cross surfaces of the knee respectively section they are wedge shaped. posterior They are attached above and below to the joint capsule. Netter Presenter Image Copyright 2005. Icon Learning Systems. All rights reserved Menisci provide a closer match between the complex shapes of the femoral and tibial surfaces. Act as shock absorbers to some extent 17  Muscles of the Hip (those not covered last week) The primary hip flexor Role in swinging leg forward during walking/running etc iliacus + psoas = iliopsoas Actions of iliopsoas: hip flexion or, with reversed origin anterior pelvic tilt, trunk flexion Proximal attachment transverse processes of lumbar vert, iliac fossa Distal attachment lesser trochanter of femur Innervated: Femoral (branch) (L1-3) Netter Presenter Image Copyright 2005. Icon Learning Systems. All rights reserved 18  Other weaker hip flexors Sartorius Pectineus Prox: ASIS Dist: superior part of medial surface of tibia Rectus femoris most force when knee is in a flexed position and hip is Tensor fascia hyperextended latae eg kicking footy The Gluteals Main hip Extensor Main Hip Abductors Assists lateral rotation And pelvic tilt (rev) Gluteus medius Gluteus Gluteus minimus maximus Prox: post. Illium Prox: lateral illium Distal: Gluteal tuberosity Distal: Greater trochanter In: Inf. Glut. Nerve (L5, S1-2 ) In: Sup. Glut. Nerve (L5, S1-2 ) 19  The iliotibial tract is a strong fascia band, like a ligament, stretching from pelvis to tibia. It is a specialised portion of the fascia latae. It is one of iliotibial tract the bracing structures of the lateral side of the knee Netter Presenter Image Copyright 2005. Icon Learning Systems. All rights reserved Tensor fascia latae is a small muscle originating on the anterior iliac crest and tensor fascia latae inserting in the iliotibial tract, along with part of gluteus maximus. It works with the big abductors, and iliotibial tract presumably helps stabilise the knee when weight bearing. Nerve supply as for the abductors Sup. Glut. Nerve (L5, S1-2 ). Netter Presenter Image Copyright 2005. Icon Learning Systems. All rights reserved 20 The 6 small lateral/external rotators (again) S1, S2 L5, S1 L5, S1 L5, S1 L3, L4 L5, S1 From Simons et al, 1999, Myofascial Pain and Dysfunction: The Trigger Point Manual Muscles of the Thigh 21  The three main muscle compartments of the thigh; -anterior (quads & sartorius) -Flexion of the hip and -Extension of the knee -medial (hip adductors) -Adduction of the hip -posterior (hamstrings) -Extension of the hip and -Flexion of the knee Netter Presenter Image Copyright 2005. Icon Learning Systems. All rights reserved Muscles of the anterior compartment 3 of the 4 quadriceps and sartorius Vastus lateralis crosses knee only extends knee Vastus medialis crosses knee only extends knee Rectus Femoris crosses hip and knee flexes hip and extends knee Sartorius Crosses hip and knee ASIS to superior/medial tibia Flexes/abduct/laterally rotate hip flexes knee 22  Deeper dissection Rectus femoris and sartorius removed. Showing vastus intermedius. Note three vastus muscles do not cross the hip But all attach distally on the tibial tuberosity and therefore act in knee extension. Netter Presenter Image Copyright 2005. Icon Learning Systems. All rights reserved Quadriceps Innervated by the Femoral Nerve (L2, L3, L4) Sartorius innervated by Femoral nerve (L2, L3) 23 Medial compartment muscles They insert at various levels on the linea aspera, except for gracilis, which inserts below the knee. They are supplied by the obturator nerve with roots L2-4, (except pectineus which receives femoral nerve, L2-L3) The pectineus conundrum… Pectineus (shortest) Sup. Pubic ramus pectineal line of femur Adductor longus (in front of magnus) Body of pubis middle third of femur (lin. asp.) Adductor brevis (in front of magnus) body of pubis/inf. Pubis ramus prox. linea aspera Adductor magnus (has hiatus) Inf. Pubic ramus linea aspera/adductor tubercle Gracilis (medial) Body pubis/inf.pubic ramus sup. medial tibia 24  Muscles in the posterior Compartment The hamstrings originate on the ischial tuberosity (except for the short head of biceps). The two semis insert medially on the tibia, and biceps inserts on the head of the fibula. They are hip extensors and knee flexors. They are supplied by the sciatic nerve, with nerve roots L5-S2. Hamstrings (ST, SM and BF) Biceps femoris: is one of the hamstring muscles and is the other main hip extensor Biceps femoris Proximal attachment short head short head-linea aspera and lateral supracondylar line of Biceps femoris long head femur. long head-ischial tuberosity Distal attachment : head of fibula 25  Semitendinous and semimenbraneous: are two muscles of the hamstring group and also extend the hip Proximal attachment ischial tuberosity (both muscles) Semimembraneous Distal attachment semitendinous- medial surface of the superior Semitendinous part of tibia semimembraneous- posterior part of medial condyle of knee MUSCLES OF THE LEG AND FOOT anterior Ant. Cural (extensor) Septum Transverse septum The three muscle compartments of the leg lateral (evertor) Post. Cural Septum superficial and deep posterior (flexor) 26  MUSCLES OF THE LEG AND FOOT Extensor hallucis longus Tibialis Extensor anterior digitorium longus The three muscle compartments of the leg Anterior Compartment (Extensors) Innervation: Deep Fibular nerve (L4, L5) The anterior (extensor) compartment of the leg 3 muscles one dorsiflexor and invertor Tibialis anterior* * two toe extensors Extensor hallucis longus Extensor digitorium longus with Fibularis Tertius Tib. Ant.: medial cuneiform and base 1st metatasal EHL: base of distal phalanx EDL: distal phalanges of digits 2-5 Netter Presenter Image Copyright 2005. Icon Learning Systems. All rights reserved 27 Tibialis anterior is the main dorsiflexor and invertor Prox: lat. Condyle of tibia and sup. half of lat.tibia Distal: medial cuneiform, base of 1st metatarsal works with Tibialis Posterior (post. compartment muscle) to invert foot. 28  MUSCLES OF THE LEG AND FOOT The three muscle compartments of the leg Fibularis longus Fibularis Lateral Compartment brevis (evertors) Innervation: Superficial Fibular Nerve (L5, S1, S2) The lateral compartment of the lower leg: two evertor muscles; Fibularis longus* (most superficial) Prox: lateral fibula Distal: base of 1st metatarsal * Fibularis brevis. (deep to FL) Prox: inf. 2/3 of lat. Surface of Fibula Distal: lat. Base of 5th metatarsal These have vital roles in ankle stability. Netter Presenter Image Copyright 2005. Icon Learning Systems. All rights reserved 29  MUSCLES OF THE LEG AND FOOT The three muscle compartments of the leg Posterior compartment (plantar flexors) Superficial Soleus Lat era l he ad lh dia Innervated by Tibial ead Me nerve (S1, S2) Gastrocnemius The posterior (flexor) compartment has superficial and deep components; The superficial group comprises the two large plantarflexors and a small plantaris muscle. Gastrocnemius is a two joint muscle Two heads: lateral and medial from lateral and medial condyles of femur respectively. Distal: Calcaneal tendon on to posterior aspect of calcaneus. Netter Presenter Image Copyright 2005. Icon Learning Systems. All rights reserved 30  plantaris Soleus* lies hidden under gastrocnemius, and only crosses the ankle. * Plantaris is a very small member of this group Netter Presenter Image Copyright 2005. Icon Learning Systems. All rights reserved MUSCLES OF THE LEG AND FOOT The three muscle compartments of the leg Posterior compartment (plantar flexors) Deep Tom, Dick and Harry Tibialis posterior All innervated by Tibial nerve Flexor Hallucis longus Flexor Digitorium longus 31  The deep flexor compartment: Tom, Dick and Harry An invertor: Tibialis posterior (L4, L5) two toe flexors: Flexor Digitorium longus (S2, S3) Flexor Hallucis longus (L4, L5, S1) Their tendons pass into the plantar region of foot around posterior to the medial malleolus. Tom: base of navicular (among others) Dick: base of distal phalanges 2-4 Harry: base of distal phalanx great toe. Netter Presenter Image Copyright 2005. Icon Learning Systems. All rights reserved Also, found deep is the Popliteus Deep thin triangular muscle Prox: lateral condyle of femur and Lateral meniscus Distal: Post. Surface of tibia. Flexes knee (weakly) Unlocks an extended knee by laterally rotating femur(5o) on a fixed tibia Innervation by Tibial nerve (L4, L5 & S1) 32  There are 4 layers of muscles in the foot 1st layer: Layer 3 (green) abductor of large abductor of small toes short toes flexors 2nd layer: Layer 4 (Blue) long extrinsics toe flexors 3rd layer: flexor of big toe Layer 2 (bright green and purple flexor of little toe Adductor of big toe Layer 1 (brown) 4th layer: Aductors and abductors of small Innervated by branches of toes (interosseus muscles) Tibial nerve (S2, S3) Collective function of these muscles? INNERVATION OF THE LOWER LIMB The lumbar and sacral plexi innervate the lower limb. Netter Presenter Image Copyright 2005. Icon Learning Systems. All rights reserved 33  Lumbar plexus; L1 L2-4 nerves give rise to; L2 - femoral nerve (L2, 3, 4) - obturator nerve (L2, 3, 4) L3 - lateral femoral cutaneous nerve (L2, 3) Skin only ant/lat. thigh L4 lateral femoral cutaneous femoral obturator Netter Presenter Image Copyright 2005. Icon Learning Systems. All rights reserved The proximal part of the femoral nerve is buried in femoral nerve psoas Netter Presenter Image Copyright 2005. Icon Learning Systems. All rights reserved 34  The femoral nerve enters the anterior thigh under sartorius with the femoral artery and vein, and quickly splits into branches to supply the anterior compartment muscles It supplies the; quadriceps muscles (L2, L3, L4), sartorius (L2, L3) pectineus (L2, L3) Netter Presenter Image Copyright 2005. Icon Learning Systems. All rights reserved Cutaneous Innervation The femoral nerve (L2, 3, 4) also supplies skin in the anterior thigh and continues below the knee as the saphenous nerve Red- lateral cutaneous cutaneous only (L2-L3) - this means all senses of the skin eg touch, temp, pressure, pain etc Netter Presenter Image Copyright 2005. Icon Learning Systems. All rights reserved 35  The obturator nerve (L2-L4) is easily seen within the pelvis before it exits into the medial thigh compartment through the obturator foramen, but is buried in the adductor muscles after entering the thigh Netter Presenter Image Copyright 2005. Icon Learning Systems. All rights reserved Cutaneous Innervation It also supplies a small area of skin over the muscles in the medial thigh Netter Presenter Image Copyright 2005. Icon Learning Systems. All rights reserved 36  The sacral plexus is supplied by L4-S3 roots. The main branch is the sciatic nerve Common fibular (L4, 5, S1, 2) L4 Tibial (L4, L5, S1, 2, 3) L5 Supplies no structures in gluteal region S1 Superior gluteal n. S2 There are many small branches to the gluteal muscles, Inferior gluteal n. S3 some small hip joint muscles and the pelvis and perineum Nerve to piriformis , sciatic nerve Pudenal Nerve Netter Presenter Image Copyright 2005. Icon Learning Systems. All rights reserved In the thigh the sciatic nerve lies under the hamstrings The sciatic nerve supplies the hamstrings (L5, S1, S2) and all muscles of the lower leg and foot (L4-S3) Netter Presenter Image Copyright 2005. Icon Learning Systems. All rights reserved 37  Above the knee the sciatic nerve divides into its components; Tibial 1. The tibial nerve which travels straight down the posterior part Common of the leg. fibular It supplies the posterior muscle compartment of the leg and continues into the plantar region of the foot. 2. The common fibular is the other component of the original sciatic that deviates towards the lateral side of the leg and continues on the dorsum of the foot. The common fibular then further divides into a superficial and deep fibular nerve superficial fibular nerve fibularis longus (L5,S1,S2) fibularis brevis (L5,S1,S2) deep fibular nerve anterior tibialis (L4, L5) extensor digitorum longus (S2, S3) extensor hallucis longus (S2, S3) -few small muscles on the dorsum of the foot Netter Presenter Image Copyright 2005. Icon Learning Systems. All rights reserved 38  The various cutaneous branches of the sciatic nerve supply the skin of the posterior thigh, lateral lower leg, and foot Netter Presenter Image Copyright 2005. Icon Learning Systems. All rights reserved Dermatomes are the total areas of skin supplied by each nerve root. They may use several branches to reach the skin, but their total area of distribution is a continuous strip Netter Presenter Image Copyright 2005. Icon Learning Systems. All rights reserved 39  BLOOD SUPPLY and VENOUS DRAINAGE OF THE LOWER LIMB External iliac a. The arterial supply differs from the Femoral a. nerve supply; nearly all of the Circumflex a. (lateral and medial) lower limb is supplied by the femoral artery, while the main Deep Femoral a. nerve supply to the lower limb is (Profunda Femoris) the sciatic nerve. Adductor Hiatus The deep venous drainage matches Popliteal a. the arterial supply Superior Genicular a. (medial and lateral) Inferior Genicular a. (medial and lateral) Netter Presenter Image Copyright 2005. Icon Learning Systems. All rights reserved 40  Knee: Anterior cruciate ligament – blood supply Supplied by the Middle genicular artery Supplies the cruciate ligaments, synovial membrane peripheral margins of menisci Peri-ligamentous vessels descend in synovial membrane Explains haemorrhagic effusion and joint haemarthrosis after rupture Toy, et al. 1995. Arterial supply to the human anterior cruciate ligament. Journal of athletic training. 30(2): 149-152. 41 The popliteal artery branches into two vessels for the posterior compartment (posterior tibial and fibular) and one in the anterior compartment (anterior tibial). Fibular a. Anterior Tibial a. Posterior Tibial a. Dorsalis pedis a. Medial and lateral plantar a. Acurate a. Deep plantar arch a. Venous drainage Deep and superficial Deep veins tend to run with the arteries of the same name 42 Superficial veins – Greater Saphenous Originates on medial aspect of Foot Dorsal vein of great toe and Dorsal venous arch Continues superiorly Anterior to medial malleolus Posterior to medial condyle of femur Enters the saphenous opening in the fascia lata just inferior to medial inguinal ligament. Empties into Femoral Vein Superficial veins –Lesser Saphenous Originates on lateral aspect of Foot Dorsal vein of little toe and Dorsal venous arch Continues superiorly posterior to lateral malleolus Medially between the two heads of Grastrocnemius Empties into popliteal vein in the popliteal fossa. Empties into Femoral Vein 43