What is the prognosis and survival duration for someone with an untreated osteomyelitis (bone infection)?

Prognosis and Survival of Untreated Bone Infection (Osteomyelitis)

Untreated osteomyelitis can lead to significant morbidity and mortality, with poor outcomes including amputation and death if left completely untreated. 1

Progression and Outcomes of Untreated Osteomyelitis

• Untreated bone infection becomes chronic and persistent, causing ongoing bone destruction, necrosis, and progressive deterioration of the affected area 2, 3
• Without treatment, osteomyelitis can lead to amputation rates as high as 50-60% in severe cases, particularly with deep tissue or bone involvement 1
• Even with appropriate treatment, poor outcomes (mostly amputations) occur in almost half of hospitalized patients with diabetic foot infections complicated by osteomyelitis 1
• Chronic untreated osteomyelitis can lead to the formation of draining fistulas, continuous shedding of infected debris into adjacent tissues, and spread to surrounding soft tissues 1, 3
• The infection can become multifocal, with formation of additional tracts that may mimic new lesions, particularly in pressure injury-related osteomyelitis 1

Factors Affecting Survival and Prognosis

• The type of causative organism significantly impacts prognosis, with Staphylococcus aureus being the most common and often associated with more aggressive disease 4, 5
• The anatomical location of the infection affects outcomes - vertebral osteomyelitis and pelvic osteomyelitis generally have worse prognosis than peripheral bone infections 1
• Presence of limb ischemia significantly worsens prognosis, synergizing with infection to accelerate tissue destruction 1
• Comorbidities, especially diabetes, significantly worsen outcomes and increase mortality risk 1, 5
• Age is a significant factor, with older patients having higher mortality rates from untreated bone infections 1

Survival Rates and Timeframes

• In a study of 344 osteomyelitis patients, the overall mortality rate was 6.7%, with 3.2% directly attributed to infectious complications 5
• Failure rates of treated osteomyelitis in most clinical studies vary between 10% and 30%, suggesting much higher failure and mortality rates for completely untreated cases 1
• Even with treatment, recurrence occurs in 20-30% of diabetic patients with foot infections, especially those with underlying osteomyelitis 1
• The progression from acute to chronic osteomyelitis typically occurs within weeks to months without appropriate intervention 6
• Chronic untreated osteomyelitis can persist for years or decades, with periods of quiescence alternating with acute flare-ups 2, 3

Treatment Considerations for Improved Survival

• Surgical intervention is strongly recommended for progressive bone destruction, neurological deficits, and spinal instability to prevent life-threatening complications 1
• Antibiotic therapy duration typically ranges from 4-6 weeks for non-surgically managed osteomyelitis 1
• Shorter antibiotic courses (1-2 weeks) may be sufficient if all infected bone is surgically removed 1
• Multidisciplinary team management significantly improves outcomes compared to single-specialty approaches 7, 2
• Factors associated with better healing include absence of exposed bone, adequate blood supply (palpable pulses), blood pressure >45 mmHg in toes or >80 mmHg in ankles, normal white blood cell count, and adequate tissue oxygenation 1

Warning Signs Requiring Immediate Intervention

• Progressive neurological deficits, deformity, or instability in spinal osteomyelitis require urgent surgical intervention 1
• Persistent or recurrent bloodstream infections without alternative source indicate need for surgical debridement 1
• Worsening pain despite appropriate medical therapy suggests treatment failure requiring surgical intervention 1
• Presence of substantial bone necrosis, exposed joints, or functionally compromised limbs requires prompt surgical management 1, 7
• Uncorrectable limb ischemia limiting antibiotic delivery to infected bone significantly worsens prognosis and may necessitate amputation 7

Without appropriate treatment, osteomyelitis becomes a chronic, progressive disease with significant morbidity and mortality. The exact survival timeline varies based on multiple factors including infection location, causative organism, host factors, and presence of complications.