Posterior fixation without debridement for vertebral body osteomyelitis and discitis

Circumferential correction of spinal deformity and instability secondary to bacterial spondylodiscitis

Background

Spinal deformity as a sequela of nontuberculous spondylodiscitis is a rarely discussed clinical entity. Sagittal plane deformity, segmental instability, and persistently active infection overlap in these patients resulting in severe restriction in activity and quality of life. The presence of multiple medical co-morbidities restricts surgical options but nonoperative care may be ineffective and result in persistent, refractory discitis for years. We describe our experience with vertebrectomy and long-segment fixation for patients with postinfectious thoracic or lumbar deformity.

Methods

A retrospective chart review of 23 consecutive patients who underwent vertebrectomy and long-segment fixation for thoracic or lumbar deformity secondary to nontuberculous bacterial spondylodiscitis was performed. Pre, peri- and postoperative data is compiled and analyzed with a focus on the perioperative management algorithm to safely perform an extensive reconstruction in this very sick patient population.

Results

Extremely low preoperative quality of life was evident with 87% (20/23) of patients bedridden primarily due to pain despite 70% (16/23) of patients being strong enough to ambulate (Frankel D or E). Most patients (87%) already had an identified infection under adequate treatment either through blood cultures, prior biopsy or decompressive surgery. A single-stage posterior-only was the primary surgical approach utilized in the majority (83%) of cases. Complications were present in 100% of patients, most commonly perioperative anemia and hypotension requiring vasopressor support and aggressive blood product replacement. One in-hospital mortality occurred secondarily to pulmonary embolism. Mean preoperative segmental angle was 18±10 degrees of kyphosis which was corrected to 1±9 degrees of lordosis (p=.001). The mean correction of the segmental angle was 19 degrees (standard deviation 23 degrees). Visual analogue scale scores improved from a preoperative value of 8.8±0.9 to a postoperative value of 2.5±1.4 (p<.001), which was obtained at the last outpatient follow-up (mean 631 days after surgery). Full self-care including ambulation was achieved in 18/23 (78%) patients, and the infection was successfully treated in 22/23 (96%) patients after long-term antibiotics.

Conclusions

Patients with refractory spondylodiscitis on appropriate care and antibiotics are typically considered extremely poor surgical candidates despite nonoperative care often being ineffective. Postinfectious deformity may also be so severe as to preclude a limited surgical treatment strategy. This study suggests that extensive circumferential reconstruction for deformity secondary to bacterial spondylodiscitis can be effective in restoring these extremely sick patients to self-care and ambulatory status.

Pedicle screw insertion into infected vertebrae reduces operative time and range of fixation in minimally invasive posterior fixation for thoracolumbar pyogenic spondylitis: a multicenter retrospective cohort study

BACKGROUND

Minimally invasive posterior fixation surgery for pyogenic spondylitis is known to reduce invasiveness and complication rates; however, the outcomes of concomitant insertion of pedicle screws (PS) into the infected vertebrae via the posterior approach are undetermined. This study aimed to assess the safety and efficacy of PS insertion into infected vertebrae in minimally invasive posterior fixation for thoracolumbar pyogenic spondylitis.

METHODS

This multicenter retrospective cohort study included 70 patients undergoing minimally invasive posterior fixation for thoracolumbar pyogenic spondylitis across nine institutions. Patients were categorized into insertion and skip groups based on PS insertion into infected vertebrae, and surgical data and postoperative outcomes, particularly unplanned reoperations due to complications, were compared.

RESULTS

The mean age of the 70 patients was 72.8 years. The insertion group (n = 36) had shorter operative times (146 versus 195 min, p = 0.032) and a reduced range of fixation (5.4 versus 6.9 vertebrae, p = 0.0009) compared to the skip group (n = 34). Unplanned reoperations occurred in 24% (n = 17) due to surgical site infections (SSI) or implant failure; the incidence was comparable between the groups. Poor infection control necessitating additional anterior surgery was reported in four patients in the skip group.

CONCLUSIONS

PS insertion into infected vertebrae during minimally invasive posterior fixation reduces the operative time and range of fixation without increasing the occurrence of unplanned reoperations due to SSI or implant failure. Judicious PS insertion in patients with minimal bone destruction in thoracolumbar pyogenic spondylitis can minimize surgical invasiveness.

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.

Treatment of Thoracolumbar Pyogenic Spondylitis with Minimally Invasive Posterior Fixation without Anterior Lesion Debridement or Bone Grafting: A Multicenter Case Study

The usefulness of minimally invasive posterior fixation without debridement and autogenous bone grafting remains unknown. This multicenter case series aimed to determine the clinical outcomes and limitations of this method for thoracolumbar pyogenic spondylitis. Patients with thoracolumbar pyogenic spondylitis treated with minimally invasive posterior fixation alone were retrospectively evaluated at nine affiliated hospitals since April 2016. The study included 31 patients (23 men and 8 women; mean age, 73.3 years). The clinical course of the patients and requirement of additional anterior surgery constituted the study outcomes. The postoperative numerical rating scale score for lower back pain was significantly smaller than the preoperative score (5.8 vs. 3.6, p = 0.0055). The preoperative local kyphosis angle was 6.7°, which was corrected to 0.1° after surgery and 3.7° at the final follow-up visit. Owing to failed infection control, three patients (9.6%) required additional anterior debridement and autogenous bone grafting. Thus, in this multicenter case series, a large proportion of patients with thoracolumbar pyogenic spondylitis could be treated with minimally invasive posterior fixation alone, thereby indicating it as a treatment option for pyogenic spondylitis.

Unexpectedly rapid decrease in the size of a spinal epidural abscess after percutaneous posterior pedicle screw fixation without decompression surgery: a case report

INTRODUCTION

Spondylodiscitis accompanying spinal epidural abscess is often treated with decompression surgery when there are neurological symptoms. We report a case of spondylodiscitis accompanying spinal epidural abscess with severe lower extremity pain that was successfully treated with percutaneous posterior pedicle screw fixation without decompression surgery.

CASE PRESENTATION

A 53-year-old man was admitted to our hospital with severe low back pain (LBP), lower extremity pain and numbness, and fever. Lumbar magnetic resonance imaging (MRI) revealed spondylodiscitis at L2-L3 and a small epidural abscess located ventrally in the spinal canal. Initially, the patient was treated conservatively with empirical antibiotics. However, the lower extremity symptoms worsened and the epidural abscess expanded cranially to the T12 level. Percutaneous pedicle screw fixation without decompression was performed thirty-three days after admission. Postoperatively, the LBP and lower extremity pain dramatically improved. A postoperative MRI performed one week post-operatively showed an unexpectedly rapid decrease in the size of the epidural abscess, although no decompression surgery was performed. Two months after surgery, the epidural abscess completely disappeared. At the final follow-up (five years postoperatively), no recurrence of epidural abscess was observed, and the patient had no symptoms or disturbance of activities of daily living.

DISCUSSION

This surgical strategy should be carefully selected for patients with spondylodiscitis with accompanying spinal epidural abscess who have lower extremity symptoms. The stabilising effect of pedicle screw fixation may be advantageous for controlling spinal infections. Percutaneous posterior pedicle screw fixation without decompression is an optional treatment for spondylodiscitis accompanying spinal epidural abscess.

Radiographic Features Associated With Increased Surgical Invasiveness in Pyogenic Vertebral Column Osteomyelitis

STUDY DESIGN

Single center retrospective cohort study.

OBJECTIVES

Assess the association between well-known radiographic features for spinal instability from the Spinal Instability in Neoplasia Score (SINS) and surgical invasiveness in treating vertebral column osteomyelitis (VCO). This will potentially help surgeons in surgical planning and aid in developing a pathology specific score.

METHODS

Patients with VCO were identified from hospital coding. On preoperative computed tomography radiographic features, including spinal alignment, vertebral body collapse, location, type of bone lesion, and posterolateral involvement were assessed and scored 0 (stable) to 15 (highly unstable). Surgical invasiveness was graded as 0 = no surgery, 1 = decompression alone, 2 = shortening or posterior stabilization, or 3 = anterior column reconstruction.

RESULTS

A total of 41 patients were included. The mean age of the cohort was 63.3 years (SD 12.0) with male comprising 78%. The mean total radiographic score for the nonsurgical group was 6.39 (3.14) and for the surgical group 10.38 (3.06), P < .001. Spinal alignment, vertebral body collapse, type of bone lesion, and posterolateral involvement correlated with surgical invasiveness (all Ps < .05). Subgroup comparison following analysis of variance showed that only spinal alignment was significantly different between groups 2 and 3.

CONCLUSIONS

Our findings show correlation of the radiographic components of the SINS with surgical invasiveness in management of pyogenic VCO-these findings should aid development of an "instability score" in pyogenic VCO. While most radiographic features assessed correlated with surgical invasiveness spinal alignment appears to be the key feature in determining the need for more invasive surgery.

Prognosis of spinal infections managed by minimal debridement: A case series in two tertiary centers

Background

Spinal infections can be challenging in their management and include spondylitis, epidural abscess, and spondylodiscitis. Usual treatment is conservative through antimicrobials or surgery to decompress neural tissue, debride all infected tissues, and fix if needed. We propose the concept of surgery without formal debridement aiming at neural protection.

Methods

The study was performed at two tertiary centers on 25 patients with clinical findings. One patient was treated conservatively and the rest surgically by laminectomy and fixation if needed. Evacuation of fluid pus was performed. In the cervical and the thoracic region, if the granulation tissue was anterior to the cord, only decompression by laminectomy was done.

Results

Low back pain was present in 22 cases (88%), 16 cases (64%) had lower limb pain, and 12 cases (48%) had weakness. The level of spinal infection was lumbar in 15 cases (60%), thoracic in 9 cases (36%) cases, and cervical in 1 case (4%). The type of infection was epidural abscess in 20 cases (80%), discitis in 16 cases (64%), and vertebral osteomyelitis in 12 cases (48%). Laminectomy was performed in 20 cases (80%) and fixation in 17 cases (68%). The symptoms improved in all cases. On follow-up, the lesion was reduced in 14 patients (56%) and disappeared in 11 cases (44%). One case required ventriculoperitoneal shunt placement due to postinfectious hydrocephalus.

Conclusion

Dealing with spinal infections surgically through decompression or fixation with minimal debridement of infected tissue appears to be a safe and effective method of management.

Posterior stabilisation without formal debridement for the treatment of non-tuberculous pyogenic spinal infection in frail and debilitated population - A systematic review and meta-analysis

Non-tuberculous pyogenic spinal infection (PSI) incorporates a variety of different clinical conditions. Surgical interventions may be necessary for severe cases where there is evidence of spinal instability or neurological compromise. The primary surgical procedure, for late-stage PSI, focuses on the anterior approach with aggressive debridement of the infected tissue regions. An alternative treatment method that employs a posterior approach without any formal debridement, is seen as controversial. To the best of our knowledge, few case series and no systematic reviews are assessing the value of this posterior technique. We aim to evaluate the effectiveness of the posterior approach without formal debridement and the associated clinical outcomes, for PSI cases requiring surgical intervention. Several databases including MEDLINE, NHS Evidence, and the Cochrane database were searched from the date of creation of each database to December 16, 2019. A selection of the keywords used includes: "posterior approach", "debridement" and "discitis". Studies were excluded if they involved the anterior approach, carried out formal debridement, or were tuberculous spinal infection cases. We accepted any study type which included adult patients, with spinal infection at any level of the vertebral column. The Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines were used to follow standard systematic review structure. The main clinical outcomes evaluated include pain, neurological recovery (Frankel Grading System, FGS) post-operative complications, and functional outcomes (Kirkaldy-Willis Criteria and Spine Tango Combined Outcome Measure Index, COMI). Post-surgical neurological improvement was demonstrated with a mean FGS improvement of 1.12 in 102 patients over the included four articles. Post-operative neurological function was found to be improved at a statistically significant level when a random-effects model was applied, with the effect size found to be at 0.68 (p < 0.001). Pain level was improved significantly postoperatively. There were also enhanced functional outcomes post-intervention when the Kirkaldy-Willis criteria and COMI scores were assessed in certain studies. Within the limit of the available literature, our results showed that the posterior approach with posterior stabilisation without formal debridement can result in successful infection resolution, improved pain scores and neurological outcomes. However, Larger series with longer follow-up duration is strongly recommended.

Anterior Spinal Fusion Using Autologous Bone Grafting via the Lateral Approach with Posterior Short-Range Instrumentation for Lumbar Pyogenic Spondylitis with Vertebral Bone Destruction Enables Early Ambulation and Prevents Spinal Deformity

Introduction

Pyogenic spondylitis of the lumbar spine markedly decreases the ability to perform activities of daily living and causes severe low back pain. The challenge is to improve low back pain and activities of daily living performance earlier and prevent post-infection sequelae, and conservative treatment with antibiotics is the mainstay of treatment.

Methods

In the present study, patients who were unable to walk following lumbar pyogenic spondylitis even in the subacute phase after successful infection control, showing bone defects expanding from endplate to vertebral body in CT, were treated with posterior percutaneous short-range instrumentation and anterior autogenous bone grafting (group S, n = 10) or with conservative treatment alone (group C, n = 10). Acute cases of absolute surgical indication with paralytic symptoms and mild cases who could walk by antibiotics administration were excluded. The two groups were compared regarding the post-treatment change in C-reactive protein level, duration of bed rest, and post-infection local spinal deformities (local scoliosis angle in the coronal plane and local kyphosis angle in the sagittal plane).

Results

Compared with group C, group S took a significantly shorter time for the C-reactive protein level to return to normal and required a significantly shorter duration of bed rest. Furthermore, surgery prevented the formation of kyphosis and scoliosis, while group C developed local kyphosis.

Conclusions

The minimally invasive surgical method of posterior percutaneous short-range instrumentation and anterior autogenous bone grafting effectively enables early control of pain and maintenance of locomotive function and prevents spinal deformity in patients with lumbar pyogenic spondylitis in the subacute phase with advanced vertebral bone destruction.

The increasing frequency of intravenous drug abuse-associated spinal epidural abscesses: a case series

OBJECTIVEFew studies have been published specifically examining intravenous drug abuse (IVDA)-associated spinal epidural abscesses (SEAs), an unfortunate sequela of the opioid crisis in the United States. Here, the authors examined a series of patients with IVDA-associated SEAs in order to shed light on this challenging disease entity.METHODSThis study is a retrospective chart review of patients presenting with IVDA-associated SEAs at the authors' institution from 2013 to 2018, spanning the statewide implementation of opioid-prescribing restrictions.RESULTSA total of 45 patients presented with IVDA-associated SEAs; 46.5% presented with a neurological deficit. Thirty-one patients underwent surgery for neurological deficit, failure of medical therapy, or both. Nineteen surgical patients underwent a fusion procedure along with decompression. The complication rate was 41.9%, and the mortality rate was 6.7%. The average length of stay was 27.6 days. Patients who underwent surgery within 24 hours of onset of neurological symptoms trended toward more improvement in their American Spinal Cord Association Impairment Scale grade than those who did not (0.5 vs -0.2, p = 0.068). Methicillin-resistant Staphylococcus aureus was isolated as the causative pathogen in 57.8% of patients. Twenty-three patients (51.5%) kept their scheduled clinic follow-up appointments. Of the fusion patients with adequate follow-up, 5 showed bony arthrodesis and 3 had pseudarthrosis. The rate of IVDA-associated SEAs increased after opioid-prescribing restrictions were put in place, from 0.54 cases per month to 1.15 cases per month (p = 0.017).CONCLUSIONSPatients with IVDA-associated SEAs are challenging to treat, with high complication rates and poor follow-up. This disease is increasing in frequency, and opioid-prescribing restrictions did not slow that rise. Community outreach to promote prevention, early medical attention, and medication compliance would benefit this largely publicly funded patient population.

Minimally Invasive Surgery Combining Cortical Bone Trajectory Screws and Pedicle Screws to Treat Spondylodiskitis: Technical Notes and Preliminary Results

OBJECTIVE

Various surgical techniques for treating spondylodiskitis have been proposed, but the most appropriate surgical treatment remains controversial. In this study, we propose a new hybrid approach combining the use of cortical bone trajectory screws and pedicle screws with the technique of transforaminal lumbar interbody debridement and fusion. With this method, we can shorten the length of the segment that needs to be fixed, minimize the extent of surgical dissection, and reduce the risk of adjacent level degeneration.

METHODS

Patients with clinical and radiographic evidences of single-level lumbar spondylodiskitis seen between January and December of 2017 were included in the study. Demographic data, including age and sex, were recorded. The intraoperative details, results of culture, functional outcome, radiologic outcome, and length of hospital stay were recorded.

RESULTS

The mean age of 15 patients was 62.8 years. The mean operative time was 135 minutes, and the mean blood loss was 260 mL. The culture rate was 80%. The mean Numeric Rating Scale score and Oswestry Disability Index score significantly improved from 6.60 to 2.47 and from 21.20 to 10.20, respectively. No major perioperative complications occurred.

CONCLUSIONS

With the proposed hybrid approach using cortical bone trajectory and pedicle screws with the transforaminal lumbar interbody debridement and fusion technique, the damaged anterior column can be debrided and reconstructed, and spinal stabilization can also be achieved.

Continuous Epidural Irrigation and Drainage Combined with Posterior Debridement and Posterior Lumbar Inter-Body Fusion for the Management of Single-Segment Lumbar Pyogenic Spondylodiscitis

Purpose: To observe the clinical curative effect of continuous epidural irrigation combined with posterior debridement and posterior lumbar inter-body fusion with instrumentation for the therapy of single-segment lumbar pyogenic spongdylodiscitis. Methods: From June 2010 to November 2013, surgical treatment was performed in 18 patients with pyogenic spondylodiscitis. The surgical indications were progressive biomechanical instability, epidural abscesses, deterioration of neurologic status, and intractable back pain. All these patients received posterior decompression with posterior instrumentation, debridement of infected tissue, and inter-body fusion. Visual Analogue Scale (VAS) scores were used to assess clinical outcomes. The neural function was evaluated by the Frankel grading system. Laboratory and radiologic results were recorded during clinical follow-up for at least one year. Results: The average follow-up period was 18 months after the operation. The VAS scores decreased from an average of 7.1 points before the procedure to 2.6 points after operation. The neurologic deficits of all the patients were recovered to Frankel grade E. All of the examined laboratory parameters were normalized gradually. Imaging-documented fusion was achieved in each patient, and no implants failure was noted. No patients showed any evidence of recurrence or persistence of infection. Conclusion: In carefully selected patients, single-segment lumbar pyogenic spondylodiscitis can be cured successfully with continuous epidural irrigation and drainage combined with posterior debridement and posterior lumbar inter-body fusion. Instrumentation could provide immediate stability and reconstruction of the spine column, and the presence of instrumentation did not result in any persistence or recurrence of infection. Continuous epidural irrigation and drainage is an effective method facilitating the elimination of residual infection.

Management of Pyogenic Spinal Infection, review of literature

Objective

To evaluate the available evidence for the management of Pyogenic Spinal Infection (PSI).

Methods and results

A comprehensive search for the relevant literature published between 1990 and 2018 to evaluate the management of PSI was conducted.Nonoperative management of carefully selected patients for an adequate duration of antibiotics can result in satisfactory outcomes with low recurrence rate. When there is an indication for surgery, posterior approach, with or without debridement of infected tissue reported to be associated with good outcomes.

Conclusion

Studies with larger sample sizes and longer duration of follow up are recommended to formulate more comprehensive evidence.

Medium-term outcome of posterior surgery in the treatment of non-tuberculous bacterial spinal infection

Objective

to evaluate the outcome of posterior spinal stabilization surgery for the management of bacterial spinal infection.

Methods

21 patients with bacterial infection were managed surgically with posterior stabilization. Outcome measures included neurological status. Follow-up data collected using Spine Tango COMI questionnaires and Euro Qol EQ-5D.

Results

The mean improvement in neurological deficits was 0.91 Frankel grade. Residual symptoms of pain had no or minor effect on the work or usual activities in 52% of subjects, with 88% reported having either no or mid problems with mobility.

Conclusion

Posterior surgery can improve neurological outcome in approximately half of the patients.

Spontaneous spondylodiscitis: review, incidence, management, and clinical outcome in 44 patients

OBJECTIVESpontaneous spondylodiscitis remains uncommon but is a serious complication of the vertebral column. Risk factors include diabetes, hemodialysis, intravenous drug abuse, and chronic steroid use, and pain is the most common presenting symptom. This study aims to review the literature and report on the incidence, management, and clinical outcome of spontaneous spondylodiscitis in 44 patients.METHODSThis is a prospective study including 44 patients with spontaneous spondylodiscitis managed in the neurosurgery department of Cairo University Hospitals during the period between January 2012 and October 2017. All patients had a full clinical assessment, laboratory tests, radiological studies in the form of MRI with and without contrast, and a postoperative follow-up of up to 12 months.RESULTSTwelve cases underwent conservative treatment in the form of complete bed rest, intravenous antibiotics, and a spinal brace. Ten cases underwent surgical intervention in the form of laminectomy, debridement, and open biopsy. Twenty-two cases underwent laminectomy and surgical stabilization with fusion. There were 15 cases of tuberculous spondylodiscitis, 6 cases of brucellosis, 6 cases of pyogenic infection, and 17 cases in which no organism could be detected.CONCLUSIONSOnce the primary diagnosis is confirmed, early and adequately prolonged antibiotic therapy is recommended for spontaneous spondylodiscitis. Some cases can be successfully treated with conservative treatment alone, whereas surgery may be needed in other cases such as severe destruction of endplates, spinal abscess formation, mechanical instability, neurological deficits, and severe pain that have failed to respond to conservative treatment.

[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.

Spontaneous Pyogenic Spondylodiscitis in the Thoracic or Lumbar Spine: A Retrospective Cohort Study Comparing the Safety and Efficacy of Minimally Invasive and Open Surgery Over a Nine-Year Period

PURPOSE

Pyogenic spondylodiscitis is a rare disease, but its incidence is increasing. Over the last decade, spinal surgery has been modified to become minimally invasive. In degenerative spinal disorders, such minimally invasive surgery (MIS) reduces blood loss, muscular trauma, and the hospital stay. However, it is not known whether MIS also confers these benefits to patients with pyogenic spondylodiscitis. This retrospective cohort study compared the safety and efficacy of MIS and the conventional open surgical procedure in patients with pyogenic spondylodiscitis.

METHODS

The study cohort consisted of all consecutive patients who underwent surgery for thoracic or lumbar pyogenic spondylodiscitis that was not caused by previous surgery or tuberculosis in our tertiary-care institution between January 2003 and December 2011.

RESULTS

Of the 148 eligible patients, 75 and 73 underwent MIS and open surgery, respectively. The 2 groups did not differ in terms of age, body mass index, American Society of Anaesthesiologists score, comorbidities, septic disease, or preoperative neurologic deficit. The 2 methods were associated with similar postoperative stays in the intensive care unit, overall hospital stays, complication rates, and postoperative survival. However, MIS was associated with a significantly shorter operating time, a lower perioperative need for blood products, and, as expected, an increased intraoperative fluoroscopy duration.

CONCLUSIONS

Our 9-year experience suggests that MIS is safe and effective for spontaneous pyogenic thoracic and lumbar spondylodiscitis.

Posterior Titanium Screw Fixation without Debridement of Infected Tissue for the Treatment of Thoracolumbar Spontaneous Pyogenic Spondylodiscitis

Study Design

Retrospective study.

Purpose

The aim of our study was to analyze the safety and effectiveness of posterior pedicle screw fixation for treatment of pyogenic spondylodiscitis (PSD) without formal debridement of the infected tissue.

Overview of Literature

Posterior titanium screw fixation without formal debridement of the infected tissue and anterior column reconstruction for the treatment of PSD is still controversial.

Methods

From March 2008 to June 2013, 18 patients with PSD underwent posterior titanium fixation with or without decompression, according to their neurological deficit. Postero-lateral fusion with allograft transplantation alone or bone graft with both the allogenic bone and the autologous bone was also performed. The outcome was assessed using the visual analogue scale (VAS) for pain and the Frankel grading system for neurological status. Normalization both of C-reactive protein (CRP) and erythrocyte sedimentation rate was adopted as criterion for discontinuation of antibiotic therapy and infection healing. Segmental instability and fusion were also analyzed.

Results

At the mean follow-up time of 30.16 months (range, 24–53 months), resolution of spinal infection was achieved in all patients. The mean CRP before surgery was 14.32±7.9 mg/dL, and at the final follow-up, the mean CRP decreased to 0.5±0.33 mg/dL (p <0.005). Follow-up computed tomography scan at 12 months after surgery revealed solid fusion in all patients. The VAS before surgery was 9.16±1.29 and at the final follow-up, it improved to 1.38±2.03, which was statistically significant (p <0.05). Eleven patients out of eighteen (61.11%) with initial neurological impairment had an average improvement of 1.27 grades at the final follow-up documented with the Frankel grading system.

Conclusions

Posterior screw fixation with titanium instrumentation was safe and effective in terms of stability and restoration of neurological impairment. Fixation also rapidly reduced back pain.

Neurosurgical approaches to spinal infections

Spinal infection is rare. Clinical suspicion is important in patients with nonmechanical neck and/or back pain to make the proper diagnosis in early disease. Before planning surgery, a thorough evaluation of the spinal stability, alignment, and deformity is necessary. Timing of surgery, side of approach, appropriate surgical technique, and spinal instruments used are crucial. Biomechanical preservation of the spinal column during and after the infection is a significant issue. Postoperative spine infection is another entity of which spinal surgeons should be aware of. Proper septic conditions with meticulous planning of surgery are essential for successful spine surgery and better outcome.

Neurologic Complications, Reoperation, and Clinical Outcomes After Surgery for Vertebral Osteomyelitis

STUDY DESIGN

A consecutive retrospective cohort study from 2008 to 2013 at a single tertiary-care institution was conducted.

OBJECTIVE

The aim of the study was to characterize recovery from pain and neurologic deficit after surgery for vertebral osteomyelitis (VO), and identify incidence of postoperative adverse events.

SUMMARY OF BACKGROUND DATA

A minority of patients with VO require surgery. Although prior studies have characterized outcomes after medical management, the morbidity after surgery is poorly defined.

METHODS

The primary outcome was change from baseline in a Modified McCormick Scale (MMS, 1-5 scale), whereas secondary outcomes included reoperation and change in self-reported pain Visual Analog Scale (VAS, 0-10 scale). MMS and VAS were collected throughout the postoperative course as surrogates for neurologic function and degree of pain. Intraoperative, short-term postoperative (<30 d), and long-term neurologic complications were recorded. New-onset neurologic deficits in the postoperative period were considered neurologic complications.

RESULTS

Fifty patients were included; a majority (52%) presented with a neurologic deficit. The median length of follow-up was 18 months. A statistically significant improvement in MMS was observed by 12 months postoperatively, whereas an improvement in VAS was observed by 3 months. The mean improvement in MMS at last follow-up was 0.35, whereas the mean improvement in VAS was 3.40. One quarter of patients required reoperation. At 24 months postoperatively, 10% died, 26% underwent reoperation, 42% experienced a neurologic complication, and 60% experienced at least one of these 3 adverse events.

CONCLUSION

This is the first study to investigate neurologic complications, reoperation, and pain in a longitudinal manner after surgery for VO. We observed statistically significant improvements in MMS and VAS in the postoperative period. Despite these improvements, the 24-month incidence of overall adverse events was 60%. Patients and clinicians should be aware of the clinical improvement but high incidence of adverse events after surgical management of VO.

LEVEL OF EVIDENCE

4.

Short Segment Spinal Instrumentation With Index Vertebra Pedicle Screw Placement for Pathologies Involving the Anterior and Middle Vertebral Column Is as Effective as Long Segment Stabilization With Cage Reconstruction: A Biomechanical Study

STUDY DESIGN

An in vitro, cadaveric biomechanical study.

OBJECTIVE

The aim of the present study was to compare single-segment posterior instrumentation and fracture-level screws with single/multilevel posterior fixation and corpectomy in a simulated, unstable burst fracture model.

SUMMARY OF BACKGROUND DATA

The optimal extent of instrumentation for surgical cases of non-neoplastic vertebral body pathologies remains uncertain. Although several clinical studies demonstrate advantages of short segment instrumentation with index-level screws over more extensive corpectomy and anterior-posterior techniques, a comprehensive biomechanical comparison of these techniques is currently lacking.

METHODS

Six bovine spines (T11-L5) were tested in flexion, extension, lateral bending (LB), and axial rotation (AR) following simulated burst fracture at L2. Posterior instrumentation included 1 level above/below (1LF) and 2 levels above/below fracture level (2LF), intermediate or index screws at fracture level (FF), and cross-connectors above/below fracture level (CC). Anterior corpectomy devices included expandable corpectomy spacers with/without integrated screws, ACDi and ACD, respectively FORTIFY-Integrated/FORTIFY; Globus Medical, Inc., PA. Constructs were tested in the following order: (1) Intact; (2) 1LF; (3) 1LF and CC; (4) 1LF and FF; (5) 1LF, CC, and FF; (6) 2LF; (7) 2LF and CC; (8) 2LF and FF; (9) 2LF, CC, and FF; (10) 2LF and ACD; (11) 2LF, ACD, and CC; (12) 1LF and ACDi; (13) 1LF, ACDi, and CC.

RESULTS

During flexion, all constructs except 1LF reduced motion relative to intact (P ≤ 0.05). Anterior support was most stable, but no differences were found between constructs (P ≥ 0.05). Every construct reduced motion in extension, though no differences were found between constructs and intact (P ≥ 0.05). During LB, all constructs reduced motion relative to intact (P ≤ 0.05); 2LF constructs further reduced motion (P ≤ 0.05). No construct returned AR motion to intact, with significant increases in 1LF and ACDi, 2LF and ACD, and 2LF, ACD, and CC (P ≤ 0.05). Cross-connectors and fracture screws reinforced each other in posterior-only constructs, providing maximum stability (P ≥ 0.05).

CONCLUSIONS

This biomechanical comparison study found no significant superiority of combined anterior-posterior constructs over short segment fracture screw fixation, only multilevel posterior instrumentation with and without anterior support, providing increased stability in LB. Biomechanical equivalency suggests that short segment fracture screw intervention may provide appropriate stabilization for non-neoplastic pathologies involving the anterior and middle vertebral columns.

LEVEL OF EVIDENCE

2.

Rigid Posterior Lumbopelvic Fixation without Formal Debridement for Pyogenic Vertebral Diskitis and Osteomyelitis Involving the Lumbosacral Junction: Technical Report

Background

Pelvic fixation with S2-alar-iliac (S2AI) screws can increase the rigidity of a lumbosacral construct, which may promote bone healing, improve antibiotic delivery to infected tissues, and avoid L5–S1 pseudarthrosis.

Purpose

To describe the use of single-stage posterior fixation without debridement for the treatment of pyogenic vertebral diskitis and osteomyelitis (PVDO) at the lumbosacral junction.

Study design

Technical report.

Methods

We describe the management of PVDO at the lumbosacral junction in which the infection invaded the endplates, disk space, vertebrae, prevertebral soft tissues, and epidural space. Pedicle involvement precluded screw fixation at L5. Surgical management consisted of a single-stage posterior operation with rigid lumbopelvic fixation augmented with S2-alar-iliac screws and without formal debridement of the infected area, followed by long-term antibiotic treatment.

Results

At 2-year follow-up, successful fusion and eradication of the infection were achieved.

Conclusion

PVDO at the lumbosacral junction may be treated successfully using rigid posterior-only fixation without formal debridement combined with antibiotic therapy.

Acute neck pain caused by septic arthritis of the lateral atlantoaxial joint with subluxation: a case report

Introduction

Crystal-induced arthritis of the lateral atlantoaxial joint may be intimately involved in acute neck pain in the elderly. Patients typically have a good prognosis, and symptoms usually subside within a few weeks. On the other hand, septic arthritis of the lateral atlantoaxial joint requires early diagnosis and antibiotic treatment. Diagnostic delay is a risk factor for an unfavorable outcome of vertebral osteomyelitis. Even though septic arthritis of the lateral atlantoaxial joint is a very rare clinical entity, it is important to differentiate septic arthritis from crystal-induced arthritis.

Case presentation

A 53-year-old Japanese man presented with neck pain, stiffness, and loss of power of his left upper extremity which started 20 days before his visit to our hospital. A physical examination revealed a limited range of motion of his neck, with rotation being especially very restricted. Atlantoaxial subluxation was seen on plain radiography of his cervical spine. During puncture of the lateral atlantoaxial joint, clear yellow fluid was collected. Cultures later grew methicillin-sensitive Staphylococcus aureus. He was diagnosed with septic arthritis of the lateral atlantoaxial joint with atlantoaxial subluxation. After diagnosis, intravenous administration of antibiotics was begun. The atlantoaxial region was stabilized with the Brooks procedure. Plain radiography showed complete bone union 8 months after operation. At a follow-up evaluation 7 years after initial onset, he had complete relief of neck pain, and there were no neurological abnormalities.

Conclusions

A patient with septic arthritis of the lateral atlantoaxial joint with subluxation presenting with acute neck pain was successfully treated with antibiotics and fusion surgery. In patients with persistent neck pain, septic arthritis of the lateral atlantoaxial joint should be considered and further examinations performed.

Vertebral osteomyelitis and epidural abscess caused by gas gangrene presenting with complete paraplegia: a case report

Introduction

Gas gangrene is most often caused by Clostridium perfringens infection. Gas gangrene is a medical emergency that develops suddenly. The mortality rate is higher with trunk involvement than with involvement of the extremities, which carries a better prognosis. With respect to vertebral involvement, there are few reports in the literature. The purpose of this paper is to report a very rare case of vertebral osteomyelitis caused by gas gangrene.

Case presentation

A 78-year-old Japanese woman with diabetes mellitus was admitted to our hospital with the chief complaints of back pain, dysuria, and complete paralysis of both legs. A computed tomography scan showed soft tissue swelling anterolaterally at intervertebral disc level T11/12 and a gas-containing epidural abscess that compressed her spinal cord. Cultures later grew Clostridium perfringens and Escherichia coli. Hemilaminectomy was done from T10 to T12, and an epidural abscess was removed. She went on to have fusion surgery 6 weeks after the initial operation and subsequently experienced complete pain relief. She was discharged 2 months later, at which time she was able to walk with a cane. Examination 18 months after surgery showed normal gait without a cane.

Conclusions

Discitis caused by gas gangrene infection was successfully treated by immediate debridement and subsequent fusion surgery.

A clinical perspective on musculoskeletal infection treatment strategies and challenges

Orthopaedic implants improve the quality of life of patients, but the risk of postoperative surgical site infection poses formidable challenges for clinicians. Future directions need to focus on prevention and treatment of infections associated with common arthroplasty procedures, such as the hip, knee, and shoulder, and nonarthroplasty procedures, including trauma, foot and ankle, and spine. Novel prevention methods, such as nanotechnology and the introduction of antibiotic-coated implants, may aid in the prevention and early treatment of periprosthetic joint infections with goals of improved eradication rates and maintaining patient mobility and satisfaction.

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.