Gluteal Region: Facts to Remember & Clinicoanatomical Problem

Topic Overview

Facts to Remember

• Gluteus maximus is the antigravity and thickest muscle of the human body, composed largely of red muscle fibers.

• Sciatic nerve is the largest and thickest nerve in the body.

• Intramuscular injections in the gluteal region are given in the upper lateral quadrant — specifically into the gluteus medius — to avoid injury to the sciatic nerve

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• The greater sciatic notch serves as the gateway of the gluteal region.

• Both the sciatic and pudendal nerves do not supply any structure in the gluteal region; they merely pass through it.

• Piriformis acts as the key muscle of the gluteal region, dividing structures passing above and below it.

• Sciatic nerve and its branches supply the hamstring muscles, muscles of all three compartments of the leg, and the muscles of the sole

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• The sciatic artery, a remnant of the axial artery of the embryo, accompanies the sciatic nerve.

• The lesser sciatic foramen serves as the gateway of the perineal region.

• The sciatic nerve lies close to the femur between the quadratus femoris and adductor magnus; prolonged sitting may compress it, causing temporary numbness (“sleeping foot”)

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Clinicoanatomical Problem

Case:
A 30-year-old woman complains of pain in her elbows and calves and is advised neurobion injections.

Question:
Where should the injection be given, and why?

Answer:

• The injection should be given intramuscularly in the upper lateral quadrant of the gluteal region.

• The gluteal region extends from the iliac crest above to the ischial tuberosity below and laterally to the greater trochanter.

• The upper lateral quadrant is safe, containing no major nerves or vessels.

• The lower and medial quadrants must be avoided, as they contain the sciatic nerve and major arteries.

• The injection is ideally placed into the gluteus medius muscle, where absorption is efficient and nerve injury risk is minimal

Clinicoanatomical Problems — Gluteal Region

1. Sciatic Nerve Injury during Gluteal Injection

• Case: A nurse administers an intramuscular injection in the lower medial quadrant of the buttock. The patient develops severe shooting pain radiating down the posterior thigh.

• Explanation: The sciatic nerve lies deep to the gluteus maximus in the lower medial quadrant. Accidental injection or injury here may cause neuropraxia or even sciatic neuritis, leading to pain, numbness, or paralysis of hamstrings and leg muscles.

• Prevention: Always inject in the upper lateral quadrant of the gluteal region to avoid the sciatic nerve

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2. Paralysis of Gluteus Maximus

• Case: A patient with muscular dystrophy cannot rise from sitting without support.

• Explanation: The gluteus maximus, supplied by the inferior gluteal nerve, is the chief extensor of the hip. Paralysis causes weakness in climbing stairs or standing from sitting — the patient uses their hands to “climb up their own thighs,” producing the classic Gower’s sign

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3. Paralysis of Gluteus Medius and Minimus — Trendelenburg Gait

• Case: After hip surgery, a patient’s pelvis drops on the opposite side when walking.

• Explanation: Paralysis of gluteus medius and minimus (supplied by the superior gluteal nerve) weakens the abductor mechanism of hip. When standing on one limb, the unsupported side of pelvis drops — known as positive Trendelenburg’s sign.

• Clinical Note: To compensate, the patient lurches toward the affected side, producing a waddling or lurching gait

  Volume 2, BD Chaurasia’s Human …

  Volume 2, BD Chaurasia’s Human …

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4. Piriformis Syndrome

• Case: A runner experiences deep buttock pain radiating down the thigh.

• Explanation: The sciatic nerve may pass through or below the piriformis muscle. Spasm or hypertrophy of piriformis compresses the sciatic nerve, causing pain in the buttock and posterior thigh — sciatica.

• Treatment: Rest, stretching, and sometimes surgical decompression

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5. Injury to Inferior Gluteal Nerve

• Case: A patient after pelvic fracture shows difficulty in climbing stairs.

• Explanation: The inferior gluteal nerve supplies the gluteus maximus. Damage causes loss of hip extension power, affecting stair climbing, running, or rising from a chair.

6. Injury to Superior Gluteal Nerve

• Case: A child after intramuscular injection walks with pelvis tilting on one side.

• Explanation: The superior gluteal nerve lies close to the upper margin of the greater sciatic foramen and may be injured by careless injection or pelvic fracture. This leads to paralysis of gluteus medius and minimus, resulting in Trendelenburg gait.

7. Compression of Sciatic Nerve — “Wallet Neuritis”

• Case: A person carrying a thick wallet in the back pocket develops pain in buttock and thigh after long sitting.

• Explanation: Constant pressure on the sciatic nerve by a hard object compresses it between the ischial tuberosity and wallet — producing sensory and motor irritation termed wallet neuritis.

8. Gluteal Bursitis (“Weaver’s Bottom”)

• Case: A tailor complains of painful swelling in the lower buttock after prolonged sitting.

• Explanation: Inflammation of the ischial bursa (between gluteus maximus and ischial tuberosity) due to friction or pressure causes pain and tenderness — ischial bursitis or weaver’s bottom.

9. Abscess in Gluteal Region

• Case: A patient with pelvic infection develops a swelling in the gluteal area.

• Explanation: Pelvic abscesses can spread through the greater sciatic foramen below piriformis into the gluteal region, presenting as deep-seated swelling in the buttock.

10. Injury to Internal Pudendal Nerve or Artery

• Case: Trauma near the ischial spine causes perineal numbness.

• Explanation: The internal pudendal vessels and pudendal nerve wind around the ischial spine; injury here can cause loss of perineal sensation and erectile dysfunction.