Contiguous Osteomyelitis Research Articles

Outcome of diabetic foot infections treated conservatively: a retrospective cohort study with long-term follow-up.

Diabetic foot lesion is associated with increased morbidity and high resource use. Although early amputation has been advocated in case of osteomyelitis, conservative treatment is a more attractive alternative. To identify criteria predictive of failure of conservative treatment of diabetic foot ulcer at time of admission to the hospital. We conducted a 5-year retrospective cohort study with prospective long-term follow-up of all diabetic patients admitted for a foot lesion at a large (1600-bed) teaching institution. Predetermined criteria were used for the diagnosis and classification of diabetic foot lesions (Wagner classification). Study variables included patient demographics and clinical parameters related to infection and diabetes. The average follow-up after hospital discharge was 2 years. Failure of conservative treatment was the main outcome measure. Independent predictor variables were selected by logistic regression analysis. A total of 120 diabetic patients were admitted for foot lesions; complications of contiguous osteomyelitis, deep tissue involvement, and/or gangrenous lesions occurred in 78 (74%) of the 105 patients for whom charts were available. Fourteen patients (13%) underwent immediate amputation. Conservative treatment was successful for 57 (63%) of the 91 remaining patients. Success was achieved in 21 (81%) of 26 patients presenting with skin ulcer, 35 (70%) of 50 patients with deep tissue infection or suspected osteomyelitis, and 1 (7%) of 15 patients with gangrene (P<.001, chi2 for trend). Independent factors predictive of failure were the presence of fever (odds ratio [OR]=1.1 per degrees Celcius; 95% confidence interval [CI], 1.0-1.2) and increased serum creatinine level (OR=1.002 per micromoles per liter; 95% CI, 1.0020-1.0021) on admission, prior hospitalization for diabetic foot lesion (OR=1.4; 95% CI, 1.2-1.6), and gangrenous lesion (OR=1.8; 95% CI, 1.5-2.2). Other patient characteristics, demographics, duration of diabetes mellitus, neutrophil count, or the anatomical site of the lesion failed to predict outcome. Conservative treatment, including prolonged, culture-guided parenteral and oral antibiotics, is successful without amputation in a large proportion of diabetic patients admitted for a foot skin ulcer or suspected osteomyelitis. Future studies comparing early amputation with novel therapeutic strategies for severe diabetic foot infection should take into account currently identified factors that predicted failure of conservative treatment on admission to the hospital.

Contiguous discitis and osteomyelitis in children.

Magnetic resonance imaging of 16 patients with contiguous discitis and osteomyelitis provided a specific diagnosis and defined the anatomic extent of vertebral and soft-tissue involvement. Altered signal changes were evident in the disc, adjacent vertebra in the end plate and metaphyseal equivalent regions, and the anterior prevertebral tissues. Significant posterior spread and disc herniation were not evident. Fourteen patients had lumbar involvement; two had cervical involvement. The patients were followed-up for an average of 4 years 5 months. Scoliosis has developed in one patient, and four continue to have a loss of lumbar lordosis. By comparing serial roentgenograms, the mean decrease of disc-space height after the acute episode was 43% (range, 51-61%). There was no restitution of normal disc-space height at the latest follow-up roentgenogram in any of the patients. A 14% (average) narrowing of the vertebral foramina was evident in seven cases. In one patient, a fusion progressively developed 7 years after the acute episode (before full skeletal maturity). However, several patients appear to be progressing toward fusion of adjacent vertebra. A study of histologic specimens elucidated vascular anatomy of the immature vertebra that further explain the disease characteristics.

Probing to Bone in Infected Pedal Ulcers

To the Editor. —I read with interest the article by Dr Grayson and colleagues. 1 The authors appropriately offered a critique of prior studies, citing retrospective design, small numbers of patients, and lack of diagnostic criteria. However, they failed to discuss the limitations of their study. In an ideal study of contiguous osteomyelitis complicating pedal ulcers, each patient would have undergone both the index test (probing to bone) and the gold standard test (histologic diagnosis). The authors referred for histologic diagnoses only 46 (92%) of 50 patients with a positive probe test and only seven (27%) of 26 patients with a negative probe test. This represents test referral bias 2 whereby patients with a positive index test (probing to bone) are more likely to receive the criterion standard test (histologic diagnosis). As a result, both the true positives and false positives are overrepresented in the study sample. If the clinical

Probing to Bone in Infected Pedal Ulcers

To assess a bedside technique for diagnosing osteomyelitis. We prospectively assessed infected pedal ulcers for detectable bone by probing with a sterile, blunt, stainless steel probe. We then examined the relationship between detection of bone and the presence or absence of osteomyelitis that was defined histopathologically and/or clinically. A tertiary care center. Seventy-five hospitalized diabetic patients with a total of 76 infected foot ulcers were studied. Osteomyelitis was diagnosed in 50 instances (66%) and was excluded in 26 instances. Bone was detected by probing in 33 of 50 ulcers with contiguous osteomyelitis; in contrast, bone was probed in only four of 26 ulcers without contiguous osteomyelitis (P < .001). Bone detected on probing was visible in only three instances. Palpating bone on probing the pedal ulcer had a sensitivity of 66% for osteomyelitis, a specificity of 85%, a positive predictive value of 89%, and a negative predictive value of 56%. Palpation of bone in the depths of infected pedal ulcers in patients with diabetes is strongly correlated with the presence of underlying osteomyelitis. If bone is palpated on probing, specialized roentgenographic and radionuclide tests to diagnose osteomyelitis are unnecessary. Probing for bone should be included in the initial assessment of all diabetic patients with infected pedal ulcers.

HISTOLOGICALLY PROVEN PRESSURE SORE-RELATED OSTEOMYELITIS IN THE SETTING OF NEGATIVE TECHNETIUM BONE SCANS

Pressure sores are common in patients with spinal cord injury, stroke or debilitating medical illness. Contiguous osteomyelitis is a well recognized complication of pressure ulcers, but remains a challenging diagnostic and management problem. Technetium bone scan is purported to be an extremely sensitive, although nonspecific diagnostic test for osteomyelitis. Indeed, a negative bone scan is thought to virtually exclude bone infection. We report three cases of pressure sore-related polymicrobial osteomyelitis where technetium bone scan was normal, yet bone biopsy demonstrated characteristic histopathologic changes of osteomyelitis. These cases raise questions regarding the sensitivity of bone scanning in the setting of pressure sores, and they demonstrate the need for further investigation into the correlation between nuclear medicine scan results and bone biopsy histopathology. Bone biopsy remains the gold standard for diagnosis of osteomyelitis, which can be present in bone underlying a pressure ulcer, even in the setting of a normal bone scan.

Epidural Abscess Associated With Intravenous Drug Abuse in a Pregnant Patient

The association between intravenous drug abuse and epidural abscess is well known; however, this association has not previously been reported in a pregnant patient. The classic manifestation of epidural abscess is a febrile patient with back pain that progresses rapidly to radicular pain, spinal cord dysfunction, weakness, and then complete paralysis. Although this condition is rare during pregnancy, these serious complications necessitate prompt diagnosis and intervention. If spinal infection is suspected, magnetic resonance imaging should be performed immediately. After epidural abscess is diagnosed, emergent decompressive laminectomy and appropriate antibiotic coverage are necessary. Herein we describe a 27-year-old pregnant patient with epidural abscess probably related to use of contaminated needles for intravenous administration of drugs and subsequent hematologic spread of staphylococci to the epidural space. The differential diagnosis of epidural abscess can be difficult, and management options must consider the well-being of both the mother and the fetus.

Changing Pattern of Bone and Joint Infections Due to Staphylococcus aureus: Study of Cases of Bacteremia in Denmark, 1959-1988

Of the 15,170 cases of bacteremia due to Staphylococcus aureus that occurred in Denmark between 1959 and 1988, we review 525 cases of acute hematogenous osteomyelitis and 185 cases of septic arthritis that developed subsequent to the bacteremia and 134 cases of contiguous osteomyelitis in which the bacteremia developed secondarily. The pattern of acute infections of bones and joints has changed over the three decades studied. The frequency of secondary bone or joint infections due to S. aureus bacteremia has changed, as have the phage-type pattern and antibiotic resistance of the infective strains. The prevalence of hospital-acquired cases has increased and the age distribution of patients has changed, as is reflected in an increasing number of older patients. The localization of hematogenous osteomyelitis has shifted, and the vertebral column is now the most common site of infection. The rate of chronic cases of osteomyelitis that occur following acute hematogenous osteomyelitis has been reduced from 34% to 6%. The mortality associated with S. aureus bacteremic infections of bones or joints is low compared to that associated with other cases of S. aureus bacteremia.

Clinical utility of new quinolones in treatment of osteomyelitis and lower respiratory tract infections.

In the eight major clinical studies published on use of oral quinolones in therapy of contiguous osteomyelitis, clinical and microbiologic cure/improvement rates were 75% and 73%, respectively, when drug therapy was combined with appropriate surgical debridement. This included many cases of polymicrobial osteomyelitis, as well as infection caused by recalcitrant pathogens such as Pseudomonas aeruginosa. In contrast, the response of staphylococcal osteomyelitis to oral quinolones, especially in cases caused by methicillin-resistant strains, appeared suboptimal. Quinolones appear to have a limited role in the treatment of community-acquired pneumonia, since other established antibiotic regimens have been proven effective in such situations. Quinolones may play an important role in the treatment of nosocomially acquired aerobic gram-negative bacillary pneumonia, either as primary parenteral therapy or as transitional oral therapy when affected patients become outpatients. In cystic fibrosis-associated acute exacerbations of chronic pseudomonal pneumonitis, the outcome of oral ciprofloxacin therapy was very satisfactory in the six major studies reported (approximately 85% improvement rates). In three comparative studies oral quinolone treatment of such pulmonary exacerbations resulted in clinical response rates equivalent to those for aminoglycoside plus beta-lactam therapy given intravenously. Quinolone-resistant Pseudomonas aeruginosa strains were commonly isolated from sputum during treatment; however, such patients continued to respond clinically to quinolone treatment, and sputum became rapidly repopulated with quinolone-susceptible Pseudomonas aeruginosa strains after discontinuation of therapy.

Treatment of skin and soft tissue infections with oral ciprofloxacin.

Thirty adult patients with severe skin and soft tissue infections (four with contiguous osteomyelitis) caused by a variety of bacterial pathogens were treated with oral ciprofloxacin. Favourable clinical responses were observed in 23 (92%) of the 25 evaluable cases. All Enterobacteriaceae and anaerobic bacteria were eradicated during treatment. Enterococci, Staphylococcus aureus, and Pseudomonas aeruginosa were usually eradicated but occasional strains persisted during treatment. Strains that persisted during treatment were associated with therapeutic failure in two cases, one with contiguous osteomyelitis and one with vascular gangrene. The only significant adverse reaction observed was nausea and/or vomiting in five of the 30 patients.

Therapy of Skin, Soft Tissue, and Bone Infections with Cefoxitin Sodium

Twenty-seven patients with skin and soft tissue infections, including three with contiguous osteomyelitis, were given cefoxitin intravenously or intramuscularly; the infections of 25 (93%) were resolved with cefoxitin therapy. Etiologic agents included staphylococci, streptococci, Enterobacteriaceae, and anaerobes. Susceptible pathogens were inhibited by less than or equal to 8 micrograms of cefoxitin/ml. This level of drug was surpassed by mean peak serum concentrations eight- to 12-fold after intravenous infusions and two- to threefold after intramuscular injections and resulted in eradication of susceptible organisms from lesions during treatment. Intravenously administered cefoxitin was well tolerated, although eosinophilia, phlebitis, elevation of levels of hepatic enzymes, and a positive direct Coombs' test were observed. Intramuscular injections of cefoxitin in 0.5% lidocaine caused pain and induration and thus were poorly tolerated.

Gonococcal Osteomyelitis

GONOCOCCAL arthritis, which usually responds readily to appropriate antimicrobial therapy, is a potentially destructive process. Before the introduction of antimicrobial agents, 23% to 85% of patients who recovered from gonococcal arthritis had residual joint damage.¹Although osteomyelitis has been described as a complication of infective arthritis caused by bacteria other than the gonococcus, it has been infrequently associated with gonococcal arthritis. We report the case of a young woman who had gonococcal arthritis with contiguous osteomyelitis. <h3>Report of a Case</h3> A 31-year-old woman was admitted to Boston City Hospital with pain and swelling of the second right metacarpophalangeal joint. She was well until six weeks prior to admission, when she noted pain in the left hand and shoulder and in both wrists. Four weeks prior to admission, she came to the emergency room because of pain and swelling of the second, third, and fourth left metacarpophalangeal and proximal interphalangeal joints.