Presence of ulcers may cause bone inflammation
Published on: Tuesday, April 09, 2019
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Atypical presentations are more common and uncommon sites more frequent.
Localised signs include limitations of the involved extremity, soft tissue swelling, erythema, warmth and point tenderness over the involved area. Systematic manifestations are seen in 50 per cent or fewer patients.
They may include fevers, chills, night sweats, anorexia and weight loss. Minimal vague symptoms may be reported by as many as 40 per cent of patients for one to two months.
Primary sub-acute pyogenic osteomyelitis (Brodie abscess). This is characterised by the indolent formation of abscess, most frequently occurring at the metaphysis of long bones. Local pain is the most common presenting symptom.
Vertebral osteomyelitis occurs more frequently in older patients and may result in either hematogenous seeding of the bone or as the results of a postoperative wound infection and contiguous spread. Risk factors include diabetes, immunodeficiency and intravenous drug users.
Pelvic osteomyelitis the presenting symptoms for this condition may be unusual, including abdominal pain, gait disturbance and sciatica.
Contiguous-focus osteomyelitis
Contiguous focus osteomyelitis due to spread from an adjacent focus of infection has some special characteristics. Postoperative infections constitute many cases of contiguous-focus osteomyelitis.
Open reduction of closed fractures is the most common predisposing surgical procedure. Less common predisposing surgeries include craniotomies, prosthetic hip and other constructive joint surgery, tumour resections and sternotomy for including metal, plastic and bone cement, which serve as a nisus of infection that is resistant to antibiotic therapy.
Contamination of bone at the time of and open fracture is also common. Contiguous soft tissue infections, with spread to the bone, can involve any site.
Osteomyelitis also may occur by spread from an infected tooth socket or sinuses, skin ulceration, wounds or decubitus ulcers and from infections introduced by foreign bodies eg puncture wounds.
Osteomyelitis frequently occurs in bone underlying pressure ulcers and is particularly difficult to diagnose. Bone biopsy may be useful.
Most patients follow an indolent course and are diagnosed within 1 to 2 months of the onset of disease. Delay in diagnosis often occurs in postoperative infections.
This is related in part to the use of prophylactic or postoperative antibiotics, disease due to atypical organisms of low pathogenicity and the presence of foreign materials.
Presenting symptoms include fever, regional soft tissue swelling, erythema and warmth. Purulent drainage from wounds and sinus tracts is common in both the acute and chronic forms. Site of involvement may affect the presentation.
Osteomyelitis of cranial bones often lacks signs or symptoms of disease, whereas infection of long bones and pelvis often presents with fever pain.
Peripheral vascular disease
Most patients with osteomyelitis associated with peripheral vascular disease are diabetic. Osteomyelitis does occur, however, in patients with severe atherosclerosis or vasculitis in the absence of diabetes. Most patients are older than 50 years and the bones of the toes and feet are most often involved.
Neuropathy is present in most diabetic patients with foot disease predisposing to mechanical or thermal injuries.
There is the tissue ischemia such that ulcers occurring as a result of trauma heal poorly, become chronic and frequently extend into the bone.
Antibiotics penetrate poorly into these ischemic areas, frequently necessitating surgical debridement.
Few patients have systemic symptoms and sepsis is rare. Local signs and symptoms predominate, including swelling and erythema. Pain may be absent in ulcers occurring over bony prominences. Osteomyelitis is more likely the more chronic deeper and wider ulcer.
Crepitus of the soft tissues may be present due to either aerobic or anaerobic infection. Foul odour may be due to the presence of anaerobes or necrotic tissue. Long standing diabetic complications are often the predominant findings.
These include neuropathy, diminished or absent arterial pulses, skin and nail changes, retinopathy and nephropathy. The presence of such complications may adversely affect disease outcome.
Diabetic foot
Foot infections are a common cause of mortality and mortality in patients with diabetes. 25 per cent of all diabetics develop severe foot or leg problems. Foot infections account for 20 per cent of diabetic hospitalisation.
At least 50 per cent of all non-traumatic lower extremity amputations occurring in the United States are performed over diabetics.
Peripheral neuropathy is likely the most important risk factor for development of foot lesions in diabetic patients. Neuropathy is present in over 80 per cent of diabetic foot lesions.
Loss of protective pain sensation due to peripheral neuropathy leads to loss of awareness of traumatic injury and subsequent breaks in the skin and skin ulceration.
Meaningful comparison of the many different studies on diabetic foot infections is hindered by lack of a uniform grading system accounting for neuropathy, ischemia and wound depth, all thought to be major predictions of poor outcome.
Both the Wagner and University of Texas wound classification systems hold promise in this regard. Non-limb-threatening versus-limb threatening infections.
Many researchers have suggested a practical clinical classification of infections that appear to be a useful approach.
In non-limb-threatening infections, patients have superficial infection and minimal cellulitis (< 2cm of extension from portal of entry) and lack systemic toxicity. If an ulcer is present, it does not penetrate fully through the skin.
These patients do not have bone or joint involvement or significant underlying ischemia.
In limb-threatening infections, patients have extensive cellulitis (> 2cm of extension from portal of entry) and lymphadenitis.
Full-thickness ulcers often are present. Infection of contiguous bones or joints occurs frequently. Significant ischemia with or without gangrene may be present.
Fever is seen in only some patients and more common in those with extensive soft tissue involvement, deep plantar abscesses, bacteremia or hematogenously seeded remote sites of infection.
Rare osteomyelitis
The cause of Sapho (Synovitis, acne, pustulosis, hyperostosis and osteomyelitis) Syndrome is unknown. Chronic recurrent multifocal osteomyelitis is the pediatric form of Sapho.
First described in 1972, by Giedion and coworkers, the pathogenesis of the disease is unclear.
More recent studies have implicated several genetic factors in the pathophysiology of the disease. Local swelling and tenderness of affected bones are often present.
Systemic symptoms of fever, weight loss and generalised malaise are rare. Osetitis typically is multifocal and affects several bones, including the chest wall bones (63 per cent), pelvis (40 per cent) and spine (33 per cent).
Bone radiographs may show lytic erosions similar to those infectious osteomyelitis affecting the metaphysics. Cultures of biopsy material are negative for bacteria, fungi and mycobacteria.
