The immediately failed lumbar disc surgery: incidence, aetiologies, imaging and management

Multimodal management strategies for chronic pain after spinal surgery: a comprehensive review

"Chronic pain after spinal surgery" (CPSS) is a nonspecific term for cases in which the end result of surgery generally does not meet the preoperative expectations of the patient and surgeon. This term has replaced the previous term i.e., failed back surgery syndrome. CPSS is challenging for both patients and doctors. Despite advancements in surgical techniques and technologies, a subset of patients continue to experience persistent or recurrent pain postoperatively. This review provides an overview of the multimodal management for CPSS, ranging from conservative management to revision surgery. Drawing on recent research and clinical experience, we aimed to offer insights into the diverse strategies available to improve the quality of life of CPSS patients.

The current role and future directions of imaging in failed back surgery syndrome patients: an educational review

BACKGROUND

Failed back surgery syndrome (FBSS) is an umbrella term referring to painful sensations experienced by patients after spinal surgery, mostly of neuropathic nature. Adequate treatment of FBSS is challenging, as its etiology is believed to be multifactorial and still not fully clarified. Accurate identification of the source of pain is difficult but pivotal to establish the most appropriate treatment strategy. Although the clinical utility of imaging in FBSS patients is still contentious, objective parameters are highly warranted to map different phenotypes of FBSS and tailor each subsequent therapy.

MAIN BODY

Since technological developments have weakened the applicability of prior research, this educational review outlined the recent evidence (i.e., from January 2005 onwards) after a systematic literature search. The state of the art on multiple imaging modalities in FBSS patients was reviewed. Future directions related to functional MRI and the development of imaging biomarkers have also been discussed.

CONCLUSION

Besides the fact that more imaging studies correlated with symptomatology in the postoperative setting are warranted, the current educational review outlined that contrast-enhanced MRI and MR neurography have been suggested as valuable imaging protocols to assess alterations in the spine of FBSS patients. The use of imaging biomarkers to study correlations between imaging features and symptomatology might hold future potential; however, more research is required before any promising hypotheses can be drawn.

Intraoperative neuromonitoring during surgery for lumbar stenosis

The indications for neuromonitoring during lumbar stenosis surgery are defined by the risks associated with patient positioning, the approach, decompression of neural elements, deformity correction, and instrument implantation. The routine use of EMG and SEP alone during lumbar stenosis surgery is no longer supported by the literature. Lateral approach neuromonitoring with EMG only is also suspect. Lumbar stenosis patients often present with multiple co-morbidities which put them at risk during routine pre-surgical positioning. Frequently encountered morbid obesity and/or diabetes mellitus may play a role in monitorable and preventable brachial plexopathy after "superman" positioning or femoral neuropathy from groin pressure after prone positioning, for example. Deformity correction in lumbar stenosis surgery often demands advanced implementation of multiple neuromonitoring modalities: EMG, SEP, and MEP. Because the bulbocavernosus reflex detects the function of the conus medullaris and sacral somato afferent/efferent fibers of the cauda equina, it may also be recorded. The recommendation to record pedicle screw thresholds has become more nuanced as surgeon dependence on 3D imaging, navigation, and robotics has increased. Neuromonitoring in lumbar stenosis surgery has been subject mainly to uncontrolled case series; prospective cohort trials are also needed.

Postoperative lumbar spine MRI: How well does a radiology report that raises suspicion for infection correlate with true clinical infection?

INTRODUCTION

Interpretation of a lumbar spine MRI in the immediate postoperative period is challenging, as postoperative tissue enhancement and fluid collections may be mistaken for infection. Radiology reports may use ambiguous language, creating a clinical problem for a surgeon in determining whether a patient needs treatment with antibiotics or revision surgery. Moreover, retrospective criticism of management in instances of a true infection may lead to medicolegal ramifications.

METHODS

A retrospective review of patients undergoing posterior-approach lumbar decompressive surgery with or without fusion over a 30-month period identified those undergoing postoperative MRI within 10 weeks of surgery. Patients initially operated upon for infection were excluded. The MRI reports were analyzed for language describing findings suspicious for infection and those of these with true infections were identified.

RESULTS

Of 487 patients undergoing posterior lumbar spine decompression surgery, 68 (14%) had postoperative MRI within 10 weeks. Of these, the radiology reports raised suspicion for infection in 20 (29%), of which 2 (10%) patients had a true infection. Two patients underwent reoperation for new motor deficit from seroma/hematoma. Of 63 patients who had MRI to evaluate complaints of back and/or leg pain without new motor deficits, the MRI significantly altered management in 3 patients (4.8%).

CONCLUSION

Radiology reports of postoperative lumbar spine MRIs frequently use language that raises suspicion for infection; but it is uncommon, however, that these patients harbor true infections. A radiology report describing possible infectious findings may not be considered significant without corroboration with other laboratory and clinical data.

Early Failures After Lumbar Discectomy Surgery: An Analysis of 62 690 Patients

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To determine the rate of early failures (readmission or reoperation for new or recurrent pain/neurological symptoms) within 30 days after lumbar discectomy and identify associated risk factors.

METHODS

A retrospective cohort study was conducted of patients undergoing lumbar discectomy in the National Surgical Quality Improvement Program database between 2013 and 2017. Rates of readmission for new or recurrent symptoms or reoperation for revision discectomy or fusion within 30 days postoperatively were measured and correlated with risk factors.

RESULTS

In total 62 690 patients were identified; overall rate of readmission within 30 days was 3.3%, including 1.2% for pain or neurological symptoms. Populations at increased risk of readmission were those with 3 or more levels of treatment (2.0%, odds ratio [OR] 2.8%, P < .01), age >70 years (1.8%, OR 1.6, P < .01), class 3 obesity (1.5%, OR 1.4, P = .04), and female gender (1.4%, OR 1.2, P = .02). The overall rate of reoperation within 30 days was 2.2%, including 1.2% for revision decompression or lumbar fusion surgery. Populations at increased risk of reoperation were revision discectomies (1.4%, OR 1.7, P < .01) and females (1.1%, OR 1.4, P < 0.01). Extraforaminal discectomies were associated with lower rates of readmission (0.7%, OR 0.6, P = 0.02) and reoperation (0.4%, OR 0.4, P = .01).

CONCLUSIONS

Early failures after lumbar discectomy surgery are rare. However, certain subpopulations are associated with increased rates of early failure: obesity, multilevel surgery, females, and revision discectomies.

Comparison of Surgical Outcomes of Microdiskectomy Procedures by Patient Admission Status

OBJECTIVE

We sought to compare the cost and in-hospital outcomes following lumbar microdiskectomy procedures by admission type.

METHODS

Patients undergoing lumbar microdiskectomy at a single institution from 2008 to 2016 following an elective admission (EL) were compared against those who were admitted from the emergency department (ED) or from elsewhere within or outside the hospital system (TR) for their perioperative outcomes and cost. Multivariable modeling controlled for age, sex, self-reported race, Elixhauser comorbidity score, payer type, number of segments, and procedure length.

RESULTS

Of the 1249 patients included in this study, 1116 (89.4%) were admitted electively while 123 (9.8%) were admitted from the ED and 10 (0.8%) were transferred from other hospitals. EL patients had significantly lower comorbidity burdens (P < 0.0001). Univariate and multivariable analyses revealed that transfer admission patients experienced significantly longer hospitalizations (ED: +1.7 days; P < 0.0001; TR: +5.3 days; P < 0.0001) and higher direct costs (ED: $1889; P < 0.0001; TR: $7001; P < 0.0001) compared with EL patients. Despite these risks, ED and TR patients only had increased odds of nonhome discharge compared with EL patients (ED: 3.4; P = 0.002; TR: 7.9; P = 0.02).

CONCLUSIONS

Patients admitted as transfers and from the ED had significantly increased hospitalization lengths of stay and direct costs compared with electively admitted patients.

Evaluation and Treatment of Foot Drop Using Nerve Transfer Techniques

Foot drop represents a complex pathologic condition, requiring a multidisciplinary approach for appropriate evaluation and treatment. Multiple etiologic factors require recognition before considering invasive/operative intervention. When considering surgical management for the treatment of foot drop, it is first and foremost imperative to establish the cause of the condition. Not all causes resulting in clinical foot drop have surgical options. Establishing a cause allows the provider to more appropriately curtail a multidisciplinary approach to working-up, and ultimately, treating the patient. The authors offer an algorithm for evaluating and treating foot drop conditions associated with lumbar spine radiculopathy and peripheral nerve lesions.

Undiagnosed Peripheral Nerve Disease in Patients with Failed Lumbar Disc Surgery

Study Design

Retrospective study (level of evidence=3).

Purpose

We examine the relationship between residual symptoms after discectomy for lumbar disc herniation and peripheral nerve (PN) neuropathy.

Overview of Literature

Patients may report persistent or recurrent symptoms after lumbar disc herniation surgery; others fail to respond to a variety of treatments. Some PN neuropathies elicit symptoms similar to those of lumbar spine disease.

Methods

We retrospectively analyzed data for 13 patients treated for persistent (n=2) or recurrent (n=11) low back pain (LBP) and/or leg pain after primary lumbar discectomy.

Results

Lumbar re-operation was required for four patients (three with recurrent lumbar disc herniation and one with lumbar canal stenosis). Superior cluneal nerve (SCN) entrapment neuropathy (EN) was noted in 12 patients; SCN block improved the symptoms for eight of these patients. In total, nine patients underwent PN surgery (SCN-EN, n=4; peroneal nerve EN, n=3; tarsal tunnel syndrome, n=1). Their symptoms improved significantly.

Conclusions

Concomitant PN disease should be considered for patients with failed back surgery syndrome manifesting as persistent or recurrent LBP.

An Amendment to the Neidre and MacNab Classification System for Lumbosacral Nerve Root Anomaly and Its Implication in Percutaneous Endoscopic Lumbar Discectomy

BACKGROUND

Lumbar disc herniation complicated with nerve root anomaly presents great challenges to diagnosis and treatment. Improper selection of surgical procedures may cause inferior outcomes and neurologic injury.

CASE DESCRIPTION

A 66-year old man presented with low back pain and radicular symptoms involving bilateral L5 and S1 nerve roots. Instead of percutaneous endoscopic lumbar discectomy, aggressive decompression was carried out because of a deviation between the examination and imaging findings. Surgical detection disclosed a confluent nerve root comprising 2 adjacent contributions that arose from the thecal sac exiting from the left L5/S1 foramen, in the absence of the root otherwise exiting through the caudal foramen. We found that the overwhelming left radicular symptoms were attributable to compression on this swelling anomalous root by a narrowed L5/S1 root cannula. Aggressive decompression and distraction of the intervertebral space successfully released the nerve root. Twenty months postoperatively, the patient experienced evident relief of the radicular symptoms and improvement of muscle strength with no complication.

CONCLUSIONS

Lumbosacral nerve root anomaly should be remembered and ruled out before selecting surgical methods. Inappropriate procedures can not alleviate the symptoms associated with the anomalous roots and may expose such patients to the risk of neural injury. In clinical practice, surgeons should select percutaneous endoscopic lumbar discectomy with caution, and stop the procedure instantly when unexplainable radicular irritation is evoked.

An Innovative Use of Cortoss Bone Cement to Stabilize a Nonunion after Interbody Fusion

A 65-year-old male originally had surgery for spondylolisthesis at L5-S1 in 2008 and then went on to have an L4-5 transforaminal lumbar interbody fusion (TLIF) with pedicle screw fixation from L4 to S1 and interbody graft in 2010. Despite having two surgical procedures, he continued with intractable back pain and was told he had a failed lumbar fusion. When he was evaluated with a computerized tomography (CT) scan from April 2015, it demonstrated an erosive nonunion of the L4-5 interbody fusion without incorporation of the polyetheretherketone (PEEK) cage. In an attempt to perform a minimally invasive stabilization of the L4-5 nonunion, he underwent a percutaneous lateral foraminal approach with an injection of Cortoss® cement (Stryker®, Malvern, PA) into the L4-5 interspace and around the graft. The objective was to stabilize the nonunion, resulting in intermediate relief of pain.

Intraoperative Myelography in Cervical Multilevel Stenosis Using 3D Rotational Fluoroscopy: Assessment of Feasibility and Image Quality

Background. Intraoperative myelography has been reported for decompression control in multilevel lumbar disease. Cervical myelography is technically more challenging. Modern 3D fluoroscopy may provide a new opportunity supplying multiplanar images. This study was performed to determine the feasibility and image quality of intraoperative cervical myelography using a 3D fluoroscope. Methods. The series included 9 patients with multilevel cervical stenosis. After decompression, 10 mL of water-soluble contrast agent was administered via a lumbar drainage and the operating table was tilted. Thereafter, a 3D fluoroscopy scan (O-Arm) was performed and visually evaluated. Findings. The quality of multiplanar images was sufficient to supply information about the presence of residual stenosis. After instrumentation, metal artifacts lowered image quality. In 3 cases, decompression was continued because myelography depicted residual stenosis. In one case, anterior corpectomy was not completed because myelography showed sufficient decompression after 2-level discectomy. Interpretation. Intraoperative myelography using 3D rotational fluoroscopy is useful for the control of surgical decompression in multilevel spinal stenosis providing images comparable to postmyelographic CT. The long duration of contrast delivery into the cervical spine may be solved by preoperative contrast administration. The method is susceptible to metal artifacts and, therefore, should be applied before metal implants are placed.