Treatment of bone infection has been tricky. At present, the overall treatment strategy includes conservative treatment, palliative debridement, En-block resection and amputation, but there has been a lack of uniform treatment standards. Operation is easily accepted by clinicians, but not all cases require surgical debridement, many infectious disease can be effectively treated with oral therapy[7–9]. Hamed reported that intravenous antibiotics (6 weeks) and oral suppression therapy were administered for cases of PJI infection, with reliable clinical efficacy. Research showed that drug therapy alone had an average success rate of 71.1%, surgical treatment alone had an average of 88.9% . Systemic intravenous antibiotics after debridement can achieve a rapid reduction of the bacterial load at the site of infection . Therefore, the industry is more inclined to surgical treatment combined with antibiotic treatment, which is beneficial to arrest the infection.
Study pointed out that the treatment of acute hematogenous osteomyelitis is intravenous antibiotics for several weeks, and then converted into oral antibiotics until symptoms and signs are alleviated [13, 14], but for chronic bone infection, debridement is often the first chose. Although research showed that oral and parenteral therapies achieve similar cure rates, clinicians accustomed to consider of intravenous antibiotics [15, 16], then converted to oral antibiotics. Reported that intravenous antibiotics for less than one week have no significant effect on prognosis [17–19]. We applied debridement plus systemic antibiotics treatment, most patients (80.6%)use intravenous antibiotics only for 2 weeks, although long-term antibiotic use has achieved good results in previous reports, our results showed the recurrence rate of IV group was not significantly different from the other two groups and the overall infection control rate was 83.6%, the infection control rate is comparable to previous reports, which support the applied of short-term systemic antibiotic treatment after debridement.
Multiple and refractory bacterial is common for bone infection, especially for those with chronic infection, so combined antibiotics treatment are commonly applied in the clinics. The most common oral combination drug is rifampicin, which have bactericidal effect to multiple Gram-positive and negative bacteria , it can achieves high intracellular levels and capable of penetrating bacterial biofilm [20, 21]. However, it is not advisable applied anti-infection alone, because it can cause resistance quickly, rifampicin should be started after an bacterial load reduction by surgery and the wound is dry[22, 23]. In this study, 307 (48.0%) patients were infected with Staphylococcus aureus and 56 (8.8%) with pseudomonas aeruginosa, accounts for more than 50% of the isolated bacteria, so levofloxacin was more applied in our clinics. Reported that levofloxacin alone was unable to eradicate methicillin-susceptible S. aureus[24, 25], for the bone infection caused by Staphylococcus aureus and P.aeruginosa, the classic antibiotic combination is levofloxacin plus rifampicin.
How long does it take for infection to be cleared after treatment of bone infection? There is no answer. Urania Rappo evaluated the efficacy of infection after 6 weeks treatment. Daver NG indicated that the infection apparent cure when it does not recur in 6 months. We evaluated infection control at 6 months after operation, which may miss some recurrence cases, but the missing cases is less, because our statistics show that most cases have a recurrence time within 2 months.
Rifampicin is rarely used alone in the treatment of bone infections, but its combination with other antibiotics can increase the treatment outcomes of other antibiotics, it diffuses very well within bone tissue and bacterial biofilms , but Rifampicin often elicits a hepatotoxic response and gastroenteropathy. Our results indicated that the ALT abnormal rate of rifampicin group is the highest, suggesting that postoperative combination may lead to liver damage. At the same time, Sahoko reported that rifampicin can cause acute renal damage, our results showed that the overall complication was acceptable in the three groups, the recurrence rate of IV group was not significantly different from the other two groups, while the oral group and rifampicin group had higher ALT and proteinuria positive rate, the abnormality may caused by the additional oral therapies. Although the proteinuria of the rifampicin group was the highest, the creatinine positive rate was not statistically significant difference, suggesting that the additional rifampicin therapies may cause early or mild renal damage.
Although there are many highlights in this article, the sample size is large, it used standard techniques. However there are several drawbacks. First, the bacteria, fixation methods and many heterogeneous patients may affect the results. Second, the abnormality of ALT and urinary protein suggested the possible damage of liver and renal, but can not determine the extent of the damage. Third, bone infection is a disease that is easy to recurrence, this study with short-term (6 months) follow-up, the long-term recurrence rate for those patients is still inconclusive.