An ischial tuberosity pressure ulcer is a localized injury to the skin and underlying tissue. Also known as pressure sores or bedsores, these ulcers develop over bony prominences due to sustained pressure, sometimes combined with shear or friction. This condition can range from mild skin reddening to significant tissue damage, representing a common concern for individuals with limited mobility.
What Is an Ischial Tuberosity Pressure Ulcer?
An ischial tuberosity pressure ulcer is a localized injury to the skin and/or underlying soft tissue, typically occurring over a bony prominence. The ischial tuberosity, known as the “sit bones,” is a large, rounded bony protrusion at the lower rear part of the pelvis. This area bears significant body weight when sitting.
The ischial tuberosity’s location makes it susceptible to pressure ulcers because skin and soft tissues are compressed between the bone and an external surface, like a wheelchair cushion or bed. Prolonged pressure obstructs blood flow, depriving tissue of oxygen and nutrients. This lack of blood supply, known as ischemia, can cause tissue damage, cell death, and ulcer formation. A pressure sore in this area can also affect the bursa, potentially leading to a larger sore than visible skin damage.
Who Is at Risk and Why?
Immobility is a primary risk, as bedridden individuals or those consistently using a wheelchair cannot easily change positions to relieve pressure on bony areas. Prolonged immobility can lead to muscle and soft tissue atrophy, reducing natural padding over bony prominences.
Sensory impairment also contributes to risk because individuals cannot feel pain or discomfort from sustained pressure, failing to recognize the need to reposition. Conditions like spinal cord injuries or neurological disorders can cause this loss of sensation.
Poor nutrition, especially protein deficiency, compromises skin health and slows wound healing. Inadequate nutrient intake and low body weight can lead to a lack of natural padding over bony sites, increasing vulnerability.
Moisture, often due to incontinence, weakens the skin and makes it more vulnerable to breakdown. Skin exposed to urine and stool becomes more fragile, increasing damage risk.
Friction, which occurs when skin rubs against surfaces like clothing or bedding, can cause superficial skin damage. Shear forces, resulting from layers of tissue moving in opposite directions (e.g., when a person slides down in bed), stretch and tear blood vessels, reducing blood flow. Underlying medical conditions, such as diabetes and spinal cord injury, also increase risk due to impaired circulation, reduced sensation, and metabolic changes affecting tissue healing.
How Are They Identified and Classified?
Identifying an ischial tuberosity pressure ulcer involves observing visual signs and symptoms, which vary by injury stage. The National Pressure Injury Advisory Panel (NPIAP) and European Pressure Ulcer Advisory Panel (EPUAP) staging system classifies severity, categorizing pressure ulcers from Stage 1 to Stage 4, along with unstageable and deep tissue injury classifications.
A Stage 1 pressure ulcer presents as intact skin with non-blanchable redness, meaning the redness does not disappear when pressure is applied. The affected area may also feel painful, firm, soft, warmer, or cooler compared to surrounding tissue. For individuals with darker skin tones, a Stage 1 ulcer might appear as persistent blue or purple hues, or a color different from the surrounding area.
Stage 2 involves partial-thickness skin loss, appearing as a shallow open ulcer with a red-pink wound bed without slough (yellow or tan tissue), or as an intact or ruptured serum-filled blister. The wound affects the epidermis and dermis but does not extend into deeper subcutaneous tissue.
Progression to Stage 3 indicates full-thickness skin loss, where the wound extends through the skin into subcutaneous fat, but bone, tendon, or muscle are not exposed. Slough or eschar (dark, hard tissue) may be present, and undermining or tunneling (channels extending from the main wound) can occur.
Stage 4 signifies full-thickness tissue loss with exposed bone, tendon, or muscle. Slough or eschar may be present, and these ulcers often include undermining and tunneling. Unstageable pressure injuries occur when the wound base is completely covered by slough or eschar, preventing accurate staging. Deep Tissue Injury (DTI) presents as intact or non-intact skin with a localized area of persistent non-blanchable deep red, maroon, or purple discoloration, or a blood-filled blister, indicating damage to underlying soft tissue from pressure and/or shear.
Managing and Treating Ischial Tuberosity Pressure Ulcers
Managing and treating ischial tuberosity pressure ulcers involves reducing pressure, promoting healing, and preventing complications. Pressure redistribution is a primary strategy, using specialized cushions and mattresses to evenly distribute weight and relieve pressure on vulnerable areas. These devices can include foam, gel, or air. Patients should change positions frequently, with repositioning schedules varying based on individual needs and the support surface.
Wound care is another central component, involving regular cleansing and appropriate dressing selection. Open sores are cleaned with water or saline each time the dressing is changed, avoiding harsh agents like hydrogen peroxide or iodine that can damage healthy tissue. Various dressing types, such as alginates, hydrocolloids, and foams, maintain a moist wound environment, promoting healing and protecting against infection.
Debridement, the removal of damaged, dead, or infected tissue, is often necessary to facilitate healing, especially for Stage 3 and 4 ulcers. This can be achieved through surgical, mechanical, enzymatic, or autolytic techniques. Infection control is important, as pressure ulcers, particularly deeper stages, are susceptible to bacterial infection. Signs of infection include warmth, swelling, pus-like drainage, or a foul odor. Topical or systemic antibiotics may be prescribed.
Pain management is also a consideration, as pressure ulcers can be painful, especially during repositioning or dressing changes. Nonsteroidal anti-inflammatory drugs (NSAIDs) or topical pain medicines can help alleviate discomfort. Nutritional support is important for wound healing, with an emphasis on adequate protein and hydration.
In severe cases, surgical interventions, such as flap surgery, may be considered to close large, non-healing ulcers. This involves transferring healthy tissue from another part of the body to cover the wound. A multidisciplinary team, including physicians, nurses, dietitians, and physical therapists, is often involved in managing these complex wounds.
Preventing Future Occurrences
Preventing ischial tuberosity pressure ulcers involves consistent strategies to protect the skin and underlying tissues. Regular skin inspection is a foundational step, ideally performed daily, especially over bony prominences. This allows for early detection of changes such as redness, warmth, or differences in skin texture, which are early indicators of pressure damage. For individuals with darker skin tones, identifying changes in color may require close attention to differences in skin tone, temperature, and tissue consistency.
Frequent repositioning is another strategy, as it helps redistribute pressure and restore blood flow to compressed areas. For bedridden individuals, repositioning is recommended regularly, with complete changes in position. Wheelchair users should perform small weight shifts and major position changes.
Using pressure-relieving devices, such as specialized cushions and mattresses, is also important to distribute weight evenly and minimize pressure on the ischial tuberosities. Maintaining good nutrition and hydration supports overall skin integrity and aids in tissue repair. Adequate intake of protein, calories, vitamins, and minerals is important for healthy skin.
Managing moisture, particularly from incontinence, is also a preventative measure. Prompt cleansing of skin after episodes of incontinence and the use of moisture barrier creams help protect the skin from breakdown and irritation. Promoting mobility whenever possible, even with assistance, helps to reduce prolonged pressure on any single area and can improve circulation.