Antibiotic Therapy for Osteomyelitis

Prolonged oral antibiotic suppression in osteomyelitis and associated outcomes in a Veterans population

OBJECTIVE

Prolonged oral antimicrobial suppression has been suggested as an alternative treatment for patients with prosthetic joint infections who are unable or unwilling to undergo surgical intervention; however, little data exists for utilizing this approach in patients with chronic osteomyelitis and no artificial hardware.

METHODS

We retrospectively reviewed the medical records of all patients over a 5-year time frame who were treated with chronic oral antibiotic suppression for osteomyelitis and who had no artificial hardware. Clinical outcomes, risk factors for treatment failure, and adverse drug reactions were evaluated.

RESULTS

A total of 20 patients were included for evaluation, of which 12 (60%) were able to achieve successful suppression of disease for a mean duration of 778 ± 408 days after discontinuation. Diabetic patients were found to be at higher risk for treatment failure (p = 0.0281). We also identified a high rate of adverse events (25%) attributable to suppressive medications. Despite elevated inflammatory markers contributing to the decision to initiate antibiotic suppression in the majority of patients, few were able to achieve normal values throughout suppressive therapy.

CONCLUSION

Further randomized, controlled studies are needed to determine the utility of antibiotic suppression. However, prolonged oral antibiotic suppression may be a reasonable last-line treatment alternative for chronic osteomyelitis, even in the absence of artificial hardware, for patients who are unwilling or unable to undergo optimal surgical intervention.

2015 Infectious Diseases Society of America (IDSA) Clinical Practice Guidelines for the Diagnosis and Treatment of Native Vertebral Osteomyelitis in Adultsa

These guidelines are intended for use by infectious disease specialists, orthopedic surgeons, neurosurgeons, radiologists, and other healthcare professionals who care for patients with native vertebral osteomyelitis (NVO). They include evidence and opinion-based recommendations for the diagnosis and management of patients with NVO treated with antimicrobial therapy, with or without surgical intervention.

Effect of Vancomycin Therapy for Osteomyelitis on Colonization by Methicillin-ResistantStaphylococcus aureus: Lack of Emergence of Glycopeptide Resistance

Background:

In treating orthopedic infections, the long-term impact of vancomycin therapy on colonization by methicillin-resistantStaphylococcus aureus(MRSA) and the emergence of vancomycin-intermediate S.aureusis unknown.

Design:

Prospective surveillance of the effect of long-term vancomycin therapy on colonization by MRSA and the emergence of vancomycin-intermediateS. aureus.

Methods:

Thirty-four patients with MRSA osteomyelitis that was microbiologically documented were longitudinally observed for the emergence of vancomycin-intermediate S.aureusat 3 body sites (wound, anterior nares, and groin) during the initial period of vancomycin therapy and at the 2-month follow-up. Twenty patients received the standard dose (20 mg/kg/d) for 34 ± 6 days and 14 patients received a high dose (40 mg/kg/d) of vancomycin for 37 ± 9 days.

Results:

During vancomycin treatment, global MRSA carriage (all body sites) fell from 100% to 25% in the group of patients receiving the standard dose of vancomycin, and from 100% to 40% in the group receiving the high dose. During the 2-month follow-up period after vancomycin therapy, global MRSA carriage increased from 25% to 55% in the group receiving the standard dose and decreased from 43% to 36% in the group receiving the high dose.

Conclusion:

Therapy with a high dose of vancomycin contributes to the sustained eradication of MRSA carriage without promoting the emergence of glycopeptide resistance.

Optimal duration of antibiotic therapy in vertebral osteomyelitis

OBJECTIVES

To compare the risk of relapse of vertebral osteomyelitis (VO), according to the duration of antibiotic therapy (< or =6 weeks versus >6 weeks).

METHODS

We performed a 10-year retrospective study to assess the risk of VO relapse and to verify that this risk was not enhanced in patients who received 6 weeks of antibiotic therapy (Group 1) as compared with those who received a longer treatment (Group 2). VO was diagnosed based on clinical manifestations, magnetic resonance imaging and/or computed tomography findings, and isolation of a pyogenic organism in blood cultures and/or a discovertebral biopsy. Relapse was diagnosed based on isolation of the same organism in blood cultures and/or a discovertebral biopsy. Outcome was evaluated 6 months post-treatment and in December 2004.

RESULTS

Group 1 included 36 patients (mean age, 58 +/- 15 years) and Group 2 included 84 patients (mean age, 67 +/- 15 years) (P = 0.003). Clinical data and microorganisms were comparable in the 2 groups. In the first 6 months, 6 (5%) patients died (Group 1, n = 2; Group 2, n = 4), and 5 (4%) in Group 2 relapsed, 2 with recurrent VO and 3 with recurrent bacteremia. In 2004, 91 patients were evaluated (mean follow-up, 40.6 +/- 31 months): 77 (85%) were cured, 13 (14%) died (Group 1, n = 3; Group 2, n = 10), 1 had VO due to a different microorganism (Group 2), and no long-term relapses occurred.

CONCLUSION

Our results suggest that antibiotic therapy of VO could be safely shortened to 6 weeks without enhancing the risk of relapse.

Management of osteomyelitis

Osteomyelitis is an infection of the medullary or cortical bone that is becoming more difficult to cure with the increasing prevalence of methicillin- and vancomycin-resistant organisms. This article discusses the etiology of osteomyelitis and the effectiveness of various treatment options.

Osteomyelitis in elderly patients

In elderly persons, osteomyelitis is second only to soft-tissue infection as the most important musculoskeletal infection. Acute osteomyelitis is usually acquired hematogenously, and the most common pathogen is Staphylococcus aureus. Acute osteomyelitis can usually be cured with antimicrobial therapy alone. In contrast, chronic osteomyelitis may be caused by S. aureus but is often due to gram-negative organisms. The causative organism of chronic osteomyelitis is identified by culture of aseptically obtained bone biopsy specimens. Because of the presence of infected bone fragments without a blood supply (sequestra), cure of chronic osteomyelitis with antibiotic therapy alone is rarely, if ever, possible. Adequate surgical debridement is the cornerstone of therapy for chronic osteomyelitis, and cure is not possible without the removal of all infected bone.

Small exotic mammal orthopedics

The basic principles of orthopedic repair are the same for small exotic mammals as for the canine or feline patient. This article assists the clinician in determining the most appropriate method of fixation and maximizes the probability of a favorable outcome.

Deep foot infections in patients with diabetes and foot ulcer: an entity with different characteristics, treatments, and prognosis

We report findings in 223 consecutively included people with diabetes, foot ulcer and a deep foot infection treated by a multidisciplinary diabetic foot care team at the University Hospital in Lund, Sweden. The aim of the present study was to evaluate type and characteristics of deep foot infections and their relation to choice of treatment and outcome. Three different groups of deep foot infections were identified; osteomyelitis only (n = 112), deep soft tissue infection only (n = 46) and combined infections (osteomyelitis and deep soft tissue infection, n = 65). The various types of deep foot infections had different characteristics, treatment and prognosis. Patients with a deep soft tissue infection only or a combined infection had a significantly (p < 0.05) higher; (1) body temperature (38.0 and 38.0 vs. 37.3 degrees C), (2) erythrocyte sedimentation rate (75 and 80 vs. 56 mm/h) and (3) white blood count (11.0 and 12.0 vs. 8 x 10(9)) at diagnosis compared with those who had osteomyelitis only. Patients with a deep soft tissue infection only or a combined infection also had a significantly (p < 0.05) shorter time to surgery (2 and 4 vs. 10 days), higher mean number of surgical procedures (1.9 and 2.1 vs. 1.4 procedures) and higher percentage of patients had intravenous antibiotics (87 and 84 vs. 46%) compared with those who had osteomyelitis only. Amputation before healing was more common in patients with a combined infection (62%) compared with those who had osteomyelitis only (37%) or a deep soft tissue infection only (30%). The findings in the present study indicate that deep foot infections in patients with diabetes is a heterogeneous entity, in which the type of deep foot infection is related to choice of treatment strategy and to outcome. Therefore, these various types of infections has to be considered in future studies of deep foot infections in people with diabetes.

Teicoplanin in the treatment of bone and joint infections: An open study

Osteomyelitis and septic arthritis caused by Gram-positive pathogens may require prolonged inpatient treatment. The glycopeptide antibiotic, teicoplanin, can be administered once daily to outpatients, and was assessed in a multicenter, open trial in patients with such infections. Patients with proven Gram-positive osteomyelitis or septic arthritis were treated with once-daily teicoplanin, 6-12 mg/kg per day, after three loading doses at intervals of 12 h, for 4-6 weeks. A total of 342 patients were recruited, of whom 220 were fully evaluable. Surgical procedures were performed in 82% of patients. Clinical success by the end of treatment was recorded in 81/90 patients (90%) with acute osteomyelitis, 70/79 patients (88.6%) with chronic osteomyelitis, and 42/51 patients (82.4%) with septic arthritis. Four patients with acute and 4 with chronic osteomyelitis and 5 patients with septic arthritis failed to respond to treatment. Relapse was known to have occurred in 10 patients with osteomyelitis and 4 with septic arthritis. Mean trough levels of teicoplanin reached during the first week of therapy were 10 mg/l (mean dose, 6 mg/kg) and 21 mg/l (mean dose, 12 mg/kg). A mean of 75% of the treatment course was given at home. One or more adverse events were reported in 166/342 patients (48.5%), 119 (34.8%) of which were thought to be related to teicoplanin, and treatment was discontinued in 59 patients. Fever, chills, and rashes were the most common side-effects, but were usually mild. Teicoplanin was shown to be a cost-effective method of treatment of bone and joint infections caused by multiple-resistant Gram-positive pathogens.

Outpatient parenteral antimicrobial therapy for osteomyelitis

OPAT for osteomyelitis is effective, safe, and well-established. There are particular considerations with osteomyelitis, however, that relate to patient selection and the plans of therapy. Orthopedic infections may impose physical considerations that need to be considered. Concomitant medical problems, such as diabetes, must be considered and may be good reasons for hospital care aside from the infection. Further investigations of treatment of osteomyelitis are clearly needed, with OPAT patients being good subjects to study.

Vertebral osteomyelitis at a Norwegian university hospital 1987-97: clinical features, laboratory findings and outcome

Altogether 40 patients aged 13-91 y (average 58 y) with vertebral osteomyelitis were treated at the Bergen University Hospital between July 1987 and June 1997. All patients presented with back pain, 33 (83%) had vertebral tenderness, and 26 (65%) patients were febrile. The duration of symptoms before diagnosis was < 3 weeks in 13 patients, and from 3 to 16 weeks in the remaining 27 patients. C-reactive protein (CRP) level and erythrocyte sedimentation rate (ESR) were elevated in 39 and 38 patients, respectively. Staphylococcus aureus was the most frequent cause of osteomyelitis followed by Streptococcus spp., Escherichia coli and Mycobacterium tuberculosis. Magnetic resonance imaging was superior to other radiological methods and demonstrated changes consistent with osteomyelitis in all 23 patients examined with this method. 35 patients survived. 18/35 surviving patients had pareses and 17 underwent surgery with drainage of abscesses or laminectomy. All 35 patients made a good recovery and only 3 patients experienced permanent pareses. The diagnosis of vertebral osteomyelitis is easily missed, and treatment is often delayed, particularly in the elderly in whom signs of sepsis may not manifest. However, persisting localized pain and tenderness over the spine together with elevated CRP and ESR should prompt the physician to consider vertebral osteomyelitis. Fever and leukocytosis may support the diagnosis, but may not always be present.

Prognostic value of the clinical examination of the diabetic foot ulcer

OBJECTIVE

To determine the value of the history, physical examination, and magnetic resonance imaging (MRI) in predicting successful primary healing of a foot ulcer in a diabetic patient.

DESIGN

Prospective cohort study.

SETTING

Durham (NC) Veterans Affairs Medical Center.

PATIENTS

Sixty-four consecutive diabetic patients with 78 dermal ulcers through the full thickness of the skin and at or distal to the malleoli of the ankle.

MEASUREMENTS AND MAIN RESULTS

A structured clinical history and physical examination were performed by two examiners, a physician participating in the study and the referring physician. Fifty of these patients with 63 ulcers underwent MRI. Patients were followed prospectively for 6 months after enrollment to ascertain healing of the ulcer, amputation, and death. During the 6-month follow-up period, 8 (13%) of the patients died. Seventeen (22%) of the ulcers were amputated, 17 (22%) of the ulcers failed to heal, and 36 (47%) healed primarily. Univariate predictors of healing at 6 months included age less than 65 years, diagnosis of diabetes within the last 15 years, painless ulcer, palpable ankle pulse, anklebrachial index greater than 0.5, and the physician's assessment of the overall likelihood of osteomyelitis. In a multivariable logistic regression model, predictors of healing included the presence of an audible pulse on Doppler examination (p = .01) and a painless ulcer (p = .04). The diagnosis of osteomyelitis on MRI did not predict healing in these patients.

CONCLUSIONS

Foot ulcers in patients with diabetes frequently have poor outcomes; fewer than half the patients in this study healed their ulcers within 6 months. The vascular components of the clinical examination are the best predictors of healing in patients with a diabetic foot ulcer.

Spinal osteomyelitis after TPN catheter-induced septicemia

Osteomyelitis of the spine is a well-recognized delayed manifestation of septicemia but has not been recognized as a complication of total parenteral nutrition. We report five cases of spinal osteomyelitis that were clinically recognized 1 to 13 months after total parenteral nutrition catheter-induced septicemia. Radiographic evidence of osteomyelitis was seen in all five patients. In three patients, culture of bony aspirates was positive for the same organism as from the blood. In one case, the diagnosis was established by histology, and in one the diagnosis was based on radiographic and radionuclide evidence of osteomyelitis. The organism responsible was Staphylococcus aureus in two cases, Candida albicans in another two cases and C tropicalis in one case. The septic episode that preceded osteomyelitis was treated with systemic antibiotics and catheter removal in four patients, and antibiotics without catheter removal in one patient. Nevertheless, osteomyelitis occurred, requiring bracing or operative debridement as well as prolonged antibiotic therapy. Spinal osteomyelitis may occur as a delayed manifestation of total parenteral nutrition catheter-induced septicemia. Prompt and effective treatment of septicemia is indicated but may not always be sufficient. Clinical suspicion is the key to the correct and early diagnosis of osteomyelitis and therefore to adequate treatment.