34 Neurovasculature

Arteries of the Lower Limb

Fig. 34.1 Arteries of the lower limb and the planta pedis

Fig. 34.2 Segments of the arteria femoralis
The blood supply to the lower limbs originates from the a. femoralis. Color is used to identify the named distal segments of this vessel.

Fig. 34.3 Arteria profunda femoris
Right leg. The artery passes posteriorly through the mm. adductores of the medial thigh to supply the muscles of the compartimentum femoris posterius via three to five aa. perforantes. Ligation of the a. femoralis proximal to the origin of the a. profunda femoris (left) is well tolerated owing to the collateral blood supply (arrows) from branches of the a. iliaca interna that anastomose with the rr. perforantes.

Fig. 34.4 Arteries of the caput femoris
Anterior view.

Clinical box 34.1

Femoral head necrosis
Dislocation or fracture of the caput femoris (e.g., in patients with osteoporosis) may tear the vessels of collum femoris, resulting in femoral head necrosis.

Veins & Lymphatics of the Lower Limb

Fig. 34.5 Superficial (epifascial) veins of the lower limb

Fig. 34.6 Deep veins of the lower limb

Fig. 34.7 Veins of the planta pedis
Right foot, plantar view.

Fig. 34.8 Clinically important venae perforantes
Right leg, medial view.

Fig. 34.9 Nodi lymphoidei superficiales
Right limb. Arrows indicate the main directions of lymphatic drainage.

Fig. 34.10 Nodi lymphoidei and drainage
Right limb, anterior view. Arrows indicate direction of lymphatic drainage. Yellow: nll. superficiales; green: nll. profundi.

Plexus Lumbosacralis

The plexus lumbosacralis supplies sensory and motor innervation to the lower limb. It is formed by the rr. anteriores of the lumbar and sacral nn. spinales, with contributions from the n. subcostalis (T12) and n. coccygeus (Co1).

Fig. 34.11 Plexus lumbosacralis
Right side, anterior view. Spinal nerve contributions to nerves of the plexus lumbalis and sacralis. Separation of the rr. anteriores into anterior and posterior divisions are not as neatly demarcated in the plexus lumbosacralis as they are in the plexus brachialis of the upper limb. Where clearly separated into nerves they are indicated as: green = anterior division, blue = posterior division. Note: Nerves of the plexus sacralis not shown: n. musculi piriformis (S1, S2), n. musculi obturatorii interni (L5, S1), and n. musculi quadrati femoris (L5, S1).

Nerves of the Plexus Lumbalis

Fig. 34.12 Cutaneous innervation of the inguen
Right male inguen, anterior view.

Clinical box 34.2

Entrapment of the n. cutaneus femoris lateralis (meralgia paresthetica) Ischemia (diminished blood flow) of the n. cutaneus femoris lateralis can result when the nerve is stretched or entrapped by the lig. inguinale (see Fig. 34.11B) during hyperextension of the hip or with increased lordosis (curvature) of the lumbar spine, as often occurs during pregnancy. This results in pain, numbness, or paresthesia (tingling or burning) on the outer aspect of the thigh. It is most commonly found in obese or diabetic individuals and in pregnant women.

Fig. 34.13 Nerves of the plexus lumbalis
Right side, anterior view with the anterior abdominal wall removed.

Nerves of the Plexus Lumbalis: Nervus Obturatorius & Nervus Femoralis

Fig. 34.14 Nervus obturatorius: Cutaneous distribution
Right leg, medial view.

Fig. 34.15 Nervus obturatorius
Right side, anterior view.

Table 34.3 Nervus obturatorius (L2–L4)

Motor branches	Innervated muscles
Direct br.	M. obturatorius externus
R. anterior	M. adductor longus
	M. adductor brevis
	M. gracilis
	M. pectineus
R. posterior	M. adductor magnus
Sensory branches
R. cutaneus

Fig. 34.16 Nervus femoralis
Right side, anterior view.

Fig. 34.17 Nervus femoralis: Cutaneous distribution
Right limb, anterior view.

Table 34.4 Nervus femoralis (L2–L4)

Motor branches	Innervated muscles
Rr. musculares	M. iliopsoas
	M. pectineus
	M. sartorius
	M. quadriceps femoris
Sensory branches
Rr. cutanei anteriores
N. saphenus

Nerves of the Plexus Sacralis

Fig. 34.18 Cutaneous innervation of the regio glutealis
Right limb, posterior view.

Fig. 34.19 Nervus cutaneus femoris posterior: Cutaneous distribution
Right limb, posterior view.

Fig. 34.20 Emerging nervus spinalis
Horizontal section, superior view.

Fig. 34.21 Nerves of the plexus sacralis
Right limb.

Clinical box 34.3

Small gluteal muscle weakness
The small gluteal muscles on the stance side stabilize the pelvis in the coronal plane (A). Weakness or paralysis of the small gluteal muscles from damage to the n. gluteus superior (e.g., due to a faulty intramuscular injection) is manifested by weak abduction of the affected hip joint. In a positive Trendelenburg's test, the pelvis sags toward the normal, unsupported side (B). Tilting the upper body toward the affected side shifts the center of gravity onto the stance side, thereby elevating the pelvis on the swing side (Duchenne's limp) (C). With bilateral loss of the small gluteals, the patient exhibits a typical waddling gait.

Nerves of the Plexus Sacralis: Nervus Ischiadicus

The n. ischiadicus gives off several direct muscular branches before dividing into the nn. tibialis and fibularis communis proximal to the fossa poplitea.

Fig. 34.22 Nervus fibularis communis: Cutaneous distribution

Fig. 34.23 Nervus fibularis communis
Right limb, lateral view.

Table 34.6 Nervus fibularis communis (L4–S2)

Nerve	Innervated muscles	Sensory branches
Direct branches from n. ischiadicus	Caput musculi bicipitis femoris	—
N. fibularis superficialis	Mm. fibulares brevis and longus	N. cutaneus dorsalis medialis N. cutaneus dorsalis intermedius
N. fibularis profundus	M. tibialis anterior Mm. extensores digitorum brevis and longus of Mm. extensores hallucis brevis and longus M. fibularis tertius	Lateral cutaneous n. of hallux I Medial cutaneous n. digitus pedis II

Fig. 34.24 Nervus tibialis
Right limb.

Fig. 34.25 Nervus tibialis: Cutaneous distribution
Right lower limb, posterior view.

Table 34.7 Nervus tibialis (L4–S3)

Nerve	Innervated muscles	Sensory branches
Direct brs. from n. ischiadicus	M. semitendinosus M. semimembranosus Caput longum musculi bicipitis femoris M. adductor magnus (medial part)	—
N. tibialis	M. triceps surae M. plantaris M. popliteus M. tibialis posterior M. flexor digitorum longus M. flexor hallucis longus	N. cutaneus surae medialis Rr. calcanei medialis and lateralis N. cutaneus dorsalis lateralis
N. plantaris medialis	M. adductor hallucis M. flexor digitorum brevis Caput mediale musculi flexoris hallucis brevis M. lumbricalis I	Nn. digitales plantares proprii
N. plantaris lateralis	Caput laterale musculi flexoris hallucis brevis M. quadratus plantae M. abductor digiti minimi M. brevis flexor digiti minimi M. opponens digiti minimi Mm. lumbricales II–IV Mm. interossei plantares I–III Mm. interossei dorsales I–IV M. adductor hallucis	Nn. digitales plantares proprii

Superficial Nerves & Vessels of the Lower Limb

Fig. 34.26 Superficial cutaneous veins and nerves of right lower limb

Fig. 34.27 Cutaneous innervation of the lower limb
Right lower limb.

Fig. 34.28 Dermatomes of the lower limb
Right lower limb.

Topography of the Inguinal Region (Inguen)

Fig. 34.29 Superficial veins and nodi lymphoidei
Right male inguen, anterior view. Removed: Fascia cribrosa over the hiatus saphenus (see pp. 150–151).

Fig. 34.30 Inguen
Right male inguen, anterior view.

Table 34.8 Structures in the inguen

Region	Boundaries	Contents
Spatium retroinguinale
Muscular compartment	Spina iliaca anterior superior Lig. inguinale Arcus iliopectineus	N. femoralis N. cutaneus femoris lateralis M. iliacus M. psoas major
Vascular compartment	Lig. inguinale Arcus iliopectineus Lig. lacunare	A. and v. femoralis R. femoralis nervi genitofemoralis Nl. inguinalis profundus proximalis
Canalis inguinalis
Anulus inguinalis superficialis	Crus mediale Crus laterale Lig. inguinale reflexum	N. ilioinguinalis R. genitalis nervi genitofemoralis Funiculus spermaticus

Fig. 34.31 Spatium retroinguinale: Muscular and vascular compartments
Right inguen, anterior view.

Topography of the Regio Glutealis

Fig. 34.32 Regio glutealis
Right regio glutealis, posterior view.

Fig. 34.33 Regio glutealis and fossa ischioanalis
Right regio glutealis, posterior view. Removed: Mm. glutei maximus and medius.

Topography of the Regiones Femoris Anterior et Posterior

Fig. 34.34 Regio femoris anterior
Right thigh, anterior view.

Fig. 34.35 Regio femoris posterior
Right thigh, posterior view.

Topography of the Compartimentum Cruris Posterius & Foot

Fig. 34.36 Compartimentum Cruris Posterius
Right leg, posterior view.

Fig. 34.37 Regio politea
Right leg, posterior view.

Fig. 34.38 Regio tarsalis
Right ankle, medial view.

Topography of the Compartimenta Cruris Laterale et Anterius and Dorsum Pedis

Fig. 34.39 Neurovasculature of the compartimentum cruris laterale
Right limb. Removed: Origins of the mm. fibularis longus and extensor digitorum longus.

Clinical box 34.4

Compartment syndrome
Muscle edema or hematoma can lead to a rise in tissue fluid pressure in the compartmenta cruris. Subsequent compression of neurovascular structures due to this increased pressure may cause ischemia and irreversible muscle and nerve damage. Patients with anterior compartment syndrome, the most common form, suffer excruciating pain and cannot dorsiflex the toes. Emergency incision of the fascia of the leg may be performed to relieve compression.

Fig. 34.40 Neurovasculature of the compartimentum cruris anterius and dorsum pedis
Right limb with foot in plantar flexion.

Topography of the Planta Pedis

Fig. 34.41 Neurovasculature of the planta pedis
Right foot, plantar view.

Fig. 34.42 Neurovasculature of the foot: Cross section
Coronal section, distal view.