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

Post-Discectomy Infection: A Critical Review and Suggestion of a Management Algorithm

Postoperative discitis (POD) accounts for 20% to 30% of all cases of pyogenic spondylodiscitis, while POD may be mis-or-under-diagnosed, due to the vague related symptomatology and the non-specific imaging findings. Most studies report infection rate of less than 1%, which increases with the addition of non-instrumented fusion to 2.4% to 6.2%. It remains controversial whether POD is caused by an aseptic or infectious process. Positive cultures are presented only in 42-73% of patients with Staphylococcus species being the most common invading organisms, while Staphylococcus aureus is isolated in almost 50% of cases. The onset of POD symptoms usually occurs at 2-4 weeks after an apparently uneventful operation. Back pain and muscle spasms are usually refractory to bed rest and analgesics. Magnetic Resonance Imaging (MRI) is the most sensitive and specific imaging diagnostic technique. Antimicrobial therapy depends on the results of tissue cultures, and along with bracing represents the mainstay of management. Surgical intervention is necessary in patients failing conservative treatment. For the majority of cases, extensive surgical debridement, antibiotic therapy, and orthosis immobilization are effective in eliminating the infection. According to this, we recommend an Algorithmic approach for the management of POD. Postoperative infections after spinal surgery pose a certain clinical challenge, and in most cases can be treated conservatively. Nevertheless, disability may be persistent, and surgery could be necessary. The purpose of this concise review is to describe the manifestation of post-discectomy infection, its pathogenesis and particularly a rational approach for its management.

A Review of Surgical Irrigation Solutions for Infection Prevention in Orthopaedic Surgery

» Intraoperative surgical irrigation is a common practice in orthopaedic procedures, although there is no universally established standard of care due to a lack of concrete data supporting an optimal irrigation agent.» Isotonic normal saline has long been considered a safe and cost effective solution for wound irrigation as compared with other antibiotic and antiseptic irrigation solutions.» Currently, the only adjunct to saline that is formally supported by American Academy of Orthopaedic Surgeons, the Centers for Disease Control and Prevention, and World Health Organization is povidone-iodine.» Further in vivo clinical studies are needed to identify the ideal irrigation solution that carries low cytotoxic effects while also exerting optimal antimicrobial properties.

Is annular repair technique useful for reducing reherniation and reoperation after limited discectomy?

The annular defect because of the primary lumbar disc herniation (LDH) or surgical procedure is considered a primary reason for recurrent herniation and eventually reoperation. Efforts to close the defect with annular repair devices have been attempted several times, but the results were controversial. The present aims to detect whether the annular repair techniques were useful for reducing the re-herniation and re- operation rate. The Pubmed, Cochrane library, and Embase databases were searched to retrieve relevant studies published before January 1, 2021. Continuous variables were compared by calculating the standard difference of the means (SDM), whereas categorical dichotomous variables were assessed using relative risks (RRs). A random-effects model was used if the heterogeneity statistic was significant; otherwise, a fixed-effects model was used. A total of 10 researches were suitable for the meta-analysis, including four different repair techniques and 1907 participates. Compared with the control group, there was no statistical difference with the ODI, VAS-leg, and VAS-back scales for patients treated with the annular repair. However, using an annular repair device was associated with a significant reduction in the re- herniation (p=0.004) and re-operation (0.004) rates. There was no difference between the groups with perioperative complications. However, much more device-related long-term complications happened in the annual repair group (p=0.031) though it still decreased the overall re-operation rate significantly (p=0.006).Our results demonstrated that using an annular repair device was safe and beneficial for reducing re-herniation and re-operation rates.

Hydrogen Peroxide: Its Use in an Extensive Acute Wound to Promote Wound Granulation and Infection Control - Is it Better Than Normal Saline?

Background: Hydrogen peroxide (H₂O₂) is used as a topical antiseptic in contaminated wounds caused by road traffic accidents. It kills bacteria by producing oxidation through local, nascent, free oxygen radicals. It also removes dirt from the wound due to its frothing action. H₂O₂ is synthesized by various cells as an active biochemical agent that affects cell biological behavior through complex chemical reactions. H₂O₂ has also been used as a wound cleaning agent, removing debris, preventing infection, and causing hemostasis due to its exothermic reaction with blood. Despite its widespread use, there is scanty literature on its use to promote granulation tissue formation. Objective: In the orthopaedics literature, studies on H₂O₂ use are very limited and its potential is underestimated. In the present study, we would like to report our protocol of use of H₂O₂ for its tremendous potential for stimulating granulation and early wound healing. Material and Methods: A total of 53 patients with large acute extensive lower limb contaminated wounds reported to the emergency department have been included with and without lower limb fracture. In group A (43 patients) wound management was done using 7% H₂O₂ and group B (10 patients) was treated by only saline dressing as a control group. Results: In the present study, daily dressing by 7% H₂O₂ solution and provide solution gives excellent results compared to the Saline group. Granulation tissue appeared much earlier with a mean SD 6.3 ± 6.8 days in the hydrogen peroxide group as compared to the Saline group where granulation tissue appeared in 9.3 ± 8.4 days. Conclusion: Spontaneous wound healing is a controlled balance between destructive and healing processes. It is mandatory to remove damaged tissue to promote healing by secondary intention and minimize infection. The dynamic effect of H₂O₂ promotes faster healing, stimulates granulation, and minimizes infection by oxidative stress.

Histopathological changes of neuronal tissue following the use of hydrogen peroxide in neurosurgical procedures

Background:

Hydrogen peroxide (HP) is routinely used in neurosurgical procedures to achieve surgical hemostasis. However, its safety profile is still debatable with various reports depicting range of adverse effects on neuronal tissue. The objective of this paper is to evaluate the safety and efficacy of HP as a hemostatic agent in normal neuronal tissue during neurosurgical procedures conducted on rats.

Methods:

One hundred rats were divided into three groups. The first and third group underwent cortical irrigation with HP and the second group underwent spinal irrigation with HP. All groups were irrigated with different concentrations of HP (1%, 3%, or 6%) for 3 min and tissue biopsies were obtained immediately afterwards (Groups A and B) or 1 week after HP irrigation (Group C). Study specimens were examined histologically and compared to control tissue.

Results:

All rats showed normal behavioral, functional, and motor neurological activity following the procedures. Histopathologically, dark neurons were observed in all HP exposed tissue. The cytoplasm revealed condensed and dark Nissl substance and the neurites and axons exhibited a corkscrew morphology. No ischemic changes or inflammatory infiltrates were detected. The majority of dark neurons were observed at the periphery of tissue fragments. These findings were present and consistent in both the short- and long-term groups.

Conclusion:

HP irrigation showed no significant short- or long-term clinical and histopathological changes in comparison to normal saline when used on rats’ neuronal tissue. This may confirm the safety of intraoperative HP usage as hemostatic agent during neurosurgical procedures.

Postoperative Lumbar Pyogenic Spondylodiscitis: An Institutional Review

Background   Postoperative discitis (POD) remains a dreaded complication in the present era of asepsis. The treatment has been traditionally conservative, but the safety of spinal implants in infective settings has prompted the surgeons to provide rigid immobilization for promoting healing. A major concern in a country like ours is huge patient inflow and long waiting list added to the woe of patient's refusal for a second operative intervention after a first undesirable outcome. Objectives  The aim of the study was to evaluate the functional and radiological outcome of conservative management of POD and determine the methods of prevention. Settings and Design   A retrospective case study series in a tertiary-level hospital. Materials and Methods   Between January 2015 and 2017, 12 cases of POD (10 own and 2 referred) were managed and followed up clinically, radiologically, and with laboratory investigation. Two cases were managed surgically-one with kyphotic deformity and the other with discharging pus. Rest were managed conservatively with analgesics and intravenously followed by oral antibiotics. At 1-year follow-up, patient satisfaction was evaluated using the MacNab outcome assessment. Statistical Analysis   The descriptive data were analyzed mainly by descriptive statistics using mean, median, standard deviation, and interquartile range. Results   Mean follow-up in our series was 15.2 months. Except for two operated cases, we did not go for the invasive procedure for isolation of organism in any of our cases. The total duration of antibiotic in our series was for the mean of 7.3 weeks. Visual analog scale score returned from8 initially to baseline and at final follow-up-4 excellent, 6 good, and 2 had fair outcome. There was no adverse outcome. Conclusions   The majority of POD can be managed conservatively. Surgery is reserved only for special cases. Magnetic resonance imaging is the investigation of choice for diagnosing discitis. Intraoperative use of gentamicin-mixed normal saline wash reduces the incidence of discitis.

The relationship between surgical site drains and reoperation for wound-related complications following posterior cervical spine surgery: a multicenter retrospective study

OBJECTIVE

Use of surgical site drains following posterior cervical spine surgery is variable, and its impact on outcomes remains controversial. Studies of drain use in the lumbar spine have suggested that drains are not associated with reduction of reoperations for wound infection or hematoma. There is a paucity of studies examining this relationship in the cervical spine, where hematomas and infections can have severe consequences. This study aims to examine the relationship between surgical site drains and reoperation for wound-related complications following posterior cervical spine surgery.

METHODS

This study is a multicenter retrospective review of 1799 consecutive patients who underwent posterior cervical decompression with instrumentation at 4 tertiary care centers between 2004 and 2016. Demographic and perioperative data were analyzed for associations with drain placement and return to the operating room.

RESULTS

Of 1799 patients, 1180 (65.6%) had a drain placed. Multivariate logistic regression analysis identified history of diabetes (OR 1.37, p = 0.03) and total number of levels operated (OR 1.32, p < 0.001) as independent predictors of drain placement. Rates of reoperation for any surgical site complication were not different between the drain and no-drain groups (4.07% vs 3.88%, p = 0.85). Similarly, rates of reoperation for surgical site infection (1.61% vs 2.58%, p = 0.16) and hematoma (0.68% vs 0.48%, p = 0.62) were not different between the drain and no-drain groups. However, after adjusting for history of diabetes and the number of operative levels, patients with drains had significantly lower odds of returning to the operating room for surgical site infection (OR 0.48, p = 0.04) but not for hematoma (OR 1.22, p = 0.77).

CONCLUSIONS

This large study characterizes current practice patterns in the utilization of surgical site drains during posterior cervical decompression and instrumentation. Patients with drains placed did not have lower odds of returning to the operating room for postoperative hematoma. However, the authors’ data suggest that patients with drains may be less likely to return to the operating room for surgical site infection, although the absolute number of infections in the entire population was small, limiting the analysis.

The Evidence Behind Peroxide in Orthopedic Surgery

Peroxide is a strong oxidizing agent and disinfectant frequently used in orthopedic surgery. The authors conducted a systematic literature review of peroxide in orthopedic surgery, evaluating use, complications, efficacy, and appropriate concentrations. One hundred seventy-five reports were identified, with 24 being eligible for analysis. Orthopedic surgeons used peroxide for irrigation and bacterial reduction in various procedures. Complications included cytotoxicity, allergic reactions, suture damage, and inflammation. Use of the standard concentration of 3% peroxide and standard time in situ are without evidence. Laboratory studies suggest that diluted concentrations retain the benefit of bacterial decolonization without increasing the risk for complications. [Orthopedics. 2018; 41(6):e756-e764.].

Risk factors for surgical site infections among 1,772 patients operated on for lumbar disc herniation: a multicentre observational registry-based study

BACKGROUND

There are no previous studies evaluating risk factors for surgical site infections (SSIs) and the effectiveness of prophylactic antibiotic treatment (PAT), specifically for patients operated on for lumbar disc herniation.

METHOD

This observational multicentre study comprises a cohort of 1,772 consecutive patients operated on for lumbar disc herniation without laminectomy or fusion at 23 different surgical units in Norway. The patients were interviewed about SSIs according to a standardised questionnaire at 3 months' follow-up.

RESULTS

Three months after surgery, 2.3% of the patients had an SSI. Only no PAT (OR = 5.3, 95% CI = 2.2-12.7, p< 0.001) and longer duration of surgery than the mean time (68 min) (OR = 2.8, 95% CI = 1.2-6.6, p = 0.02) were identified as independent risk factors for SSI. Numbers needed to have PAT to avoid one SSI was 43.

CONCLUSIONS

In summary, this study clearly lends support to the use of PAT in surgery for lumbar disc herniation. Senior surgeons assisting inexperienced colleagues to avoid prolonged duration of surgery could also reduce the occurrence of SSI.

Hydrogen Peroxide Wound Irrigation in Orthopaedic Surgery

As the burden of deep hardware infections continues to rise in orthopaedics, there is increasing interest in strategies for more effective debridement of colonized tissues and biofilm. Hydrogen peroxide has been used medically for almost a century, but its applications in orthopaedic surgery have yet to be fully determined. The basic science and clinical research on the antiseptic efficacy of hydrogen peroxide have demonstrated its efficacy against bacteria, and it has demonstrated potential synergy with other irrigation solutions such as chlorhexidine and povidone-iodine. While hydrogen peroxide is effective in infection reduction, there are concerns with wound healing, cytotoxicity, and embolic phenomena, and we recommend against hydrogen peroxide usage in the treatment of partial knee replacements, hemiarthroplasties, or native joints. Additionally, due to the potential for oxygen gas formation, hydrogen peroxide should not be used in cases of dural compromise, when pressurizing medullary canals, or when irrigating smaller closed spaces to avoid the possibility of air embolism. Finally, we present our protocol for irrigation and debridement and exchange of modular components in total joint arthroplasty, incorporating hydrogen peroxide in combination with povidone-iodine and chlorhexidine.

Surgical site infections following spine surgery: eliminating the controversies in the diagnosis

Surgical site infection (SSI) following spine surgery is a dreaded complication with significant morbidity and economic burden. SSIs following spine surgery can be superficial, characterized by obvious wound drainage or deep-seated with a healed wound. Staphylococcus aureus remains the principal causal agent. There are certain pre-operative risk factors that increase the risk of SSI, mainly diabetes, smoking, steroids, and peri-operative transfusions. Additionally, intra-operative risk factors include surgical invasiveness, type of fusion, implant use, and traditional instead of minimally invasive approach. A high level of suspicion is crucial to attaining an early definitive diagnosis and initiating appropriate management. The most common presenting symptom is back pain, usually manifesting 2–4 weeks and up to 3 months after a spinal procedure. Scheduling a follow-up visit between weeks 2 and 4 after surgery is therefore necessary for early detection. Inflammatory markers are important diagnostic tools, and comparing pre-operative with post-operative levels should be done when suspecting SSIs following spine surgery. Particularly, serum amyloid A is a novel inflammatory marker that can expedite the diagnosis of SSIs. Magnetic resonance imaging remains the diagnostic modality of choice when suspecting a SSI following spine surgery. While 18F-fluorodeoxyglucose-positron emission tomography is not widely used, it may be useful in challenging cases. Despite their low yield, blood cultures should be collected before initiating antibiotic therapy. Samples from wound drainage should be sent for Gram stain and cultures. When there is a high clinical suspicion of SSI and in the absence of superficial wound drainage, computed tomography-guided aspiration of paraspinal collections is warranted. Unless the patient is hemodynamically compromised, antibiotics should be deferred until proper specimens for culture are secured.

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.

Prevention of post-operative infections in spine surgery by wound irrigation with a solution of povidone-iodine and hydrogen peroxide

INTRODUCTION

Starting from January 2009, we systematically irrigated the surgical wounds of patients undergoing spine surgery with a solution of povidone-iodine (PVP-I) and hydrogen peroxide (H(2)O(2)).

METHOD

We prospectively recorded the clinical data of patients who underwent spine surgery during 2009 and we compared the results with retrospectively reviewed clinical records of patients operated during 2008. Patients were analyzed for preoperative risk factors, type of surgical procedure, onset of the infection, clinical presentation, treatment, and outcome. We performed 460 spine surgeries during 2008 and 490 during 2009.

RESULTS

We recorded seven post-operative infections in 2008 compared to none in 2009.

CONCLUSION

We consider the solution of PVP-I plus H(2)O(2) effective in further reducing the rate of post-operative infection in spine surgery.

Cefuroxime prophylaxis is effective in noninstrumented spine surgery: a double-blind, placebo-controlled study

STUDY DESIGN

Double-blind, placebo-controlled randomized clinical trial.

OBJECTIVE

To assess the efficacy of 1 preoperative 1.5 g dose of cefuroxime in preventing surgical site infection after surgery for herniated disc.

SUMMARY OF BACKGROUND DATA

Antibiotic prophylaxis was only tested in nonconclusive trials in this setting.

METHODS

The study was conducted in 2 university hospitals in Switzerland. Patients were assessed for occurrence of surgical site infection (defined by the criteria of the Centers for Diseases Control and Prevention), other infections, or adverse events up to 6 months after surgery. Outcome measures were compared in a univariate, per-protocol analysis.

RESULTS

Baseline characteristics were similar in patients allocated to cefuroxime (n = 613) or placebo (n = 624). Eight (1.3%) patients in the cefuroxime group and 18 patients (2.8%) in the placebo group developed a surgical site infection (P = 0.073). A diagnosis of spondylodiscitis or epidural abscess was made in 9 patients in the placebo group, but none in the cefuroxime group (P < 0.01), which corresponded to a number necessary to treat of 69 patients to prevent one of these infections. There were no significant adverse events attributed to either cefuroxime or placebo.

CONCLUSION

A single, preoperative dose of cefuroxime significantly reduces the risk of organ-space infection, most notably spondylodiscitis, after surgery for herniated disc.

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.

Reduction of epidural fibrosis in lumbar surgery with Oxiplex adhesion barriers of carboxymethylcellulose and polyethylene oxide

BACKGROUND CONTEXT

Postsurgical epidural adhesions and fibrosis after surgery for lumbar disc herniation are a consequence of normal wound healing. The presence of fibrosis renders reoperations risky, and in some patients fibrosis may lead to nerve root tethering.

PURPOSE

One approach to minimizing the risk of developing epidural adhesions is to provide a barrier between the dural membrane and the healing connective tissues. The purpose of these studies was to evaluate such a barrier device.

STUDY DESIGN/SETTING

In vivo investigation in an animal model at a university laboratory.

PATIENT SAMPLE

Rabbit.

OUTCOME MEASURES

Gross and histomorphic evaluation.

METHODS

Barriers comprised of carboxymethylcellulose (CMC) and polyethylene oxide (PEO) (Oxiplex; FzioMed, Inc., San Luis Obispo, CA) were studied as devices to reduce epidural adhesion formation in rabbit laminotomy and laminectomy models. The barriers tested were either a gel alone (gel) or a gel covered with a film (gel/film combination). Two laminotomy or laminectomy sites (depending on the surgical method) were created in each rabbit at L4 and L6. One site was treated with a CMC/PEO gel, or CMC/PEO gel/film combination, and the other site served as a surgical control. Two surgical models that differed in the extent of adhesion formation at untreated injury sites and the method of injury generation were used.

RESULTS

Model A, which did not incorporate dural abrasion, resulted in up to 40% adhesion-free laminectomy sites in controls. Model B, which did incorporate abrasion of the dural membrane, resulted in less than 10% adhesion-free laminotomy sites in controls. Compositions of CMC/PEO gels (2.5% to 10% PEO) and films (22.5% PEO) were tested in both models. Efficacy parameters included measuring the number of sites free of epidural fibrosis and reduction in the severity of fibrosis (adhesions). Both gels and gel/film combinations consistently reduced the frequency and the extent of epidural fibrosis in both models. Gels of CMC/PEO containing a higher content of PEO (10%) and a higher molecular weight of PEO (4.4 mD) were most effective in Model B and resulted in up to 84% laminotomy sites with minimal or no epidural fibrosis, whereas controls exhibited over 90% of the sites with epidural fibrosis. Histological evaluation of the surgical sites indicated that the reduction of epidural fibrosis was accompanied by normal bone healing. In addition, these experiments demonstrated that the gel/film combination provided no additional benefit to that obtained by the gel alone.

CONCLUSIONS

Gels of CMC/PEO reduced epidural fibrosis and did not impair normal heal ing.

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.

Spontaneous disc space infections in adults

BACKGROUND

Spontaneous discitis typically affects children; much less is known about the disease in adults. We examined the clinical characteristics and the role of surgery in spontaneous infectious discitis in adults.

METHODS

Twenty-nine consecutive adult patients (16 men, 13 women) with spontaneous infectious discitis were treated by a single surgeon (MJE) over a 5-year period. These patients were compared to 19 consecutive patients with postoperative discitis over the same time period. Mean follow-up was 2.4 years.

RESULTS

The average age of patients with spontaneous discitis was 69.0 years. Eleven of these patients (38%) were diabetic and 9 (31%) had a known concurrent infection. Infections occurred at cervical (10%), thoracic (34%), and lumbar interspaces (59%), and at multiple disc spaces in eight cases (28%). Ten patients (34%) had an elevated serum leukocyte count and 21 patients (72%) had an elevated erythrocyte sedimentation rate. While Gram-positive infection was most common, a broad spectrum of microbes was isolated. All patients were treated with i.v. antibiotics for a mean duration of 6 weeks. Four patients required surgical fusion; the rest were treated with external immobilization. At follow-up, 21 patients (72%) were symptom-free, 3 patients (10%) had ongoing disease, and 5 patients (17%) had died of unrelated causes. Compared to patients with postoperative discitis treated over the same time period, spontaneous discitis in adults affected older patients and required a broader spectrum of antibiotic coverage. Outcomes were similar between the two groups.

CONCLUSIONS

While spontaneous discitis has predominantly been reported in children, the disease also affects older adults. Spontaneous discitis in adults is associated with advanced age, diabetes mellitus, and systemic infection. Elevated serum leukocyte count lacks diagnostic sensitivity. A high cure rate is achieved with antibiotics and external immobilization. Surgical treatment is rarely required.

The penetration of cefoperazone and sulbactam into the lumbar intervertebral discs

Six patients received 1 g and six other patients received 2 g of cefoperazone and sulbactam 15 minutes before lumbar disc surgery. Liquid chromatographic analysis of disc tissue revealed that only patients receiving the 2-g dose had mean tissue levels above the minimum inhibitory concentration for Staphylococcus aureus and epidermidis.

Review of safety in endoscopic laser foraminoplasty for the management of back pain

OBJECTIVE

The purpose of this study was to analyze the incidence and gravity of reported complications that arise in spinal surgery and assess the comparative safety, or otherwise, of endoscopic laser foraminoplasty (ELF).

BACKGROUND DATA

Chemonucleolysis, decompression, discectomy, and fusion have long been cited as treatments for chronic low back pain. Over recent years newer, less invasive surgical techniques have become available, one such being ELF. Although minimally invasive, the beneficial outcome must be interpreted in relation to concerns regarding the safety of the procedure and its risks relative to those of other forms of spinal surgery. The Spinal Foundation, Rochdale has performed 958 ELFs and has collated a comprehensive database of the results of all these operations. These prospective records provided the basis for a comparison of the safety of ELF to that reported with other spinal surgical techniques.

METHODS

A total of 958 procedures have been performed on 716 patients. Complications that arose during the operation and the postoperative phase of 6 weeks following the procedure were elicited from patient records. These data were correlated and compared to a meta-analysis of randomized controlled clinical trial data of complications arising during and after conventional spinal surgery. The SPSS (statistical package for social sciences) and CIA (confidence interval analysis) statistical packages were used to draw conclusions regarding the safety of ELF.

RESULTS

The cohort integrity of operation and outpatient review records at 6 weeks after surgery was 100%. In 958 ELFs performed, 24 complications occurred in 23 patients. There were 9 cases of discitis (1 infective, 8 aseptic) (0.9%), 1 dural tear (0.1%), 1 deep wound infection (0.1%), 2 patients suffered a foot drop (1 transient) (0.2%), 1 myocardial infarction (0.1%), 1 erectile dysfunction (0.1%), and 1 patient who developed panic attacks post-operatively (0.1%). This amounts to an overall surgical complication rate of 1.6%. Magnetic resonance imaging (MRI) follow up of clinically symptomatic patients highlighted 8 residual disc herniations (0.8%). Meta-analysis of randomized controlled trials of conventional spinal surgery for adult onset degenerative disc disease and/or sciatic pain reported overall complication rates for fusion (11.8%), decompression (7.6%), discectomy (6.0%), and chemonucleolysis (9.6%).

CONCLUSIONS

The complication rate of ELF is shown to be significantly lower than that reported following conventional spinal surgery (p < 0.01). From these results, we conclude that ELF as a treatment for chronic low back pain and sciatica presents less risk to a patient than conventional methods of spinal surgery.

The postsurgical lumbosacral spine. Magnetic resonance imaging evaluation following intervertebral disk surgery, surgical decompression, intervertebral bony fusion, and spinal instrumentation

It should be clear to those who perform and interpret medical images of the spine following one or more forms of surgical therapy that the images are often difficult to interpret in part because of the superimposition of the original disease process, alteration engendered by the surgery, or a complication of the surgical procedure. Although long-term experience in this area is helpful in regard to improving interpretive skills, certain sequela can be predicted regardless of the interpreter's background. Once the normal or expected postsurgical findings are understood, the subtle and gross changes that depart from these observations can be analyzed better. The importance of a high level of competence in the domain of post-therapeutic neurodiagnostic imaging is in the knowledge that the patient returning for restudy may be acutely in distress or even in medical danger (e.g., postoperative spondylitis). In fact, the clinical presentation posttherapeutically may well be more severe or dire than was observed pretherapeutically. An indepth appreciation of the broad range of clinicoradiologic possibilities as presented [figure: see text] here should place the medical imaging physician in an excellent position to provide an experienced diagnostic evaluation in the patient presenting with recurrent or new signs and symptoms following any one of the spectrum of possible spinal surgical procedures.

Spondylodiscitis after lumbar discectomy. Incidence and a proposal for prophylaxis

STUDY DESIGN

An analysis of the incidence of spondylodiscitis after lumbar disc surgery in 1642 patients. In 508 patients no prophylactic antibiotics were given. In 1134 patients a collagenous sponge containing gentamicin was placed in the cleared disc space.

OBJECTIVES

To report the incidence of postoperative spondylodiscitis in cases in which no antibiotic prophylaxis was used, and to define the value of a collagenous sponge containing gentamicin in preventing disc space infections.

SUMMARY OF BACKGROUND DATA

Spondylodiscitis is considered to be a rare complication of lumbar disc surgery. The retrospective design of most studies and the rare use of magnetic resonance imaging for early radiologic diagnosis suggest that the reported incidence rates may be underestimates. Postoperative spondylodiscitis is the result of intraoperative contamination and, theoretically, could be prevented by treating these patients with prophylactic antibiotics.

METHODS

In 1642 patients, 1712 discectomies were performed. In 508 of these patients no prophylactic antibiotics were given; in 1134 of these patients a collagenous sponge containing gentamicin was placed in the cleared disc space. Clinical reexamination and, in cases of unsatisfactory results, laboratory and radiologic investigations were performed 4-8 weeks after surgery.

RESULTS

In nineteen of the 508 patients who were not treated with antibiotic prophylaxis (3.7%) a postoperative spondylodiscitis developed, whereas none of the 1134 patients who received antibiotic prophylaxis became symptomatic (P < 0.00001).

CONCLUSION

In the current study, a 3.7% incidence of postoperative spondylodiscitis was found in the absence of prophylactic antibiotics. Gentamicin-containing collagenous sponges placed in the cleared disc space were effective in preventing postoperative spondylodiscitis.

The C-reactive protein for detection of early infections after lumbar microdiscectomy

The tendency for short hospitalization after lumbar microdiscectomy implies the need for early confirmation or disapproval of serious postoperative infections such as spondylodiscitis or deep wound infections. The C-reactive protein (CRP) is a well-known screening parameter for monitoring postoperative infectious complications in other fields. Our objective was to establish the diagnostic significance of CRP-in comparison with ESR and WBC-for monitoring infectious complications after lumbar microdiscectomy. Over a 15 months period we studied prospectively a homogeneous group of N = 400 patients with lumbar disc herniations who were operated on a single level for the first time. CRP, ESR and WBC values were determined in all patients pre-operatively, and on postoperative days 1 and 5. Clinical and laboratory findings were correlated and the diagnostic significance of CRP, ESR and WBC calculated. N = 385 (96%) patients had an uneventful postoperative course. N = 15 (4%) patients developed infectious complications, of which N = 6 (1.5%) were unrelated and N = 9 (2.5%) related to surgery. Evaluation of the laboratory values showed: The CRP baseline is a very individual value of no prognostic relevance. A high postaggression peak is typical and essential as a reference value for only the future time course will disclose any infection. We found 0% false negative and 4% false positive results on day 5. The sensitivity for serial CRP testing was calculated as 100% and specificity as 95.8%. ESR (sensitivity: 78.1%/specificity: 38.1%) and WBC (sensitivity: 21.4%/specificity: 76.8%) both failed to reach such distinct diagnostic significance on day 5. The C-reactive protein has thus proved to be a reliable, simple and economical screening test for infectious complications after lumbar microdiscectomy, superior to classical laboratory parameters.

PMN granulocyte elastase--an early indicator of postoperative spondylodiscitis?

The diagnosis of spondylodiscitis after lumbar disc surgery has been based so far on clinical abnormalities, non-specific changes in chemical laboratory parameters [erythrocyte sedimentation rate (ESR), C-reactive protein (CRP)] and radiological examinations such as MRI. Such techniques do not enable any clear diagnosis to be made before the 3rd postoperative week. The PMN elastase released from stimulated polymorphonuclear granulocytes has been proved to be a good laboratory parameter by which it is possible to prognosticate bacterial and abacterial organ complications in surgical patients with a high degree of probability. Under investigation were 12 patients with spondylodiscitis out of 1162 operations on herniated lumbar discs. PMN elastase was determined on the 7th postoperative day. In patients with spondylodiscitis and a mean value of 110.5 micrograms/l, the elastase was on average higher by a factor of 2.6 as compared to 88 randomly selected control patients. Since spondylodiscitis is a rare complication, this results in a positive value of only 7%, which does not allow a reliable diagnosis of spondylodiscitis by the elastase assay. But because the negative predictive value is 100%, it is possible to exclude a postoperative spondylodiscitis already on the 7th postoperative day, if the elastase value is normal.

Spondylodiscitis after lumbar disk surgery

The value of perioperative prophylactic use of antibiotics in lumbar disc surgery is investigated, based on a retrospective study of the operative results of 5041 patients. The rate of occurrence of postoperative spondylodiscitis was significantly higher during the period in which no perioperative prophylaxis was carried out, than it was during the period, in which perioperative prophylaxis was routine. Thus the perioperative prophylactic use of antibiotics seems highly recommendable.

Peri-operative elastase-alpha-1 proteinase inhibitor in patients with postoperative intervertebral discitis

In a prospective study of 251 patients operated upon for lumbar disc herniation it has been investigated whether the preoperative and early postoperative values of Elastase-alpha-1 Proteinase Inhibitor (EPI)-an indicator of inflammatory processes-and C-reactive Protein (CRP)-a well known predictor of some postoperative complications-were correlated to the later development of discitis. Postoperatively discitis developed in 14 patients. A randomly chosen group of 15 complication-free patients out of the total of 251 cases was used as control group. Elevated EPI plasma values, especially in the pre-operative and first postoperative days, turned out to be significantly related to the likelihood of later discitis development, but no such relation for the CRP plasma values could be established. Thus and early prediction of patients at risk for this complication seems to be possible by pre- and postoperative measurement of EPI. It could be justified-but its usefulness has yet to be proven-to give antibiotics prophylactically and other anti-inflammatory medication in patients with elevated pre- and postoperative EPI values.

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.

Postoperative spondylodiscitis: results of a prospective study about the aetiology of spondylodiscitis after operation for lumbar disc herniation

In 412 patients undergoing surgery for herniated lumbar discs from September 1986 to September 1987 and from January 1988 to July 1989 a microbiological specimen was taken from the intervertebral disc space and from the cover of the operating microscope. Also the tips of the wound drains were examined microbiologically after removal. 17% of the patients had a positive bacteriological culture from their intervertebral disc space; 12% of the specimen from the operating microscope were positive. These results favour the hypothesis that intra-operative contamination of the disc space, in contrast to haematogenous spread, causes spondylodiscitis. On the other hand we saw during this time course only one case of clinical spondylodiscitis, which implies a possible involvement of other predisposing factors such as pre- or perioperative infections or compromised patient immunologically. It is also possible, that the routine application of local antibiotic or antiseptic solutions into the disc space at the end of the operation could decontaminate the operative site and prevent clinical infection despite positive culture findings.

The role of magnetic resonance imaging (MRI) in the diagnosis of spondylodiscitis

Spondylodiscitis is a well-known as well unavoidable complication of lumbar disc surgery. For diagnosis typical clinical symptoms and diagnostic procedures such as x-ray and scintigram are important but MRI proved to be the most sensitive and reliable. However, meaningful results can only be obtained with MRI if the measurement parameters are carefully considered, where by the field strength of the magnet plays a subordinate role. Therapy of spondylodiscitis using a light cast corset is described and it's advantages over other methods are shown.

Prophylaxis of postoperative lumbar spondylodiscitis

Spondylodiscitis after lumbar disc surgery is a well-known complication with a frequency of 0.1 to 3%. According to the authors, the etiological factors are: combination of operated segment instability, damage to the lower and upper plates due to disc space curettage and transmission of germs. After treatment of 100 selected cases, all with increased risk of postoperative spondylodiscitis, distinct possibilities for prevention have been discovered. Basic treatment consisted of 3 x 80 mg perioperative doses of Gentamicin i.m. In addition a collagen sponge (Sulmycin Implant) containing 50 mg Gentamycin was inserted in the cleared disc spaces of 50 patients. Complications in this procedure were not observed. The following is recommended for prevention of postoperative spondylodiscitis: a careful operating technique, perioperative antibiotics, and in particularly endangered patients, insertion of Sulmycin Implant in the disc-spaces.