Infection of intervertebral discs after operation

Is it a requirement or a preference to use cross-links in lumbar instrumentation?

Background/Aim: The use of cross-links (CL) is controversial due to reasons such as cost increases and instrument redundancy. While there are many biomechanical studies, the clinical data is limited. The aim of this study is to present the clinical effects of CL by putting forward postoperative clinical outcomes and long-term results of patients with (CL+) and without (CL-) CL augmentation. Methods: In this retrospective cohort study, patients who underwent lumbar posterior instrumentation with CL+ (n = 164) and without CL- (n = 111) augmentation were evaluated. Demographic data, surgical results, preoperative and postoperative visual analogue scale (VAS), the Oswestry Disability Index (ODI) differences, and pseudoarthrosis and adjacent segment disease (ASD)-related recurrence for more than three years of follow-up were determined. Data of CL+ and CL- groups were compared. Results: CL+ and CL- groups were similar in terms of age and gender (P = 0.319 and P = 0.777, respectively) There was no difference between the two groups in terms of bleeding amount, duration of surgery, and duration of hospitalization (P = 0.931, P = 0.669 and P = 0.518, respectively). Groups were similar in terms of VAS and ODI differences (P = 0.915 and P = 0.983, respectively), yet there was one case of infection in the CL+ group and two cases of infection detected in the CL- group. There were 13 ASDs in the CL+ group, and eight ASDs in the CL- group. Pseudoarthrosis was seen seven times in the CL+ group, while it was four in the CL- group. Conclusion: It was observed that adding CL in patients who underwent lumbar instrumentation did not change the early period surgical results. The prevalence of complications was compatible with the scientific literature. In our study, there was no preventive advantage in terms of clinical or postoperative complications found in the use of CL.

Minimally invasive debridement and drainage using intraoperative CT-Guide in multilevel spondylodiscitis: a long-term follow-up study

Background

Spondylodiscitis is an unusual infectious disease, which usually originates as a pathogenic infection of intervertebral discs and then spreads to neighboring vertebral bodies. The objective of this study is to evaluate percutaneous debridement and drainage using intraoperative CT-Guide in multilevel spondylodiscitis.

Methods

From January 2002 to May 2017, 23 patients with multilevel spondylodiscitis were treated with minimally invasive debridement and drainage procedures in our department. The clinical manifestations, evolution, and minimally invasive debridement and drainage treatment of this refractory vertebral infection were investigated.

Results

Of the enrolled patients, the operation time ranged from 30 minutes to 124 minutes every level with an average of 48 minutes. Intraoperative hemorrhage was minimal. The postoperative follow-up period ranged from 12 months to 6.5 years with an average of 3.7 years. There was no reactivation of infection in the treated vertebral segment during follow-up, but two patients with fungal spinal infection continued to progress by affecting adjacent segments prior to final resolution. According to the classification system of Macnab, one patient had a good outcome at the final follow-up, and the rest were excellent.

Conclusions

Minimally invasive percutaneous debridement and irrigation using intraoperative CT-Guide is an effective minimally invasive method for the treatment of multilevel spondylodiscitis.

Value of procalcitonin as a marker of surgical site infection following spinal surgery

AIM

To compare the value of Procalcitonin (PCT) as a marker of surgical site infection to other inflammatory markers, including C-Reactive Protein (CRP), White Cell Count (WCC) and Erythrocyte Sedimentation Rate (ESR) in patients undergoing a number of spinal procedures. This study also aims to describe the biokinetic profile of the above-named markers in patients developing surgical site infection and those remaining infection-free post-operatively.

METHODS

200 patients undergoing four routine elective spinal procedures were included for analysis. All patients had blood specimens taken at baseline, day 1, 2, 3, 4 and 5 post-operatively for analysis of PCT, CRP, ESR and WCC levels. All patients were monitored for early surgical site infection. Patients with other sources of infection in the early postoperative period were excluded.

RESULTS

Procalcitonin was the most sensitive and specific marker for the detection of surgical site infection in the immediate post-operative period with sensitivity and specificity of 100% and 95.2% respectively. Although Procalcitonin is an inflammatory marker, extent of surgical physiological insult did not alter its biokinetics as opposed to the other inflammatory markers making it a valuable marker of infection.

CONCLUSION

Procalcitonin was found to be superior to the other inflammatory markers investigated in this study as a marker for early surgical site infection in patients undergoing spinal surgery.

Management of Postoperative Discitis: A Review of 31 Patients

BACKGROUND

The aim of the study was to retrospectively evaluate the outcome of medical management of postoperative discitis (POD).

MATERIALS AND METHODS

A total of 31 patients treated for POD were included in the study. Clinical, radiological, and laboratory data of all patients were collected and evaluated. All patients were treated initially with bed rest and antibiotic therapy after radiological diagnosis. Surgical management was undertaken after failure of 4 weeks of conservative management. All cases were followed clinically with laboratory and radiological investigations.

RESULTS

Five cases failed to respond to medical management and were treated surgically with debridement and transpedicular fixation. All patients showed clinical recovery till the last follow-up.

CONCLUSION

Early diagnosis and proper management are the keys to successful outcome of postoperative spndylodiscitis. Surgical debridement and fusion are required when conservative treatment fails.

Postoperative initial single fungal discitis progressively spreading to adjacent multiple segments after lumbar discectomy

OBJECTIVE

To report multiple cases and investigate etiology of initially single fungal spondylodiscitis that progressively spread to adjacent segments following lumbar discectomy, resulting in multiple spinal involvements.

METHODS

From January 2005 to May 2013, ten adult patients were admitted or referred to our institution with postoperative discitis. Fungal infections were confirmed by microbiologic and pathologic examinations. The clinical appearance, radiographic features, and treatments of this pathology were investigated.

RESULTS

All the patients were previously healthy. The average interval between the occurrence of symptoms and primary lumbar discectomy was 61 days (range, 15-120 days). All the patients were treated with anterior surgical debridement, interbody fusion, and prolonged antifungal therapy. Three patients additionally received combined posterior instrumented fusion. Despite aggressive surgical debridement and antifungal therapy, spread of the infections to adjacent multiple discs was observed. No deaths, severe neurologic deficits, or deterioration of neurologic status were noted. The infections were completely resolved in all cases with spontaneous fusion within an average follow-up of 32.4 months.

CONCLUSION

Fungal spondylodiscitis after surgery represents an intractable and troublesome complication, and surgical debridement may not impede the progression of the infection in cases where an insufficient course of antifungal treatment is administered. Such cases may require prolonged antifungal treatment with regular consultation by an infectious disease specialist.

Single-level lumbar pyogenic spondylodiscitis treated with minimally invasive anterior debridement and fusion combined with posterior fixation via Wiltse approach

The effect and safety of anterior debridement and fusion with a minimally invasive approach combined with posterior fixation via the Wiltse approach were assessed in the single-level lumbar pyogenic spondylodiscitis. Seventeen patients from 2007 to 2009 underwent anterior debridement and fusion with a minimally invasive approach combined with posterior fixation via the Wiltse approach. Postoperative follow-up time was 24-41 months. Data included the patients' general information, microbiology, operative time, intraoperative blood loss, postoperative complications, intervertebral fusion rate, and preoperative and final follow-up scores for American Spinal Injury Association (ASIA) impairment, visual analogue scale (VAS), and Oswestry Disability Index (ODI). Ten patients had undergone a prior spinal invasive procedure, and 7 had hematogenous infection. The infected segments included L1-2, L2-3, L3-4, and L4-5 in 1, 2, 5, and 9 cases, respectively. Thirteen bacterial cultures were positive for Staphylococcus aureus (5 cases), Staphylococcus epidermidis (4), Streptococcus (3), and Escherichia coli (1). The operative time was 213.8±45.6 min, and the intraoperative blood loss was 180.6±88.1 mL. Postoperative complications consisted of urinary retention (2 cases), constipation (3), and deep vein thrombosis (2). On the final follow-up, VAS scores and ODIs were significantly lower than those of preoperation, while the ASIA grades improved. All the cases achieved good intervertebral bony fusion. Anterior debridement and fusion with a minimally invasive approach combined with posterior fixation via the Wiltse approach can successfully treat single-level lumbar pyogenic spondylodiscitis, with less trauma and reliable immobilization. It is a viable option for clinical application.

The seasonality of postoperative infection in spine surgery

OBJECT

Studies from many disciplines have found an association with the summer months, elevated temperature, humidity, and an increased rate of infection. The "July effect," a hypothesis that the inexperience of new house staff at the beginning of an academic year leads to an increase in wound complications, has also been considered. Finally, an increase in trauma-related admissions in the summer months is likely to result in an increased incidence of postoperative infections. Two previous studies revealed mixed results concerning perioperative spinal wound infections in the summer months. The purpose of this study was to determine the months and/or seasons of the year that display significant fluctuation of postoperative infection rate in spine surgery. Based on the idea that infection rates are susceptible to seasonal factors, the authors hypothesized that spinal infections would increase during the summer months.

METHODS

Inclusion criteria were all spine surgery cases at a single tertiary referral institution between January 2005 and December 2009; 8122 cases were included. Patients presenting with a contaminated wound or active infection were excluded. Infection rates were calculated on a monthly and seasonal basis and compared.

RESULTS

A statistically significant increase in the infection rate was present on both a seasonal and monthly basis (p = 0.03 and p = 0.024) when looking at the seasonal change from spring to summer. A significant decrease in the infection rate was seen on a seasonal basis during the change from fall to winter (p = 0.04). The seasonal rate of infection was highest in the summer (4.1%) and decreased to the lowest point in the spring (2.8%) (p = 0.03).

CONCLUSIONS

At the authors' institution, spine surgeries performed during the summer and fall months were associated with a significantly higher incidence of wound infection compared with the winter and spring. These data support the existence of a seasonal effect on perioperative spinal infection rates, which may be explained by seasonal variation in weather patterns and house staff experience, among other factors.

Is surgical case order associated with increased infection rate after spine surgery?

STUDY DESIGN

Retrospective database review.

OBJECTIVE

To determine whether surgical site infections are associated with case order in spinal surgery.

SUMMARY OF BACKGROUND DATA

Postoperative wound infection is the most common complication after spinal surgery, with incidence varying from 0.5% to 20%. The addition of instrumentation, use of preoperative prophylactic antibiotics, length of procedure, and intraoperative blood loss have all been found to influence infection rate. No previous study has attempted to correlate case order with infection risk after surgery.

METHODS

A total of 6666 spine surgery cases occurring between January 2005 and December 2009 were studied. Subjects were classified into 2 categories: fusion and decompression. Case order was determined, with each procedure labeled 1 to 5 depending on the number of previous cases in the room. Variables such as the American Society of Anesthesiologists score, number of operative levels, wound class, age, sex, and length of surgery were also tracked. A step-down binary regression was used to analyze each variable as a potential risk factor for infection.

RESULTS

Decompression cases had a 2.4% incidence of infection. Longer surgical time and higher case order were found to be significant risk factors for lumbar decompressions. Fusion cases had a 3.5% incidence of infection. Posterior approach and revision cases were significant risk factors for infection in cervical cases. For lumbar fusion cases, longer surgical time, higher American Society of Anesthesiologists score, and older age were all significant risk factors for infection.

CONCLUSION

Decompressive procedures performed later in the day carry a higher risk for postoperative infection. No similar trend was shown for fusion procedures. Our results identify potential modifiable risk factors contributing to infection rates in spinal procedures. Specific risk factors, although not defined in this study, might be related to contamination of the operating room, cross-contamination between health care providers during the course of the day, use of flash sterilization, and mid-day shift changes.

Postoperative spondilodiscitis

INTRODUCTION

Postoperative spondylodiscitis is a primary infection of the nucleus pulposus with secondary involvement of the cartilaginous endplate and vertebral bone. Although uncommon, postoperative spondylodiscitis causes major morbidity and may be associated with serious long-term sequelae. Several risk factors had been identified, including immunosuppression, obesity, alcohol, smoking, diabetes and malnutrition.

MATERIALS AND METHODS

A review of the literature was done to analyse the diagnosis, treatment and prevention of postoperative spondylodiscitis.

RESULTS

We found that the principles of conservative treatment are to establish an accurate microbiological diagnosis, treat with appropriate antibiotics, immobilise the spine, and closely monitor for spinal instability and neurological deterioration. The purpose of surgical treatment is to obtain multiple cultures of bone and soft tissue, perform a thorough debridement of infected tissue, decompress neural structures, and reconstruct the unstable spinal column with bone graft with or without concomitant instrumentation.

CONCLUSIONS

Appropriate management requires aggressive medical treatment and, at times, surgical intervention. If recognised early and treated appropriately, a full recovery can often be expected. Therefore, clinicians should be aware of the clinical presentation of such infections to improve patient outcome. A review of the literature was done to advance our understanding of the diagnosis, treatment, prevention and outcome of these infections.

Postoperative disc space infection after discectomy: a report on thirty-five patients

PURPOSE

The focus of this study was to analyse the patient with disc space infection and the need for re-exploration.

METHOD

Thirty-five patients were analysed within the period from April 1992 and May 2011. The diagnosis was confirmed by the cardinal clinical features, raised erythrocyte sedimentation rate [ESR], raised C-reactive protein and MRI findings. All received 500-mg intravenous amikacin and one gram ceftriaxone at the time of anaesthetic induction and six hours after surgery.

RESULTS

Age range was between 25-62 years. The appearance of symptoms was between four days and three weeks. Nine patients had silent chronic urinary tract infection. Twenty-nine patients had re-exploration while the others did well on conservative treatment. Neurological deficit was not recorded. All recovered well within six to nine months.

CONCLUSION

Re-exploration is recommended if no response is achieved after four day's conservative treatment for or if the patient's condition is critical.

Bacterial wound contamination during simple and complex spinal procedures. A prospective clinical study

BACKGROUND CONTEXT

Spinal procedures have a potential of intraoperative contamination. C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) have been used to diagnose postoperative infections after spinal surgery. However, it has not been demonstrated if there is an association between surgical site contamination and clinical manifestation of postoperative infection based on inflammatory markers and patients' clinical course.

PURPOSE

The purpose of this prospective study was to evaluate the association between surgical site contamination and the development of a postoperative infection in simple and complex surgical procedures. C-reactive protein and ESR levels were observed. The correlation between their values, surgical time, type of surgical procedures, and contaminated surgical sites was investigated.

STUDY DESIGN

Prospective clinical study.

PATIENT SAMPLE

The study consisted of 40 patients divided into two groups. Group A included 20 patients (mean age, 46.2 years; 12 women and 8 men) who underwent an open discectomy for a lumbar herniated disc. Group B consisted of 20 patients (mean age, 67.9 years; 11 women and 9 men) who underwent a decompression and instrumented fusion for lumbar spinal stenosis. They were followed up for an average of 26.7 months (range, 11-40 months).

OUTCOME MEASURES

Samples were obtained for cultures in standard time intervals during surgery. The types of bacteria cultured were evaluated, and CRP and ESR levels were measured.

METHODS

Simple lumbar discectomy (Group A, 20 patients) and instrumented lumbar decompression for degenerative lumbar stenosis (Group B, 20 patients) were performed in a prospective consecutive series of patients. All patients were operated by the same surgeon in the same operating room. Surgical site preparation in each patient was done by a standard manner. Samples were obtained for cultures in standard time intervals during surgery. C-reactive protein and ESR levels were measured preoperatively on the 3rd, 7th, and 21st postoperative days, and the clinical course of each patient was recorded.

RESULTS

From 40 patients, three patients in Group A and five patients in Group B, a total of eight patients (20%) had positive cultures for bacteria. There was no statistical significance between contamination and duration of surgery in both groups. None of the patients with positive intraoperative cultures developed any clinical signs of superficial or deep postoperative spinal infection, and no additional antibiotic treatment was administered. Three patients with negative cultures developed a postoperative infection. There were no differences in CRP and ESR values between patients with contamination and noncontamination in both groups. C-reactive protein and ESR levels were significantly elevated in complex procedures (Group B) than in simple procedures (Group A). Statistical analysis of CRP and ESR values in both groups and types of bacteria cultured intraoperatively are presented.

CONCLUSIONS

The results of this study demonstrate that intraoperative contamination can occur during simple and complex spinal procedures. In the absence of postoperative signs of infection in patients with intraoperative contamination, there is no need of continuing antibiotic treatment. Postoperative kinetics of CRP and ESR showed to be the same in patients with and without intraoperative contamination. Higher levels of inflammatory markers were noted in complex spinal procedures where instrumentation was applied.

Postoperative antimicrobial prophylaxis following spinal decompression surgery: is it necessary?

BACKGROUND

Antimicrobial prophylaxis (AMP) can reduce the risk of surgical-site infection (SSI) following many types of surgery, particularly spinal surgery. After publication of the Guideline for Prevention of Surgical Site Infection by the Centers for Disease Control and Prevention in 1999, a large number of studies confirmed the effectiveness of AMP. However, because the concept of AMP is not clear in Japan, the duration of postoperative AMP tends to be long. The purpose of this study was to compare the infection rates following spinal surgery for postoperative AMP versus no postoperative AMP.

METHODS

The study comprised 284 patients who underwent spinal surgery without instrumentation at our hospital from October 2003 to August 2009. The patients were divided into two groups based on the method of AMP administration: a postoperative dose group and a no postoperative dose group. SSI incidences were calculated for the two groups.

RESULTS

The incidence of SSI was 2.1% (6/284) overall and 2. 8% (4/141) vs. 1.4% (2/143) for the postoperative dose and no postoperative dose groups, respectively. The infection rate difference between the two groups was not significant. The incidence of SSI showed a downward trend as the frequency of antibiotics decreased. Two cases of pseudomembranous colitis, both in the postoperative dose group, were the only complications of the antibiotics.

CONCLUSIONS

AMP duration was not related to the SSI rate. SSIs trended lower in the no postoperative dose group compared with the postoperative dose group. Postoperative administration of AMP appears to be unnecessary for spinal decompression surgery without instrumentation.

Postoperative lumbar discitis

We analysed 13 cases of lumbar disc infection following surgical discectomy. Two groups of patients were identified. The six patients in group A reported that the initial symptoms of discitis had appeared a mean of 15 days after surgery; on average, antibiotic treatment was started 31 days following operation and continued for 62 days, and symptoms regressed after 3.9 months. Four patients showed moderate changes, while two had extensive osteolytic lesions of one or both vertebral bodies adjacent to the involved disc. In the 7 cases in group B, discitis was suspected a mean of 5 days and antibiotics were initiated a mean of 8 days following surgery; on average, symptoms regressed 1.8 months after operation. Only four patients showed vertebral radiographic changes and none had marked destructive lesions. In both groups erythrocyte sedimentation rate exceeded 70 mm/h in cases in which discitis was suspected. Tomograms and magnetic resonance studies were the most diagnostic imaging studies in the initial stages of the disease. All patients obtained satisfactory clinical results at the last follow-up. Careful observation of the early postoperative clinical course usually allows detection of disc space infection. Early and adequately prolonged antibiotic treatment may shorten the course of the disease and avoid extensive osteolytic vertebral lesions.

Fungal postoperative spondylodiscitis due to Scedosporium prolificans

BACKGROUND CONTEXT

Postoperative fungal spondylodiscitis is a rare infectious disease.

PURPOSE

We report the first case of postoperative spondylodiscitis because of Scedosporium prolificans and review postoperative vertebral infection caused by fungi.

STUDY DESIGN/SETTING

Medline search.

METHODS

Case report and literature review.

RESULTS

On reviewing the cases of postoperative fungal spondylodiscitis reported so far in the literature, we found eight were caused by mold, and five by yeast. Clinically, the disease presents similar to postoperative vertebral osteomyelitis caused by bacteria, and a high clinical index of suspicion may be required to perform appropriate cultures to establish a diagnosis. Our review revealed a significant number of cases that were cured after surgical debridement and/or antifungal therapy.

CONCLUSIONS

On the basis of this limited assessment, it appears that the clinical course and prognosis of postoperative fungal spondylodiscitis is similar to that reported for postoperative pyogenic spondylodiscitis.

Antimicrobial prophylaxis for spinal surgery

BACKGROUND

The concept of antimicrobial prophylaxis (AMP) did not exist in Japan until recently. Therefore, postoperative administration of antimicrobial drugs has long been practiced under the pretext of prophylaxis against surgical site infection (SSI). In recent years, however, the concept of AMP and prophylactic countermeasures against SSI, based on evidence of the effectiveness of AMP, has gradually spread in Japan. From 2000 onward, we have undertaken prophylactic countermeasures against SSI in patients undergoing spinal surgery referring to the Guideline for Prevention of Surgical Site Infection published by the Centers for Disease Control and Prevention in 1999. The purpose of this study was to investigate the type of AMP that would be appropriate for spinal surgery and the manner in which it should be used.

METHODS

The subjects were 1415 patients who underwent spinal surgery at our department from January 1990 to March 2008. The patients were classified into four groups according to the method of AMP administration: group 1, AMP was employed for 7 days, only postoperatively; group 2, initial AMP dosing was administered at the time of anesthesia induction, followed by administration of AMP for 5 days, including the day of the operation; group 3, initial AMP dosing was administered at the time of anesthesia induction, and AMP was administered for 3 days, including the day of the operation; group 4, the initial dosing was administered at the time of anesthesia induction, and AMP was administered for 2 days, including the day of the operation. The frequency of SSI was assessed in the four groups.

RESULTS

The frequencies of SSI in groups 1-4 were 2.6% (14/539), 0.9% (5/536), 0% (0/257), and 0% (0/83), respectively. Thus, the frequency of SSI decreased as the duration of the AMP administration period decreased.

CONCLUSIONS

As a result of thorough implementation of preventive measures against perioperative occurrence of infections, which included additional preoperative and intraoperative administration of AMP, the incidence of SSI could be decreased despite shortening the duration of AMP administration to 2 days.

Long-term intravenous administration of antibiotics for lumbar spinal surgery prolongs the duration of hospital stay and time to normalize body temperature after surgery

STUDY DESIGN

Comparative study of differing durations of antibiotics for spinal surgery.

OBJECTIVE

To compare rate of infection, duration of hospital stay, days until normal body temperature, and a panel of blood tests after surgery between long-term and short-term administration of antibiotics for spinal surgery using instrumentation.

SUMMARY OF BACKGROUND DATA

Recent studies have reported that long-term administration of intravenous antibiotics is not necessary to avoid superficial and deep infections. We therefore changed the duration of administration from 9 to 2 days in our lumbar surgery patients.

METHODS

We examined 135 patients (average age, 64.9 years) who underwent lumbar spinal surgery to insert a pedicle screw system to treat spinal canal stenosis. We administered 2 g of cefotiam daily to 60 patients for 9 days after surgery and to 75 patients for 2 days after surgery. Surgical time, loss of blood, rate of infection, duration of hospital stay, days until normal body temperature, and data from blood analysis (white blood cell count, and C-reactive protein [CRP] level) were statistically compared between the 2 groups.

RESULTS

No significant differences in intraoperative measures of surgical invasion were observed between the 2 groups (surgical time, 209 vs. 220 minutes; blood loss, 530 vs. 576 mL; blood transfusion, 344 vs. 380 mL for the long-term and short-term groups, respectively). No acute infections occurred in either group. However, the duration of hospital stay (20.7 days), time until normal body temperature (5.1 days), and CRP level (2.23 mg/dL) at day 7 after surgery were significantly less in the short-term group than those in the long-term group (27.9 days, 6.8 days, and 3.13 mg/dL, respectively; P < 0.05).

DISCUSSION

These results indicate that short-term intravenous administration of antibiotics did not elevate the infection rate after spinal surgery using instrumentation. However, long-term administration of antibiotics prolonged the duration of hospital stay, inhibited normalization of body temperature, and elevated CRP levels. Long-term administration of antibiotics may suppress normal, beneficial bacteria, thereby having an adverse effect on patient recovery.

Is aggressive surgery necessary for acute postoperative deep spinal wound infection?

STUDY DESIGN

A retrospective study of the clinical results of conservative treatment of patients with acute postoperative deep spinal infection.

OBJECTIVE

To determine the efficacy of antibiotic only treatment of postoperative deep spinal infection.

SUMMARY OF BACKGROUND DATA

Traditionally, aggressive surgical treatment combined with antibiotics has been viewed as the gold standard for treating postoperative deep spinal infection. There are, however, disadvantages to surgical treatment including higher treatment cost, multiple anesthesia and surgeries, and the risk of perioperative morbidity and mortality particularly in immunocompromised patients. Although many new antibiotics and new methods of antibiotic treatment have recently become available, the role of conservative treatment using antibiotics alone to treat postoperative acute infection has not yet been determined.

METHODS

Ten consecutive patients with acute postoperative spinal infection were treated using antibiotics alone. The mean onset of the symptoms of infection after surgery was 15.4 days (range, 5-18 days). Seven patients had purulent wound drainage; 3 had healed wounds without discharge. Bacterial culture of the discharge showed methicillin-resistant Staphylococcus aureus (1 patient), methicillin-resistant coagulase negative Staphylococcus (4 patients), methicillin-sensitive coagulase negative Staphylococcus (1 patient). One patient had a negative culture. Patients with wound drainage were treated with intravenous vancomycin or teicoplamin for 4 to 6 weeks followed by oral antibiotics (quinolone with/without rifampin) for 1 to 3 months. All other patients were treated with oral antibiotics for 3 months.

RESULTS

One patient could not complete treatment because of allergy to antibiotics. Infection was controlled in the remaining patients without surgical intervention and did not reoccur. All wound drainage ceased within 2 weeks. The C-reactive protein level of most patients returned to normal range within 10 weeks.

CONCLUSION

Antibiotic treatment alone may be effective in the treatment of acute postoperative spinal infection when diagnosis is prompt. Aggressive surgery may be not necessary and may be reserved for patients who fail conservative treatment.

Bacterial shedding in common spine surgical procedures: headlamp/loupes and the operative microscope

STUDY DESIGN

Simulated discectomy was performed using 1) headlamp/loupes, 2) the operative microscope, or 3) neither; and bacterial shedding was assessed using air sampler/settle plate techniques.

OBJECTIVES

To determine the potential contribution of these 2 commonly used systems of magnification/illumination to postoperative infection by using a controlled, experimental setting to limit confounding factors.

SUMMARY OF BACKGROUND DATA

Postoperative infections following surgery on the degenerative lumbar spine generally range from 0.6% to 6%. Headlamp/loupes and the operative microscope may contribute to potential infection, but, to date, the contribution to shedding rates while using these tools has not been assessed.

METHODS

Seventy samples from simulated discectomies within the usual sterile operative setting were collected using a 2-stage air sampler/settle plate technique. Group 1 (30 samples) used the operative microscope, Group 2 (30 samples) used headlamp/loupes, and Group 3 (10 samples) used neither as a control. Collected samples were examined for bacterial growth using blood agar plates and were assessed qualitatively and quantitatively.

RESULTS

Greater than half of the collected samples in Groups 1 and 2 demonstrated bacterial growth with coagulase negative Staphylococcus being found in nearly all positive samples and secondary species being common. No statistical differences between the 2 groups were noted for number of samples with growth, species of bacterial growth, number with growth of secondary species, or colony counts. Both groups demonstrated significantly greater number of samples with growth relative to the control Group 3.

CONCLUSIONS

The use of headlamp/loupes or the operative microscope is associated with bacterial shedding. Proper techniques of cleaning, storage, and draping should be used to minimize their contribution to potential postoperative infection. No significant difference was noted between the 2 test groups, suggesting that infection risk should not come into play when choosing techniques of illumination/magnification.

Postoperative spinal wound infections and postprocedural diskitis

BACKGROUND/OBJECTIVE

Postprocedural infections are a significant cause of morbidity after spinal interventions.

METHODS

Literature review. An extensive literature review was conducted on postprocedural spinal infections. Relevant articles were reviewed in detail and additional case images were included.

RESULTS

Clinical findings, laboratory markers, and imaging modalities play important roles in the detection of postprocedural spinal infections. Treatment may range from biopsy and antibiotics to multiple operations with complex strategies for soft tissue management.

CONCLUSIONS

Early detection and aggressive treatment are paramount in managing postprocedural spinal infections and limiting their long-term sequelae.

A comparison of autologous and homologous transfusions in spinal fusion

Autologous transfusion has been used to overcome adverse effects of homologous transfusion. Clinical studies evaluating general orthopaedic postoperative results have been designed to compare these transfusion methods. However, few studies have evaluated postoperative results in spinal fusion surgeries, which have larger blood loss volumes. The purpose of this study is to determine if there are differences in postoperative infection and clinical results of spinal fusion with autologous, as compared to homologous, blood transfusion. A total of 62 patients who underwent instrumented spinal fusion and received autologous (n = 30) or homologous (n = 32) transfusions were reviewed. Information on gender, age, preoperative and 3-day postoperative hematologic features, total transfused units, segmental estimated blood loss, transfused units, and surgery time were collected. In addition, postoperative infection data on wound infection, pneumonia, urinary tract infection, cellulitis, and viral disease, incidence and duration of fever, as well as clinical results, fusion rates, and patient feedback were collected. No differences in postoperative infection and clinical results were found between the two types of transfusions; however, homologous transfusion was associated with an increased number of total units transfused, longer duration of fever, and decreased patient satisfaction regarding the transfusion.

General principles in the medical and surgical management of spinal infections: a multidisciplinary approach

OBJECT

Infections along the spinal axis are characterized by an insidious onset, and the resulting delays in diagnosis are associated with serious neurological consequences and even death. Infections of the spine can affect the vertebral bodies, intervertebral discs, spinal canal, and surrounding soft tissues. Neurological dysfunction occurs when the spinal cord becomes compressed, edematous, or ischemic due to compression by abscess or vascular compromise. The aim of this paper was to detail general diagnostic and management principles for this disease.

METHODS

Recent progress in medical technologies, including the development of potent antimicrobial drugs, advanced imaging, and improved surgical methods, have dramatically reduced morbidity and mortality rates for spinal infections; however, debate still exists on the proper management of this disease. In this paper, the authors review the current management protocols for spinal infections at their institution, focusing on medical and surgical treatments for vertebral osteomyelitis, intervertebral disc space infections, and spinal canal and soft-tissue abscesses.

CONCLUSIONS

Technological advances in imaging modalities, pharmaceutics, and surgery have resulted in excellent outcomes and have greatly reduced the morbidity and mortality rates associated with spinal infections. Currently, treatment of spinal infections requires a multidisciplinary team that includes infectious diseases experts, neuroradiologists, and spine surgeons. The key to successful management of spinal infections is early detection.

Single versus multiple dose antibiotic prophylaxis in lumbar disc surgery

STUDY DESIGN

Retrospective review.

OBJECTIVES

To determine the efficacy of preoperative antibiotics alone in preventing wound infections following lumbar diskectomy.

SUMMARY OF BACKGROUND DATA

It is well documented that antibiotics given perioperatively reduce the rate of postoperative wound infections in lumbar disc surgery. At our institution, the current protocol for patients undergoing lumbar diskectomy is a single preoperative antibiotic dose. This study was conducted to compare the rate of postoperative wound infection incurred for single versus multiple perioperative antibiotic doses. It was hypothesized that no significant difference in infection rates would be identified.

METHODS

This retrospective chart review compared the rates of postoperative wound infections incurred when single versus multiple perioperative antibiotic doses were given to patients having lumbar laminotomy for herniated discs. The procedures were performed between 1993 and March 1999. There were 434 patients in the multiple dose group and 201 in the single dose group. The multiple dose group received one preoperative and at least three postoperative doses of antibiotics. The single dose group received one preoperative dose of antibiotics. A postoperative infection was deemed present by either clinical diagnosis or culture results. The medical records were reviewed for 6 weeks after surgery for all patients.

RESULTS

There were 5 out of 435 (1.15%) infections in the multiple dose group and 3 out of 201 (1.49%) in the single dose group. Statistical analysis showed no significant difference between the two study groups.

CONCLUSION

These results support the use of single preoperative dose of antibiotics in lumbar disc surgery. This is relevant as many lumbar diskectomy patients are candidates for early hospital discharge. At our institution, no increased risk of infection occurred for the single dose group.

Espondilodiscites sépticas: diagnóstico e tratamento

Estudamos retrospectivamente 24 pacientes com espondilodiscite séptica de diferentes etiologias (hematogênica, primária e infantil) e os diferentes aspectos envolvidos em seu diagnóstico e tratamento. Constatamos que a velocidade de hemossedimentação é um bom parâmetro laboratorial para acompanhar a evolução da doença, mas deve ser sempre interpretada conjuntamente com o quadro clínico e os achados de neuroimagem. Biópsias devem ser reservadas para os casos de diagnóstico duvidoso e o tratamento clínico realizado sempre que afastadas as seguintes condições: sepse, déficit neurológico, deformidade severa, abscesso epidural e corpo estranho (discite primária). A abordagem cirúrgica deve ser planejada levando em conta o estágio da doença, sendo preferencialmente por via posterior nas fases supurativas e anterior nas demais. Baseados em nossa experiência e em revisão da literatura, propomos um algoritmo para orientar o diagnóstico e o tratamento das espondilodiscites sépticas.

Cefazolin prophylaxis in neurosurgery monitored by capillary electrophoresis

Prophylactic use of antibiotics to prevent postoperative infections is a routine method in neurosurgery. Little is known about the period of effectiveness of antibiotics applied only for the purposes of operation. The actual concentration of cefazolin was determined in the serum, in the contents of wound drains, and in the cerebrospinal fluid in a 24-hour postoperative period after the administration of 1 g of cefazolin just prior to skin incision in 8 patients undergoing lumbar discectomy and 11 patients undergoing craniectomy. The concentration of the antibiotic was then compared with the minimal inhibitory concentration values of cefazolin for 10 different bacterial species. For evaluating the concentration of cefazolin, capillary electrophoresis was used, which is a new clinical application of this separation technique. Results showed that the antibiotic was effective against bacterial breeding in the serum and in the drainage up to 12 hours. The drug concentration in the cerebrospinal fluid remained less than the value of the serum, and it exceeded the minimal inhibitory concentration values only for approximately 5 hours.

Distant skip level discitis and vertebral osteomyelitis after caudal epidural injection: a case report of a rare complication of epidural injections

STUDY DESIGN

A case report of distant discitis and vertebral osteomyelitis involving skip levels after caudal epidural steroid injection.

OBJECTIVES

To report and investigate the occurrence of distant infective discitis and vertebral osteomyelitis involving skip levels after epidural injection.

SUMMARY OF THE BACKGROUND DATA

Distant discitis and vertebral osteomyelitis is a serious but rare complication after epidural injection. A case involving skip levels and without the occurrence of epidural abscess formation has apparently not been previously reported in the literature.

METHODS

An elderly woman presenting with clinical, radiologic, and magnetic resonance imaging evidence of spinal canal stenosis involving L3/4 and L4/5 levels and degenerative spondylolisthesis of the L4/5 level was given an epidural injection of steroids and lignocaine via the caudal route. A month later, she presented with worsened low back pain, elevated serum acute phase reactants, and plain radiographic evidence of L4/5 infective discitis. Magnetic resonance imaging and microbiologic examination of computed tomographically guided biopsy specimens confirmed infective discitis involving L2/3 and L4/5 intervertebral levels, together with adjacent vertebral osteomyelitis.

RESULTS

The patient was successfully treated with antibiotics targeted at Pseudomonas aeruginosa, which was isolated in the culture of the biopsy specimens. Follow-up improvements in the clinical condition, serum acute phase reactants levels, radiographs, and magnetic resonance imaging were noted.

CONCLUSIONS

Distant discitis and vertebral osteomyelitis involving skip levels and without the occurrence of epidural abscess formation is a serious but rare complication after epidural injection.

Serratia spondylodiscitis after elective lumbar spine surgery: a report of two cases

STUDY DESIGN

This report describes two cases of acute spondylodiscitis, caused by, complicating two different conditions: microdiscectomy for herniated nucleus pulposus and decompressing laminotomy for spinal stenosis.

OBJECTIVE

To describe a rare and life-threatening spinal infection and discuss its successful management.

SUMMARY OF BACKGROUND DATA

To our knowledge, no published reports in the English language have described this potentially devastating infection as a complication of elective noninstrumented discectomy or decompressive laminotomy.

METHODS

Two cases of a very early onset of acute spondylodiscitis, caused by, after minimally invasive lumbar spine surgeries are presented. The elapsed time between these two complications was 1 week. The clinical presentation was characteristically stormy in both cases. On postoperative day 2, the patients developed high fever with intense chills and concomitant acute low back pain rapidly increasing in severity. The overall clinical appearance was alarming. The patients were carefully investigated immediately and scrutinized for possible origin of the infection. Treatment consisted of prompt intravenous antibiotics and surgical debridement.

RESULTS

The history and clinical manifestations of postoperative spondylodiscitis were corroborated with magnetic resonance imaging findings and bacteriologic and hematologic laboratory examination. Blood cultures revealed as the responsible pathogenic microorganism. The source of the pathogens was contaminated normal saline used for surgical lavage. Both patients were able to completely resume their previous occupations after aggressive surgical debridement/irrigation and 3 months of antibiotic treatment.

CONCLUSIONS

may become a potential pathogen, causing severe spinal infection after elective surgery. For prompt diagnosis and effective treatment of this life-threatening infection, one should maintain high index of suspicion and should not procrastinate in initiating treatment, which should consist of appropriate intravenous antibiotics and surgical debridement.

Management of postprocedural discitis

BACKGROUND CONTEXT

Fortunately, the incidence of postprocedural discitis is relatively uncommon. The paucity of physical examination findings behooves the spine care practitioner to have a high index of suspicion in any patient presenting with increasing back pain after an invasive spinal procedure. The diagnosis can often be established in a timely fashion based on the history, physical examination, laboratory studies (erythrocyte sedimentation rate, C-reactive protein and blood cultures) and imaging studies (plain radiographs, magnetic resonance imaging, computed tomography and radionuclide scanning).

PURPOSE

To review the English literature on the subject of postprocedural discitis. The incidence, pathophysiology, laboratory markers and imaging findings are discussed. Recommendations on treatment strategies are presented along with long-term clinical outcomes of this postprocedure complication.

METHODS

A contemporary English literature search of MEDLINE and PubMed on the topic of postoperative discitis was performed.

RESULTS

The incidence of postprocedural discitis is approximately 0.2%. The most common etiologic agent is Staphylococcus aureus. The C-reactive protein is the most sensitive clinical laboratory marker to assess the presence of infection and effectiveness of treatment response. Magnetic resonance imaging is the imaging modality of choice in the diagnosis of spinal infection. The majority of patients are managed adequately with organism-specific antibiotics and spinal immobilization with good long-term outcomes. Operative intervention (open biopsy followed by antibiotic treatment and spinal immobilization or debridement and reconstruction) in patients who fail to respond to nonoperative treatment or in the presence of neurologic worsening has been demonstrated.

CONCLUSION

Postprocedural discitis is a rare complication after any invasive spinal procedure. It is imperative for the treating surgeon to maintain a high index of suspicion. Appropriate laboratory and imaging studies are invaluable in establishing a timely diagnosis. In the majority of patients, antibiotic treatment along with spinal immobilization has been shown to produce good long-term outcomes. Operative intervention is rarely necessary in patients failing conservative treatment.

Clinical experience and results with 389 PLDD procedures with the Nd:YAG laser, 1986 to 1995

From 1986 to the present, a period of 9 years, our group has performed 389 PLDD procedures in 322 patients with an overall success rate according the MacNab criteria of 75% and a complication rate of 1%. This compares to the 2.4% of traditional open surgery. Of our patients 33 required subsequent surgery, an incidence of approximately 10%.

Penetration of ceftriaxone into the intervertebral disc

Concentrations of ceftriaxone in serum and intervertebral disc tissue were determined with high-pressure liquid chromatography in forty-five patients after a single intravenous loading dose of 1000 milligrams given at different intervals before an operation on the spine. The mean serum concentrations in this study corresponded well with reported values. The mean tissue concentrations were 5.6 micrograms per gram (95 per cent confidence interval, 3.6 to 6.8 micrograms per gram) one to less than two hours after administration of the antibiotic, 6.4 micrograms per gram (95 per cent confidence interval, 2.8 to 10.0 micrograms per gram) two to less than four hours, and 3.6 micrograms per gram (95 per cent confidence interval, 0.6 to 6.6 micrograms per gram) at fourteen to less than sixteen hours. These drug concentrations exceed the minimum inhibitory concentration that was effective against 90 per cent of the bacteria for methicillin-sensitive Staphylococcus aureus; for Streptococcus pyogenes, agalactiae, viridans, pneumoniae, and bovis; and for community-acquired Enterobacteriaceae. The average serum-to-tissue ratio was 191:1 at less than one-half hour and 13:1 at less than one and a half hours. The lower values of the 95 per cent confidence intervals for the concentration of the antibiotic exceeded the minimum inhibitory concentrations in the disc tissue against most susceptible bacteria during the period between one and a half and four hours, but a larger bolus would be needed to maintain this level for a longer period (such as in a longer operation) and as prophylaxis against methicillin-sensitive Staphylococcus aureus and coagulase-negative staphylococci.

Surgery for herniated lumbar discs: a literature synthesis

OBJECTIVE

To assess the risks and benefits of surgery for herniated lumbar discs (discectomy) and to evaluate the methodologic quality of the literature.

DESIGN

Literature synthesis. STUDY SELECTION AND DATA ANALYSIS: A structured MEDLINE search identified studies of standard, microsurgical, or percutaneous discectomy. Eligible studies had adult subjects, sample sizes of > or = 30, clinical outcome data for > or = 75% of patients, and follow-up of > or = 1 year. Summary rates of successful outcomes, reoperations, and complications were obtained by a random-effects logistic regression model. Methodologic quality was assessed using established study design criteria.

RESULTS

Eighty-one studies met inclusion criteria. Most had substantial design flaws and/or omitted important clinical data. Randomized trials of standard discectomy showed better short-term sciatica relief following surgery; 65% to 85% of patients reported no sciatica one year after surgery, compared with only 36% of conservatively treated patients. No data from randomized trials were available for microdiscectomy or percutaneous discectomy, although most outcomes appeared comparable to those of standard discectomy. Approximately 10% of discectomy patients underwent further back surgery, and rates increased over time. The rate of serious complications, including death and permanent neurologic damage, was less than 1%.

CONCLUSIONS

Most studies were poorly designed and reported. Standard discectomy appears to offer better short-term outcomes than does conservative treatment, but long-term outcomes are similar. Discectomies are relatively safe procedures, though reoperations are common and increase over time. Decisions for elective surgery must balance faster pain relief against the risks and costs of surgery.

Percutaneous nucleotomy with CT and fluoroscopic guidance

Automated percutaneous diskectomy was performed with use of computed tomographic (CT) and fluoroscopic monitoring. Degenerative disease of the intervertebral disk was treated with local administration of anesthesia and use of a nucleotome. One hundred ten patients with neurologic symptoms and morphologic changes of one segment were selected for treatment. Previous conservative therapy had been unsuccessful. Patients with completely prolapsed and sequestered fragments of herniated disks ("uncontained disk"), narrow intervertebral spaces, posterior osteophytes, diseased facet joints, and spinal stenoses were not considered candidates for percutaneous nucleotomy (PNT). After PNT, 82% of the patients had complete remission of their neurologic symptoms; Lasègue sign was negative or improved in 92%. In 18% (20 patients), the symptoms did not improve sufficiently; 11% (12 of 110) of these patients underwent surgical nucleotomy. There were no serious complications, in particular, no injuries to vital structures (nerves, thecal sac, arteries, veins), except for one case of spondylodiskitis. Guiding PNT with CT and fluoroscopy provides a safe procedure with good clinical results. The addition of CT has shortened the operation but increased over-all procedure time. In the future, a shift to outpatient treatment may offset the additional time and cost of including CT guidance.

Prognosis in postoperative discitis. A retrospective study of 111 cases

111 cases of postoperative discitis during 1968-1986 were analyzed retrospectively. The diagnosis was confirmed by lumbar tomography. Low back pain appeared at an average of 16 days postoperatively. Laboratory findings were of minor value in the diagnosis since elevated ESR, white blood cell count, and body temperature were inconstant findings. Compared with a matched control group, there was a higher incidence of chronic low back pain and vocational handicap in the discitis patients. There was no difference in the consumption of analgetics, the subjective evaluation of the final outcome, spinal mobility or neurologic findings.

Infection of the intervertebral space following conventional and microsurgical operation on the herniated lumbar intervertebral disc. A controlled clinical trial

Review of the literature reveals that considerable knowledge has accumulated on intervertebral space infection following lumbar disc surgery. This is based on more than 400 observations. There are, however, no unifying concepts regarding the pathogenesis of the condition. While the reported incidence has seemed to increase in the last three decades, we noticed a significant reduction in frequency of this important complication of lumbar disc surgery after introducing microsurgical techniques. The significance of this finding is discussed with respect to pathogenesis.

Postoperative intervertebral discitis

Discitis is a rare complication of disc operation. During a 10-year-period 1100 patients were operated for lumbar disc herniation and only eight patients developed postoperative discitis. The symptoms began 3 weeks after the operation and the most prominent clinical feature was back pain with muscle spasm. The sedimentation rate was highly elevated but the body temperature was slightly elevated for only a few days. Typical radiographic findings were narrowing of the affected disc space and end-plate resorption 3-4 weeks after the initial symptoms. In the early phase, CT showed hypodense disc material in the affected disc space, which may be the first radiological sign of discitis.

Congenital stenosis of lumbar spinal canal: comparison of results of surgical treatment for this and other causes of lumbar syndrome

The operative results in 37 consecutive patients suffering from developmental stenosis of the lumbar spinal canal, compared with those in spondylosis and disc herniations, are discussed. The diagnostic certainty of stenosis, suspected on the bases of clinical and radiographic data, is reached only at the operating table. To judge the usefulness of the operation we have considered not only the patients' verdicts, but also the improvements in neurological signs and the appearance of new deficits. Satisfactory results are around 80%, slightly less good with stenosis than with the other causes of lumbar syndrome. Radiographic study with contrast medium is mandatory. Dimer-X has been used with very clear radiographic findings and very few complications. Operating technique is also described: a wide laminectomy with facetectomy is advised. The great importance of early physiotherapy is emphasized.