sign in sign up
<<
Home , Hinge joint, Subtalar joint

END OF SEM ANATOMY MASTER REVISION

CONTENTS: 1. & LEGS 2. & 3. VERTEBRAL COLUMN 4. CERVICAL SPINE 5. THORACOLUMBAR SPINE & PELVIS 6. DIAPHRAGM, PELVIC FLOOR & ABDOMINALS

KNEE KNEE COMPLEX TIBIOFEMORAL Joint (femoral condyles + tibial plateau) ❖ Hinge Joint = Predominantly Uniaxial (limited rotation) ❖ Great Stability in E w/ Screw Home Mechanism ❖ F/E along Sagittal Plane on Coronal Axis ❖ Mobility in F (allow foot clearance & optimal orientation of foot) ❖ Poor degree of interlocking joint surfaces (dependent on active & passive structures such as , menisci & muscles) ❖ Large Lever (therefore, predisposed to injury due to long ) ❖ Femoral Articular Surface > Tibial Articular Surface (due to differences in condyle size) *5o of HE is critically important for knee function *Can’t rotate & fibula voluntarily *Recurvatum = hyperextension of kneecap

Knee Alignment Q Angle (between axis of tibia & femur): Measured along ASIS  Patella (centre)/ Tibial Tuberosity ❖ 14o = Men ❖ 17o = Women

5o Genu Valgus: Tibia is laterally inclined in relation to femur; medial fem condyle extends slightly more distally. Alignment of the femoral condyles on the transverse plane determine the orientation of the F/ E axis of Knee

Mechanical Axis of Lower Limb = 2-3o Varus (tibial midline  HOF) ❖ Shortens width of Base of Support to for better weight-bearing & gait

Knee Tendon Attachment ❖ Semimembranosus Tendon attaches posteriorly to Tibial Medial Condyle, superior to Popliteus ❖ Sartorius, Gracilis & Semitendinosus (Medial  Lateral) ❖ Oblique Popliteal blends in with Posterior Capsule

Synovial Membrane ❖ Synovial surfaces surround all articular areas, capsule surrounds the entirety of joint ❖ An intracapsular extrasynovial space exists between menisci

1

❖ Actively supported by: 1) Quad attachments 2) laterally by ITB 3) medially by Tibial Collateral Ligament 4) posteriorly reinforced by Oblique Popliteal ligament (restricts HE) 5) posterolaterally (pierced by popliteus)

Tibial Meniscal Discs ❖ Circular fibrocartilage pieces that ↑ articular contact & congruency, ↓ compression stress & protect articular cartilage

❖ After total meniscectomy, contact areas ↓ ~75% & peak local contact stress ↑ ~235%

❖ Medial Menisci (MM) ↑ AP length w/ thicker posterior horn (as the primary coverage over tibial plateau, it bears a large portion of the articular stress). Thus, the Screw Home Mechanism IR to the MM during Knee E for ↑ weight-bearing

❖ LM are narrower, more mobile compared to MM which is anchored to TCL

‘SCREW HOME’ Mechanism ❖ Tibiofemoral Joint initiates ‘screw home’ mechanism by slightly rotates during a primary action to tighten its ligaments (especially ACL & PCL) for ↑ stability, a ↑ contact area w/ MM ❖ Flexion + LR ❖ Extension + MR ❖ Occurs @ 20oF – 0oE ❖ In terminal extension, this mechanism locks up the knee for greater stability, apart from tightening ligaments, ↑ interlocking between the

❖ If tibia is not fixed on the floor, it will LR for the screw home mechanism, if foot is fixed on the ground it will then femur will MR after posteriorly sliding

❖ Popliteus locks TFJ w/ femur IR, to unlock the extended leg it must ER femur during F

Femoral/Tibial Gliding ❖ During movement, the kneecap has two directions of movement, sliding (AP) & rolling (of either the tibia or femur), both directions will not happen purely but in conjunction

❖ *ACL/PCL tightens during flexion or gliding, pulling femur back into a slide backwards or forwards

❖ For tibial extension, tibia will slide & roll anteriorly ❖ For femoral extension, it will slide backwards but still roll anteriorly ❖ To prevent excessive knee F, the ACL will tighten, forcing the femur into an anterior slide

PATELLOFEMORAL Joint ❖ Patellar glides upon Patella Groove on the Femur ❖ ↑ Leverage of Quads by altering its LOA & ↑ distance from axis (thus moment ). Net pull towards HOF (in a slightly valgus direction)

❖ Provides protection to the exposed cartilage of femoral condyles in Knee F ❖ Distributes forces & pressure placed on the femur

❖ ↓ Friction of Quads Tendon as it will rub upon the fem condyles w/o Patella ❖ Patella is most inclined to dislocate laterally even w/ the VMO’s medial pull resistance and the greater height of the lateral portion of the Patella Groove

❖ Patellectomy = ↓ Quads Moment Arm, ↓ Knee ROM, Anterior Instability & Loss of Trochlea Protection ❖ Patella glides distally permitted by the unfolding of the Suprapatellar Pouch

Translations ❖ Glides distally on femur during Knee F

2

❖ Glides medially during 0-30oF then lateral during 30-90oF Rotations ❖ Laterally tilts during flexion Contact Area ❖ w/ increasing knee flexion, the patella moves proximally to ↑ contact area

Patella Bursae & Spaces Bursae Location Suprapatellar Above patellar, deep to the Subcutaneous Prepatellar Superficial to patellar Subcutaneous Infrapatellar Superficial to patellar tendon, below patellar Deep Infrapatellar Inferior to patellar, deep to patellar tendon Infrapatellar Fat Deep to Infrapatellar bursae Semimembranosus Behind femorotibial joint Subsartorial (pes anserinus) On medial side of the tibia

❖ Fat Pad separates Quads Tendon from Femur (↑ moment arm) ❖ Articular Genus pulls Suprapatellar Bursae back from being pinched during Knee E ❖ Bursae promotes frictionless Knee movement, but pain sensitive and susceptible to inflammation

Knee Movement Range ❖ Motion Range o Gait: 60-70o o Stairs: >110o o Sitting: 93o o Shoe Tying: 106o ❖ Loading o Level Ground: 3x BW o Stairs: 4.25x BW

Movement Range Flexion 140o Hyperextension 5o Accessory Movements AP Glide

Medial/ Lateral Rotation  Superior Tibiofibular Joint Medial/ Lateral (Transverse) Glide Arthrodial (Plane) Joint

ABD/ADD

3

KNEE MUSCLE COMPLEMENT Action Muscles Extension Quads Flexion Hamstrings (weak contribution from gastro, soleus & sartorius) Internal Rotation Semitendinosus, Semimembranosus, Popliteus, Gracilis & Sartorius External Rotation Biceps Femoris & TFL *popliteus unlocks knee from screw mechanism as well as assisting the PCL w/ resisting anterior gliding

Muscle Origin Insertion Innervation Function Anterior Compartment (Knee E) Rectus Femoris (deep Knee E AIIS to satorius) F Medial Lip of Linea Vastus Medialis Aspera & Intertrochanteric Line Patellar via Femoral N (L2-4) Vastus Intermedius Anterior surface of Quadriceps Tendon Knee E (deep to RF) femur Greater Trochanter & Vastus Lateralis Lateral Lip of Linea Aspera Hip F, ADD & LR Sartorius ASIS Pes Anserinus Femoral N (L2-3) Knee MR Medial Compartment (Adduction) Adductor Longus Superior Ramus of (anterior) Pubis Linea Aspera Obturator N (L2-4) Adductor Brevis Pectineal Line & Inferior Hip ADD & F (superior) Pubic Ramus (Hip E only @ Inferior Ramus & 90oF) Adductor Magnus Linea Aspera & Obturator N (L2-4) Ischiopubic Ramus & (posterior, largest) Adductor Tubercle & Tibial N (L4) Ischial Tuberosity Inferior Pubic Ramus & Gracilis Pes Anserinus Obturator N (L2-3) Hip ADD Pubic Pecten Pubis (like Femoral N (L2-3) & Pectineus Pectineal Line Hip ADD, F & MR superior pubic ramus) Obturator N (L3-4) Posterior Compartment (Knee Flexion) Long: Ischial Tuberosity Knee F & LR Biceps Femoris Head of Fibula & Hip E (long head *Long Head (left) Lateral Condyle of Short: Lateral Lip of only) *Short Head (right) Tibia Linea Aspera *Tibial ER Semitendinosus Tibial N (L5-S2) (lateral, more posterior Pes Anserinus Knee F & MR to semimembranosus) Ischial Tuberosity Hip E Medial Condyle of *Tibial IR Semimembranosus Tibia *posterior muscles are biarticular (crosses two joints)

KNEE LIGAMENT STRUCTURES Ligament Attachments Resists Anterior Tibial Head  Posteriorly Posterolateral Band (PLB): largest, tightest in E Anterior (ACL) below Lateral Menisci Anteromedial Band (AMB): tightens in F Posterior Cruciate Ligament Posterior Tibial Head  > Anteriorly Anterior Gliding (during Tibial/ Femoral E) (PCL) below Medial Menisci Medial Femoral Condyle  Midline of Superficial (longer): Valgus Force (throughout Tibial (medial) Collateral Ligament Medial Tibia F) (TCL) Medial Femoral Condyle  Posterior Deep (shorter): Anterior Displacement of Tibia Edge of Medial Tibial Condyle Posterior Edge of Lateral Condyle  (ALL) Tibial IR @ 30oF + Anterolateral Stability Lateral Head of Tibia Fibular (lateral) Collateral Ligament Posterior Edge of Lateral Condyle  Varus Force (FCL) Head of Fibula 4

Posterior Tibiofibular Ligament (PTL) Inferior Posterior Tibia  Fibula Stability of TFJ Lateral Femoral Epicondyle  Medial Oblique Popliteal Ligament (OPL) Knee HE Tibial Condyle Anterior Gliding of Anterior Menisci Horns (as Connects Anterior Lateral & Medial Transverse Ligament they are somewhat mobile & being pinched by Menisci the femur OR tibia) Inferior edges of LM & MM  Knee Coronary Ligaments Anchors Menisci @ four points onto the tibia Capsule Posterior Meniscofemoral Posterior Horn of LM  Femur ??? *TCL tends to be part of capsule while the FCL is more prominently outside the capsule

ANTERIOR CRUCIATE LIGAMENT ❖ Resists anterior translation of tibia on femur ❖ Resists posterior translation of femur on tibia ❖ ↑ rotation stability ❖ Resists valgus forces ❖ Tightens @ terminal E (but not main restraint) ❖ Tightens @ 10oIR & 30oER

Injury ❖ Large valgus moment that creates excessive knee ABD & tibial ER ❖ Commonly caused by pivoting sports w/ females being 3-5x more likely to suffer from this injury

ACL Deficiency Test: Lachman’s Test (done @ 15o knee F) & Anterior Drawer Test (@ 90o knee F) done by gliding the tibia in an AP manner, lack of resistance = compromised ACL

POSTERIOR CRUCIATE LIGAMENT ❖ Resists posterior translation of tibia on femur ❖ Resists anterior translation of femur on tibia

Injury ❖ Throw against “dashboard” during car crash ❖ Hyperflexion or HE

PCL Deficiency Test: Sag Test by placing the knee @ 90oF, if there is a deficiency than the knee should have a slight backwards bend to it (meaning that the tibia is gliding posteriorly & the femur is anterior translating)

5

ANKLE

ANKLE JOINT COMPLEX Stability & Mobility Demands ❖ Support of Entire Body Weight ❖ Control of Leg & Stabilisation over Foot ❖ Adjustment over irregular surfaces ❖ Elevation of Body ❖ Shock Absorption *function is dependent upon 3 intrinsic foot arches, ligament support & dynamic muscle contractions

3 Axes of Movement ❖ Dorsiflexion (300)/ Plantarflexion (50-600) only happens @ talocrucial joint (sagittal plane) ❖ ABD/ADD happens @ forefoot (transverse plane) ❖ Inversion/Eversion (40o total ROM, may be more on one side than other) happens at subtalar joint (on coronal plane) ❖ Pronation (DF + Eversion + ABD)/ Supination (PF + Inversion + ADD) (triplanar movement, requires all three joints)

Close-Packed Positions ❖ Ankle – DF (end feel is firm) ❖ Metatarsophalangeal (MTP) – extension ❖ Tarsal Joints – full inversion ❖ Interphalangeal (IP) – extension

Force Transfer ❖ Largest distally & proximally, force transfer thru tibia ❖ Anterior Tibia under tension forces ❖ Posterior Tibia under compression forces ▪ 90% of Tibial Stress Fractures is located posteromedial ▪ 20-40o External Tibial Torsion ❖ Navicular Stress Fractures occurs @ the central zone of force between the medial & intermediate cuneiform whereupon medial & lateral compressive forces are directed thru 1st & 2nd Ray, this can cause hypovascularity (lack of blood supply)

FIBULA ❖ Muscle Attachment ❖ Talocrural Joint Stability ❖ Ligament Attachment *not a structural , only for the attachments of important active structures

Regions of Foot ❖ Rearfoot (talus & calcaneal) ❖ Midfoot (navicular, cuboid, lateral, intermediate & medial cuneiform) ❖ Forefoot (phalanges) • 1st, 2nd & 3rd Ray: corresponding cuneiform w/ phalange • 4th & 5th Ray: just 4th & 5th phalange *2nd ray is least mobile while 1st ray provides stable medial side for push-off during gait

6

Tendons ❖ 2 sesamoid bones in tendons of FHB under 1st MTP prevents weight- bearing from compressing the tendon & aligns tendon ❖ fibularis tendon sulcus on lateral facilitates passing of the fibularis tendons

DISTAL TIBIOFIBULAR Joint (DTFJ) ❖ Fibrous Syndesmosis Joint ❖ Stability of Distal Tibiofibular Joint is crucial for the stability of the Talocrural Joint ❖ Consists of: o Anterior Tibiofibular Ligament (ATL) o Posterior Tibiofibular Ligament (PTL) o (IOM)

TALOCRUCAL Joint ❖ Synovial Hinge ❖ Widest part of the talus firmly fits into the mortise (inverted cup formed by the tibia & fibular) in DF, if ER of the foot is experienced the talus’s widest side is angled & jammed into the mortise, possibly causing separation of the distal fibula & tibia OR tearing anterior tibiofibular ligament OR fractures fibula OR fractures at the corners of the talar dome

❖ DF is the close-packed position of the talocrural joint, providing most stability

❖ In PF, the talus’s narrow part is moved into the mortise

SUBTALAR (Talocalcaneal) Joint (STJ) ❖ 3 articular facets between talus & calcaneus, vital for supination & pronation ❖ Translates movements of the foot to the leg, i.e. foot pronation = tibial IR ❖ Inclined ~45o anterior to posterior, slightly medial to the long axis of the foot

Transverse Tarsal Joint = Talonavicular & Calcaneocuboid forms joint between rearfoot & midfoot

Calcaneocuboid (Convex  Debate between function Talonavicular Concave)/ of joint & its actual range Talocalcaneonavicular Ball & Socket Joint *rest are plane joint*

Arches of the Foot - Medial Longitudinal Arch (stabilised by fibularis longus, abductor hallucis, TA & TP) - Lateral Longitudinal Arch (stabilised by fibularis brevis) - Transverse Arch *arches serve as shock absorbers & energy returners (during gait)

*arches protect the blood vessels, neural & musculoskeletal structures underneath the foot during weight-bearing

*the medial arch can be tested w/ the Navicular Drop Test, comparing the differences in height between the arch and the floor when load is placed on the foot

Arch Muscular Support Medial Arch - TA, TP, FHL, FDL & Fibularis Longus, Plantar Aponeurosis, Long & Short Plantar Lateral Arch - Fibularis Longus & Brevis, FDL Ligament + Spring Ligament (for medial arch) Transverse Arch - Fibularis Longus, TP & Adductor Hallucis

ANKLE MUSCLE COMPLEMENT Action Muscles Inversion TA/ TA Eversion FB & FL Dorsiflexion TA/ EHL & ED Plantarflexion Triceps Surae (Gastro, Soleus, Popliteus, Plantaris)

7

Muscle Origin Insertion Innervation Action Anterior Compartment (DF & Inversion) DF (agonist) Medial Cuneiform & 1st Tibialis Anterior Lateral Tibia Condyle Midfoot Inversion MT Deep Fibular N (contributes) (L4-5) Extensor Hallucis Fibula & Interosseous Base of Distal Phalanx of Longus Membrane 1th Digit PF Extensor Digitorum Lateral Tibia Condyle + Distal Phalanges of 2nd-5th Deep Fibular N Longus Interosseous Membrane Digit (L5-S1) Posterior Compartment (PF & Knee Flexion) Popliteus Lateral Femoral Condyle Posterior Tibia Tibial N (L4-S1) Knee MR & F Posterior Interosseous Navicular Tuberosity, All Inversion (agonist) & PF Tibialis Posterior Tibial N (L4-5) Membrane Cuneiforms & 2nd-4th MT (slight contribution) Lateral & Medial PF (agonist) & Inversion Gastrocnemius Femoral Condyles (small contribution as it Soleus (deep to Calcaneal Tendon is aligned medially) Posterior Head of Fibula Tibial N (S1-2) plantaris) (Archimedes tendon) Plantaris (deep to Posterior Lateral Femoral (Knee F only for Gastrocnemius) Condyle Gastro) Flexor Digitorum Posterior Tibia Plantar 2nd-5th DP Longus Tibial N (S2-3) PF (agonist) Interosseous Membrane Flexor Hallucis Longus Base of Distal 1st Phalanx & Posterior of Fibula Lateral Compartment (Eversion)

Fibularis Brevis 5th MT Tuberosity Superficial Fibular Eversion (agonists) Lateral Fibula Base of 1st MT (wraps N (L5-S2) PF (small contribution) Fibularis Longus underneath foot) Intrinsic Foot (supports arches) Extensor Hallucis Dorsal 1st MTP 1st Ray E Brevis (medial to EDB) Superolateral surface of Deep Fibular N Extensor Digitorum Calcaneus (L5-S1) Dorsal 2nd-4th PIP 2nd-4th Ray E Brevis Flexor Digitorum Calcaneal Tuberosity & Plantar 2nd-4th MP 2nd-5th Ray F Brevis Plantar Aponeurosis Plantar Cuboid, Lateral Flexor Hallucis Brevis Cuneiform & medial 1st Plantar 1st PP 1st Ray F Medial Plantar N MTT (S2-3) Flexor Digiti Minimi Base of 5th MT 5th PP 5th Ray F Brevis Medial Calcaneal Abductor Hallucis Dorsal 1st MTP 1st Ray ABD Tuberosity Oblique: Base of MT Adductor Hallucis Lateral Base of 1st PP 1st Ray ADD Transverse: 2nd-4th MTP Lateral Plantar N Flexor Digiti Minimi Plantar 5th MMT 5th Ray F (S2-3) Abductor Digiti Minimi Calcaneal Tuberosity & Plantar 5th MTP 5th Ray ABD (lateral to FDB) Plantar Aponeurosis Medial side of FDL Medial & Lateral Lumbricals Medial side of MTP IP E while MTP F Tendons Plantar N (S3) Assists FDL w/ F (also Calcaneal Tuberosity & Quadratus Plantae Tendon of FDL realigns angle of FDP Long Plantar Ligament pull) Lateral Plantar N Plantar Interossei Medial side of 3rd-5th MT Medial Side of 3rd-5th PP ADD 2nd – 4th Ray (S2-3) Both sides of 2nd PP, but Dorsal Interossei Between all MT only on lateral side of 3rd & ABD 2nd – 4th Ray 4th PP

8

9

ANKLE LIGAMENT STRUCTURES Ligament Attachments Resists Fibular Ligaments Distal Anterior Tibia  Distal Anterior Anterior Tibiofibular Ligament (ATL) Fibula (consists of 2 separate superior & inferior bands) Separation & Stability of TFJ Distal Posterior Tibia  Distal Posterior Posterior Tibiofibular Ligament (PTL) Fibula Interosseous Membrane (IOM) Within the Tibiofibular Joint Lateral Posterior Lateral Talus  Posterior Anterior Talofibular Ligament (ATFL) Distal Fibula Lateral Anterior Talus  Anterior Distal TCJ Stability & Excessive Inversion Posterior Talofibular Ligament (PTFL) Fibula (CFL) Lateral Calcaneus  Apex of Fibula Intrinsic Ligaments Creates the Tarsal Tunnel, anchors flexor Flexor Retinaculum Medial Malleolus  Calcaneus & TP tendons Lateral Anterior Calcaneus Lateral Talocalcaneal Interosseous Talar – Calcaneal Stability Anterior Talus (w/ sinus tarsi) Dorsal Calcaneonavicular Dorsal Calcaneus  Posterior Lateral Calcaneus – Navicular Stability Bifurcated Ligaments ↑ ↓ Navicular Dorsal Calcaneocuboid Dorsal Calcaneus  Cuboid (x3 bands) Calcaneus – Cuboid Stability Calcaneus  Talus (much like CFL but Resists Inversion & Stability of Calcaneus/ Cervical Ligament anterior) Talus Long Plantar Ligament Base of 4th & 5th MT  Plantar Calcaneus Plantar Lateral Cuneiform  Plantar Maintains Lateral Arch Short Plantar Ligament Calcaneus Plantar Calcaneonavicular (Spring) Plantar MTP Capsules  Plantar Calcaneus Stores energy during gait & releases energy Ligament (medial side) as a spring during push-off phase 2x tensile strength of plantar ligaments, Plantar PIP  Plantar Medial Calcaneal rich in proprioceptors, maintains rigid foot Plantar Fascia Tuberosity during step-off in gait (during MTP HE & PF pushes calcaneal tuberosity posteriorly Tibial Ligaments (Deltoid Ligaments) Anterior Tibiotalar Ligament (ATTL) Anterior Distal Tibia  Anterior Talar Posterior Tibiotalar Ligament (PTTL) Posterior Distal Tibia  Posterior Talar Tibiocalcaneal (& Tibiospring) Excessive Inversion Medial Distal Tibia  Medial Calcaneal Ligament Tibionavicular Ligament Distal Tibia  Dorsal Navicular

10

Ankle Osteology ❖ Subtalar joint is formed by posterior, lateral & anterior talar articular surfaces between the calcaneus & talus

❖ Sustentaculum Tali is a shelf between the lateral & posterior articular surfaces ❖ Tarsi Sinus is the cavity created between the calcaneus & talus

11