Treatment of chronic staphylococcal osteomyelitis with cloxacillin and dicloxacillin--a comparative study in 12 patients

The History of Antibiotic Treatment of Osteomyelitis

Antibiotic treatment of osteomyelitis has evolved substantially over the past 80 years. Traditional teachings (eg, that antimicrobials must be given parenterally, selected based upon ratios of achieved bone vs serum drug levels, and continued for 4–6 weeks) are supported by limited data. New studies are challenging this dogma, however. In this review, we seek to contextualize the discussion by providing a narrative, chronologic review of osteomyelitis treatment spanning the pre-antibiotic era through the present day and by describing the quality of evidence supporting each component of traditional osteomyelitis therapy.

Antibiotics for treating chronic osteomyelitis in adults

BACKGROUND

Chronic osteomyelitis is generally treated with antibiotics and surgical debridement but can persist intermittently for years with frequent therapeutic failure or relapse. Despite advances in both antibiotic and surgical treatment, the long-term recurrence rate remains around 20%. This is an update of a Cochrane review first published in 2009.

OBJECTIVES

To determine the effects of different systemic antibiotic treatment regimens for treating chronic osteomyelitis in adults.

SEARCH METHODS

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (October 2012), the Cochrane Central Register of Controlled Trials (The Cochrane Library 2012, Issue 9), MEDLINE (January 1948 to September Week 4 2012), EMBASE (January 1980 to 2012 Week 40), LILACS (October 2012), the WHO International Clinical Trials Registry Platform (June 2012) and reference lists of relevant articles.

SELECTION CRITERIA

Randomised controlled trials (RCTs) or quasi-RCTs addressing the effects of different antibiotic treatments given after surgical debridement for chronic osteomyelitis in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened papers for inclusion, extracted data and appraised risk of bias in the included trials. Where appropriate, we pooled data using the fixed-effect model.

MAIN RESULTS

We included eight small trials involving a total of 282 participants with chronic osteomyelitis. Data were available from 248 participants. Most participants were male with post-traumatic osteomyelitis, usually affecting the tibia and femur, where recorded. The antibiotic regimens, duration of treatment and follow-up varied between trials. All trials mentioned surgical debridement before starting on antibiotic therapy as part of treatment, but it was unclear in four trials whether all participants underwent surgical debridement.We found that study quality and reporting were often inadequate. In particular, we judged almost all trials to be at moderate to high risk of bias due to failure to conceal allocation and inadequate follow-up.Four trials compared oral versus parenteral route for administration of antibiotics. There was no statistically significant difference between the two groups in the remission at the end of treatment (70/80 versus 58/70; risk ratio (RR) 1.04, 95% confidence interval (CI) 0.92 to 1.18; four trials, 150 participants). There was no statistically significant difference between the two groups in the remission rate 12 or more months after treatment (49/64 versus 44/54; RR 0.94, 95% CI 0.78 to 1.13; three trials, 118 participants). There was also no significant difference between the two groups in the occurrence of mild adverse events (11/64 versus 8/54; RR 1.08, 95% CI 0.49 to 2.42; three trials, 118 participants) or moderate and severe adverse events (3/49 versus 4/42; RR 0.69, 95% CI 0.19 to 2.57; three trials, 91 participants). Superinfection occurred in participants of both groups (5/66 in the oral group versus 4/58 in the parenteral group; RR 1.08, 95% CI 0.33 to 3.60; three trials, 124 participants).Single trials with few participants found no statistical significant differences for remission or adverse events for the following four comparisons: oral only versus parenteral plus oral administration; parenteral plus oral versus parenteral only administration; two different parenteral antibiotic regimens; and two different oral antibiotic regimens. No trials compared different durations of antibiotic treatment for chronic osteomyelitis, or adjusted the remission rate for bacteria species or severity of disease.

AUTHORS' CONCLUSIONS

Limited and low quality evidence suggests that the route of antibiotic administration (oral versus parenteral) does not affect the rate of disease remission if the bacteria are susceptible to the antibiotic used. However, this and the lack of statistically significant differences in adverse effects need confirmation. No or insufficient evidence exists for other aspects of antibiotic therapy for chronic osteomyelitis.The majority of the included trials were conducted over 20 years ago and currently we are faced with a far higher prevalence of bacteria that are resistant to many of the available antibiotics used for healthcare. This continuously evolving bacterial resistance represents another challenge in the choice of antibiotics for treating chronic osteomyelitis.

Antibiotics for treating chronic osteomyelitis in adults

BACKGROUND

Chronic osteomyelitis is generally treated with antibiotics and surgical debridement but can persist intermittently for years with frequent therapeutic failure. Despite advances in both antibiotics and surgical treatment, the long-term recurrence rate remains at approximately 20% to 30%.

OBJECTIVES

To determine the effects of different systemic antibiotic treatment regimens for treating chronic osteomyelitis in adults.

SEARCH STRATEGY

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (October 2008), the Cochrane Central Register of Controlled Trials (The Cochrane Library 2008, Issue 3), MEDLINE (January 1966 to October 2008), EMBASE (January 1980 to October 2008), LILACS (October 2008) and reference lists of relevant articles.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials addressing the effects of different antibiotic treatments given after surgical debridement for chronic osteomyelitis in adults.

DATA COLLECTION AND ANALYSIS

Two authors independently screened papers for inclusion, extracted data and appraised the quality of included trials. Where appropriate, we pooled data using the fixed-effect model.

MAIN RESULTS

We included eight small trials (257 participants in total, with data available from 228). Study quality was often inadequate: in particular, concealment of allocation was not confirmed and there was an absence of blinding of outcome assessment. The antibiotic regimens, duration of treatment and follow-up varied between trials. Five trials compared oral versus parenteral antibiotics. There was no statistically significant difference between the two groups in the remission rate 12 or more months after treatment (risk ratio 0.94, 95% confidence interval 0.78 to 1.13; 3 trials). Antibiotic treatment for osteomyelitis was associated with moderate or severe adverse events in 4.8% of patients allocated oral antibiotics and 15.5% patients allocated parenteral antibiotics (risk ratio: 0.40, 95% confidence interval 0.13 to 1.22; 4 trials). Single trials with very few participants found no statistical significant differences for remission or adverse events for the following three comparisons: parenteral plus oral versus parenteral only administration; two oral antibiotic regimens; and two parenteral antibiotic regimens. No trials compared different durations of antibiotic treatment for chronic osteomyelitis, or adjusted the remission rate for bacteria species or severity of disease.

AUTHORS' CONCLUSIONS

Limited evidence suggests that the method of antibiotic administration (oral versus parenteral) does not affect the rate of disease remission if the bacteria are sensitive to the antibiotic used. However, this and the lack of statistically significant differences in adverse effects need confirmation. No or insufficient evidence exists for other aspects of antibiotic therapy for chronic osteomyelitis.

Antibiotic treatment of osteomyelitis: what have we learned from 30 years of clinical trials?

OBJECTIVES AND DESIGN

To determine the most appropriate approach to antibiotic therapy for osteomyelitis, the medical literature for articles published from 1968 to 2000 was reviewed.

RESULTS

Ninety-three clinical trials in children and adults were identified using almost every antibiotic class. Most studies were non-comparative and the comparative trials involved relatively few patients. Publications generally did not provide clinically important information regarding infection staging or classification, surgical treatment provided, or the presence of orthopedic hardware. The median duration of follow-up after treatment was only 12 months. The clinical outcome was better for acute than chronic osteomyelitis in eight of the 12 studies allowing comparison. In the comparative trials, few statistically significant differences were observed between the tested treatments. In one small trial, the combination of nafcillin plus rifampin was more effective than nafcillin alone. In pediatric osteomyelitis, oral therapy with cloxacillin was more effective than tetracycline in one study, and oral clindamycin was as effective as parenteral anti-staphylococcal penicillins in another. In several investigations oral fluoroquinolones were as effective as standard parenteral treatments.

CONCLUSIONS

Although the optimal duration of antibiotic therapy remains undefined, most investigators treated patients for about six weeks. Despite three decades of research, the available literature on the treatment of osteomyelitis is inadequate to determine the best agent(s), route, or duration of antibiotic therapy.

Systematic review and meta-analysis of antibiotic therapy for bone and joint infections

We set out to evaluate the clinical efficacy of individual antibiotic agents for bone and joint infections in adults. Published and unpublished controlled trials reported between 1966 and 2000 were reviewed to determine if they involved random or quasi-random allocation to systemically administered antimicrobials or local antibiotic therapy for osteomyelitis and septic arthritis. Quiescence of infection after 1 year of follow-up was defined as the primary outcome measure. 22 trials containing 927 patients were eligible for final analysis. Varying proportions of the entire study population could be evaluated with respect to primary and secondary endpoints. Methodological quality was poor among most studies, and interpretability of results was further limited by small sample sizes, missing descriptions of patient populations and disease characteristics, and the frequent application of concomitant antibiotics. A trend towards improved, long-lasting infection control was observed in favour of a rifampicin-ciprofloxacin combination versus ciprofloxacin monotherapy for the treatment of staphylococcal infections related to orthopaedic devices (absolute risk difference [ARD] 28-9%; 95% CI -0.7 to 54.4%). Obviously unbalanced comparative studies showed some benefit of ticarcillin for bone infections caused by Pseudomonas species. No significant differences in therapeutic efficacy were found among trials comparing oral fluoroquinolones with intravenous beta-lactam drugs for both end-of-treatment (OR 0.8; 0.5 to 1.4) and long-term results (OR 1.3; 0.8 to 2.1). A variety of drugs was used as controls, thereby leading to inconsistent findings of drug-related side effects. Only one randomised trial was suitable to investigate the impact of polymethylmethacrylate gentamicin bead chains compared with parenteral antibiotics for skeletal infections, although this study was biased by patients receiving both combined local and systemic antibiotic therapy. Whereas intention-to-treat evaluation suggested a therapeutic advantage of systemic over local therapy, this trend diminished in the per-protocol analysis (1-year follow-up ARD -2.3;-17.5 to 10.8%). There exists little high-quality evidence on antibiotic therapy for osteomyelitis and septic arthritis. The observed heterogeneity among patient populations and medical and surgical treatment concepts preclude reliable inferences from the available data.

Treatment of chronic osteomyelitis; a prospective study of 55 cases treated with radical surgery and primary wound closure

A prospective and consecutive series of 55 patients were treated for chronic osteomyelitis occurring mainly in the lower extremity and after fractures treated with internal fixation. The mean duration of osteomyelitis was 27 months. Sixty-five per cent had previously undergone operations and had been hospitalized for an average of 131 days. Staphylococcus aureus was cultured in 72 per cent of the cases as the solitary agent. In 6 cases no bacteria were found. The remaining cases had more than one species. The treatment consisted of radical operation, removal of all internal fixation, sequestrectomy, partial decortication and primary wound closure with suction drainage. External fixation was used for bone stabilization. In 13 cases plastic procedures were carried out. Antibiotics appropriate for the sensitivity patterns were given for a maximum of 3 months. Primary wound healing was obtained in 98 per cent of the cases. In practically all cases the sedimentation rate normalized within 4 weeks after the operation. The results in the available literature indicate that radical operation is effective in the treatment of osteomyelitis and this treatment seems economical as regards hospitalization time and quantity of antibiotics required.

Dicloxacillin and flucloxacillin twice daily with probenecid in staphylococcal infections. A clinical and pharmakokinetic evaluation

The therapeutic efficacy of decloxacillin or flucloxacillin, 1--2 g orally with probenecid twice daily was evaluated in staphylococcal infections. Excellent results were obtained with this as long-term maintenance therapy in 4 patients with relapsing chronic osteomyelitis and in 6 patients with postoperative infections. No side effects were observed in these patients. In 35 patients with furunculosis twice daily administration of dicloxacillin was used as a primary therapeutic regimen. All healed, but 4 recurrencies occurred during a 3-month observation period after therapy. In 5 patients allergic reactions were noted. The unbound fraction of flucloxallin in serum exceeded MIC values of methicillin-susceptible Staphylococcus aureus during 11 of 24 h. Pharmacokinetic data on flucloxallin with and without probenecid are given.