Origin (O), insertion (I)

Junctional region between thigh and trunk

Incorporates lower abdominal wall, inguinal canal, femoral triangle, and femoral adductor muscles

Pubic bone

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  Pubic tubercle : Small protuberance, lateral border pubic crest

  
  
  
  
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    Attachment: Inguinal ligament

  
  
  
  
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  Superior and inferior rami : Extend from pubis

  
  
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  Pecten : Ridge, posterior aspect superior pubis

  
  
  
  
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    O of pectineus muscle

    
    
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    I of conjoint tendon (internal oblique and transverse abdominis)

  
  
  
  
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  Pubic crest : Superior surface, anterior aspect pubic body

  
  
  
  
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    O of rectus abdominis muscle

    
    
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    I of transversus abdominis and external oblique muscles

  
  
  
  
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  Pubic symphysis : Cartilaginous joint between pubic bodies

  
  
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  Superior pubic ligament : Laterally extends to pubic tubercles

Abdominal wall muscles

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  Rectus abdominis : Paired midline muscles

  
  
  
  
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    O: Superior pubic ramus, pubic crest

    
    
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    I: Xiphoid process, costal cartilages 5-7

  
  
  
  
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  Linea alba : Aponeurotic junction of rectus femoris, transverse abdominis, and internal and external oblique muscles

  
  
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  External oblique : Most superficial

  
  
  
  
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    O: Ribs 5-12

    
    
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    I: Pubic crest, anterior iliac crest, linea alba

    
    
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    Lower border of aponeurosis contributes to inguinal ligament

  
  
  
  
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  Internal oblique : Between external oblique, transversus abdominis

  
  
  
  
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    O: Lateral inguinal ligament, iliac crest, thoracolumbar fascia

    
    
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    I: Pecten (conjoined tendon), pubic crest, inferior aspect of ribs 10-12, linea alba

    
    
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    O: Anterior to deep inguinal ring

    
    
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    I: Lateral to rectus abdominis muscle, posterior and medial to superficial inguinal ring

    
    
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    Arches over inguinal canal, forming roof

  
  
  
  
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  Transversus abdominis : Deepest

  
  
  
  
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    O: Iliac crest, posterior aspect of lateral inguinal ligament, thoracolumbar fascia

    
    
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    I: Pubic crest, pecten (conjoined tendon), linea alba

    
    
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    Remains posterior to inguinal canal

  
  

Thickening inferior border of external oblique aponeurosis

Attachments: Anterior superior iliac spine and pubic tubercle

Separates lower extremity from pelvis

Fascia lata attaches to inferior border

Subinguinal space : Deep to inguinal ligament

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  Passageway for femoral vessels and nerve, iliopsoas muscle into femoral triangle

  
  
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  External iliac vessels become femoral vessels upon entering this space

Entrance: Deep inguinal ring

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  Located midinguinal ligament

  
  
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  Opening of evaginated transversalis fascia through which spermatic cord/round ligament pass

Exit: Superficial inguinal ring

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  Division of external oblique aponeurosis lateral to pubic tubercle

Contents: Ilioinguinal nerve; small arteries and veins; male: Spermatic cord; female: Round ligament

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  Covered by evaginated transversalis fascia

Adductor longus muscle : Thin tendon arises from medial superior pubic ramus

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  Overlies O of gracilis, adductor brevis, and magnus muscles

Gracilis muscle : O from anterior aspect of symphysis pubis and medial aspect of inferior pubic ramus

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  O medial to adductor brevis muscle, deep to adductor longus muscle

Superficial inguinal nodes

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  Lie in subcutaneous tissues below inguinal ligament and alongside great saphenous vein

  
  
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  Subdivided into 3 groups of lymph nodes

  
  
  
  
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    Inferior group are located distal to saphenous opening and receive drainage from lower limb

    
    
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    Superolateral group are located lateral to saphenous opening and receive drainage from lateral buttock and lower anterior abdominal wall regions

    
    
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    Superomedial group are located medial to saphenous opening and receive drainage from perineum and external genitalia

  
  

Deep inguinal nodes

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  3-5 nodes located in femoral triangle just medial to femoral vein

  
  
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  Cloquet node is most proximal of deep inguinal lymph nodes located just below inguinal ligament

Usual imaging pathway for assessing groin pathology includes radiography &/or ultrasound

Use curvilinear abdominal transducer for deeper structures in addition to/or high-resolution linear transducers

Dynamic imaging is important, particularly in assessment of hernias or other position dependent pathology