Treatment of spondylodiscitis in human immunodeficiency virus-infected patients: a comparison of conservative and operative therapy

Pyogenic spondylodiscitis in HIV-positive patients under antiretroviral therapy: A case series

Background: The incidence of pyogenic spondylodiscitis has been increasing in countries of Europe and North America, probably due to an increasing number of persons with risk factors for this infection. It is unclear whether HIV infection in the era of antiretroviral therapy (ART) increases the risk for spondylodiscitis. Method: We present 7 cases of pyogenic spondylodiscitis of the cervical, thoracic, and lumbar spine in six individuals living with HIV under ART with suppressed viral load. Results: All patients presented with severe non-radicular pain and elevated inflammatory markers. Diagnosis was confirmed by magnetic resonance imaging (MRI) scan and isolation of the pathogen. Staphylococcus aureus was the causative pathogen in five patients. One patient suffered from an infection with Klebsiella pneumoniae followed by a mixed infection with Cutibacterium acnes and Bacillus circulans 18 months later. All patients needed surgical intervention, and the mean duration of antibiotic treatment was 17 weeks (range 12-26). Five patients recovered fully, including two persons who also suffered from endocarditis. One patient died from multi-organ failure. Conclusion: Spondylodiscitis may be seen more frequently in persons living with HIV as they grow older and suffer from comorbidities which put them at risk for this infection. HIV physicians should be aware of the infection and its risk factors.

Conservative versus early surgical treatment in the management of pyogenic spondylodiscitis: a systematic review and meta-analysis

Spondylodiscitis is the commonest spine infection, and pyogenic spondylodiscitis is the most common subtype. Whilst antibiotic therapy is the mainstay of treatment, some advocate that early surgery can improve mortality, relapse rates, and length of stay. Given that the condition carries a high mortality rate of up to 20%, the most effective treatment must be identified. We aimed to compare the mortality, relapse rate, and length of hospital stay of conservative versus early surgical treatment of pyogenic spondylodiscitis. All major databases were searched for original studies, which were evaluated using a qualitative synthesis, meta-analyses, influence, and regression analyses. The meta-analysis, with an overall pooled sample size of 10,954 patients from 21 studies, found that the pooled mortality among the early surgery patient subgroup was 8% versus 13% for patients treated conservatively. The mean proportion of relapse/failure among the early surgery subgroup was 15% versus 21% for the conservative treatment subgroup. Further, it concluded that early surgical treatment, when compared to conservative management, is associated with a 40% and 39% risk reduction in relapse/failure rate and mortality rate, respectively, and a 7.75 days per patient reduction in length of hospital stay (p < 0.01). The meta-analysis demonstrated that early surgical intervention consistently significantly outperforms conservative management in relapse/failure and mortality rates, and length of stay, in patients with pyogenic spondylodiscitis.

Surgical Outcomes of Human Immunodeficiency Virus-positive Patients Undergoing Lumbar Degenerative Surgery

STUDY DESIGN

This was a retrospective cohort studying using a national administrative database.

OBJECTIVE

The objective of this study was to determine the postoperative complications and quality outcomes of the human immunodeficiency virus (HIV)-positive patients undergoing surgical management for lumbar degenerative disease (LDD).

METHODS

This study identified patients with who underwent surgery for LDD between 2007 and 2016. Patients were stratified based on whether they were HIV positive at the time of surgery. Multivariate regression was utilized to reduce the confounding of baseline covariates. Patients who underwent 3 or more levels of surgical correction were under the age of 18 years, or those with any prior history of trauma or tumor were excluded from this study. Baseline comorbidities, postoperative complication rates, and reoperation rates were determined.

RESULTS

A total of 120,167 patients underwent primary lumbar degenerative surgery, of which 309 (0.26%) were HIV positive. In multivariate regression analysis, the HIV-positive cohort was more likely to be readmitted at 30 days [odds ratio (OR)=1.9, 95% confidence interval (CI): 1.2-2.8], 60 days (OR=1.7, 95% CI: 1.2-2.5), and 90 days (OR=1.5, 95% CI: 1.0-2.2). The HIV-positive cohort was also more likely to experience any postoperative complication (OR=1.7, 95% CI: 1.2-2.3). Of the major drivers identified, HIV-positive patients had significantly greater odds of cerebrovascular disease and postoperative neurological complications (OR=3.8, 95% CI: 1.8-6.9) and acute kidney injury (OR=3.4, 95% CI: 1.3-7.1). Costs of index hospitalization were not significantly different between the 2 cohorts ($30,056 vs. $29,720, P=0.6853). The total costs were also similar throughout the 2-year follow-up period.

CONCLUSION

Patients who are HIV positive at the time of LDD surgery are at a higher risk for postoperative central nervous system and renal complications and unplanned readmissions.

Reconstruction and repair, using mini-plate and bone graft for persons living with HIV with giant cell tumor of long bone: retrospective analysis of a single-center experience

Background

To evaluate the effect of reconstruction and repair, using a mini-plate and bone graft for HIV -positive patients with giant cell tumor of long bone.

Methods

We conducted a retrospective analysis of 12 HIV positive patients with giant cell tumor of long bone. A non-HIV-positive cohort of patients, matched for age, sex, and disease type, was selected as the control group. From June 2012 to August 2020, curettage by ultrasonic scalpel was performed in all patients, combined with min- plate and bone graft treatment. All patients were followed- up for 18 to 60 months. Limb function was evaluated, using the MSTS93 scoring system, and any examples of postoperative recurrence, distant metastasis, complications, MSTS93 score, and fracture prognosis were recorded.

Results

The mean age of HIV group was 43.5 years. The ratio of men to women was 11: 1. In all cases the histopathological diagnosis was clear, except the patients with primary malignant giant cell tumor of bone, including five, three, two, and two cases in the proximal tibia, distal femur, distal tibia, and talus, respectively. Following their surgery, all patients were followed up with an average of 31.24 ± 11.84 months. No local recurrence or pulmonary metastases were observed. Post-surgery, all the 12 patients showed good bone morphologic repair and reconstruction, good bone healing, good joint function, and no pathological fractures around their lesion. In the HIV group, one case of giant cell tumor in the proximal tibia showed mild articular surface collapse and mild valgus deformity of the knee joint but retained good joint function. The MSTS scores of excellent or good in the two groups comprised 83.3%, thus, there was no significant difference between them (P > 0.05). Compared with preoperatively, the MSTS scores in the HIV group were significantly improved, ranging from 7 to 11 points preoperatively to 24 to 27 points postoperatively; this difference was statistically significant (P < 0.05).

Conclusion

Reconstruction and repair, using a mini-plate and bone graft for HIV -positive patients with giant cell tumor of long bone can achieve satisfactory results. The mini- plate requires little space and is flexible during reconstruction and fixation, significantly reducing complications such as surgical site infection, as well as preserving joint function and avoiding amputation; therefore, it is a safe and effective treatment method.

Preclinical models of vertebral osteomyelitis and associated infections: Current models and recommendations for study design

Spine-related infections, such as vertebral osteomyelitis, discitis, or spondylitis, are rare diseases that mostly affect adults, and are usually of hematogenous origin. The incidence of this condition has gradually risen in recent years because of increases in spine-related surgery and hospital-acquired infections, an aging population, and intravenous (IV) drug use. Spine infections are most commonly caused by Staphylococcus aureus, while other systemic infections such as tuberculosis and brucellosis can also cause spondylitis. Various animal models of vertebral osteomyelitis and associated infections have been investigated in mouse, rat, chicken, rabbit, dog, and sheep models by hematogenous and direct inoculation in surgery, each with their strengths and limitations. This review is the first of its kind to concisely analyze the various existing animal models used to reproduce clinically relevant models of infection. Spine-related infection models must address the unique anatomy of the spine, the avascular nature of its structures and tissues and the consequences of tissue destruction such as spinal cord compression. Further investigation is necessary to elucidate the specific mechanisms of host-microbe response to inform antimicrobial therapy and administration techniques in a technically demanding body cavity. Small-animal models are not suitable for large instrumentation, and difficult IV access thwarts antibiotic administration. In contrast, large-animal models can be implanted with clinically relevant instrumentation and are resilient to repeat procedures to study postoperative infection. A canine model of infection offers a unique opportunity to design and investigate antimicrobial treatments through recruitment a rich population of canine patients, presenting with a natural disease that is suitable for randomized trials.

Pyogenic spondylodiscitis : The quest towards a clinical-radiological classification

BACKGROUND

Pyogenic spondylodiscitis (PS) is a debilitating condition laden with orthopedic and neurological complications. The choice of the best step in management is often delayed due to the controversy encompassing its multiple facets. Several classification systems were proposed in the literature to define optimal management; however, consensus was not achieved.

OBJECTIVE

The aim of this study was to review the literature and critically appraise the classification systems of PS and the rationale behind the classification criteria.

METHODS

A literature search was conducted in PubMed. Titles and abstracts of articles were searched using different synonyms of spondylodiscitis and its classification. No restrictions regarding language of publication or date of publication were applied.

RESULTS

A total of 43 papers with 5 encompassing 3 main classifications were found in the literature. These classifications were overlapping but different. They encompassed neurologic deficits, abscess formation and segmental instability, laboratory parameters and morphological changes in magnetic resonance imaging (MRI) as the most important factors used to classify PS, assess the severity and guide treatment.

CONCLUSION

The current classification schemes overlap and encompass the most clinically relevant factors; however, some could be too complex for interdisciplinary clinical practice and do not adequately address unique entities, such as PS of the cervical spine, anterolisthesis and retrolisthesis. Most importantly, some criteria must be utilized in concert with recently published guidelines and should be re-assessed for validity and reliability. A uniform orthopedic parlance is required to optimize the management of this debilitating and life-threatening condition.

Dual Invasive Fungal Infection Presenting with Cervical Myelopathy

Disseminated fungal infections are often seen in immunocompromised patients. Here we present a case of a previously healthy woman presenting with cervical myeloradiculopathy found to have two separate fungal infections in the setting of depressed CD4 cell counts and a genetic mutation predisposing to invasive fungal infections.

Conservative Treatment of Spondylodiscitis: Possible Therapeutic Solution in Case of Failure of Standard Therapy

Introduction:

Spondylodiscitis (SD) is an uncommon disease but not rare, because it represents around 3–5% of all cases of osteomyelitis. Late diagnosis and/or inadequate treatment often cause irreversible damage to cause neurological deficit. Most require only conservative treatment, sometimes a surgical approach is required.

Aim:

The purpose of this study is to propose a conservative protocol to treat spondylodiscitis when the standard conservative treatment has failed. This alternative treatment has been for a long time at the Codivilla-Putti Institute.

Methods:

We performed a prospective cohort study of 192 consecutive patients who underwent paravertebral intramuscular injections of antibiotic associated with standard treatment at our Center from January 2010 to December 2015 with SD. Of this 192 patients we selected 98 who had already undergone standard antibiotic therapy at another hospital without resolution of the disease. All patients have performed our protocol that provides a total of 3 cycles, each of 3 weeks, repeated at approximately 5 weeks apart. For each patient we evaluated Erythrocyte Sedimentation Rate (ESR), C-Reactive Protein (CRP), White Blood Cells (WBC) indexes, SF36 and VAS Score at the beginning and at the end of the treatment.

Results:

At a mean follow up of 22 months (range 60-12), clinical healing was achieved in 87 patients (88,9%) of cases with significant reduction in back pain and functional limitation. The VAS Score and the SF36 were better at the end of treatment compared to previous “GOLD STANDARD” treatments in the previous hospitalization in another hospital. In most cases there were slightly reduced in inflammatory indexes.

Conclusion:

There are no studies in the literature demonstrating the effective efficacy of local infiltrative treatment with antibiotics, associated with standard treatment protocol. We believe that our protocol in treating SD, favors an early functional recovery, and be able to offer more chance of success than the standard treatment.

Full Endoscopic Discectomy, Debridement, and Drainage for High-Risk Patients with Spondylodiscitis

OBJECTIVE

To evaluate the efficacy and clinical results of full endoscopic debridement and drainage (FEDD) for high-risk patients with spondylodiscitis.

METHODS

Fourteen patients who underwent FEDD at our institution between November 2015 and September 2017 were retrospectively reviewed. All patients had single-level infectious spondylodiscitis and were high-risk candidates for surgery. Their general condition was evaluated according to the American Society of Anesthesiologists grading system. The Charlson Comorbidity Index was used for comprehensive assessment of comorbidity status. Outcomes were evaluated by numeric rating scale (NRS) pain score, Oswestry Disability Index, modified Macnab criteria, and radiographic images at follow-up.

RESULTS

All 14 patients experienced immediate relief of back pain after FEDD, with no procedure-related complications. The causative bacteria were identified in 10 of the 14 patients (71.5%). Half of the 14 patients had an American Society of Anesthesiologists score of ≥3. The average Charlson Comorbidity Index was 5.1 ± 1.6 points. Compared with the preoperative NRS score of 8.2 ± 0.9, the NRS scores at 1 week and 12 months after surgery were 3.4 ± 1.1 and 1.4 ± 1.2, respectively. A significant improvement in Oswestry Disability Index was observed after surgery (preoperative, 30.1 ± 3.9; 12 months postoperatively, 17.6 ± 6.2; P < 0.05). Satisfaction rate was 85.7% based on the Macnab criteria (excellent or good outcome). None of the patients developed any significant kyphotic deformity after FEDD.

CONCLUSIONS

FEDD may be an effective alternative to extensive open surgery in patients with infectious spondylodiscitis, especially those who are high-risk candidates for surgery (elderly patients with multiple comorbidities and patients in poor general condition).

Presentation and Outcomes After Medical and Surgical Treatment Versus Medical Treatment Alone of Spontaneous Infectious Spondylodiscitis: A Systematic Literature Review and Meta-Analysis

STUDY DESIGN

Systematic literature review.

OBJECTIVES

The aims of this study were to (1) describe the clinical features, disabilities, and incidence of neurologic deficits of pyogenic spondylodiscitis prior to treatment and (2) compare the functional outcomes between patients who underwent medical treatment alone or in combination with surgery for pyogenic spondylodiscitis.

METHODS

A systematic literature review was performed using PubMed according to PRISMA guidelines. No year restriction was put in place. Statistical analysis of pooled data, when documented in the original report (ie, number of patients with desired variable and number of patients evaluated), was conducted to determine the most common presenting symptoms, incidence of pre- and postoperative neurologic deficits, associated comorbidities, infectious pathogens, approach for surgery when performed, and duration of hospitalization. Outcomes data, including return to work status, resolution of back pain, and functional recovery were also pooled among all studies and surgery-specific studies alone. Meta-analysis of studies with subgroup analysis of pain-free outcome in surgical and medical patients was performed.

RESULTS

Fifty of 1286 studies were included, comprising 4173 patients undergoing either medical treatment alone or in combination with surgery. Back pain was the most common presenting symptom, reported in 91% of patients. Neurologic deficit was noted in 31% of patients. Staphylococcus aureus was the most commonly reported pathogen, seen in 35% of reported cases. Decompression and fusion was the most commonly reported surgical procedure, performed in 80% of the surgically treated patients. Combined anterior-posterior procedures and staged surgeries were performed in 33% and 26% of surgeries, respectively. The meta-analysis comparing visual analog scale score at follow-up was superior among patients receiving surgery over medical treatment alone (mean difference -0.61, CI -0.90 to -0.25), while meta-analysis comparing freedom from pain in patients receiving medical treatment alone versus combined medical and surgical treatment demonstrated superior pain-free outcomes among surgical series (odds ratio 5.35, CI 2.27-12.60, P < .001), but was subject to heterogeneity among studies (I ² = 56%, P = .13). Among all patients, freedom from pain was achieved in 79% of patients, and an excellent outcome was achieved in 73% of patients.

CONCLUSION

Medical management remains first-line treatment of infectious pyogenic spondylodiscitis. Surgery may be indicated for progressive pain, persistent infection on imaging, deformity or neurologic deficits. If surgery is required, reported literature shows potential for significant pain reduction, improved neurologic function and a high number of patients returning to a normal functional/work status.

[Spondylodiscitis : Current strategies for diagnosis and treatment]

Spondylodiscitis is a severe infectious disease of the intervertebral discs and of the adjacent parts of the vertebral bodies, culminating in destruction of the mobile segment. It is accompanied by a mortality rate of approximately 15%. Severe courses of the disease can also lead to abscess formation and dispersal of sepsis. Malpositioning of the axis organ and deficits in neurological function up to paraplegia are also possible complications. Timely diagnostics and targeted therapy contribute to minimizing the risk of significant health disorders. This review article gives a summary of important algorithms in the diagnostics and treatment and discusses them against the background of currently available literature. According to the current state of knowledge the surgical treatment of spondylodiscitis provides many advantages and is therefore the method choice, even if a conservative approach can be successful in selected cases. The endpoints of treatment are cleansing of the infection with normalization of laboratory parameters of inflammation and the osseous fusion of the mobile segment.

FDG PET Assessment of Osteomyelitis: A Review

This article discusses the role of [(18)F]Fluorodeoxyglucose (FDG) PET and PET/computed tomography in diagnosis and therapeutic response assessment for the management of patients with osteomyelitis, to increase awareness of imaging pitfalls and to improve understanding of specific technical and diagnostic challenges in patients with posttraumatic chronic osteomyelitis, spinal infections, prosthetic joint infections, and diabetic foot infections. This article focuses on the usefulness of modern imaging modalities in the setting of suspected infection or inflammation and on the role of FDG-PET in the management of patients with suspected or confirmed infection in the bones.

Vertebral osteomyelitis in adults: an update

INTRODUCTION

The incidence of vertebral osteomyelitis is increasing, attributed to an ageing population with inherent co-morbidities and improved case ascertainment.

SOURCES OF DATA

References were retrieved from the PubMed database using the terms 'vertebral osteomyelitis' and 'spondylodiscitis' between January 1, 2009 and April 30, 2014 published in English as checked in May 2014 (>1000 abstracts checked).

AREAS OF AGREEMENT

Blood cultures and whole spine imaging with magnetic resonance imaging are essential investigations. Thorough debridement is the mainstay of surgical management, although placing metalwork in active infection is becoming increasingly common.

AREAS OF CONTROVERSY

The extent of pursuing spinal biopsies to determine aetiology, antimicrobial choices and duration, monitoring the response to treatment, and surgical techniques and timing all vary widely in clinical practice with heterogeneous studies limiting comparisons. Surgery, rather than conservative approaches, is being proposed as the default management choice, because it can, in carefully selected patients, offer faster reduction in pain scores and improved quality of life.

AREAS TIMELY FOR DEVELOPING RESEARCH

Further studies are needed to define the most effective technique for spinal biopsies to maximize determining aetiology. High-quality trials are required to provide an evidence base for both the medical and surgical management of vertebral osteomyelitis, including challenging medical management as the default option.

Outcome of conservative and surgical treatment of pyogenic spondylodiscitis: a systematic literature review

BACKGROUND

Spondylodiscitis is a spinal infection affecting primarily the intervertebral disk and the adjacent vertebral bodies. Currently many aspects of the treatment of pyogenic spondylodiscitis are still a matter of debate.

PURPOSE

The aim of this study was to review the currently available literature systematically to determine the outcome of patients with pyogenic spondylodiscitis for conservative and surgical treatment strategies.

METHODS

A systematic electronic search of MEDLINE, EMBASE, Cochrane Collaboration, and Web of Science regarding the treatment of pyogenic spondylodiscitis was performed. Included articles were assessed on risk of bias according the Cochrane Handbook for Systematic Reviews of Interventions, and the quality of evidence and strength of recommendation was evaluated according the GRADE approach.

RESULTS

25 studies were included. Five studies had a high or moderate quality of evidence. One RCT suggest that 6 weeks of antibiotic treatment of pyogenic spondylodiscitis results in a similar outcome when compared to longer treatment duration. However, microorganism-specific studies suggest that at least 8 weeks of treatment is required for S. aureus and 8 weeks of Daptomycin for MRSA. The articles that described the outcome of surgical treatment strategies show that a large variety of surgical techniques can successfully treat spondylodiscitis. No additional long-term beneficial effect of surgical treatment could be shown in the studies comparing surgical versus antibiotic only treatment.

CONCLUSION

There is a strong level of recommendation for 6 weeks of antibiotic treatment in pyogenic spondylodiscitis although this has only been shown by one recent RCT. If surgical treatment is indicated, it has been suggested by two prospective studies with strong level of recommendation that an isolated anterior approach could result in a better clinical outcome.

Prevalence, Comorbidities, and Risk of Perioperative Complications in Human Immunodeficiency Virus-Positive Patients Undergoing Cervical Spine Surgery

STUDY DESIGN

Retrospective database analysis.

OBJECTIVE

To evaluate outcomes of human immunodeficiency virus (HIV) positive patients after cervical spine surgery.

SUMMARY OF BACKGROUND DATA

Highly active antiretroviral medications have qualitatively altered the natural history of HIV, thus increasing the number of HIV-positive patients seeking treatment for chronic degenerative conditions. Minimal data exist on HIV patients undergoing degenerative cervical spine surgery.

METHODS

The Nationwide Inpatient Sample was examined from 2002 to 2011. Hospitalizations were identified using International Classification of Diseases Ninth Revision, Clinical Modification (ICD-9-CM) procedural codes for cervical spine surgery and diagnoses codes for degenerative conditions of the cervical spine, and HIV. Statistical analysis was conducted to evaluate associations between HIV status and perioperative complications.

RESULTS

A total of 1,602,129 patients underwent degenerative cervical spine surgery, of which 3700 patients (0.23%) had HIV. The prevalence of HIV increased over the study period from 0.19% to 0.33% (P < 0.001). Patients with HIV were younger (48.6 yrs vs. 53.4 yrs, P < 0.001) and more likely to be male (P < 0.001). HIV patients had significantly greater odds of having chronic pulmonary disease, liver disease, and drug abuse. Unadjusted analysis did not reveal increased rate of acute complications among HIV-positive patients compared with negative controls (3.8% vs. 3.7%, P = 0.62). Multivariate analysis did not identify HIV as a significant predictor of complication (odds ratio = 1.04, P = 0.84). HIV was associated with a 1.5 day increased length of stay AND 1.29 fold increase in median costs compared with controls ($14,551 vs. 18,846, P < 0.001).

CONCLUSION

The prevalence of HIV patients undergoing degenerative cervical spine surgery is increasing. A diagnosis of HIV was not associated with an increased risk of perioperative complication among patients undergoing degenerative cervical spine surgery. Further clinical studies are needed to evaluate predictors of complications among HIV patients and long-term outcomes.

LEVEL OF EVIDENCE

4.

Non-contiguous multifocal vertebral osteomyelitis caused by Serratia marcescens

Serratia marcescens is a common nosocomial infection but a rare cause of osteomyelitis and more so of vertebral osteomyelitis. Vertebral osteomyelitis caused by this organism has been reported in few studies. We report a case of S. marcescens vertebral discitis and osteomyelitis affecting multiple non-contiguous vertebras. Although Staphylococcus aureus is the most common cause of vertebral osteomyelitis, rare causes, such as S. marcescens, need to be considered, especially when risk factors such as intravenous heroin use, post-spinal surgery and immunosuppression are present. Therefore, blood culture and where necessary biopsy of the infected region should be undertaken to establish the causative organism and determine appropriate antibiotic susceptibility. Prompt diagnosis of S. marcescens vertebral osteomyelitis followed by the appropriate treatment can achieve successful outcomes.

Spondylodiscitis: standards of current treatment

BACKGROUND

Spinal infections are an important clinical problem that often require aggressive medical therapy, and sometimes even surgery. Known risk factors are advanced age, diabetes mellitus, rheumatoid arthritis, immunosuppression, alcoholism, long-term steroid use, concomitant infections, poly-trauma, malignant tumor, and previous surgery or invasive procedures (discography, chemonucleolysis, and surgical procedures involving or adjacent to the intervertebral disc space). The most common level of involvement is at the lumbar spine, followed by the thoracic, cervical and sacral levels: lesions at the thoracic spine tend to lead more frequently to neurological symptoms.

OBJECTIVE

The aim of the current paper is to describe current evidence-based standards of therapy in the management of SD by emphasizing pharmacological therapy and principles and indications for bracing and surgery.

METHODS

A PubMed and Google Scholar search using various forms and combinations of the key words: spondylodiscitis, spine, infection, therapy, surgery, radiology, treatment. Reference citations from publications identified in the literature search were reviewed. Publications highlighted in this article were extracted based on relevancy to established, putative, and emerging diagnostic and therapeutic standards, either conservative (antibiotic therapy and bracing) or surgical.

FINDINGS

To date, conservative therapy, based on targeted antibiotic therapy plus bracing, represents the mainstay in the management of SD. Proper diagnosis and tailored therapy can improve clinical results and decrease the chance of failure. Surgery should be an option only for patients with complications of this disease, namely deformity, neural compression and neurological compromise. Current standards in the setting of SD are continuously evolving, as can be seen in the recent advances in the field of radiological diagnostics, and the use of growth factors and cell-therapy strategies to promote infection eradication and bone healing after surgery.

Primary pyogenic infection of the spine in intravenous drug users: a prospective observational study

STUDY DESIGN

A prospective comparative analysis of surgically-treated nontuberculous primary pyogenic infection of the spine (PPIS).

OBJECTIVE

To evaluate and compare the demographics, presentation, treatment and outcomes of surgically-treated PPIS between intravenous drug users (IVDU) and non-IVDU patients.

SUMMARY OF BACKGROUND DATA

This is the first prospective cohort comparative analysis of the clinical outcomes of surgically-treated PPIS between IVDU and non-IVDU populations. This is also the largest cohort of consecutive surgically-treated PPIS in a population of IVDU.

METHODS

Data on all patients with PPIS presenting to a quaternary referral center during a 4-year period from 2004 were collected in a prospectively maintained customized database.

RESULTS

During the study period there were 102 patients treated for PPIS of which 51 were IVDU. Of this IVDU group, the mean age was 43 years (range: 25-57). Twenty-three had human immunodeficiency virus, 43 had hepatitis C, and 13 had hepatitis B. All were using cocaine, 26 were also using heroin and 44 were using at least 3 recreational drugs. Thirty patients presented with axial pain of a mean duration of 51 days (range: 3-120 days). Of the IVDU patients with neurological deficit on presentation, the mean American Spinal Injury Association (ASIA) motor score was 58.6. The most common ASIA motor levels involved were C4 and C5. Mean duration of neurological symptoms was 7 days (range: 1-60 days). Twenty-six were already receiving i.v. antibiotics for known spinal infection and 33 patients had an identifiable organism on blood cultures (19 methicillin-sensitive Staphylococcus aureus, 9 methicillin-resistant S. aureus). Forty-four of the 51 IVDU patients were treated surgically. Thirty-four of the 44 surgically treated cases involved the cervical spine. Twenty-two had a posterior approach alone, 13 had anterior only while 9 required combined anterior and posterior approaches at the index surgery. Seven required early revision for hardware failure (none of whom has combined approach) and 2 developed a postoperative surgical site infection (SSI). Thirty-seven of the 51 IVDU patients were apprehended at least once using illicit drugs while in hospital. Mean duration of antibiotic treatment after surgery was 62 days. At discharge, 28 of 44 patients had neurological improvement (mean = 20 ASIA points, range: 1-55), 11 had neurological deterioration during treatment (mean = 13, range = 1-50), and 5 were unchanged. Among the IVDUs there were no in-hospital deaths. At 2 years after index admission 13 IVDU patients were dead, and none were attending for follow-up despite all efforts to locate the patients. In the non-IVDU group, the mean age of the 51 patients was 56 years (range 25-83). Thirty-four patients presented with axial pain with a mean duration of 105 days (range 2-365). Mean ASIA motor score of patients with neurological deficit on admission was 74. Most common ASIA level was T12. Mean duration of neurological symptoms was 12 days (range 1-84). Thirteen patients were receiving i.v. antibiotics for known spinal infection and 20 patients had an identifiable organism on blood culture (30% methicillin-sensitive S. aureus, 50% methicillin-resistant S. aureus). Forty-four of these 51 non-IVDU patients were treated surgically. Thirty-five of the 44 surgically-treated cases involved the thoracic or lumbar spines. Twenty-nine had a posterior approach alone, 3 had anterior alone while 12 required combined approaches. No early hardware failures were seen in the non-IVDU group while 4 developed SSI. Mean duration of antibiotic treatment after surgery was 45 days. At discharge 21 patients had neurological improvement (mean 9 ASIA points, range: 1-17). Five had neurologic deterioration with a mean motor loss of 16 points (10-23). There were 4 in-hospital deaths among the non-IVDU group. At 2 years after index admission, 19 patients were dead and the remainder were all available for follow-up.

CONCLUSION

There are significant differences in demographics, presentation, treatment and outcomes of primary spinal pyogenic infection between a population of IVDU and a comparable cohort of non-IVDU. The IVDU group presents with cervical quadriplegia while it is the thoracolumbar spine that is almost exclusively involved in the non-IVDU group. Among the IVDUs, surgical management is complex with a high incidence of early hardware failure. SSI is significantly more common among non-IVDU. Significant neurological improvement can be expected in the majority of IVDU patients with a high mortality rate among the non-IVDU. IVDU are unreliable patients and in-hospital, in-halo incarceration is recommended where possible.

Disparities in rates of spine surgery for degenerative spine disease between HIV-infected and uninfected veterans

STUDY DESIGN

Retrospective analysis of nationwide Veterans Health Administration clinical and administrative data.

OBJECTIVE

Examine the association between HIV infection and the rate of spine surgery for degenerative spine disease.

SUMMARY OF BACKGROUND DATA

Combination antiretroviral therapy has prolonged survival in HIV-infected patients, increasing the prevalence of chronic conditions such as degenerative spine disease that may require spine surgery.

METHODS

We studied all HIV-infected patients under care in the Veterans Health Administration from 1996 to 2008 (n = 40,038) and uninfected comparator patients (n = 79,039) matched on age, sex, race, year, and geographic region. The primary outcome was spine surgery for degenerative spine disease, defined by International Classification of Diseases, Ninth Revision procedure and diagnosis codes. We used a multivariate Poisson regression to model spine surgery rates by HIV infection status, adjusting for factors that might affect suitability for surgery (demographics, year, comorbidities, body mass index, combination antiretroviral therapy, and laboratory values).

RESULTS

Two hundred twenty-eight HIV-infected and 784 uninfected patients underwent spine surgery for degenerative spine disease during 700,731 patient-years of follow-up (1.44 surgeries per 1000 patient-years). The most common procedures were spinal decompression (50%) and decompression and fusion (33%); the most common surgical sites were the lumbosacral (50%) and cervical (40%) spine. Adjusted rates of surgery were lower for HIV-infected patients (0.86 per 1000 patient-years of follow-up) than for uninfected patients (1.41 per 1000 patient-years; incidence rate ratio 0.61, 95% confidence interval: 0.51-0.74, P < 0.001). Among HIV-infected patients, there was a trend toward lower rates of spine surgery in patients with detectable viral load levels (incidence rate ratio 0.76, 95% confidence interval: 0.55-1.05, P = 0.099).

CONCLUSION

In the Veterans Health Administration, HIV-infected patients experience significantly reduced rates of surgery for degenerative spine disease. Possible explanations include disease prevalence, emphasis on treatment of nonspine HIV-related symptoms, surgical referral patterns, impact of HIV on surgery risk-benefit ratio, patient preferences, and surgeon bias.

Tuberculous spondylitis and paravertebral abscess formation after kyphoplasty: a case report

STUDY DESIGN

Case report.

OBJECTIVE

To report a patient with spinal tuberculosis (TB) and paravertebral abscess formation after kyphoplasty of L1. The literature is reviewed, and diagnostic options are discussed.

SUMMARY OF BACKGROUND DATA

Kyphoplasty is a well-established procedure in the treatment of osteoporotic compression fractures and metastatic tumors of the vertebrae. Although complication rates are low, there is evidence for an increased risk of serious local infections after kyphoplasty in patients with any history of systemic infection. Spinal TB accounts for 2% of all TB cases with a trend toward an increased incidence in parallel with the growing number of immunocompromised patients. To our knowledge, only 1 article had reported a patient suffering from Pott disease after vertebroplasty.

METHODS

A 70-year-old patient with compression fracture of L1 underwent percutaneous kyphoplasty using polymethyl methacrylate.

RESULTS

Two weeks after kyphoplasty, the patient was readmitted with backache and signs of acute infection. Magnetic resonance imaging confirmed the diagnosis of spondylitis with paravertebral abscess formation. A tissue specimen obtained by computed tomography-guided percutaneous biopsy did not yield any pathogen. As broad-spectrum antibiotic therapy failed, combined surgery consisting of posterior instrumentation of Th11-L3 and anterior debridement, corporectomy of L1, and interposition of a titanium mesh cage filled with autologous rib graft was performed. Histologic examination of resected tissue and PCR and culture results confirmed diagnosis of spinal TB. Despite adequate antibiotic treatment and local surgical interventions, the patient died from septic multiple organ failure.

CONCLUSION

Indication for kyphoplasty in patients with any history of local or systemic infection should be scrutinized rigorously. Symptoms of spinal TB are often nonspecific, and the clinician should be aware of this entity. Active investigation including microbiological and histologic examination is of utmost importance to avoid any delay in correct diagnosis and specific treatment.

Distribution of HIV-1 in the genomes of AIDS patients

The localization of HIV-1 proviruses in compositional DNA fractions from 27 AIDS patients during the chronic phase of the disease with depletion of CD4+ and different levels of viremia showed the following. (1) At low viremia, proviruses are predominantly localized in the GC-richest isochores, which are characterized by an open chromatin structure; this result mimics findings on HIV-1 integration in early infected cells in culture. (2) At higher viremia, an increased distribution of proviruses in GC-poor isochores (which match the GC poorness of HIV-1) was found; this suggests a selection of cells in which the 'isopycnic' localization leads to a higher expression of proviruses and, in turn, to higher viremia. (3) At the highest viremia, integrations in GC-rich isochores are often predominant again, but generally not at the same level as in (1); this may be the consequence of new integrations from the extremely abundant RNA copies.