Definition and Overview

A pressure ulcer is an injury to the skin caused by prolonged and constant pressure. It is very common in patients who are wheelchair-bound or bedridden and usually forms over bony areas such as the sacrum. The sacrum is the triangular bone located at the inferior end of the spine. A pressure ulcer results from lack of movement, which leads to reduced blood supply to the skin. When left untreated, the condition can result in an open sore and even cell death, ischemia, and tissue necrosis in severe cases.

Pressure ulcers can be mild, moderate, or severe. Mild cases appear as red areas on the surface of the skin while severe cases are characterised by a tissue damage that can lead to bone or skin infection. While mild cases can heal without treatment, severe cases require surgery. The procedure removes dead tissue and wound debris so the wound would heal. It also involves closing the wound with a primary suture, skin flap, or skin graft depending on the size and depth of the wound.

Who Should Undergo and Expected Results

The excision of a sacral pressure ulcer is reserved for serious cases especially when the damage has already reached the deeper layers of the skin. It is also prescribed if bones and muscles in the area are already affected. Severe cases of pressure ulcer are hard to treat and may take a long time to heal especially if the patient is suffering from other medical conditions such as diabetes.

Sacral pressure ulcers are very common among patients who have to stay in the hospital for an extended period. These patients typically have impaired movement due to an injury or a medical condition that slows down healing. Pressure ulcers develop due to prolonged pressure on the skin and tissues, a shear force that causes the skin to fold over itself, and friction burns.

Although in principle, sacral pressure ulcers are preventable, they continue to be among the most serious problems faced by persons who are ill, functionally impaired, or recovering from an illness. These include those who are paralysed, comatose, and with spinal cord injuries as their condition makes it difficult for them to move and change position while in bed or seated. Those who smoke and have medical conditions that increase the risk of tissue damage tend to suffer from severe cases of sacral pressure ulcer. They are also harder to treat, as their wounds tend to heal more slowly.

How is the Procedure Performed?

Prior to the excision of sacral pressure ulcer, a thorough physical examination is carried out to evaluate the patient’s overall state of health, mental and nutritional status, and comorbidities. It is important to ensure that the patient is medically stable and able to benefit from the procedure.

The physician then decides on the most appropriate form of treatment based on the stage of the pressure ulcer, which could be:

Stage I

  • The skin appears red but not broken.
  • The skin shows discolouration and does not blanch when touched.
  • The site may be painful and warm.

Stage II

  • The skin and parts of its underlying layers are damaged.
  • The wound appears like a ruptured blister.

Stage III

  • The wound exposes some fat.
  • The bottom of the wound has a yellowish dead tissue.
  • The damage extends to the layers of healthy skin around the wound.

Stage IV

  • The wound exposes tendons, bone, or muscle.
  • Dead tissue appears at the bottom of the wound.
  • The damage extends to the layers of healthy skin around the wound.

Treating severe cases of sacral pressure ulcer involves a multidisciplinary team of medical professionals. These include a primary care physician who specialises in wound care, a physical therapist, and a dietitian. For cases where the muscles and bones are also affected, the team may also include orthopaedic and reconstructive surgeons.

The procedure starts by surgically cutting away dead tissue. The goals at this stage are to improve hygiene and the appearance of the sore, treat or prevent infection, and reduce fluid loss. The doctor will then continue by marking the ulcer before removing it as a whole (en bloc excision) using a mallet and a curved osteotome. If the damage has reached the underlying bones, the surgeon will also perform an ostectomy. The wound is then washed with antiseptic solution and checked for bleeding. Depending on the size of the resulting wound, it can be closed with a primary suture, skin flap, skin graft, or myocutaneous flap.

Possible Risks and Complications

Patients who undergo the procedure are at risk of suffering from:

  • Delayed wound healing
  • Flap necrosis
  • Hematoma
  • Seroma
  • Wound dehiscence
  • Wound infection


  • Fonder MA, Lazarus GS, Cowan DA, Aronson-Cook B, Kohli AR, Mamelak AJ. Treating the chronic wound: a practical approach to the care of nonhealing wounds and wound care dressings. J Am Acad Dermatol

  • Siebers MJ. Pressure ulcers. In: Duthie EH, Katz PR, Malone ML, eds. Practice of Geriatrics. 4th ed. Philadelphia, PA: Saunders Elsevier; 2007:chap 20.

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