Long-term results of the NECK trial-implanting a disc prosthesis after cervical anterior discectomy cannot prevent adjacent segment disease: five-year clinical follow-up of a double-blinded randomised controlled trial.

BACKGROUND CONTEXT: Motion preserving anterior cervical disc arthroplasty (ACDA) in patients with cervical radiculopathy was introduced to prevent symptomatic adjacent segment disease as compared to anterior cervical discectomy and fusion (ACDF). PURPOSE: To evaluate the long-term outcome in patients with cervical radiculopathy due to a herniated disc undergoing ACDA, ACDF or ACD (no cage, no plate) in terms of clinical outcome measured by the Neck Disability Index (NDI). Likewise, clinically relevant adjacent segment disease is assessed as a long-term result. STUDY DESIGN: Double-blinded randomized controlled trial. PATIENT SAMPLE: A total of 109 patients with one level herniated disc were randomized to one of the following treatments: ACDA, ACDF with intervertebral cage, ACD without cage. OUTCOME MEASURES: Clinical outcome was measured by patients' self-reported NDI, Visual Analogue Scale (VAS) neck pain, VAS arm pain, SF36, EQ-5D, perceived recovery and reoperation rate. Radiological outcome was assessed by radiographic cervical curvature and adjacent segment degeneration (ASD) parameters at baseline and up until five years after surgery. METHODS: To account for the correlation between repeated measurements of the same individual Generalized Estimated Equations (GEE) were used to calculate treatment effects, expressed in difference in marginal mean values for NDI per treatment group. RESULTS: Clinical outcome parameters were comparable in the ACDA and ACDF group, but significantly worse in the ACD group, though not reaching clinical relevance. Annual reoperation rate was 3.6% in the first two years after surgery, declined to 1.9% in the years thereafter. The number of reoperations for ASD was not lower in the ACDA group, while the number of reoperations at the index level was higher after ACD, when compared to ACDF and ACDA. CONCLUSIONS: A persisting absence of clinical superiority was demonstrated for the cervical disc prosthesis five years after surgery. Specifically, clinically relevant adjacent level disease was not prevented by implanting a prosthesis. Single level ACD without implanting an intervertebral device provided worse clinical outcome, which was hypothesized to be caused by delayed fusion. This stresses the need for focusing on timely fusion in future research.

Efficiency of minimal oblique resection of the uncinate process during an anterior cervical discectomy and fusion.

ABSTRACT: Hypertrophy of the uncinate process (UP) can cause radiculopathy. Minimal UP resection is considered to remove the lesion while minimizing the risk of complications. This study aimed to elucidate the surgical results of minimal oblique resection of the UP. This study is a retrospective review of about sixty segments in 34 patients who underwent anterior cervical discectomy and fusion (ACDF) with minimal oblique uncinectomy between 2016 and 2018. The cross-sectional area of the UP was measured pre- and postoperatively. The interspinous distance, segmental Cobb angle, subsidence, fusion rate, surgical time, estimated blood loss, and postoperative complications were evaluated. The mean resected areas of the UP were 17.4 ±â€Š8.7 mm2 (25.9%) on the right and 17.3 ±â€Š11.2 mm2 (26.2%) on the left. The difference in interspinous distance in flexion-extension was 7.1 ±â€Š3.2 and 1.6 ±â€Š0.6 mm pre- and postoperatively, respectively (P = .000). The fusion rate after ACDF was 91.7% when measured according to segment (55/60) and 91.2% when measured according to patients (31/34). The difference in the segmental Cobb angle in flexion-extension was 8.3 ±â€Š6.2° and 1.9 ±â€Š0.3° pre and postoperatively, respectively (P = .000). Subsidence occurred in 4 (11.8%) patients and 5 (8.3%) segments. The average surgical time per segment was 68.8 ±â€Š9.3 minute, and the estimated blood loss was 48.5 ±â€Š25.0 mL. Postoperative complications comprised 1 case each of neck swelling, wound infection, pneumonia, and gastrointestinal bleeding. Our findings therefore revealed that minimal oblique uncinectomy during an ACDF can maintain the stability of the uncovertebral joint while sufficiently decompressing the neural foramen.

Spinal arachnoid sleeves and their possible causative role in cauda equina syndrome and transient radicular irritation syndrome.

INTRODUCTION: We have previously described arachnoid sleeves around cauda equina nerve roots, but at that time we did not determine whether injections could be performed within those sleeves. The purpose of this observational study was to establish whether the entire distal orifice of a spinal needle can be accommodated within an arachnoid sleeve. MATERIALS AND METHODS: We carefully dissected the entire dural sacs off four fresh cadavers, opened them by longitudinal incision, and immersed them in saline. Under direct vision, we penetrated the cauda equina roots nerves traveling almost vertically downward at 30 locations each with a 27- and a 25-G pencil-point needle (60 punctures total). We captured the images with a stereoscopic camera. RESULTS: The nerve root offered no noticeable resistance to needle entry. Although the arachnoid sleeves could not be identified with the naked eye, they were translucent but visible under microscopy. In 21 of 30 attempts with a 27-gauge needle, and in 20 of 30 attempts with a 25-gauge needle, the distal orifice of the spinal needle was completely within the arachnoid sleeve. CONCLUSION: It seems possible to accommodate the distal orifice of a 25- or a 27-gauge pencil-point spinal needle completely within the space of the arachnoid sleeve. An injection within this sleeve could potentially lead to a neurological syndrome, as we have previously proposed.

A real-world evidence of a consecutive treatment of 42 spine-related pain using dorsal root ganglion-pulsed radiofrequency (DRG-PRF).

OBJECTIVES: Spine-related pain is oftentimes not managed satisfactorily by analgesic medications and physiotherapy. Pulsed radiofrequency targeting on dorsal root ganglion (DRG-PRF) is able to precisely relieve pain without permanent damage to nervous tissue. In this article, we provide a short-term result of DRG-PRF for spine-related pain. PATIENTS AND METHODS: A retrospective chart review of a consecutive of 42 patients who underwent PRF between 2015-2016 was conducted. All patients had received pharmaceutical treatment or physiotherapy before PRF. The diagnoses included cervicogenic headache, cervicalgia, upper back, middle back and lower back pain with or without radiculopathy. All of them were treated with DRG-PRF according to corresponding segmental dermatomes. Preoperative and postoperative 1-week, 1-month and 3-month numerical rating scale (NRS) and the usage of analgesic medicines were recorded and analyzed. RESULTS: The mean age was 56.9 ± 14.8 years and 50 % of them were men. Seventy-six percent of patients underwent PRF had their pain originated from cervical and lumbar spine. Sixty percent of PRF procedures were to treat new chronic pain (duration less than 6 months). The preoperative NRS was 7.6 ± 1.1; the postoperative 1-week, 1-month and 3-month NRS were 2.5 ± 2.1, 3.0 ± 2.4 and 3.2 ± 2.4, respectively. DRG-PRF provided significantly NRS decrease in spine-related pain (p < 0.001). DRG-PRF also significantly decrease and deescalate the usage of analgesic medicines at postoperative 3 months (p < 0.001). The drop of NRS from preoperative state to postoperative 1 week was more significant in new chronic pain than in established chronic pain group (1.6 ± 1.4 vs. 3.0 ± 2.2, p = 0.015), however, both groups achieved similar pain reduction at postoperative 3 months (3.1 ± 2.2 vs. 3.3 ± 2.7, p = 0.903). No permanent neurological sequela was found, except 2 patients (4.7 %) had transient paresthesia with mild motor weakness after PRF which resolved within hours spontaneously. CONCLUSION: DRG-PRF significantly decrease NRS and decrease and deescalate the usage of analgesic medicines in post-procedure 3 months in spine-related pain patients. DRG-PRF is effective for both new chronic and established chronic pain, and offers similar pain reduction for patients with radicular or non-radicular pain.

Accuracy of t-EMG stimulation of the middle pedicle track to prevent radiculopathies as a result of misplaced lumbar screws.

OBJECTIVE: To describe the accuracy of middle pedicle track stimulation for the detection of pedicle breaches causing misplaced lumbar screws and subsequent neurological symptoms. PATIENTS AND METHODS: In a comparative observational study with two cohorts, 1440 lumbar pedicle screws were implanted using the freehand technique in 242 patients undergoing surgery for spinal deformities. In the first two-year period (2011-2012), the accuracy of screw placement (802 screws) was assessed by conventional intraoperative palpation of the pedicle track, t-EMG screw stimulation, and fluoroscopic monitoring. In the second period (2012-2013), the middle aspect of the lumbar pedicle tracks was systematically stimulated with a probe (638 screws). When thresholds in the middle track showed <9 mA, potential neurological risk was considered, and therefore, new pedicle tracks were performed. RESULTS: Six patients (4.4 %) in the first period presented postoperative radicular pain and a normal intraoperative screw t-EMG threshold. CT scans showed seven screws (0.9 %) with >2-mm medial-caudal invasion of the foramen. Before screw removal, t-EMG thresholds of these screws were again normal (≥10 mA). After removal of the screws. t-EMG of the middle part of the pedicle track showed thresholds below 9 mA (mean 5.2 mA). In the second period, the pedicle tracks were systematically stimulated. Low t-EMG thresholds (<9 mA) were found in 11 tracks (1.7 %) and were therefore reworked before screw placement. CT scans in these 10 patients showed that all of the 11 screws were correctly repositioned. CONCLUSIONS: This study shows that caudal or medial pedicle cortical breaches can be detected effectively by stimulating the middle part of the pedicle track. This technique is strongly recommended to prevent postoperative lumbar radiculopathies due to screw malposition.

A contemporary medicolegal claims analysis of injuries related to neuraxial anesthesia between 2007 and 2016.

STUDY OBJECTIVE: To provide a contemporary medicolegal analysis of claims brought against anesthesia providers in the United States related to neuraxial blocks for surgery and obstetrics. DESIGN: In this retrospective analysis, we analyzed closed claims data from the Controlled Risk Insurance Company (CRICO) Comparative Benchmarking System (CBS) database between 2007 and 2016. SETTING: Closed claims from inpatient and outpatient settings related to neuraxial anesthesia for surgical procedures and obstetrics. PATIENTS: Forty-five claims were identified for analysis. These patients underwent a variety of surgical procedures, included both children and adults, and with ages ranging from 6 to 82. INTERVENTIONS: Patients receiving neuraxial anesthesia (spinals, epidurals) for surgery or obstetrics. MEASUREMENTS: Data collected includes patient demographics, alleged injury type/severity, surgical specialty, likely contributors to the alleged damaging event, and case outcome. Some of the data were drawn directly from coded variables in the CRICO database, and some were gathered from narrative case summaries. MAIN RESULTS: Settlement payments were made in 20% of claims. Reported adverse outcomes ranged from temporary minor to permanent major injuries. Most closed claims were classified as permanent minor injuries. The greatest number of claims involved residual weakness and radiculopathy resulting from epidurals. The largest contributing factor to these injuries was noted to be "Technical Knowledge/Performance" of the anesthesia provider followed by "Missing or Documentation Error." Over half of the claims arose from obstetric patients (31%) and patients undergoing orthopedic surgery (27%). CONCLUSIONS: Patients with pre-existing radiculopathy or comorbidities may warrant more thorough informed consent about the increased risk of injury. Additionally, prompt follow-up, monitoring, and documentation of post-operative symptoms, such as weakness or radiculopathy, are crucial for improving patient safety and satisfaction. More timely communication with the patient and the surgical team regarding residual neurologic symptoms is important for earlier diagnosis of injury.

Surgical Strategies to Prevent Adjacent Segment Disease in the Cervical Spine.

The most popular approach to treating symptomatic cervical disk disease is anterior cervical discectomy and fusion. Although this procedure has significant long-term clinical success, it is associated with progressive adjacent segment degeneration with an annual incidence of ∼3%. Total disk arthroplasty was designed as an alternative to fusion that could preserve segmental motion at the operative level and potentially delay or prevent adjacent-level breakdown. The etiology of adjacent segment pathology (ASP) is multifactorial, and it is likely that most cases of ASP are unavoidable. When attempting to surgically prevent ASP, it is important to consider nonfusion alternatives, be judicious in one's level selection, and attempt to restore sagittal alignment. When ASP becomes a clinical problem, it is important to have an algorithm for how best to treat it.

Nanoparticle fullerol alleviates radiculopathy via NLRP3 inflammasome and neuropeptides.

The present study aimed to evaluate the analgesic effect of the antioxidant nanoparticle fullerol in a mouse radiculopathy and a dorsal root ganglion (DRG) culture models. Intervertebral disk degeneration causes significant hyperalgesia and nerve inflammation. Pain sensitization and inflammatory reaction were counteracted by fullerol when disk material was bathed in 10 or 100µM of fullerol prior to implantation. Immunohistochemistry showed similar massive IBA1 positive macrophage infiltration surrounding implanted disk material among groups, but IL-1ß and IL-6 expression was decreased in the fullerol treated group. In the DRG explant culture, after treatment with TNF-α, the expression of IL-1ß, NLRP3, and caspase 1 was significantly increased but this was reversed by the addition of fullerol. In addition, fullerol also decreased the expression of substance P and CGRP in the cultured DRGs. Nanoparticle fullerol effectively counteracts pain sensitization and the inflammatory cascade caused by disk degeneration.

Outcome of L5 radiculopathy after reduction and instrumented transforaminal lumbar interbody fusion of high-grade L5-S1 isthmic spondylolisthesis and the role of intraoperative neurophysiological monitoring.

PURPOSE: To evaluate the incidence and course of iatrogenic L5 radiculopathy after reduction and instrumented fusion of high-grade L5-S1 isthmic spondylolisthesis and the role of intraoperative neurophysiological monitoring (IONM). METHODS: Consecutive patients treated for high-grade spondylolisthesis with IONM from 2005 to 2013 were screened for eligibility. Prospectively collected clinical and surgical data as well as radiographic outcomes were analyzed retrospectively. Patients completed the multidimensional Core Outcome Measures Index (COMI) before and at 3, 12, and 24 months after surgery. RESULTS: Seventeen patients were included, with a mean age of 26.3 (±9.5) years. Mean preoperative L5-S1 slip was 72% (±21%) and was reduced to 19% (±13%) postoperatively. Mean loss of reduction at last follow-up [mean 19 months (±14, range 3-48 months)] was 3% (±4.3%). Rate of new L5 radiculopathy with motor deficit (L5MD) after surgery was 29% (five patients). Four patients fully recovered after 3 months, one patient was lost to neurologic follow-up. IONM sensitivity and specificity for postoperative L5MD was 20 and 100%, respectively. COMI, back pain and leg pain scores showed significant (p < 0.001) improvements at 3 months postoperatively, which were retained up to 24 months postoperatively. CONCLUSIONS: Transient L5 radiculopathy after reduction and instrumented fusion of high-grade spondylolisthesis is frequent. With IONM the risk of irreversible L5 radiculopathy is minimal. If IONM signal changes recover, full clinical recovery is expected within 3 months. Overall, patient-reported outcome of reduction and instrumented fusion of high-grade spondylolisthesis showed clinically important improvement.

[Clinical and Radiological Results after Anterior Cervical Corpectomy with Cage Fusion - a Retrospective Comparison of PEEK vs. Titanium Cages]. / Implantatassoziierte Komplikationen sowie klinischer und radiologischer Verlauf nach anteriorer zervikaler Korpektomie und Cage-Fusion ­ retrospektiver Vergleich von PEEK- gegen Titan-Cages.

Background Anterior cervical corpectomy and fusion (ACCF) has become a standard procedure for patients with spondylotic myelopathy due to multisegmental stenosis of the cervical canal. Beside the fusion technique using autogenous bone grafts, synthetic cages have been increasingly used in recent years. Published information on the clinical and radiological results of different cage materials for ACCF is still limited. The study presented here is the largest series to date reporting clinical and radiological outcomes and complication rates after one- to three-level ACCF using structural polyetheretherketone (PEEK) or titanium cages augmented by anterior plate-screw osteosynthesis. Materials and Methods Retrospective comparative study on 126 patients after cage ACCF using modular PEEK (n = 101) or distractable titanium (n = 25) cages with a minimum follow-up of 6 months. The numbers of hardware failures and implant-related surgical revisions were determined. The rate of subsidence and fusion and the course of lordotic alignment (segmental and regional Cobb's angles) were analysed. Neck Disability Index (NDI) and European Myelopathy Score (EMS) were assessed. Results Significantly greater number of screw and cage complications were detected in the titanium cage group (36 vs. 7.9 % and 64 vs. 36.6 %, respectively). Non-significant trend to a higher rate of implant related revision rate in the titanium cage group (16 vs. 2.97 %). Significantly greater rate of grade I or II fusion in the PEEK cage group after 6 months (82 vs. 52 %). NDI, EMS and lordotic alignment improved significantly in both groups. There were neither significant differences between the two groups nor significant correlations between these clinico-radiological parameters and the cage material. Partial correlations performed with control of parameters showing inhomogenous distribution (patient age, fusion distance, rate of multilevel corpectomy and the rate of intraoperative segmental overdistraction) showed no significant correlations for any of the clinical or radiological outcome parameters and the complications or revisions to the cage material. Conclusion Cages are a safe and effective alternative to autogenous bone graft for ACCF. A significant improvement in clinical and radiological parameters can be achieved with both titanium and PEEK implants. Significant differences between the two cage material groups or significant correlations of clinico-radiological outcome and cage material were not proven. Moreover there is no evidence in the literature for clinical advantages of one special cage material, to date. Therefore further prospective randomised evaluation of different fusion techniques in ACCF is still necessary.

Secreting Follicle-Stimulating Hormone Pituitary Carcinoma with Cervical Metastasis.

BACKGROUND: Pituitary carcinoma is defined by either metastases outside the central nervous system or noncontiguous foci within the central nervous system. This case report details the first documented case of a pathologically isolated follicle-stimulating hormone-secreting pituitary carcinoma and its presentation of metastasis. CASE DESCRIPTION: A 63-year-old man developed intrascapular pain radiating up his neck to his occiput. He had undergone a transsphenoidal hypophysectomy 2 years previously for an atypical pituitary macroadenoma. Subsequent magnetic resonance imaging identified a focal, solitary, well-circumscribed, homogeneous T2 high-signal intradural, extramedullary enhancing mass at C2-3 in a right ventral parasagittal location, extending toward the exit foramina. On surgical excision with a laminectomy, the mass demonstrated a morphologic appearance of a malignant neuroendocrine tumor with an immunoprofile similar to the original atypical pituitary adenoma. This was in keeping with metastatic disease secondary to a follicle-stimulating hormone-secreting pituitary carcinoma. CONCLUSIONS: Although rare, metastatic spread is recognized in patients with atypical pituitary adenoma. This should form the differential diagnosis for such patients presenting with symptoms that could be attributed to metastatic lesions within the neuraxis. In these patients, who undergo regular surveillance in joint neuroendocrine clinics, more urgent investigation of new spinal pain should be instigated to exclude metastatic disease.

Cervical Myelopathy Caused by Bilateral Laminar Cleft of the Axis: Case Report and Review of Literature.

BACKGROUND: Cervical myelopathy due to bilateral laminar cleft of the axis is extremely rare, and few cases have been previously reported. However, its treatment is relatively simple. Surgical removal of the anomalous bony structure compromising the spinal canal can sufficiently achieve a good outcome. CASE DESCRIPTION: A 56-year-old man presented with a 2-year history of stiffness of the left upper and lower extremities. Cervical spine computed tomography showed a bony cleft at both laminae of the posterior arch of the axis, with obvious cord compression on magnetic resonance imaging. Although absence of right pedicle and spina bifida of C7 were also detected, there was no cord compression at this level. The patient underwent surgical removal of the anomalous laminar cleft and the spinous process of the axis. Postoperatively, he improved rapidly and was discharged on the seventh postoperative day. He was asymptomatic at the 3-year follow-up. After surgery, the preoperative myelopathy status was much improved. About 7 years after surgery, radiographs showed no kyphosis and instability. CONCLUSION: Invaginated bilateral laminar cleft of the axis is a rare cause of cervical myelopathy. The findings in our case should broaden the radiographic differential diagnosis in patients with cervical myelopathy. Surgical removal is an appropriate and simple treatment for this patient, resulting in a satisfactory outcome.

Traumatic Lumbar Subdural Hematoma in the Absence of Intracranial Disease.

BACKGROUND: Traumatic spinal subdural hematoma is an exceedingly rare condition, with those occurring in the absence of intracranial disease being particularly uncommon. Only 13 such cases have been reported. Although theories exist to describe the pathophysiology of traumatic spinal subdural hematoma, the precise mechanism and guidelines for management remain unclear. CASE DESCRIPTION: This report describes a 37-year-old woman who suffered a traumatic assault who developed progressive low back pain with radicular symptoms 2 days after presentation. Magnetic resonance imaging revealed a lumbar subdural hematoma extending from L1 to L5. No intracranial disease was detected on imaging. CONCLUSIONS: Definitive guidelines for management of this condition are uncertain; however, successful use of conservative management, lumbar drainage, and surgical evacuation has been reported. This patient underwent a lumbar laminectomy with evacuation of the hematoma, resulting in immediate pain relief and resolution of symptoms within 1 week of the procedure.

A Transtubular Microsurgical Approach to Treat Lateral Cervical Disc Herniation.

OBJECTIVE: Different surgical options are available to treat radicular pain syndromes of the cervical spine. Use of the posterior approach for foraminotomy and sequestrectomy (Frykholm) fusion can be avoided, but neck pain affects the postoperative course. This retrospective study compares the classical Frykholm approach and the transtubular microsurgical approach for foraminotomy. METHODS: From 2004 to 2012, 40 patients fulfilled the inclusion criteria and were enrolled into this retrospective study. The classical Frykholm approach was performed on 25 affected levels. The transtubular microsurgical approach was used on 19 affected levels. Endpoints were neck pain, radicular pain, surgery time, duration of hospital stay, and long-term outcomes. RESULTS: For the transtubular microsurgical approach and the classical Frykholm approach, the mean surgery time was 77.65 ± 23 minutes and 104 ± 27.59 minutes (P = 0.003), respectively. Radicular pain improved in all patients regardless of the technical approach. Significant differences were observed in neck pain on the first postoperative day (P = 0.003) and at discharge (P = 0.006), resulting in a shorter hospital stay of 4.82 days ± 2.1 for the transtubular microsurgical approach in comparison with 7.43 days ± 3.2 for the Frykholm approach (P = 0.005). According to the criteria of Odom, the rate of an excellent or good outcome was 97.5% (67.5% excellent and 30% good), without any differences between the compared approaches. CONCLUSION: The transtubular microsurgical approach shows advantages regarding postoperative neck pain, surgery time, and hospital stay with a trend towards an earlier return to work.

[Prevention of lumbosacral radiculopathy in coal miners].

The authors consider results of retrospective analysis of primary consultations of 2791 coal miners with occupational lumbosacral radiculopathy over 1976-2014 in Rostov regional occupational center. Findings are that 975 miners (34.9%) underwent examination of the disease connection with occupation, and occupational lumbosacral radiculopathy was diagnosed on primary consultation, but in 1816 miners (65.1%) recurrent lowerback pain and health-injury by occupational hazards were diagnosed. Recurrent lower back pain in miners was considered as a predictor of occupational lumbosacral radiculopathy. The authors suggested a way of prevention for occupational lumbosacral radiculopathy and comorbid conditions in miners during periodic medical examinations in occupational pathology center.

[The causes and prevention of C5 nerve root palsy after anterior cervical decompression and fusion].

OBJECTIVE: To analyze the causes of muscular paralysis due to C5 nerve root injury after anterior cervical decompression and fusion (ACDF) and explore its prevention way. METHODS: From January 2005 to December 2015, 310 patients underwent ACDF in our hospital. Of them, 9 cases occurred muscular paralysis due to C5 nerve root injury after operation. The clinical data of 9 patients were retrospectively analyzed. There were 8 males and 1 female, aged from 51 to 84 years with an average of 64 years. Two cases underwent internal fixation and intervertebral fusion with one segment, 6 cases with two segments, 1 case with three segments. Simple deltoid muscle weakness, pain, numbness happened in 7 cases, simultaneously biceps brachii muscle weakness, pain, numbness in 2 cases. Muscle strength was 0 grade in 1 case, 1 grade in 3 cases, 2 grades in 4 cases, 3 grades in 1 case. RESULTS: The follow up time of 9 patients was more than 12 months and the longest was 24 months with an average of 14 months. Muscle strength of 7 patients recovered to 4-5 grades. Recovering time after operation was directly proportional to the degree of injury, those patients with muscle strength level more than 2, usually could have significant improvement within 3 weeks. The JOA score improved from 10.89±1.89 preoperatively to 8.92±1.91 postoperative C5 nerve root palsy to 14.48±2.10 at final follow up, with significant difference(P<0.05). CONCLUSIONS: More complicated factors result in C5 nerve root injury after ACDF. Except those suffered severe grinding contusion and amputation, most of the patients can get satisfactory prognosis. Strict control of the operation indication, selection of the right surgical segment with accurate manipulation, control of the distraction of intervertebral space and the width of the multilevel anterior cervical corpectomy, are main methods to prevent the complication.

[Sciatica. From stretch rack to microdiscectomy]. / Ischias. Von der Streckbank zur Mikrodiskektomie.

In ancient times as well as in the Middle Ages treatment options for discogenic nerve compression syndrome were limited and usually not very specific because of low anatomical and pathophysiological knowledge. The stretch rack (scamnum Hippocratis) was particularly prominent but was widely used as a therapeutic device for very different spinal disorders. Since the beginning of the nineteenth century anatomical knowledge increased and the advances in the fields of asepsis, anesthesia and surgery resulted in an increase in surgical interventions on the spine. In 1908 the first successful lumbar discectomy was initiated and performed by the German neurologist Heinrich O. Oppenheim (1858-1919) and the surgeon Fedor Krause (1857-1937); however, neither recognized the true pathological condition of discogenic nerve compression syndrome. With the landmark report in the New England Journal of Medicine in 1934, the two American surgeons William Jason Mixter (1880-1958) and Joseph Seaton Barr (1901-1963) finally clarified the pathomechanism of lumbar disc herniation and furthermore, propagated discectomy as the standard therapy. Since then interventions on intervertebral discs rapidly increased and the treatment options for lumbar disc surgery quickly evolved. The surgical procedures changed over time and were continuously being refined. In the late 1960s the surgical microscope was introduced for spinal surgery by the work of the famous neurosurgeon Mahmut Gazi Yasargil and his colleague Wolfhard Caspar and so-called microdiscectomy was introduced. Besides open discectomy other interventional techniques were developed to overcome the side effects of surgical procedures. In 1964 the American orthopedic surgeon Lyman Smith (1912-1991) introduced chemonucleolysis, a minimally invasive technique consisting only of a cannula and the proteolytic enzyme chymopapain, which is injected into the disc compartment to dissolve the displaced disc material. In 1975 the Japanese orthopedic surgeon Sadahisa Hijikata described percutaneous discectomy for the first time, which was a further minimally invasive surgical technique. Further variants of minimally invasive surgical procedures, such as percutaneous laser discectomy in 1986 and percutaneous endoscopic microdiscectomy in 1997, were also introduced; however, open discectomy, especially microdiscectomy remains the therapeutic gold standard for lumbar disc herniation.

Iatrogenic neurologic deficit after lumbar spine surgery: A review.

Iatrogenic neurologic deficits after lumbar spine surgery are rare complications, but important to recognize and manage. Complications such as radiculopathy, spinal cord compression, motor deficits (i.e. foot drop with L5 radiculopathy), and new onset radiculitis, while uncommon do occur. Attempts at mitigating these complications with the use of neuromonitoring have been successful. Guidance in the literature as to the true rate of iatrogenic neurologic deficit is limited to several case studies and retrospective designed studies describing the management, prevention and treatment of these deficits. The authors review the lumbar spinal surgery literature to examine the incidence of iatrogenic neurologic deficit in the lumbar spinal surgery literature. An advanced MEDLINE search conducted on May 14th, 2015 from January 1, 2004 through May 14, 2015, using the following MeSH search terms "postoperative complications," then subterms "lumbar vertebrae," treatment outcome," "spinal fusion," and "radiculopathy" were included together with "postoperative complications" in a single search. Postoperative complications including radiculopathy, weakness, and spinal cord compression were included. The definition of iatrogenic neurologic complication was limited to post-operative radiculopathy, motor weakness or new onset pain/radiculitis. An advanced MEDLINE search conducted on May 14th, 2015 using all of the above terms together yielded 21 results. After careful evaluation, 11 manuscripts were excluded and 10 were carefully reviewed. The most common indications for surgery were degenerative spondylolisthesis, spondylosis, scoliosis, and lumbar stenosis. In 2783 patients in 12 total studies, there were 56 patients who had reported a postoperative neurologic deficit for a rate of 5.7. The rates of deficits ranged from 0.46% to 17% in the studies used. The average rate of reported neurologic complications within these papers was 9% (range 0.46-24%). Thirty patients of a total of 731 (4.1%) had a new onset neurologic injury after anterior lumber interbody fusion or lateral lumber interbody fusion. Thirty-seven out of 2052 (1.9%) patients had a neurologic injury after posterior decompression and fusion. Screw malposition was responsible for 11 deficits. Spinal surgery for lumbar degenerative disease carries a low but definite rate of neurologic deficits. Despite the introduction of neuromonitoring, these complications still occur. Interpretation of neurologic injury rates for lumbar surgery is limited by the few prospective and cohort-matched controlled studies. Likewise, most injuries were associated with the placement of instrumentation despite the type of approach.

C2 nerve dysfunction associated with C1 lateral mass screw fixation.

The C1 lateral mass screw technique is widely used for atlantoaxial fixation. However, C2 nerve dysfunction may occur as a complication of this procedure, compromising the quality of life of affected patients. This is a review of the topic of C2 nerve dysfunction associated with C1 lateral mass screw fixation and related research developments. The C2 nerve root is located in the space bordered superiorly by the posterior arch of C1 , inferiorly by the C2 lamina, anteriorly by the lateral atlantoaxial joint capsule, and posteriorly by the anterior edge of the ligamentum flavum. Some surgeons suggest cutting the C2 nerve root during C1 lateral mass screw placement, whereas others prefer to preserve it. The incidence, clinical manifestations, causes, management, and prevention of C2 nerve dysfunction associated with C(1) lateral mass screw fixation are reviewed. Sacrifice of the C2 nerve root carries a high risk of postoperative numbness, whereas postoperative nerve dysfunction can occur when it has been preserved. Many surgeons have been working hard on minimizing the risk of postoperative C2 nerve dysfunction associated with C1 lateral mass screw fixation.

Screw perforation features in 129 consecutive patients performed computer-guided cervical pedicle screw insertion.

STUDY DESIGN: A cross-sectional study of the data retrospectively collected by chart review. OBJECTIVES: This study aimed to clarify screw perforation features in 129 consecutive patients treated with computer-assisted cervical pedicle screw (CPS) insertion and to determine important considerations for computer-assisted CPS insertion. CPS fixation has been criticized for the potential risk of serious injury to neurovascular structures. To avoid such serious risks, computed tomography (CT)-based navigation has been used during CPS insertion, but screw perforation can occur even with the use of a navigation system. METHODS: The records of 129 consecutive patients who underwent cervical (C2-C7) pedicle screw insertion using a CT-based navigation system from September 1997 to August 2013 were reviewed. Postoperative CT images were used to evaluate the accuracy of screw placement. The screw insertion status was classified as grade 1 (no perforation), indicating that the screw was accurately inserted in pedicle; grade 2 (minor perforation), indicating perforation of less than 50 % of the screw diameter; and grade 3 (major perforation), indicating perforation of 50 % or more of the screw diameter. We analyzed the direction and rate of screw perforation according to the vertebral level. RESULTS: The rate of grade 3 pedicle screw perforations was 6.7 % (39/579), whereas the combined rate of grades 2 and 3 perforations was 20.0 % (116/579). No clinically significant complications, such as vertebral artery injury, spinal cord injury, or nerve root injury, were caused by the screw perforations. Of the screws showing grade 3 perforation, 30.8 % screws were medially perforated and 69.2 % screws were laterally perforated. Of the screws showing grades 2 and 3 perforation, 21.6 % screws were medially perforated and 78.4 % screws were laterally perforated. Furthermore, we evaluated screw perforation rates according to the vertebral level. Grade 3 pedicle screw perforation occurred in 6.1 % of C2 screws; 7.5 % of C3 screws; 13.0 % of C4 screws; 6.5 % of C5 screws; 3.2 % of C6 screws; and 4.0 % of C7 screws. Grades 2 and 3 pedicle screw perforations occurred in 12.1 % of C2 screws, 22.6 % of C3 screws, 31.5 % of C4 screws, 22.2 % of C5 screws, 14.4 % of C6 screws, and 12.1 % of C7 screws. C3-5 screw perforation rate was significantly higher than C6-7 (p = 0.0024). CONCLUSIONS: Careful insertion of pedicle screws is necessary, especially at C3 to C5, even when using a CT-based navigation system. Pedicle screws tend to be laterally perforated.