Lower Limb Anatomy PDF

The Leg Part 2 Lower Limb Anatomy Rachel H Dunn, PhD [email protected] The anatomy of the arteries of the human body, with its applications to pathology and operative surgery. Richard Quain (Anatomist), Joseph Maclise (Artist) London, 1844 Lower Limb Anatomy Manual, Chapter 6 Lecture Objectives List the...

The Leg Part 2 Lower Limb Anatomy Rachel H Dunn, PhD [email protected] The anatomy of the arteries of the human body, with its applications to pathology and operative surgery. Richard Quain (Anatomist), Joseph Maclise (Artist) London, 1844 Lower Limb Anatomy Manual, Chapter 6 Lecture Objectives List the arteries of the leg, including branches and anastomoses. List the nerves of the leg, including their cutaneous and motor branches and the structures they supply. Understand the anatomical basis and presentation of common nerve injuries of the leg. 2 Arteries of the Leg Femoral Popliteal Popliteal 1 3 5 4 Posterior tibial Popliteal (from femoral) Genicular arteries (5) Sural arteries (2) Anterior tibial artery 2 Anterior tibial Fibular Posterior tibial recurrent Anterior tibial recurrent Circumflex fibular Dorsalis pedis Posterior tibial artery Nutrient artery to tibia Posterior medial malleolar Communicating branch to fibular Medial & lateral plantar Fibular artery Dorsalis pedis Nutrient artery to fibula Posterior lateral malleolar Communicating branch to posterior tibial Perforating branch 3 Arteries: Popliteal Branches: Genicular arteries (5) Superior medial Superior lateral Inferior medial Inferior lateral Middle Sural arteries Medial & lateral Anterior tibial Posterior tibial Sural arteries are muscular branches supplying the plantaris, soleus, & gastrocnemius Popliteal Superior medial genicular Sural (M) Middle genicular Inferior medial genicular Posterior tibial Superior lateral genicular Sural (L) Sural (M) Sural (L) Inferior lateral genicular Anterior tibial 4 Arteries: Anterior Tibial Branches: Posterior tibial recurrent Anterior tibial recurrent Circumflex fibular* Anterior malleolar Medial & lateral Dorsalis pedis Posterior tibial recurrent Anterior tibial recurrent Posterior tibial recurrent artery branches from anterior tibial in the popliteal fossa and ascends deep to the popliteus muscle *Circumflex fibular Anterior tibial Anterior lateral malleolar Anterior medial malleolar Dorsalis pedis Posterior tibial recurrent Posterior tibial Anterior tibial Medial tarsal Lateral tarsal *origin of circumflex fibular artery is variable usually from anterior tibial artery (40%) from posterior tibial (32%) Arcuate 5 Arteries: Posterior Tibial & Fibular Fibular Branches: Nutrient artery to fibula Communicating branch to posterior tibial Perforating branch Posterior lateral malleolar Lateral Calcaneal Posterior tibial Posterior Tibial Branches: Nutrient artery to tibia Communicating branch to fibular Posterior medial malleolar Medial calcaneal Medial & Lateral plantar Nutrient artery (to tibia) Fibular Nutrient artery (to fibula) Fibular Anterior tibial Perforating branch Lateral tarsal Dorsalis pedis Communicating branch Posterior medial malleolar Posterior lateral malleolar Lateral calcaneal Medial calcaneal 6 Genicular Anastomosis A.K.A.: Circumpatellar anastomosis Network of arteries around the patella that supply the knee joint Includes branches from: Femoral Profunda femoris Popliteal Anterior tibial Descending genicular (from femoral) Descending branch of lateral circumflex femoral (from profunda femoris) Superior & inferior lateral genicular (from popliteal) Superior & inferior medial genicular (from popliteal) Posterior tibial recurrent (from anterior tibial) Circumflex fibular (from anterior tibial*) *origin of circumflex fibular artery is variable usually from anterior tibial artery (40%) from posterior tibial (32%) Anterior tibial recurrent (from anterior tibial) 7 Veins Superficial veins drain into deep veins Great saphenous Great saphenous Femoral Popliteal vein (with popliteal artery) Popliteal Small saphenous An Small saphenous Lateral marginal Medial marginal Distal to the popliteal fossa, deep veins form venae comitantes surrounding arteries Posterior tibial Small saphenous (with sural nerve) te r Fi b io r u la tib ia l r Superficial Deep 8 Questions ? Worried Bat Happy Bat Evil Tarsier Cliffs of Mohr, Ireland 9 Cutaneous Innervation S3 L1 L2 S4 S3 S4 Saphenous nerve from femoral Lateral sural cutaneous nerve from common fibular Superficial fibular nerve Posterior femoral cutaneous nerve Lateral sural cutaneous nerve from common fibular Medial sural cutaneous nerve from tibial L2 L3 L3 L4 S2 L5 L5 S1 Sural nerve from tibial & common fibular Deep fibular nerve Sural nerve from tibial & common fibular L4 S1 L5 Remember that cutaneous nerves are not the same as dermatomes! Injury to cutaneous nerves and dermatomes result in different sensory deficits that can aid in diagnosis 10 Sural Nerve Tibial Medial sural cutaneous Common fibular Lateral sural cutaneous Sural nerve = medial sural cutaneous (from tibial) + communicating branch of lateral sural cutaneous (from common fibular) Tibial Communicating branch Medial sural cutaneous Common fibular Lateral sural cutaneous Communicating branch Sural (with small saphenous) Lateral dorsal cutaneous Sural 11 Motor Innervation Sciatic Common fibular Sciatic Tibial Common fibular Deep fibular Common fibular nerve Superficial fibular Superficial fibular nerve Lateral compartment Eversion / Pronation Deep fibular nerve Tibial nerve Anterior compartment Dorsiflexion Posterior Compartment Plantarflexion, Supination / inversion 12 Tibial & Common Fibular Branches Tibial n. (with popliteal a.) Muscular br. (with sural aa.) Common fibular n. Recurrent articular (with anterior tibial recurrent a.) Superficial fibular n. Tibial nerve branches Tibial n. (with posterior tibial a.) Muscular branches to gastrocnemius & soleus Medial sural cutaneous Medial calcaneal Medial & Lateral plantar Common fibular nerve branches Lateral terminal branch (with lateral tarsal a.) Medial calcaneal n. (with medial calcaneal a.) Deep fibular (with anterior tibial a.) Lateral sural cutaneous Superficial fibular Medial & Intermediate dorsal cutaneous Deep fibular Recurrent articular Medial & Lateral terminal Medial terminal branch (with dorsalis pedis a.) 13 Gait Cycle Think about what muscles are active during each of these points and how an injury to the muscle or nerve could affect gait. Stance Phase Dorsiflexors prevent toes from slapping the ground Plantarflexors resist dorsiflexion to control forward motion Swing Phase Plantarflexors propel body forward Dorsiflexors prevent toes from dragging 14 Clinical Case A 46-year-old male sustained a laceration approximately 11 cm proximal to the ankle joint when a butcher knife was dropped onto his leg. The wound was 9 cm in length and the laceration extended proximally and distally to visualize the zone of injury. No pulsatile bleeding was observed. The tibialis anterior (50%) and extensor digitorum longus (25%) were partially torn. What nerve is most vulnerable in this injury? A. B. C. D. E. Tibial Superficial fibular Deep fibular Sural Saphenous Would injury to this nerve at this level cause any muscular deficits? A. B. C. Yes No Maybe? 15 Nerve Injuries Common fibular nerve Subcutaneous in position around neck of fibula Common location of injury Common fibular n. Injury to other nerves in leg not as common, but may be affected by compartment syndrome Compartment syndrome Trauma to structures within compartments may result in hemorrhage, edema, or inflammation Strength of crural fascia prevents outward swelling of tissues leading to compression of neurovasculature Treatment includes fasciotomy of affected compartment If untreated, may to ischemia, necrosis, or atrophy of affected tissues 16 Common Fibular Nerve Injury Loss of innervation to dorsiflexors Unable to dorsiflex during swing phase “Foot drop” Results in compensatory gaits Waddling, Swing-out, Steppage Common fibular Superficial fibular Deep fibular Deep fibular nerve Can be compressed deep to inferior extensor retinaculum “Ski boot syndrome” Foot drop Waddling Swing-out Steppage **Study Questions** Superficial fibular What sensory deficits would be present in common fibular nerve injury? How would you tell the difference between injury to the common fibular nerve vs. Deep fibular nerve? Superficial fibular nerve? 17 Tibial Nerve Injury Injury to tibial nerve is rare but can happen as a result of: Compartment syndrome Posterior dislocation of knee Entrapment by soleus Entrapment at flexor retinaculum **Study Questions** What muscular deficits would occur if the tibial nerve were injured? What compartment would be most affected? What sensory deficits would manifest? How would the effects differ if the injury occurred at the soleus? The flexor retinaculum? 18 Questions ? Koshka Nimue Kira Nimue 19 Image Credits Images are taken from the sources listed below …other sources cited when appropriate Copyright Notice This presentation may contain copyrighted material used for educational purposes under the guidelines of fair use and the teach act and is intended only for use by students enrolled 20 in this course. Reproduction or distribution is prohibited. Unauthorized use is a violation of the DMU integrity code and may also violate federal copyright protection laws Review Questions The posterior tibial recurrent is usually a direct branch of which artery? 1. Popliteal 2. Posterior tibial 3. Anterior tibial 4. Fibular Which nerve is injured in a patient with weakness in dorsiflexion only (all other actions are unaffected)? 1. Common fibular 2. Deep fibular 3. Superficial fibular 4. Tibial 21 Answers to Review Questions The posterior tibial recurrent is usually a direct branch of which artery? 1. Popliteal 2. Posterior tibial 3. Anterior tibial 4. Fibular Which nerve is injured in a patient with weakness in dorsiflexion only (all other actions are unaffected)? 1. Common fibular 2. Deep fibular 3. Superficial fibular 4. Tibial 22