Key features of bone and joint infections following the implementation of reference centers in France.

OBJECTIVES: French reference centers for bone and joint infections (BJI) were implemented from 2009 onwards to improve the management of complex BJIs. This study compared BJI burden before and after the implementation of these reference centers. PATIENTS AND METHODS: BJI hospital stays were selected from the 2008 and 2013 national hospital discharge database using a validated algorithm, adding the new complex BJI code created in 2011. Epidemiology and economic burden were assessed. RESULTS: BJI prevalence increased in 2013 (70 vs. 54/100,000 in 2008). Characteristics of BJI remained similar between 2008 and 2013: septic arthritis (50%), increasing prevalence with age and sex, case fatality 5%, mean length of stay 17.5 days, rehospitalization 20%. However, device-associated BJIs increased (34 vs. 26%) as well as costs (€421 million vs. €259 in 2008). Similar device-associated BJI characteristics between 2008 and 2013 were: septic arthritis (70%), case fatality (3%), but with more hospitalizations in reference centers (34 vs. 30%) and a higher cost per stay. Among the 7% of coded complex BJIs, the mean length of stay was 22.2 days and mean cost was €11,960. CONCLUSIONS: BJI prevalence highly increased in France. Complex BJI prevalence assessment is complicated by the absence of clinical consensus and probable undercoding. A validation of clinical case definition of complex BJI is required.

Espondilodiscitis: análisis de 19 casos internados en un hospital de tercer nivel / Spondylodiscitis: analiysis of 19 inpatients at a referral hospital in Rosario, Argentina

Introducción: la espondilitis representa un desafío diagnóstico, ya que el dolor lumbar, su principal manifestación clínica, constituyeun motivo de consulta muy frecuente en la práctica cotidiana y carece de especificidad. Por lo tanto, resulta indispensablemantener una elevada sospecha clínica. Objetivo: Analizar las características clínicas, analíticas, microbiológicas e imagenológicas,el tratamiento, la evolución y los factores pronósticos de pacientes internados por espondilodiscitis en el Hospital Provincial delCentenario, desde enero de 2011 a marzo de 2015, excluyéndose los casos postquirúrquicos. Resultados: Se analizaron 19 pacientescon una edad media 48±11 años, 63% varones. Se identificaron como comorbilidades: diabetes (37%), obesidad (16%), etilismo(21%), insuficiencia renal crónica en hemodiálisis (16%), HIV (11%), adicción EV (11%). Los gérmenes más frecuentes fueron losestafilococos (52%). Al ingreso el 94% presentó dolor, 73% fiebre y 36% foco neurológico. La media de tiempo de evolución desíntomas hasta ingreso fue 62±80 días (rango 4-360 días). La velocidad de eritrosedimentación fue elevada en todos los pacientes,y sólo 37% presentaban leucocitosis. La vancomicina fue el antibiótico más utilizado. El 37% de los pacientes presentaba infeccióndiseminada. La mortalidad fue del 26%. Los pacientes que tuvieron un tiempo de evolución al ingreso mayor a 25 días presentaronpeor evolución (colecciones, foco neurológico o muerte) (p<0,05). Conclusiones: en esta serie, la asociación de la consulta tardíacon la mala evolución destaca la importancia de considerar las pautas de alarma en centros de atención primaria para posibilitar undiagnóstico más temprano.

Introduction: Spondylodiscitis represents a diagnostic challenge since the main clinical manifestation, low back pain, is very frequent andnonspecific, and often impedes a timely diagnosis. Clinical suspicion is essential. Objective: to analyze the clinical, analytical, microbiological,and radiological features, as well as outcome and prognostics factors, in patients with spondylodiscitis admitted to the Hospital Provincialdel Centenario (Rosario, Argentina), from January 2011 to March 2015. Postsurgical cases were excluded. Results: Nineteen patients wereincluded. Mean age was 48±11 years, 63% were males. We identified the following comorbid diseases: diabetes (37%), obesity (16%),alcoholism (21%), hemodialysis-dependent chronic kidney disease (16%), HIV (11%), intravenous drug abuse (11%). The most frequentcausative organism was Staphylococcus sp. (52%). Upon admission 94% of patients presented pain, 73% fever, and 36% neurologicalinvolvement. The average time from the onset of symptoms to diagnosis was 62±80 days (range 4-360). The erythrocyte sedimentation ratewas raised in all the patients, and only 37% had leukocytosis. Vancomycin was the most frequently prescribed antibiotic. Disseminatedinfection was present in 37% of patients. The mortality rate was 26%. Patients with a time lag to diagnosis higher than 25 days had worseoutcome (suppurative collections, neurological involvement, or death) compared to those with earlier diagnosis (p <0.05). Conclusions:The association of late consultation with poor outcome in this study emphasizes the importance of educating the general population toencourage attendance to medical centers. Physicians in primary care settings must be trained to identify pain pattern, and incorporateclinical perspectives capable of recognizing a defined syndrome at first contact, in other to achieve a better outcome.Key words: Spondylodiscitis, comorbid conditions, diagnostic delay, outcome.

Management of Postoperative Spondylodiscitis with and without Internal Fixation.

Postoperative spondylodiscitis is relatively uncommon. This complication is associated with increased cost, and long-term of inability to work, and even morbidity. Although the majority of postoperative spondylodiscitis cases can be well managed by conservative treatment, postoperative spondylodiscitis after internal fixation and those cases that are unresponsive to the conservative treatment present challenges to the surgeon. Here, a review was done to analyze the treatment of postoperative spondylodiscitis with/without internal fixation. This review article suggested that majority of postoperative spondylodiscitis without internal fixation could be cured by conservative treatment. Either posterior or anterior debridement can be used to treat postoperative spondylodiscitis without internal fixation when conservative treatment fails. In addition, minimally invasive debridement and drainage may also be an alternative treatment. In case of postoperative spondylodiscitis after internal fixation, surgical treatment was required. In the cervical spine, it can be well managed by anterior debridement, removal of internal fixation, and reconstruction of the spinal stability by using bone grafting/cage/anterior plate. Postoperative spondylodiscitis after internal fixation is successfully managed by combined anterior debridement, fusion with posterior approach and removal of pedicle screw or extension of pedicle screw beyond the lesion site, in the thoracic and lumbar spine.

MRI of transforaminal lumbar interbody fusion: imaging appearance with and without the use of human recombinant bone morphogenetic protein-2 (rhBMP-2).

PURPOSE: To describe the vertebral endplate and intervertebral disc space MRI appearance following TLIF, with and without the use of rhBMP-2, and to determine if the appearance is concerning for discitis/osteomyelitis. MATERIALS AND METHODS: After institutional review board approval, 116 TLIF assessments performed on 75 patients with rhBMP-2 were retrospectively and independently reviewed by five radiologists and compared to 73 TLIF assessments performed on 45 patients without rhBMP-2. MRIs were evaluated for endplate signal, disc space enhancement, disc space fluid, and abnormal paraspinal soft tissue. Endplate edema-like signal was reported when T1-weighted hypointensity, T2-weighted hyperintensity, and endplate enhancement were present. Subjective concern for discitis/osteomyelitis on MRI was graded on a five-point scale. Generalized estimating equation binomial regression model analysis was performed with findings correlated with rhBMP-2 use, TLIF level, graft type, and days between TLIF and MRI. RESULTS: The rhBMP-2 group demonstrated endplate edema-like signal (OR 5.66; 95% CI [1.58, 20.24], p = 0.008) and disc space enhancement (OR 2.40; 95% CI [1.20, 4.80], p = 0.013) more often after adjusting for the TLIF level, graft type, and the number of days following TLIF. Both groups had a similar temporal distribution for endplate edema-like signal but disc space enhancement peaked earlier in the rhBMP-2 group. Disc space fluid was only present in the rhBMP-2 group. Neither group demonstrated abnormal paraspinal soft tissue and discitis/osteomyelitis was not considered likely in any patient. CONCLUSIONS: Endplate edema-like signal and disc space enhancement were significantly more frequent and disc space enhancement developed more rapidly following TLIF when rhBMP-2 was utilized. The concern for discitis/osteomyelitis was similar and minimal in both groups.

Preventing L5-S1 discitis associated with sacrocolpopexy.

OBJECTIVE: To further characterize the anatomy of the fifth lumbar to first sacral (L5-S1) disc space and to provide anatomic landmarks that can be used to predict the locations of the disc, sacral promontory, and surrounding structures during sacrocolpopexy. METHODS: The lumbosacral anatomy was examined in 25 female cadavers and 100 computed tomography (CT) studies. Measurements were obtained using the midpoint of the sacral promontory as a reference. Data were analyzed using Pearson χ, unpaired Student's t test, and analysis of covariance. RESULTS: The average height of the L5-S1 disc was 1.8±0.3 cm (range 1.3-2.8 cm) in cadavers and 1.4±0.4 cm (0.3-2.3) on CT (P<.001). The average angle of descent between the anterior surfaces of L5 and S1 was 60.5±9 degrees (39.5-80.5 degrees) in cadavers and 65.3±8 degrees (42.6-88.6 degrees) on CT (P=.016). The average shortest distance between the S1 foramina was 3.4±0.4 cm in cadavers and 3.0±0.4 cm on CT (P<.001). The average height of the first sacral vertebra (S1) was 3.0±0.2 cm in cadavers and 3.0±0.3 on CT (P=.269). CONCLUSION: In the supine position, the most prominent structure in the presacral space is the L5-S1 disc, which extends approximately 1.5 cm cephalad to the "true" sacral promontory. During sacrocolpopexy, awareness of a 60-degree average drop between the anterior surfaces of L5 and S1 vertebra should assist with intraoperative localization of the sacral promontory and avoidance of the L5-S1 disc. The first sacral nerve can be expected approximately 3 cm from the upper surface of the sacrum and 1.5 cm from the midline. LEVEL OF EVIDENCE: II.

Does surgical technique affect the incidence of spondylodiscitis post-lumbar microdiscectomy? A retrospective analysis of 3063 patients.

STUDY DESIGN: Retrospective audit in a single center during a period of 7 years operated by 3 groups of surgeons after 3 different surgical techniques. OBJECTIVE: Our study aimed to determine whether surgical technique had any influence on the incidence of spondylodiscitis in patients undergoing lumbar microdiscectomy and to compare this with published rate of incidence of spondylodiscitis. SUMMARY OF BACKGROUND DATA: The incidence of spondylodiscitis post-lumbar microdiscectomy ranges from 0.2% to 15%. There is limited evidence to compare different techniques and the incidence of spondylodiscitis. METHODS: A total of 3063 patients were analyzed from 2005 to 2011 for discitis postoperatively. The first group followed a standard microdiscectomy technique, the second group used antiseptic (Savlon; Novartis Consumer Health UK Limited, Surrey, UK) irrigation at the end of the procedure to irrigate the disc space, and the third group followed standard microdiscectomy along with usage of a separate disc instruments when discectomy was performed. The number of patients operated in the individual groups was 559, 1122, and 1382. RESULTS: The total number of patients who had postoperative discitis was 3 (0.10%), with a range of 0.07% to 0.18%. There was 1 case of discitis in each group. The incidence of spondylodiscitis in groups A, B, and C were 0.18%, 0.09%, and 0.07%, respectively. CONCLUSION: This study concluded that different techniques used for lumbar microdiscectomy revealed that standard microsurgical technique with usage of antiseptic irrigation for the disc space and usage of separate disc instruments had lesser incidence of spondylodiscitis in comparison with standard microdiscectomy. The overall incidence of postoperative discitis remains less in our series. So far, to our knowledge, this report involves the largest number of patients studied to determine the incidence of discitis in patients undergoing lumbar microdiscectomy. LEVEL OF EVIDENCE: 3.

Postprocedural discitis of the vertebral spine: challenges in diagnosis, treatment and prevention.

BACKGROUND: Although post-procedural discitis is relatively uncommon, the consequences can be very clinically significant. AIM: We reviewed aspects on the diagnosis, management and prevention of post-procedural discitis. METHODS: We reviewed the literature published in English over the last twenty years using a variety of appropriate search terms. RESULTS: Clinical features, microbiology results, imaging and inflammatory makers should be used in diagnosis. Every effort should be made to confirm infection to avoid unnecessary antibiotics and to facilitate targeted therapy. Surgical debridement or source control is a crucial aspect of treatment and can provide diagnosis specimens to guide antibiotic treatment. When culture results are positive, antibiotic treatment should be based on the results of antibiotic susceptibilities. There are no definitive guidelines on antibiotic therapy. A combination of agents, such as a quinolone or clindamycin, with fusidic acid or rifampicin, is indicated for empirical therapy. Early intravenous to oral switch and a minimum of six weeks of antibiotic treatment is recommended. Prevention involves antimicrobial prophylaxis perioperatively, good surgical technique and minimally invasive surgery where possible. CONCLUSION: Much of the information currently available is sub-optimal with the absence of good clinical trials. Further research is required on alternative approaches to routine culture and on the potential role of local antibiotics as prevention measures.

Postoperative spondilodiscitis.

INTRODUCTION: Postoperative spondylodiscitis is a primary infection of the nucleus pulposus with secondary involvement of the cartilaginous endplate and vertebral bone. Although uncommon, postoperative spondylodiscitis causes major morbidity and may be associated with serious long-term sequelae. Several risk factors had been identified, including immunosuppression, obesity, alcohol, smoking, diabetes and malnutrition. MATERIALS AND METHODS: A review of the literature was done to analyse the diagnosis, treatment and prevention of postoperative spondylodiscitis. RESULTS: We found that the principles of conservative treatment are to establish an accurate microbiological diagnosis, treat with appropriate antibiotics, immobilise the spine, and closely monitor for spinal instability and neurological deterioration. The purpose of surgical treatment is to obtain multiple cultures of bone and soft tissue, perform a thorough debridement of infected tissue, decompress neural structures, and reconstruct the unstable spinal column with bone graft with or without concomitant instrumentation. CONCLUSIONS: Appropriate management requires aggressive medical treatment and, at times, surgical intervention. If recognised early and treated appropriately, a full recovery can often be expected. Therefore, clinicians should be aware of the clinical presentation of such infections to improve patient outcome. A review of the literature was done to advance our understanding of the diagnosis, treatment, prevention and outcome of these infections.

Postoperative spondylodiscitis following transforaminal percutaneous endoscopic lumbar discectomy: clinical characteristics and preventive strategies.

INTRODUCTION: We aimed to demonstrate the unique clinical characteristics and outcomes of spondylodiscitis after transforaminal percutaneous endoscopic lumbar discectomy (PELD), and we also discuss about adequate preventive methods of this unexpected complication. METHODS: The medical records of 9821 consecutive cases treated with PELD between January 2001 and December 2009 were reviewed. All cases of postoperative infection were identified. The clinical course, infection type, laboratory results and treatment options for each case were available from their records. RESULTS: Of the 9821 patients, 12 (0.12%) were identified as having postoperative infections, and in all these cases, the infection manifested as spondylodiscitis. Four patients were treated with only antibiotic therapy; two patients were treated with surgical debridement; and the remaining six patients who were unresponsive to the initial therapies finally required lumbar interbody fusion with posterior instrumentation surgery. The mean Oswestry Disability Index (ODI) improved from 60.4% ± 19.4% to 29.3% ± 15.4%. Based on the modified MacNab criteria, 7 of the 12 patients (58.3%) showed an excellent or good outcome. CONCLUSION: Postoperative spondylodiscitis following PELD is relatively rare. However, its clinical progression could be more rapid and more serious than that after open surgery. Therefore, thorough preventive strategies for postoperative spondylodiscitis are mandatory.

Routinely using prophylactic antibiotic may not effectively prevent intervertebral disc infection: a new strategy to preventing postoperative intervertebral disc infection.

After spine surgery, intervertebral disc infection is a less common but disastrous complication. Since invasive techniques and procedures are increasingly used in the diagnosis and treatment of human disc diseases, the possibility of disc infection also increases. Today a large proportion of spinal operation is contributed to degenerative disc diseases (DDDs) in the elderly. With the degeneration of the disc, vertebral end plate undergoes sclerosis, and then the efficacy of antibiotics depends upon the permeability of the intervertebral disc, it is therefore likely that the penetration of the antibiotics is totally different in normal and degenerative discs. Antibiotics are often administrated prophylactically in spinal procedures to reduce the risk of infection of the disc space. However, the guideline for prophylactic use of antibiotics does not take into account the unique environment of intervertebral disc and the changes occurred in degenerative disc. Routinely using prophylactic antibiotic may not result in adequate antibiotic concentration in intervertebral disc to prevent disc infection, especially in DDD patients. We hypothesized that during the administration of antibiotic, prolonged lying flat on bed could decrease the internal pressure of the disc, and then increase the penetration of antibiotic into disc. According to different stages of end-plate sclerosis on MRI, combination of lying flat and increasing duration and concentration of antibiotics may be a new strategy to prevent postoperative intervertebral disc infection.

[A study on blocking effect of polylactic acid patch on intra-discal inflammation after annulus puncture].

OBJECTIVE: Polylactic acid (PLA) patch has proper steric configuration, sufficient mechanic strength, and flexibility, to investigate the blocking effect on the intra-discal inflammation after annulus puncture sticked by medical glue so as to seal the pinhole left after annulus puncture. METHODS: Twenty healthy New Zealand white rabbits (weighing 2.0-2.5 kg) were randomly divided into 4 groups (n = 5): groups A, B, C, and D. In group A, the rabbits underwent exposure of intervertebral disc and transverse process at L2-7 as a control; in group B, the rabbits received annulus puncture at L2-7 with an 18-gauge needle; and in groups C and D, the pinholes were sealed respectively with a PLA patch sticked with medical gel and medical gel alone after annulus puncture at L2-7. General condition of rabbits was observed after operation. The intervertebral disc tissue was harvested 1 week after operation. The tissue structure was observed by HE and Masson staining. And the expressions of inflammatory factors like interleukin 1beta (IL-1beta), tumor necrosis factor alpha (TNF-alpha), and inducible nitric oxide synthase (iNOs) were detected with immunohistochemistry and ELISA. RESULTS: All the animals survived till the end of the experiment. In group A at 1 week, the nucleus pulposus tissue had normal structure. In group B at 1 week, leak of nucleus pulposus from the pinhole and slight adhesion to the adjacent tissue could be seen, and the nucleus pulposus tissue had significant degenerative change by histological observation. In groups C and D, clots of coagulated medical gel and extensive adhesion to the adjacent tissue could be seen; histological observation suggested that the nucleus pulposus tissue of group C had similar histology manifestation to that of group A; while group D had similar histology manifestation to group B with obviously-decreased cells and disorder of matrix. ELISA test showed remarkably elevated expression level of inflammatory factors including IL-1beta, TNF-alpha, and iNOs in groups B and D when compared with groups A and C, showing significant differences (P < 0.05), and similar expression level were observed in groups A and C, groups B and D (P > 0.05). CONCLUSION: The PLA patch sticked with medical gel is effective in blocking the intra-discal inflammation 1 week after annulus puncture.

In vitro assessment of the antibiotic efficacy of contrast media and antibiotics and their combinations at various dilutions.

Discography is a controversial diagnostic procedure involving the injection of radiographic contrast medium (RCM) into the intervertebral disc. Iatrogenic bacterial discitis is a rare but serious complication. The intervention has been increasingly performed in our patients here in the United Arab Emirates. Prophylactic intravenous antibiotic administration can reduce post-interventional discitis; however, this may favour the development of bacterial resistance. Direct intradiscal injection of an antibiotic together with the RCM is a potential alternative. To date, there has been only one study on the efficacy of antibiotics added to an RCM. Equally, there are only limited data regarding the potential direct effect of RCM on bacterial growth. The purpose of this study was to determine whether the efficacy of antibiotics is affected when RCM are added. In an in vitro study, the effect of non-ionic RCM on the growth of five laboratory bacterial strains, alone and in combination with three broad-spectrum antimicrobials, was tested. Bacterial growth was assessed in the absence and the presence of RCM, antibiotics and their combinations. All three RCM alone demonstrated some inhibition of bacterial growth at high concentrations. In the presence of the RCM, all three antibiotics retained their inhibitory effect on bacterial growth. In conclusion, our in vitro experiments did not reveal any changes in the antimicrobial efficacy of the three antibiotics in the presence of the three tested RCM. Subsequent clinical trials will need to assess whether intradiscal antibiotic administration may be a suitable substitute for, or a supplement to, prophylactic systemic antibiotics before discography.

The prevention of discitis during discography.

BACKGROUND CONTEXT: Because of the severe complications, discitis represents the most feared complication stemming from discography. Varying needle techniques have been used to prevent discitis, and evidence for the use of intravenous (IV) and/or intradiscal antibiotics is conflicting and often lacking. Consequently, no consensus has been formed for disc infection prevention during discography. PURPOSE: The objectives of this review are to summarize and integrate all the available basic science, animal, and clinical evidence regarding prevention of infection from discography and to develop areas of future research. STUDY DESIGN: A comprehensive review of the literature dealing with discitis stemming from discography was conducted. METHODS: The MEDLINE and SCOPUS databases were searched focusing on prospective and retrospective studies and published case reports on the prevention of discitis. A meta-analysis could not be completed because of the scarcity of data and published randomized controlled trials. RESULTS: Of the seven articles that specifically focused on the prevention of discitis, no randomized or controlled trials were located. Two prospective, nonrandomized trials, three retrospective case series, and two literature reviews have been published, but no consensus has been formed for the prevention of discitis during discography. Fifteen articles focused on penetration, efficacy, and dosage of antibiotics into intervertebral discs for the prevention of discitis. There are 14 additional articles that report incidences of discitis. CONCLUSIONS: Based on the available clinical evidence, IV or intradiscal antibiotics during discography have not been conclusively shown to decrease the rate of discitis over sterile technique alone. Animal model research supports prophylactic antibiotic use when used before iatrogenic inoculation of intervertebral discs. Both single- and double-needle techniques when used with stylettes are superior to nonstyletted techniques.

Therapeutic use of cephazolin to prevent complications of spine surgery.

Discitis, caused by pyogenic organisms, is a potential complication of any procedure which involves entering the intervertebral disc during open or percutaneous procedures. While there are wide variations in the severity of symptoms, the characteristic feature of discitis is the development of increasingly severe back pain, which is not relieved by rest, or narcotic analgesics. While there is a tendency to spontaneous resolution over time, a self-limiting course does not always eventuate. Serious complications resulting from spread of the infective process can lead to vertebral osteomyelitis or to the formation of an epidural abscess with further risk of neural compression. Clinical and experimental evidence now supports the prophylactic use of a suitable antibiotic, but some uncertainties exist about the benefits of antibiotic therapy in treating established discitis. While cephazolin is a widely favoured choice of antibiotic, the timing of its administration to prevent or treat discitis has been complicated by the lack of suitable methods for detecting and measuring the concentration of cephazolin in the plasma and disc in experimental and clinical conditions. This paper describes a high-performance liquid chromatography technique for detecting the antibiotic cephazolin. The results conclude cephazolin can be detected in the plasma and disc after administering an intravenous bolus dose. However, concentration of cephazolin in the outer disc was 12 times greater than that of the inner disc.

Preventing and treating discitis: cephazolin penetration in ovine lumbar intervertebral disc.

Infection can occur after any spinal procedure that violates the disc and although it is not common, the potential consequences are serious. Treatment of discitis is not always successful and the key to management is prevention. Intradiscal prophylaxis with antibiotic is routinely used in spinal surgery, but there is a limited understanding of how well antibiotics can enter the avascular disc after intravenous injection. An in vivo ovine study to optimise prophylactic and parenteral treatment of discitis is described to assess the effectiveness of cephazolin in preventing and treating infection. The concentration of cephazolin was measured in disc tissue from normal and degenerate sheep discs to determine if cephazolin can enter the disc and if disc degeneration affects antibiotic uptake. Fourteen sheep were deliberately inoculated with bacteria to induce discitis. Eight sheep ("prophylaxis" group) were given either a 0, 1, 2 or 3 g dose of prophylactic cephazolin before inoculation while the remaining sheep ("treatment" group) were treated with cephazolin commencing 7 days after inoculation for 21 days at a dose of 50 mg/kg/day. Histopathology and radiography were used to assess the effect of the different treatments. Cephazolin was given 30 min prior to sacrifice and the intradiscal concentration was measured by biochemistry. In the "prophylaxis" group all doses of antibiotic provided some protection against infection, although it was not dose dependent. In the "treatment" group discitis was confirmed radiologically and histologically in all animals from 2 weeks onwards. Biochemical assay confirmed that antibiotic is distributed throughout the disc but was present in higher concentration in the anulus fibrosus than the nucleus pulposus. This study demonstrated that whilst the incidence of iatrogenic discitis can be reduced by antibiotic prophylaxis, it could not be abolished in all incidences with a broad-spectrum antibiotic such as cephazolin. Furthermore, antibiotics were ineffective at preventing endplate destruction once an intradiscal inoculum was established.

Prophylactic cephazolin to prevent discitis in an ovine model.

STUDY DESIGN: An ovine model of discitis was used to determine the efficacy of the antibiotic cephazolin for prophylactic use in spinal surgery. OBJECTIVES: To determine in juvenile and adult sheep spines if 2-g cephazolin given at intervals over a 4-hour period would prevent iatrogenic discitis, and determine the concentration of cephazolin in nucleus and anulus tissue after administration of a bolus dose. SUMMARY OF BACKGROUND DATA: It is standard practice at our institutions to give patients undergoing spinal surgery a single prophylactic (1-2 g) dose of cephazolin with a second dose for prolonged (>4 hours) procedures. Although this regimen provides therapeutic serum levels, the levels of antibiotic in the intervertebral disc are significantly lower. Because cephazolin is a negatively charged molecule, it is thought to diffuse poorly into the disc, raising questions about its efficacy as a prophylactic antibiotic for spinal procedures. METHODS: There were 18 animals, including 9 lambs and 9 sheep, that received a single 2-g dose of cephazolin intravenously at 30-minute intervals over a 4-hour period. Two control animals (1 sheep and 1 lamb) did not receive antibiotic. All animals had diskograms at 2 previously incised lumbar levels and 2 nonincised levels using contrast that was deliberately contaminated with bacteria. Lateral spine radiographs were taken at postoperative intervals. After 12 weeks, all animals received another 2-g dose of cephazolin intravenously at intervals before the spines were removed for pathologic and biochemical analysis. RESULTS: Discitis was detected in all control animals. Of those animals given cephazolin, discitis developed in 1 sheep and 4 lambs. Discitis did not develop in any of the sheep that received cephazolin 30 minutes before inoculation. Cephazolin was detected throughout the disc but was more concentrated in the anulus fibrosus. Disc levels of cephazolin peaked at 15 minutes, at which time serum levels were up to 50 times higher. Cephazolin levels in nonoperated and incised discs were not significantly different. CONCLUSIONS: A single prophylactic 2-g dose of cephazolin administered anytime over a 4-hour period prevented discitis in almost all animals but was not as effective in lambs. Although lambs have a higher vascular supply to deliver antibiotics to the disc, it is likely that some other physiologic factor may be responsible for the increased infection rate. This study supports that timing of antibiotic prophylaxis is critical to prevent iatrogenic disc infection.

The use of intradiscal antibiotics for discography: an in vitro study of gentamicin, cefazolin, and clindamycin.

STUDY DESIGN: In vitro determination of minimum inhibitory concentrations (MICs) of gentamicin, cefazolin, and clindamycin, alone and in combination with iohexol against laboratory strains of Eschericia coli B, Staphylococcus aureus, and Staphylococcus epidermidis. OBJECTIVE: To study the effects of iohexol on the efficacy of gentamicin, cefazolin, and clindamycin. SUMMARY OF BACKGROUND DATA: Prophylactic antibiotics have been advocated to prevent discitis following discography. Intravenous cefazolin administered before discography has been shown to penetrate the intervertebral disc. However, the use of systemic antibiotics for prophylaxis may lead to bacterial resistance. Intradiscal antibiotic administration is an attractive alternative to systemic antibiotic prophylaxis before discography, but there is no data documenting the efficacy of commonly used antibiotics in the presence of iohexol. METHODS: MICs were determined by adding standard concentrations of bacteria to serial dilutions of antibiotic with and without the addition of iohexol in Todd-Hewitt Broth medium. MICs were determined as the lowest concentration well that demonstrated inhibition of cell growth. RESULTS: Gentamicin, cefazolin, and clindamycin remain efficacious in the presence of iohexol. MICs were lower for cefazolin and gentamycin than for clindamycin. Iohexol alone also demonstrated some inhibition of cell growth. CONCLUSION: This study supports the use of intradiscal antibiotics for prophylaxis of disc space infection during discography. lntradiscal placement of antibiotic should obviate the need for systemic antibiotic prophylaxis and its attendant risk of generating antimicrobial resistance.

Routine replacement of tunneled, cuffed, hemodialysis catheters eliminates paraspinal/vertebral infections in patients with catheter-associated bacteremia.

BACKGROUND: Management of tunneled, cuffed, central venous catheters in hemodialysis (HD) patients with bacteremia remains a challenge. Attempts to salvage the catheter with systemic antibiotics alone have been associated with increased risk of metastatic infectious complications. METHODS: Retrospective case series of patients with infectious complications in a chronic dialysis unit, affiliated with a tertiary care university hospital. RESULTS: Between 1996 and 1999, when we treated HD catheter-associated bacteremia with systemic antibiotics alone, we encountered a clustering of 8 cases of paraspinal/vertebral infections in a population of 162 patients. After changing our protocol, i.e., routine catheter exchange over a guide wire at approximately 48 h, while on systemic antibiotic therapy, we did not encounter any new cases of paraspinal/vertebral infections over a 15-month period. CONCLUSION: Our experience suggests that routine exchange of tunneled, cuffed catheters over a guide wire in HD patients presenting with bacteremia may significantly reduce serious infectious complications, e.g., epidural abscess/vertebral osteomyelitis.

[Prophylactic antibiotics in lumbar disc surgery: analysis of 1,030 procedures]. / Antibiotikaprophylaxe bei lumbalen Bandscheibenoperationen: Eine Analyse von 1,030 Operationen.

OBJECTIVE: The purpose of this study was to investigate the efficacy of perioperative antibiotic administration in the prophylaxis of wound infection in lumbar disc surgery. METHODS: In 1989, 541 conventional lumbar discectomies were performed to treat nucleus pulposus prolapse in 533 patients at the neurosurgical department of the Benjamin-Franklin-Hospital (Free University of Berlin). Each patient received 2 g of the antibiotic Cefotiam intravenously at induction of anesthesia. During the previous year no antibiotic was administered in 636 similar operations (in 628 Patients). Acquisition of data was performed retrospectively. After statistical stratification there remained 492 procedures in 461 patients in the prophylaxis group and 538 procedures in 475 patients in the control group. Regarding patients age, duration of the surgical procedure and distribution of individual surgeons there were no significant differences between these two groups. RESULTS: The rate of infection was 0.2 % (n=1) in operations performed after antibiotic administration versus 2.8 % (n=15) in procedures without antibiotic prophylaxis. This difference is statistically significant (p < 0.0001). CONCLUSION: In accordance with the reviewed literature, this study confirms that one preoperative intravenous ('single shot') administration of Cefotiam is effective in decreasing the rate of postoperative wound infections in lumbar disc surgery.