Vertebral osteomyelitis: an analysis of 38 surgically treated cases

Unidirectional porous beta-tricalcium phosphate as a potential bone regeneration material for infectious bony cavity without debridement in pyogenic spondylitis

An 81-year-old man was initially diagnosed with T11 osteoporotic vertebral fracture. The fractured vertebral body was filled with unidirectional porous beta-tricalcium phosphate (β-TCP) granules, and posterior spinal fixation was conducted using percutaneous pedicle screws. However, the pain did not improve, the inflammatory response increased, and bone destructive changes extended to T10. The correct diagnosis was pyogenic spondylitis with concomitant T11 fragility vertebral fracture. Revision surgery was conducted 2 weeks after the initial surgery, the T10 and T11 pedicle screws were removed, and refixation was conducted. After the revision surgery, the pain improved and mobilization proceeded. The infection was suppressed by the administration of sensitive antibiotics. One month after surgery, a lateral bone bridge appeared at the T10/11 intervertebral level. This increased in size over time, and synostosis was achieved at 6 months. Resorption of the unidirectional porous β-TCP granules was observed over time and partial replacement with autologous bone was evident from 6 months after the revision surgery. Two years and 6 months after the revision surgery, although there were some residual β-TCP and bony defect in the center of the vertebral body, the bilateral walls have well regenerated. This suggested that given an environment of sensitive antibiotic administration and restricted local instability, unidirectional porous β-TCP implanted into an infected vertebral body may function as a resorbable bone regeneration scaffold without impeding infection control even without debridement of the infected bony cavity.

An unusual case of a persistent, infected retroperitoneal fluid collection 5 years after anterior lumbar fusion surgery: illustrative case

BACKGROUND

Anterior lumbar fusion procedures have many benefits and continue to grow in popularity. The technique has many potential approach- and procedure-related complications. Symptomatic retroperitoneal fluid collections are uncommon but potentially serious complications after anterior lumbar procedures. Collection types include hematomas, urinomas, chyloperitoneum, cerebrospinal fluid collections, and deep infections.

OBSERVATIONS

The authors present an unusual case of a patient with persistent symptoms related to a retroperitoneal collection over a 5-year period following anterior lumbar fusion surgery. To the authors’ knowledge, no similar case with such extensive symptom duration has been described. The patient had an infected encapsulated fluid collection. The collection was presumed to be a postoperative lymphocele that was secondarily infected after serial percutaneous drainage procedures.

LESSONS

When retroperitoneal collections occur after anterior retroperitoneal approaches, clinical clues, such as timing of symptoms, hypotension, acute anemia, urinary tract infection, hydronephrosis, elevated serum creatinine and blood urea nitrogen, low-pressure headaches, anorexia, or systemic signs of infection, can help narrow the differential. Retroperitoneal collections may continue to be symptomatic many years after anterior lumbar surgery. The collections may become infected after serial percutaneous drainage or prolonged continuous drainage. Encapsulated, infected fluid collections typically require surgical debridement of the capsule and its contents.

Vertebral Osteomyelitis: A Comparison of Associated Outcomes in Early Versus Delayed Surgical Treatment

Background

The recommended timing of surgical intervention for vertebral osteomyelitis (VO) is controversial; however, most studies are not sufficiently powered. Our goal was to investigate the associated effects of delaying surgery in VO patients on in-hospital complications, neurologic deficits, and mortality.

Methods

Retrospective review of the National Inpatient Sample. Patients who underwent surgery for VO from 1998 to 2013 were identified using codes from the International Classification of Disease, Ninth Revision, Clinical Modification. Patients were stratified into groups based on incremental delay of surgery: 0-day delay (same-day surgery), 1-day delay, 2-day delay, 3- to 6-day delay, 7- to 14-day delay, and 14- to 30-day delay. Univariate analysis compared demographics and outcomes between groups. Multivariate logistic regression models calculated independent predictors of any complication, mortality, and neurologic deficits. A 0-day delay was the reference group.

Results

A total of 34 465 patients were identified. Delayed groups were older (same day: 53.5 vs. 7-14-day delay: 61.1) and had a higher Deyo-Charlson score (same day: 0.4901 vs. 14-30-day delay: 1.66), length of stay (same day: 4.2 vs. 14-30-day delay: 34.04 days), and total charges (same day: $63,390.78 vs. 14-30-day delay: $245,752.4), all P < .001. Delayed groups had higher surgical combined-approach rates (same day: 9.1% vs. 14-30-day delay: 31.5%) and lower anterior-approach rates (same day: 42.4% vs. 14-30-day delay: 24.2%). Delayed groups had increased mortality and complication rates. Regressions showed delayed groups as the strongest independent indicators of any complication (14-30-day delay: odds ratio [OR] 3.384), mortality (14-30-day delay: OR 10.658), and neurologic deficits (14-30-day delay: OR 3.464), all P < .001.

Conclusion

VO patients who operate within 24 hours of admission are more likely to have desirable outcomes. Patients with delayed surgery had a significantly increased risk of developing any complication, mortality, and discharging with neurologic deficits.

Level of Evidence

III.

Clinical Relevance

Medically fit patients may benefit from earlier surgical management in order to reduce risk of postoperative complications, improve outcomes, and reduce overall hospital costs.

Retrospective feasibility analysis of modified posterior partial vertebrectomy with 360-degree decompression in destructive thoracic spondylodiscitis

BACKGROUND

Advanced states of vertebral osteomyelitis accompanied by spinal instability, epidural abscess formation, and neurological deficits require surgical decompression, stabilization, and often reconstruction of the anterior and posterior columns. The efficacy of a posterolateral approach with resection of inflammatory tissue, and interbody (titanium cages) and dorsal fusion was investigated and the clinical and radiological parameters (correction of kyphosis and fusion rates) were evaluated.

METHOD

From 2011 to 2014, ten consecutive patients were treated at our institution using the modified technique of a transversecomy without costal resection to decompress neural structures and resect inflammatory tissue in destructive thoracic vertebral osteomyelitis. Flattening of the endplates without complete corpectomy, 360-degree stabilization, and correction of kyphosis by posterior shortening instead of anterior distraction were performed to avoid an additional ventral approach. Clinical and radiological data were retrospectively analyzed.

RESULTS

All ten patients (six male and four female, mean age, 66 years) suffered from severe and destructive osteomyelitis. Surgery was performed successfully in all ten patients. Mean surgical time was 308 min. Mean follow-up was 19 months (range, 2-32 months). Neither approach-related or pulmonary complications nor recurrence of osteomyelitis were observed. All patients experienced pain relief after the procedure (mean back pain VAS was 8.8 pre-treatment and 3.2 at the final follow-up). Fusion was observed in all patients on the basis of computerized tomography scans. The mean radiological segmental kyphosis was corrected from 20° preoperatively to 7° after surgery and 9° at the final follow-up.

CONCLUSIONS

The modified posterior transversectomy with 360-degree decompression and anterior wall reconstruction with titanium cages in combination with posterior instrumentation for sagittal alignment correction is a reliable, effective, and safe treatment option.

Use of permanently placed metal expandable cages for vertebral body reconstruction in the surgical treatment of spondylodiscitis

This is a retrospective study of 15 patients treated for spondylodiscitis with implanted metal cages. The purpose of this study is to investigate the outcomes of patients treated with permanently placed metal hardware in vertebral body reconstruction for spondylodiscitis. The use of metal implants in the face of infection has classically been discouraged in orthopedic literature because of the ability of bacteria to form biofilms on metal surfaces. Traditional treatment of spondylodiscitis has been aggressive debridement followed by reconstruction with bone grafts. Expandable metallic cages made reconstruction of these defects significantly easier. However, concern exists that metallic implants affect the resolution of infection. A search of the authors' patient database from 2005 to 2009 revealed 21 patients with spondylodiscitis treated with anterior debridement and reconstruction with an expandable metallic cage. Fourteen patients (15 cases) had sufficient documented clinical follow-up and were available for review. Resolution of infection was determined by evaluating symptoms, laboratory data, and final radiographic result. Of the 15 cases, all had clinical resolution of infection with an average follow-up time of 25 months. An average loss of 1.9° of correction was observed when comparing final follow-up radiographs with initial postoperative radiographs. Radiograph review revealed no extensive osteolysis around the hardware or progressive collapse. These results suggest that the use of expandable metal cages maintains alignment while not perpetuating infection. The spine appears to provide a unique environment that permits the use of metal implants in the setting of infection.

Pott's Disease in a 2-Year-Old Child Treated by Decompression and Anterior-Posterior Instrumented Fusion

Introduction. Paraplegia and kyphotic deformity are two major disease-related problems of spinal tuberculosis, especially in the early age disease. In this study a 2-year-old boy who underwent surgical decompression, correction, and 360° instrumented fusion via simultaneous anterior-posterior technique for Pott's disease was reported. Case Report. A 2-year-and-9-month-old boy presented with severe back pain and paraparesis of one-month duration. Thoracic magnetic resonance imaging demonstrated destruction with a large paraspinal abscess involving T5-T6-T7 levels, compressing the spinal cord. The paraspinal abscess drained and three-level corpectomy was performed at T5-6-7 with transthoracic approach. Anterior instrumentation and fusion was performed with structural 1 autogenous fibula and rib graft using screw-rod system. In prone position pedicle screws were inserted at T4 and T8 levels and rods were placed. Six months after surgery, there was no weakness or paraparesis and no correction loss at the end of follow-up period. Discussion. In cases of vertebral osteomyelitis with severe anterior column destruction in the very early child ages the use of anterior structural grafts and instrumentation in combination with posterior instrumentation is safe and effective in maintenance of the correction achieved and allows efficient stabilization and early mobilization.

Treatment of thoracolumbar spinal infections through anterolateral approaches using expandable titanium mesh cage for spine reconstruction

Pyogenic vertebral osteomyelitis (PVO) is still a rare pathology. However, its incidence is on the rise. This is due to an increasing population with predisposing factors. Also, the availability of more effective diagnostic tools has brought it increasingly to the surgeon's attention. In this study the patients were treated in the Neurosurgery Division of the Department of Neurological Sciences and Psychiatry of the Sapienza University of Rome, between 2001 and 2009. They had thoracolumbar pyogenic spondylitis. This study was undertaken in order to identify the correct diagnostic and therapeutic treatment needed in such cases. From the cases studied here, it is evident that spinal infections can be extremely insidious and that diagnosis tends to be reached late. Surgery, along with the antibiotic treatment, allows for eradication of the causes of the pathology by the reclamation of the affected region. Surgery is also fundamental in helping to recover vital functions and in restoring as much as possible the correct curvature of the rachises. The use of an anterolateral approach is dictated by the necessity of obtaining 360° stability as well as by the need to clear away extensive infections, which are not always reachable using a posterior approach.

Pyogenic spondylitis

Pyogenic spondylitis is a neurological and life threatening condition. It encompasses a broad range of clinical entities, including pyogenic spondylodiscitis, septic discitis, vertebral osteomyelitis, and epidural abscess. The incidence though low appears to be on the rise. The diagnosis is based on clinical, radiological, blood and tissue cultures and histopathological findings. Most of the cases can be treated non-operatively. Surgical treatment is required in 10–20% of patients. Anterior decompression, debridement and fusion are generally recommended and instrumentation is acceptable after good surgical debridement with postoperative antibiotic cover.

A missed injury leading to delayed diagnosis and postoperative infection of an unstable thoracic spine fracture - case report of a potentially preventable complication

Background

Patients suffering from polytrauma often present with altered mental status and have varying levels of examinability. This makes evaluation difficult. Physicians are often required to rely on advanced imaging techniques to make prompt and accurate diagnoses. Occasionally, injury detection on advanced imaging studies can be challenging given the subtle findings associated with certain conditions, such as diffuse idiopathic skeletal hyperostosis (DISH). Delayed or missed diagnoses in the setting of spinal fracture can lead to catastrophic neurological injury.

Case presentation

A man struck by a motor vehicle suffered multiple traumatic injuries including numerous rib fractures, a mechanically unstable pelvic fracture, and also had suspicion for an aortic injury. Unfortunately, the upper thoracic segment (T1-5) was only visualized with axial images based on the electronic data. Several days later, a contrast CT scan obtained to check the status of suspected aortic injury revealed T3-T4 subluxation indicative of an unstable extension-type fracture in the setting of DISH. Due to the missed injury and delay in diagnosis, surgery was not performed until eight days after the injury. At surgery, the patient was found to have left T3-T4 facet joint infection as well as infected hematoma surrounding a left T4 transverse process fracture and a traumatic T4 costo-transverse joint fracture-subluxation. Despite presence of infection, an instrumented posterior spinal fusion from T1-T6 was performed and the patient recovered well after antibiotic treatment.

Conclusion

A T3-T4 unstable DISH extension-type fracture was initially missed in a polytrauma patient due to inadequate imaging acquisition, which caused a delay in treatment and bacterial seeding of fracture hematoma. Complete imaging is especially needed in obtunded patients that cannot be thoroughly examined.

Comparative study on the efficacy of two-staged (posterior followed by anterior) surgical treatment using spinal instrumentation on pyogenic and tuberculotic spondylitis

INTRODUCTION

Between 1997 and 2006, we treated 11 patients with tuberculotic spondylitis and 19 with pyogenic spondylitis using a two-staged operation (posterior spinal instrumentation, followed by anterior debridement and fusion).

METHOD

We compared changes in inflammatory reactions, postoperative complications, organisms obtained during anterior debridement, neurological status, bone union, and suppression of the infection between the patients with tuberculotic and pyogenic spondylitis.

PATIENTS

All patients in both groups achieved bone union and suppression of the infected sites. Decreases in C-reactive protein and erythrocyte sedimentation rate were significantly slower in the patients with tuberculotic spondylitis. Positive bacterial cultures at the second anterior debridement were obtained from 26% of patients with pyogenic spondylitis and 55% of patients with tuberculotic spondylitis. Frankel types improved in 57% of patients, but there were no differences in neurological improvement. The efficacy of the two-staged operation did not differ between the patients with pyogenic and tuberculotic spondylitis.

RESULTS

Although the baselines were different, there were no significant differences in relative operating parameters, neurological improvement, or postoperative complications between the two groups. At the final follow-up, all patients finally achieved suppression of spinal infection and solid bone fusion in both groups, although the decline in inflammatory parameters was slower in the T group than in the P group.

Safety of instrumentation in patients with spinal infection

OBJECT

Treatment of spine infection remains a challenge for spine surgeons, with the most effective method still being a matter of debate. Most surgeons agree that in early stages of infection, antibiotic treatment should be pursued; under certain circumstances, however, surgery is recommended. The goals of surgery include radical debridement of the infective focus. In some cases, when surgery causes mechanical spinal instability, the question arises whether the risk of recurrent infection outweighs the benefits of spinal instrumentation and stabilization. The authors report their series of cases in which instrumentation was placed in actively infected sites and review the relevant literature.

METHODS

The authors performed a retrospective analysis of all cases of spinal infection that were surgically treated with debridement and placement of instrumentation at their institution between 2000 and 2006. Patient presentation, risk factor, infective organism, surgical indication, level of involvement, type of procedure, and ultimate outcome were reviewed. Improved outcome was based on improvement of initial American Spinal Injury Association Impairment Score.

RESULTS

Forty-seven patients (32 men, 15 women) were treated with instrumented surgery for spinal infection. Their average age at presentation was 54 years (range 37-78 years). Indications for placement of instrumentation included instability, pain after failure of conservative therapy, or both. Patients underwent surgery within an average of 12 days (range 1 day to 5 months) after their presentation to the authors' institution. The average length of hospital stay was 25 days (range 9-78 days). Follow-up averaged 22 months (range 1-80 months). Eight patients died; causes of death included sepsis (4 patients), cardiac arrest (2), and malignancy (2). Only 3 patients were lost to follow-up. Using American Spinal Injury Association scoring as the criterion, the patients' conditions improved in 34 cases and remained the same in 5. Complications included hematoma (2 cases), the need for hardware revision (1), and recurrent infection (2). Hardware replacement was required in 1 of the 2 patients with recurrent infection.

CONCLUSIONS

Instrumentation of the spine is safe and has an important role in stabilization of the infected spine. Despite the presence of active infection, we believe that instrumentation after radical debridement will not increase the risk of recurrent infection. In fact, greater benefit can be achieved through spinal stabilization, which can even promote accelerated healing.

Evaluation of conservative treatment of non specific spondylodiscitis

The objective of this study was to analyse the presentation, aetiology, conservative management, and outcome of non-tuberculous pyogenic spinal infection in adults. We performed a retrospective review of 56 patients (35 women and 21 men) of pyogenic spinal infection presenting over a 7-year period (1999-2006) to the Department of Spinal Surgery of Hesperia Hospital. The medical records, radiologic imaging, bacteriology results, treatment, and complications of all patients were reviewed. The mean age at presentation was 47.8 years (age range 35-72 years), the mean follow-up duration was 12.5 months. The most common site of infection was lumbar spine (n: 48), followed by the thoracic spine (n: 8). Most patients were symptomatic for between 4 and 10 weeks before presenting to hospital. The frequently isolated pathogen was Staphylococcus aureus in 31 of 56 cases (57.6%). Percutaneous biopsies were diagnostic in 57% of patients; the open biopsy was indicated if closed biopsy failed and when the infection was not accessible by percutaneous technique. The patients were managed by conservative measures alone, including antibiotic therapy and spinal bracing. The mean period of antibiotic therapy was 8.5 weeks (range 6-9 weeks), followed by oral antibiotics for 6 weeks. All patients had a supportive spinal brace for mean 8 weeks (range 6-10 weeks). The duration of the administration of oral antibiotics was dependent on clinical and laboratory evidence (white cell count, erythrocyte sedimentation rate, C-reactive protein) that the infection was resolved. The follow-up MR gadolinium scans were essential to monitor the response to medical treatment. The diagnosis of pyogenic spinal infection should be considered in any patient presenting with severe localised unremitting back and neck pain, especially when accompanied with systemic features, such as fever and weight loss and in the presence of elevated inflammatory markers. The conservative management of infection with antibiotic therapy and spinal bracing was very successful.

The use of allograft or autograft and expandable titanium cages for the treatment of vertebral osteomyelitis

OBJECTIVE

The results of the surgical treatment of osteomyelitis with expandable titanium cages and either allograft or autograft are presented.

METHODS

Thirty-six patients with vertebral osteomyelitis are presented. There were 7 cervical, 17 thoracic, 4 thoracolumbar (involving T12-L1), 5 lumbar, and 3 lumbosacral (involving L5-S1) lesions. The most frequently identified organisms were Staphylococcus aureus, Mycobacterium tuberculosis, and Coccidioides immitis. Imaging studies included x-rays, computed tomographic scans, and magnetic resonance imaging scans. All patients were treated with corpectomies and expandable cage reconstruction. Fusion was performed with rib autograft, iliac crest autograft, or allograft. Most patients who had an anterior approach also underwent posterior instrumentation, whereas a few had anterior instrumentation only. Four patients underwent a posterior approach (transpedicular corpectomy) only.

RESULTS

The median follow-up period was 21 months. There were no implant failures. Two recurrences of infection were noted: 1 case involved allograft, and the other involved autograft. At follow-up, neurological deficits improved in all patients, and 81% of patients were pain-free.

CONCLUSION

This study suggests that the treatment of vertebral column osteomyelitis can be performed with expandable titanium cages, and allograft does not appear to increase the rate of recurrence, as compared with autograft.

Pyogenic vertebral osteomyelitis: a systematic review of clinical characteristics

OBJECTIVES

Vertebral osteomyelitis is a cause of back pain that can lead to neurologic deficits if not diagnosed in time and effectively treated. The objective of this study was to systematically review the clinical characteristics of pyogenic vertebral osteomyelitis (PVO).

METHODS

The authors conducted a systematic review of the English literature. The inclusion criteria included studies with 10 or more subjects diagnosed with PVO based on the combination of clinical presentation with either a definitive bacteriologic diagnosis or pathological and/or imaging studies.

RESULTS

The 14 studies that met selection criteria included 1008 patients with PVO. Of them, the majority (62%) were men, with back pain and fever as the most common presenting symptoms. Diabetes mellitus was the most common underlying medical illness, while the urinary tract was the commonest source of infection. Staphylococcus aureus was the most commonly isolated organism. Computed tomographic guided or open biopsy yielded the causative organism more often than blood cultures (77% versus 58%). Plain radiography showed abnormalities in 89% of the cases, while bone scanning and computed tomography or magnetic resonance imaging were positive in 94% of the cases, revealing lumbar as the most commonly affected area. The attributable mortality was 6%, while relapses and neurological deficits were described in the 32% and 32% of the cases, respectively.

CONCLUSION

PVO is an illness of middle-aged individuals with underlying medical illnesses. Although the mortality rate is low, relapses and neurological deficits are common, making early diagnosis a major challenge for the physician.

Long-term functional outcome in pyogenic spinal infection

STUDY DESIGN

Retrospective.

OBJECTIVE

To assess long-term adverse functional outcome following pyogenic spinal infection using standardized outcome measures, Oswestry disability index (ODI), and medical outcomes study short form-36 (SF-36).

SUMMARY OF BACKGROUND DATA

There is minimal published data regarding the long-term functional outcome in pyogenic spinal infection. Previous studies have used heterogeneous, unreliable, and nonvalidated measure instruments yielding data that is difficult to interpret.

METHODS

All cases of pyogenic spinal infection presenting to a single institution managed operatively and nonoperatively from 1994 to 2004 were retrospectively identified. Follow-up was by clinical review and standardized questionnaires. Inclusion in each case was on the basis of consistent clinical, imaging, and microbiology criteria.

RESULTS

Twenty-nine cases of pyogenic spinal infection were identified. Twenty-eight percent were managed operatively and 72% with antibiotic therapy alone. Nineteen patients (66%) had an adverse outcome at a median follow-up of 61 months, despite only 5 patients (17%) having persistent neurologic deficit. A significant difference in SF-36 physical function scores was observed between patients with adverse outcome and patients who recovered (P = 0.003). SF-36 scores of all patients, regardless of management or outcome, failed to reach those of a normative population. A strong correlation was observed between ODI and SF-36 physical function scores (rho = 0.61, P < 0.05). Seventeen percent (n = 5) of admissions resulted in acute sepsis-related death. Delay in diagnosis of spinal infection (P = 0.025) and neurologic impairment at diagnosis (P < 0.001) were significant predictors of neurologic deficit at follow-up. Previous spinal surgery was associated with adverse outcome in patients requiring readmission within 1 year of hospital discharge following first spinal infection (P = 0.018). No independent predictors of adverse outcome, persistent neurologic impairment, readmission within 1 year, or acute death were identified by logistical regression analysis.

CONCLUSION

High rates of adverse outcome detected using SF-36 and ODI suggest under-reporting of poor outcome when American Spinal Injury Association score alone is used to qualify outcome.

Corpectomy followed by the placement of instrumentation with titanium cages and recombinant human bone morphogenetic protein–2 for vertebral osteomyelitis

Object

The treatment of vertebral osteomyelitis includes antibiotics with or without surgical intervention. The decision to place instrumentation into an infected spinal column remains controversial. The use of recombinant human bone morphogenetic protein–2 (rhBMP-2) in patients with osteomyelitis is also extremely controversial. The authors review their experience in performing corpectomy and fusion with titanium cages and rhBMP-2 in patients with vertebral instability and/or neurological compromise due to vertebral osteomyelitis.

Methods

Data obtained in 15 patients treated between 2001 and 2005 were included in this analysis. Nine patients presented primarily with axial pain and six with radiculopathy or myelopathy. Seven patients had an associated epidural abscess. The cervical spine was affected in six patients, the thoracic spine in five, and the lumbar spine in four. All patients underwent corpectomy of the involved vertebral bodies; the authors then performed spinal reconstruction, placing a titanium cage–plate system with morcellized allograft/autograft and rhBMP-2. In 10 patients, supplemental posterolateral screw–rod fixation was conducted.

A one-level corpectomy was performed in one patient, a two-level corpectomy in 13, and a six-level corpectomy in one. A morcellized allograft and rhBMP-2–filled titanium cage was used in 10 patients, and an autograft and rhBMP-2–filled cage in five patients. The most common pathogen wasStaphylococcus aureus. All patients received intravenous antibiotics for at least 6 weeks postoperatively, and life-long antibiotic therapy was required in three patients with coccidiomycoses, candida, and tuberculosis osteomyelitis, respectively. There were no recurrent infections. Radiography demonstrated evidence of fusion in all patients at the last follow-up examination. The mean follow-up period was 20 months.

Conclusions

Corpectomy followed by titanium cage–plate reconstruction and the placement of rhBMP-2 may be a safe and effective treatment for selected patients with vertebral osteomyelitis. This surgical therapy does not appear, at least based on preliminary results, to lead to recurrent hardware infections. Based on the results obtained in this limited series, the authors found that rhBMP-2 can be used in the setting of active infection with excellent fusion rates and without complication. The morbidity associated with the autograft donor site is avoided when using cages. Antibiotic therapy tailored to the specific organism should be continued for at least 6 weeks after surgery, and life-long therapy is required in cases of fungal or tuberculosis infections.

Diagnostic performance of pyogenic vertebral osteomyelitis

OBJECTIVE

Early diagnosis of pyogenic vertebral osteomyelitis (PVO) is frequently difficult. There are, however, few studies that have investigated the diagnostic performance of PVO in Japan. Our aim was to analyze the diagnostic performance and identify clinical factors associated with the diagnostic delay of PVO.

MATERIALS AND METHODS

We performed hospital-based retrospective case analysis. All patients with PVO were identified from the computerized medical database at Okinawa Chubu Hospital in Okinawa, Japan, from January 1985 to December 2004. We collected the following data; baseline information; laboratory tests; clinical and microbiologic outcomes; and diagnostic process. We used multivariable-adjusted linear regression to identify significant factors associated with patient and hospital delay to the diagnosis of PVO.

RESULTS

We reviewed total of 209,428 patients hospitalized during the 20-year study period. Of those, we identified 51 patients with PVO. Eighty percent of these patients were misdiagnosed at their initial clinical encounters. Median duration from the symptom onset to the diagnosis was 19 days. Median durations of patient factor and hospital factor that contributed to the total delay were 1 and 8 days, respectively. Significant patient factor that contributed to delay was cognitive dysfunction.

CONCLUSIONS

Cognitive dysfunction is a risk factor for patient delay for visiting physicians in patients with PVO. Diagnosis of PVO is difficult at the initial clinical encounter. High index of suspicion is needed for more rapid diagnosis of PVO.

Vertebral Osteomyelitis

Vertebral osteomyelitis (VO) is an infectious disease of the vertebral body that requires early diagnosis with identification of the infecting organism to direct antibiotic therapy. Most VO can be treated nonsurgically, but 10% to 20% of cases require open surgical treatment. Excellent clinical outcomes can be achieved with appropriate medical and surgical treatment.

Pyogenic vertebral osteomyelitis: a review of 14 cases

PURPOSE

To review and evaluate the management of 14 patients with pyogenic vertebral osteomyelitis at National University Hospital, Singapore between 1998 and 2001.

METHODS

Demographic pattern, predisposing factors, clinical presentation, co-morbidities, microbiology, treatment, and complications of 14 patients were retrospectively reviewed.

RESULTS

The mean age at presentation was 62.5 years and the male to female ratio was 6:1. The mean follow-up duration was 12.5 months. The most common predisposing condition was diabetes mellitus (n=5). The most common site of infection was the lumbar spine (n=8), followed by the thoracic (n=4) and cervical (n=2) spine. Staphylococcus aureus was the most common causative organism isolated (n=9), followed by methicillin-resistant S aureus (n=3), Pseudomonas pseudomallei (n=1), and Streptococcus agalactiae (n=1). 12 patients were treated surgically: 8 by an anterior approach, 3 by a posterior approach, and one by a combination of the 2. The mean period of antibiotic use was 11.4 weeks. One patient with melioidosis involving the T9 to T11 vertebrae caused by P pseudomallei died of empyema and septicaemia 22 months after presentation.

CONCLUSION

Pyogenic vertebral osteomyelitis is not uncommon in the elderly, especially those with predisposing conditions such as diabetes mellitus. Computed tomography-guided needle biopsy is recommended to investigate causative microorganisms. Aggressive surgical debridement and prolonged antibiotic therapy were necessary in patients with methicillin-resistant S aureus, P pseudomallei, and S agalactiae.

[Multistep surgery for spondylosyndesis. Treatment concept of destructive spondylodiscitis in patients with reduced general condition]

OBJECTIVE

Retrospective assessment of multistage surgery in the treatment of progressive spondylodiscitis in patients with critical physical status.

PATIENTS

A total of 34 patients (mean age 58.6 years) with 37 progressive spondylodiscitis foci and destruction of one to three vertebral segments (1.9 mean) were recorded within an 8-year period. Time between first complaints and operative treatment was 3 months (mean). Preoperative health status was critically reduced in 11 patients (ASA IV) and poor general condition (ASA III) was seen in 23 patients when vital indication was seen preoperatively. Considerable systemic disease (n=31), further infection focus (n=18), and nosocomial trauma (n=5) were causally related. Spondylodiscitis was seen more frequently in the lumbar (n=20) and thoracolumbar than in the thoracic (n=10) and cervical spine (n=1). Staphylococcus aureus was detectable from operative specimens and hemoculture in 15 cases, MRSA in 6 of these.

METHODS

In cases of monosegmentary involvement (n=7) ventral debridement, biopsy, and application of antibiotic chains were followed by autologous interbody bone grafting in a second stage operation. In 29 cases with destruction of two (n=27) and three (n=3) segments, posterior instrumentation including laminectomy in 4 patients was completed by anterior debridement and application of antibiotic chains during a first surgical intervention. After stabilization of physical condition and having reached a macroscopically indisputable implant bed, the ventral fusion with autologous interbody bone grafting or cage in combination with a plate or internal fixation system was performed as the last of several surgical steps.

RESULTS

No case of perioperative mortality was observed. Intensive care continued 9.1 days and hospitalization 49.5 days (mean). During a 37.6-month follow-up two late recurrences were observed.

CONCLUSION

A multistep surgical procedure under protection of dorsal instrumentation can limit perioperative mortality in patients in critical general condition by avoiding an extended one stage dorsoventral spondylodesis. After eradication of further infection foci and stabilization of physical condition, ventral instrumentation is completed under elective conditions.

Hematogenous Vertebral Osteomyelitis Due to Staphylococcus aureus in the Adult: Clinical Features and Therapeutic Outcomes

OBJECTIVE

Staphylococcus aureus is the most common cause of hematogenous vertebral osteomyelitis in adults. To better define clinical features and therapeutic outcomes, the charts of 40 adult patients with S aureus hematogenous vertebral osteomyelitis were retrospectively reviewed.

METHODS

Retrospective chart review using standardized data collection form.

RESULTS

S aureus hematogenous vertebral osteomyelitis commonly occurred in the settings of recent invasive procedures (55% of patients), insulin use (28%), and hemodialysis (20%). Ten percent of patients had S aureus bacteremia or vascular catheter infection within the preceding 6 months. Median time from first symptom to diagnosis was 51.3 days. A portal of entry for S aureus was identified in 13 patients (32.5%); intravenous catheters were the likely origin in 9 of those 13 patients. Concurrent endocarditis was present in 4 patients. Forty-eight percent of patients had neurologic abnormalities and 60% of patients had an epidural, paraspinous, or psoas abscess demonstrated by neuroimaging. S aureus was isolated through fine-needle aspiration in 17 of 23 patients (74%) and from blood cultures in 23 of 34 patients (68%). Infection was due to methicillin-susceptible S aureus in 67.5% of patients. All patients received intravenous antibiotics for a mean duration of 58.6 days; 36 of 40 (90%) also received concomitant rifampin. Twenty-seven percent and 12.5% of patients underwent surgical debridement and CT-guided drainage of abscesses, respectively. After intravenous therapy, 19 of 30 eligible patients received oral continuation treatment. The mean duration of total antibiotic therapy was 142.2 days.

CONCLUSIONS

Cure of infection was achieved in 83% (24/29) of evaluable patients, but 50% of those achieving cure still had infection-related sequelae. Intravenous antibiotic therapy for at least 8 weeks was the only clinical factor associated with cure (P = 0.05, two-tailed Fisher exact test).

Diagnosis and management of adult pyogenic osteomyelitis of the cervical spine

Establishing the diagnosis of cervical osteomyelitis in a timely fashion is critical to prevent catastrophic neurological injury. In the modern imaging era, magnetic resonance imaging in particular has facilitated the diagnosis of cervical osteomyelitis, even before the onset of neurological signs or symptoms. Nevertheless, despite advancements in diagnosis, disagreement remains regarding appropriate surgical treatment. The role of instrumentation and type of graft material after cervical decompression remain controversial. The authors describe the epidemiological features, pathogenesis, and diagnostic evaluation, and the surgical and nonsurgical interventions that can be used to treat osteomyelitis of the cervical spine. They also review the current debate about the role of instrumentation in preventing spinal deformity after surgical decompression for cervical osteomyelitis. Based on this review, the authors conclude that nonsurgical therapy is appropriate if neurological signs or symptoms, instability, deformity, or spinal cord compression are absent. Surgical decompression, debridement, stabilization, and deformity correction are the goals once the decision to perform surgery has been made. The roles of autogenous graft, instrumentation, and allograft have not been clearly delineated with Class I data, but the authors believe that spinal stability and decompression override creating an environment that can be completely sterilized by antibiotic drugs.

Single-stage debridement and instrumentation for pyogenic spinal infections

Surgical intervention is indicated for pyogenic vertebral discitis and osteomyelitis in patients in whom medical therapy has failed, and in those with neurological compromise, mechanical instability, epidural abscess, or intractable pain. Surgical management has evolved to include single-stage operations for debridement and stabilization as well as more aggressive reconstruction strategies with respect to instrumentation. A review of the literature demonstrates excellent outcomes with single-stage operations and placement of hardware wherever it is required. Using this method, the authors have treated 16 patients without a single incidence of recurrent infection or hardware failure after almost 2 years of follow up.

Treatment of pyogenic vertebral osteomyelitis with anterior debridement and fusion followed by delayed posterior spinal fusion

STUDY DESIGN

Case series.

OBJECTIVES

The results of surgical treatment of osteomyelitis with anterior debridement and fusion followed by delayed posterior stabilization and fusion are presented.

METHODS

Forty-two patients with vertebral osteomyelitis are presented. There were 5 cervical, 12 thoracic, 1 thoracolumbar, 19 lumbar, and 5 lumbosacral lesions. The most frequently identified organism was Staphylococcus aureus. Most patients had significant comorbidities, including diabetes, or were immunocompromised. Ninety percent had elevated erythrocyte sedimentation rates and C-reactive proteins, while white blood cell counts were less reliably elevated. Imaging studies included radiographs, CT scans, and MRIs. All patients were treated with anterior debridement and strut grafting followed by 14.4 days of intravenous antibiotics and delayed instrumented posterior fusions and received 6 weeks of intravenous antibiotics after surgery.

RESULTS

All patients had resolution of their infections with no recurrence. There were two deaths. Neurologic deficits resolved in all patients. The diagnosis of pyogenic vertebral osteomyelitis is frequently delayed and presents a significant surgical challenge. The indications for surgical debridement were neurologic compromise, failed medical treatment, soft tissue extension, extensive vertebral body and disc space destruction, and progressive deformity. Many of these patients were severely ill at presentation and required urgent treatment. Anterior debridement and fusion followed by intravenous antibiotics allows for restoration of anterior column support and control of the infection before posterior instrumentation and fusion.

CONCLUSION

This study demonstrates that anterior surgical debridement with fusion, followed by a period of intravenous antibiotics and delayed instrumented posterior fusion, is highly effective in the treatment of pyogenic osteomyelitis that has failed medical management.

Titanium cages in the surgical treatment of severe vertebral osteomyelitis

The role of spinal implants in the presence of infection is critically discussed. In this study 20 patients with destructive vertebral osteomyelitis were surgically treated with one-stage posterior instrumentation and fusion and anterior debridement, decompression and anterior column reconstruction using an expandable titanium cage filled with morsellised autologous bone graft. The patients' records and radiographs were retrospectively analysed and follow-up clinical and radiographic data obtained. At a mean follow-up of 23 months (range 12-56 months) all cages were radiographically fused and all infections eradicated. There were no cases of cage dislocation, migration or subsidence. Local kyphosis was corrected from 9.2 degrees (range -20 degrees to 64 degrees ) by 9.4 degrees to -0.2 degrees (range -32 degrees to 40 degrees ) postoperatively and lost 0.9 degrees during follow-up. All five patients with preoperative neurological deficits improved to Frankel score D or E. Patient-perceived disability caused by back pain averaged 7.9 (range 0-22) in the Roland-Morris score at follow-up. In cases of vertebral osteomyelitis with severe anterior column destruction the use of titanium cages in combination with posterior instrumentation is effective and safe and offers a good alternative to structural bone grafts. Further follow-up is necessary to confirm these early results.