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Fractures of the Humerus — Long Answer (S Das: A Manual on Clinical Surgery, 13th Edition)

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ANATOMY OVERVIEW

1. Upper end — Surgical neck, anatomical neck, greater tuberosity
2. Shaft — Mid-shaft
3. Lower end — Supracondylar, T/Y-shaped, condylar epiphysis, capitulum

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PART I: FRACTURE OF THE UPPER END OF THE HUMERUS

A. Fracture of the Neck of the Humerus and the Greater Tuberosity

• Usually a fall on the outstretched hand — the surgical neck breaks and the upward thrust may shear off the greater tuberosity.
• A direct injury on the point of the shoulder may cause fracture at the anatomical neck.

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B. Fracture Through the Surgical Neck

• Both AP and lateral views are essential.
• In abduction type: the shaft is abducted relative to the humeral head — outer half of fracture is impacted.
• In adduction type: the shaft is adducted relative to the humeral head — inner half of fracture is impacted.

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C. Fracture Through the Anatomical Neck

• Very difficult to diagnose clinically without X-ray.
• May be associated with anterior dislocation of the shoulder.

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D. Fracture of the Greater Tuberosity

• Occurs by direct injury on the greater tuberosity, or by a fall on the abducted arm where the greater tuberosity impinges against the acromion process.
• May occur in association with dislocation of the shoulder and fracture neck of the humerus.

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E. Clinical Examination — Shoulder Region (S Das Method)

• Attitude: arm supported by the other hand; contour of the shoulder joint lost/flattened.
• Note whether the greater tuberosity is at its normal position.

1. Palpates the acromion processes of both sides, slides fingers downwards to the greater tuberosity.
2. Disappearance of the greater tuberosity → dislocation of the shoulder.
3. Local bony tenderness and bony irregularity at the surgical neck of the humerus → fracture neck of humerus.
4. The medial epicondyle normally shows the direction of the head of the humerus; the lateral epicondyle shows the direction of the greater tuberosity. Disturbance of this relation suggests fracture at the neck or shaft.
5. In dislocation: rotating the flexed elbow — if no transmitted rotation of the head + crepitus + pain at neck of humerus → fracture-dislocation.
6. Marked tenderness just below the acromion process → fracture of the greater tuberosity or rupture of the supraspinatus tendon.

• Length of the arm may be increased in fracture of the upper end of the humerus.

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PART II: FRACTURES AROUND THE LOWER END OF THE HUMERUS

A. SUPRACONDYLAR FRACTURE

Types:

Clinical Features:

• Inspection:
  • Young child with swollen, flexed elbow supported by the other hand — classic presentation.
  • From behind: olecranon appears unduly prominent (in children, more likely supracondylar fracture than posterior dislocation); olecranon may be displaced sideways.
  • From the side: antero-posterior broadening of elbow.
  • Carrying angle (normally 10°–15°): becomes cubitus valgus (increased angle) or cubitus varus (decreased angle) with malunion.
• Palpation:
  • Palpate both epicondyles with thumb and fingers; check for abnormal mobility with the other hand steadying the upper humerus.
  • Abnormal mobility + crepitus → supracondylar fracture (test done with utmost gentleness).
  • In supracondylar fracture: the normal relationship of the three bony points (two epicondyles + olecranon) is preserved in the flexed position (distinguishes from posterior dislocation where this relationship is disturbed).
  • Abnormal broadening of the lower end of humerus with distortion of condyles → T/Y-shaped fracture.

• Midposterior line of the arm (Fig. 13.16): A line drawn along the posterior midline of the arm normally passes through the olecranon process. Any sideways deviation of the olecranon is demonstrated by this line.
• The anterior humeral line on lateral X-ray: A line along the anterior surface of the humerus normally divides the circular trochlea into anterior 1/3 and posterior 2/3. Posterior displacement disrupts this.

Urgent Assessment:

• Brachial artery injury — check radial pulse
• Nerve injuries — ulnar, median, radial nerves (all three may be damaged)
• Volkmann's ischaemic contracture — impending sign

Treatment (S Das principle):

• Immediate reduction of the displaced fracture is essential.
• Elbow kept flexed in collar and cuff in a position where the radial pulse is well palpated (to avoid vascular compromise).

Complications of Supracondylar Fracture:

1. Malunion
2. Cubitus valgus or varus (most common long-term deformity)
3. Myositis ossificans traumatica
4. Injury to the brachial vessels
5. Volkmann's ischaemic contracture
6. Injury to nerves — ulnar, median and/or radial

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B. T- AND Y-SHAPED FRACTURES

• More common in adults.
• Caused by falls on the point of the elbow, driving the olecranon process upwards and splitting the two condyles apart.
• Palpation: abnormal broadening of the lower end of the humerus with distortion of the condyles.

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C. FRACTURE-SEPARATION OF THE LATERAL CONDYLAR EPIPHYSIS (Children)

• Occurs in children; presents as localized lateral swelling.

D. FRACTURE-SEPARATION OF THE MEDIAL EPICONDYLE (Children)

• Presents as medial tenderness; may be associated with elbow dislocation.

E. FRACTURED CAPITULUM (Adults)

• Localized tenderness on palpation of the capitulum.

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PART III: COMPLICATIONS OF FRACTURES AND DISLOCATIONS OF THE HUMERUS

• Late nerve injury (Tardy palsy): The most common example is tardy ulnar palsy occurring as a late complication of supracondylar fracture of the humerus (due to progressive cubitus valgus stretching the ulnar nerve).
• Axillary nerve injury: In subcoracoid dislocation of the humerus and fracture of the neck of the humerus, the axillary nerve may be injured → paralysis of the deltoid.
• Radial nerve injury: May occur in fracture of the shaft of the humerus.

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PART IV: X-RAY INTERPRETATION — KEY POINTS (S Das)

1. Always take both AP and lateral views.
2. Know all epiphyseal centres around the elbow to avoid misdiagnosing epiphyseal lines as fracture lines:
   • Capitulum: 1st year
   • Medial epicondyle: 4th year (F) / 6th year (M)
   • Head of radius: ~same age as medial epicondyle
   • Medial trochlea: 9th year (F) / 10th year (M)
   • Olecranon epiphysis: ~9th–10th year
   • Lateral epicondyle: ~12th year
   • Lateral epicondyle + capitulum + trochlea fuse at puberty, then unite with shaft at 14th year (F) / 16th year (M)
3. The anterior humeral line on lateral X-ray divides the trochlea into anterior 1/3 and posterior 2/3 — important for detecting posterior displacement in supracondylar fracture.
4. In supracondylar fracture, the centre of ossification for the capitulum must not be mistaken for the head of the radius.

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SUMMARY TABLE

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• Part I — Fractures of the upper end (surgical neck, anatomical neck, greater tuberosity) with types, X-ray findings, and clinical examination method (S Das)
• Part II — Fractures of the lower end (supracondylar with both types, T/Y-shaped, condylar epiphysis, capitulum) with clinical features, special tests, treatment, and complications
• Part III — Complications (tardy ulnar palsy, axillary nerve injury, radial nerve injury, Volkmann's contracture)
• Part IV — X-ray interpretation with the full ossification centre table (CRITOE sequence) and anterior humeral line
• Summary Table — All fractures with age group, mechanism, key sign, and key complication