Osteomyelitis Management in Diabetic Patients: A Case Study

Introduction to Osteomyelitis in Diabetic Patients

Osteomyelitis is an infection of the bone or bone marrow, typically categorized as acute, subacute, or chronic.¹ It is characteristically defined according to the causative organism (pyogenic bacteria or mycobacteria) and the route, duration, and physical location of the infection site.² Infection usually takes one of three forms: direct bone contamination from an open fracture, puncture wound, bone surgery, total joint replacement, or traumatic injury; extension of a soft tissue infection such as a vascular ulcer; or hematogenous (blood-borne) spread from other infected areas of the body such as the tonsils, teeth, or upper respiratory system.^2(p807) Bacteria such as Staphylococcus aureus, Pseudomonas, Klebsiella, Salmonella, and Escherichia coli are the most common causative agents of the disease, although viruses, parasites, and fungi may also lead to the development of osteomyelitis.³

Patients most at risk include the elderly, obese, and malnourished, as well as those suffering from impaired immune systems or chronic illness such as rheumatoid arthritis.^3(p348) Other risk factors include long-term skin infections, arteriosclerosis, high blood pressure, cigarette smoking, high cholesterol, intravenous drug use, sickle cell anemia, and cancer.⁴ The disease is very common in diabetic patients.⁵

This case study examines osteomyelitis in the diabetic patient and includes an in-depth look at a diabetic patient who sustained a foot wound. Over time, the wound stalled, became chronic, and resisted healing. Eventually, this led to an infection that reached the bone, resulting in osteomyelitis. This hypothetical study illustrates that an effective nursing management plan can help diabetic patients facing this condition avoid complications and painful, expensive, and intrusive surgeries.⁶ In extreme cases, the disease can even lead to amputation. The occurrence of osteomyelitis in diabetics can be avoided with routine medical attention and proper patient education.

There are roughly 14 million diabetics in the United States.^5(p1019) Foot complications are among the most serious and costly complications of diabetes.^6(p236) Between 15% and 25% of diabetics will have a foot ulcer in their lifetime.⁷ For 14–24%, this will lead to amputation of all or part of a lower extremity.^2(p806)

Symptoms and Complications

Diabetic foot lesions frequently result from two or more risk factors occurring together. In the majority of patients, diabetic peripheral neuropathy plays a central role: up to 50% of people with Type 2 diabetes have neuropathy and at-risk feet.^2(p810) Neuropathy leads to insensitivity and sometimes deformity of the foot and bony prominences, often resulting in an abnormal walking pattern and foot loading. In people with neuropathy, minor trauma — caused, for example, by ill-fitting shoes, walking barefoot, or an acute injury — can precipitate a chronic foot ulcer.⁸ Loss of sensation and limited joint mobility can also result in abnormal biomechanical loading of the foot and the formation of calluses. Calluses further contribute to the patient's discomfort and increase abnormal weight loading, which often results in subcutaneous hemorrhage.^7(p17) Whatever the primary causes, should a patient continue walking on an insensitive foot, healing will be impaired. The breakdown of skin often leads to a deep foot infection with osteomyelitis.^3(p349)

The onset of osteomyelitis can be sudden. Clinical manifestations include chills, high fever, rapid pulse, and general malaise.⁹ Osteomyelitis can be difficult to treat, especially if it is undetected at its onset. Systemic symptoms are often more prevalent than local symptoms. As the infection spreads through the cortex of the bone, it involves the periosteum and soft tissue.^2(p811) This often results in swelling, pain, and tenderness. Many patients describe a "continuous, throbbing pain" that may intensify with movement due to collecting pus.^4(pS20) Once bone becomes infected, pus is produced within the bone, creating an abscess that deprives the bone of its blood supply.

Diagnosis

Infection in a diabetic foot presents a direct threat to the affected limb and should be treated promptly and actively.^4(pS21) Signs and symptoms of infection — such as fever, pain, or elevated white blood cell counts — are often absent. However, if infection is present, substantial tissue damage and risk of osteomyelitis are likely.

The diagnosis of osteomyelitis is based primarily on clinical findings, with data from personal history, physical examination, and laboratory tests also considered in treatment planning.^9(p886) Leukocytosis and elevations in the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) level may be noted. Blood cultures and bone biopsies are also used to inform diagnosis.

Many diabetic patients complain of sensory loss. Healthcare practitioners can assess neuropathy using techniques such as pressure perception (e.g., Semmes-Weinstein monofilaments), vibration perception (e.g., 128 Hz tuning fork), discrimination (e.g., pinprick without skin penetration), tactile sensation (e.g., cotton wisp on the dorsum of the foot), and Achilles tendon reflexes.^{9(p888–890)} Sensory exams are generally conducted in relaxed settings, with patients in reclined positions and feet elevated for proper inspection. When patients fail to respond protectively to two out of three applications of any method, they are considered at high risk of ulceration and possibly osteomyelitis, particularly in combination with other risk factors.^3(p349)

Radiographic evidence often provides the clearest diagnostic confirmation of the disease, highlighting bone destruction caused by osteomyelitis.^11(p38) However, indications may not appear until approximately two weeks after the start of infection. Radiographs may reveal osteolysis or periosteal reaction.^4(pS21) In severe cases, sequestra can occur — a condition in which segments of necrotic bone separate from living bone, creating an environment favorable to microorganism growth.¹⁰ This can lead to chronic osteomyelitis. A bone abscess uncovered during the subacute or chronic stage of hematogenous osteomyelitis is known as a Brodie's abscess and may require drainage.^7(p18)