The use of a new high-speed shielded curved drill is associated with improved intraoperative and clinical outcomes after cervical corpectomy and fusion procedures: a retrospective case series.

BACKGROUND: Anterior cervical corpectomy and fusion (ACCF) is an effective technique to address multi-level degenerative cervical myelopathy. However, as the number of surgical levels increases, the outcomes worsen with respect to complication rates, range of motion and length of surgery. This study aimed to determine the clinical outcome of ACCF procedures performed using a new distally curved and shielded drilling device. METHODS: A retrospective study was conducted on 43 ACCF procedures in which the device was used for osteophyte removal. Patient files were reviewed to assess the early clinical results and complications following ACCF. Clinical outcomes were evaluated using patient neck and arm pain scores and SF-36 questionnaires. Hospitalization characteristics were compared with historical controls. RESULTS: All procedures were uneventful and without major complications or neurological deterioration. Single-level ACCF procedures required an average of 71 min and followed by an average hospitalization of 3.3 days. Osteophyte removal, verified by intraoperative imaging, was satisfactory. Average neck pain score was improved by 0.9 points (p = 0.24). Average arm pain score was improved by 1.8 points (p = 0.06). SF-36 scores were improved in all domains. CONCLUSIONS: The new curved device enabled safe and efficient removal of osteophytes sparing adjacent vertebral removal in ACCF procedures, thus improving the clinical outcome.

Economic Analysis of Transforaminal Lumbar Interbody Fusion Surgery Utilizing a Curved Bone Removal Device.

BACKGROUND: Transforaminal lumbar interbody fusion (TLIF) represents a commonly performed spinal procedure that poses a significant financial burden on patients, hospitals and insurers. Reducing these costs, while maintaining efficacy, may be assisted by a new powered endplate preparation device, designed to shorten procedural time while offering positive impacts on other elements that contribute to the cost of care. OBJECTIVE: The aim of the study was to assess and compare the individual cost elements of TLIF procedures with and without the use of the device, to determine whether application of this technology translated into any material procedural savings. METHODS: The records of 208 single-level TLIF procedures in a single hospital were reviewed. Surgical time, length of hospital stay, blood loss, infection rate, and other parameters were compared for the cases where the device was used (device group; n = 143) and cases which used standard tools (control group; n = 65). The cost per unit of each element was derived from the literature, online resources, and the hospital's financial department. RESULTS: The analysis revealed a shorter surgery duration in the device group (23 min, after controlling for procedure year and patient characteristics; statistically significant at p < 0.001) and lower complication and readmission rates (p = 0.67 and p = 0.21, respectively) associated with the use of the device, leading to a statistically significant cost reduction of approximately 2060 US dollars (US$) (p < 0.01). CONCLUSION: The study suggests that use of the device may lead to a cost reduction and shorter procedure without deteriorating the clinical outcome.

Intraoperative monitoring of corticospinal tracts in anterior cervical decompression and fusion surgery: Excitability differentials of lower extremity muscles.

OBJECTIVE: This study examines and compares excitability characteristics of tibialis anterior (TA) and abductor hallucis (AH) transcranial motor evoked potentials (tcMEP) during anterior cervical decompression and fusion (ACDF) surgery. METHODS: Electrophysiological and clinical data of 89 patients who underwent ACDF procedure were retrospectively reviewed. TcMEP data of TA and AH muscles from 178 limbs were analyzed for availability, robustness and stability during the procedure. RESULTS: TA tcMEP was available at 83% whereas AH tcMEP was available at 99% of the monitored lower limbs at preposition baseline. Availability of both TA and AH tcMEP was demonstrated in 147/178 limbs. The baseline amplitude of AH tcMEP was significantly greater than that of TA tcMEP recorded from the same limb (744.6 ±â€¯54.0 and 326.9 ±â€¯33.3 µV, respectively). Simultaneous deterioration of TA and AH tcMEP data was demonstrated in 10/147 limbs. Deterioration of either TA or AH tcMEP data accompanied by unchanged tcMEP data from the other lower limb muscle was noted in 32/147 compared to 1/147 limbs, respectively. The deteriorated TA and AH tcMEP data returned to baseline before closing at incidence of 17% compared to 46%, respectively. No new lower extremity (LE) neurological deficit was presented postoperatively in any patient. CONCLUSIONS: AH tcMEP is a more reliable candidate than TA tcMEP for intraoperative LE monitoring in ACDF procedure. SIGNIFICANCE: The excitability differentials in LE tcMEP in ACDF is a variable that need to be considered while interpreting intraoperative neurophysiological data.

A New High-Speed Shielded Curved Device Allowing Safe Posterior Thoracic Discectomy Through a Modified Transforaminal Thoracic Interbody Fusion Approach: Technique Description and Case Series.

BACKGROUND: The appropriate approach for surgical removal of thoracic disc herniations is controversial. The posterior approach historically acquired a bad reputation due to high rates of neurologic deterioration subsequent to spinal cord manipulation. The anterior approach has consequently gained popularity but entails a larger magnitude of surgery if open and is technically demanding if approached thoracoscopically. Approaching the thoracic disc posteriorly following unilateral facetectomy and pediculectomy was suggested in 1978. This study presents a technique for posterior unilateral thoracic discectomy through a hemilaminectomy, unilateral facetectomy, and hemipediculectomy, facilitated by a novel curved dorsally shielded high-speed device. Introducing the device ventral to the dural sac allows removal of calcified and soft disc fragments without relying on forceful manual maneuvers and avoiding manipulation of the spinal cord. METHODS: The maximal disc protrusion side is approached through a hemilaminectomy, unilateral facetectomy, and hemipediculectomy removing the superior half of the pedicle and exposing the disc transforaminally, allowing its removal using the device. Pedicle fixation and fusion concluded all procedures (TTIF). Between June 2014 and November 2018, 12 patients (6 men and 6 women) ages 23 to 74 years underwent posterior thoracic discectomy applying the above approach. The affected levels were D3 to D4 (1), D5 to D6 (1), D7 to D8 (1), D9 to D10 (1), D10 to D11 (3), D11 to D12 (4), and D12 to L1 (1). RESULTS: All patients presented with neurologic deterioration and all but 2 with pyramidal signs. All procedures were uneventful, without dural tears. None of the patients deteriorated neurologically. Average back pain visual analog scale scores decreased by 1.2, from 6.6 to 5.4. Average leg pain visual analog scale scores decreased by 2.2, from 6.6 to 4.4. Improvement was noted in Oswestry Disability Index scores and 6 SF-36 metrics. CONCLUSIONS: The new curved device and approach allow for a faster, safer thoracic disc herniation removal. CLINICAL RELEVANCE: The proposed technique allows a safer treatment for thoracic disc herniations, reducing complication rates and improving patient outcome.

Effect of Intra- and Extraoperative Factors on the Efficacy of Intraoperative Neuromonitoring During Cervical Spine Surgery.

INTRODUCTION: The purpose of the present study was to examine the effect of various extra- and intraoperative factors on the ability of neuromonitoring to predict neurological complications. METHODS: We reviewed the data from 592 patients who had undergone cervical spine surgery with neuromonitoring at Assuta Medical Center from 2006 to 2013. We compared the somatosensory evoked potentials, transcranial electric motor evoked potentials, and electromyographic signals collected throughout surgery with the patient surgical outcome measures, demographic data, pre-existing pathological features found on neurological examination, and radiographic findings. Descriptive and inferential analyses were used to estimate the relative explanatory power contributed by these factors. RESULTS: We included 468 patients in the present study. Neuromonitoring changes occurred in 100 patients, and the appropriate clinical intervention was undertaken in all 100, with recovery of the signals in 69. A transient neuromonitoring change was not associated with a poor outcome (only 8 of 69 patients). However, a permanent neuromonitoring change was associated with a new neurological deficit (13 of 31 patients) Changes occurring during positioning or decompression were associated with better clinical outcomes than were changes occurring during the rest of the procedure. Extraoperative factors were not associated with an increased risk of neuromonitoring changes during surgery or poorer surgical outcomes. CONCLUSIONS: Permanent neuromonitoring changes predicted for new neurological deficits. However, transient changes were not associated with a new deficit. Neuromonitoring changes occurring during positioning and decompression had better clinical outcomes compared with those occurring during the rest of the procedure.

Suitability of Administrative Databases for Durotomy Incidence Assessment: Comparison to the Incidence Associated With Bone-Removal Devices, Calculated Using a Systemic Literature Review and Clinical Data.

BACKGROUND: Durotomy is a major complication of spinal surgery, potentially leading to additional clinical complications, longer hospitalization, and increased costs. A reference durotomy incidence rate is useful for the evaluation of the safety of different surgical aspects. However, the literature offers a wide range of incidence rates, complicating this comparison. Theoretically, a reference incidence value can be extracted from administrative databases, containing a large number of procedures. However, it is suspected that these databases suffer from underreporting of complications. This study aims to evaluate durotomy incidence using several large-scale databases and to assess the ability to use it as a reference by comparison to durotomy incidences directly associated with 4 bone removal devices, including the commonly used high-speed drill. METHODS: Durotomy overall incidence was estimated from several administrative databases using different methods in order to achieve minimal and maximal estimations. Durotomy incidences for 3 bone removal devices were derived using literature meta-analysis, and the incidence for the fourth device was calculated using clinical data. RESULTS: The incidence range of durotomy according to the databases was 2.8-3.5%. The calculated incidence of durotomy for the studied devices was 0.4-2.91%. The highest rate, 2.91%, is associated with the commonly used high-speed drill combined with Kerrison Rongeur and bone punches. Since bone-removal devices are just one of the possible causes of dural tears, the general incidence is expected to be higher than the incidence associated with the devices, yet even the maximal estimation, 3.5%, was only slightly higher, suggesting that the speculation of underreporting of dural tears to these databases is probably true, as also supported by the mostly higher incidences reported in the literature. CONCLUSIONS: Hospital administrative databases seem to show a lower-than-reasonable incidence of durotomy, suggesting possible underreporting. Researchers should therefore use this tool with caution. Reduction of the absolute durotomy incidence by approximately 2.5% can be achieved by improving the safety of bone-removal devices.

Efficacy of Head Repositioning in Restoration of Electrophysiological Signals During Cervical Spine Procedures.

PURPOSE: To evaluate the frequency of loss of neurophysiological potentials during head positioning, the usefulness of head repositioning to restore the potentials, and the effect on neurological outcome. METHODS: We retrospectively reviewed consecutive cervical spine surgeries performed at the Israel Spine Center, Assuta Medical Center, during 2006 to 2013. Surgeries performed with neuromonitoring (transcranial-electric motor evoked potentials, somatosensory evoked potentials, electromyographic recordings) were included. Demographic data, medical history, findings at neurological examination and imaging, electrophysiological data recorded during surgery, and neurological outcomes were collected and analyzed. RESULTS: Three hundred eighty-one patients met inclusion criteria. Loss of potentials detected in nine patients during patient positioning and repositioning was undertaken with the aim of restoring electrophysiological signals. In 5/9 patients, repositioning resulted in immediate reappearance of potentials; in 1/5, potentials were affected again during decompression. In 4/9, repositioning did not immediately restore electrophysiological signals; in », potentials reappeared later during the decompression and in ¾, potentials had not recovered till the conclusion of surgery. There were new neurological deficits in 2/9, including one patient with loss of potential that was not restored with repositioning and the one in whom potential was restored but lost again during decompression. CONCLUSIONS: Intraoperative neuro monitoring is an efficient tool to alert the surgical team to potential neurological damage. Head reposition often restores the electrophysiological signals with possible prevention of impending sequelae.

Remote Cerebellar Hemorrhage Complicating Unintended Durotomy in Lumbar Spine Surgery.

STUDY DESIGN: Case reports and retrospective review of accidental durotomies in lumbar surgeries during 5 years. OBJECTIVES: To draw attention to a potentially serious complication of incidental durotomy-remote cerebellar hemorrhage. SUMMARY AND BACKGROUND DATA: Accidental durotomy is a frequent complication of spinal surgery. In most cases the outcome of incidental durotomy is favorable. A delayed potentially serious complication of CSF loss during and after lumbar surgery is remote cerebellar hemorrhage (RCH). METHODS: During 2008-2012, 1169 lumbar spine procedures were performed at our spine center. In 210 surgeries incidental or intentional durotomies occurred. All patients with durotomies were managed with suturing of the dural wound followed by deep wound drainage left for 5 days and tight wound closure. RESULTS: Of the 210 patients with CSF loss three patients were identified to suffer from RCH-an incidence of 0.26%. The three patients ages 56, 67 and 75 years developed RCH between 36-192 hours after surgery. All three were managed with supportive treatment and close clinical supervision. A gradual clinical and radiological improvement was noted in all three patients. CONCLUSIONS: Severe headache after spinal surgery and or declining mental status should not be attributed only to low CSF pressure secondary to dural tearing. It can also be the result of remote cerebral or cerebellar hemorrhage. Once the diagnosis of RCH is made, close clinical supervision is mandatory. In most cases non-operative supportive treatment may lead to eventual full clinical recovery.

[Acute subdural hematoma following spine surgery].

Spinal anesthesia and lumbar puncture may lead to intracerebral, subdural or subarachnoid bleeding and there have been previous reports on patients who developed subdural hematoma a few days after surgery on the spine. This is a case report of a patient who developed acute subdural hematoma during surgery performed to remove an intradural spine tumor. This report suggests that the possibility of an intracranial hematoma should be considered in cases of neurological deterioration following spinal surgery.

Instrumented slip reduction and fusion for painful unstable isthmic spondylolisthesis in adults.

BACKGROUND CONTEXT: Although in situ posterolateral fusion is considered the gold standard for surgical treatment of low-grade adult spondylolisthesis, correction of the sagittal translation by instrumented slip reduction is more controversial in adults; nevertheless it may delay adjacent level disc degeneration. PURPOSE: The present study was undertaken to evaluate the safety and clinical outcome of operative instrumented slip reduction in 12 adults with isthmic spondylolisthesis accompanied by advanced disc degeneration at that level. STUDY DESIGN: This study was a retrospective review of 12 consecutive lumbar or lumbosacral isthmic slip, which underwent operative slip reduction in our institute. PATIENT SAMPLE: All adult patients having operative instrumented slip reduction of isthmic spondylolisthesis from January 2000 to December 2005 were assessed. OUTCOME MEASURES: Outcome measures included the Oswestry Disability Index (ODI) for low back pain and the visual analog scale (VAS) of back and leg pain. Patient outcome was assessed by work status, participation in sports activities and intake of pain medications. METHODS: Between January 2000 and December 2005, we performed slip reduction on 12 adults aged 28 to 62 years (average 47) with symptomatic lumbar or lumbosacral isthmic spondylolisthesis. The indications for surgery were long-standing low back and leg pain that had not responded to nonoperative management. RESULTS: The vertebral slip ranged between 15% and 90% (average 34%). Radiologic evidence of adult slip progression was available in 5 patients, one had a de novo slip formation and the others had increased sagittal translation on flexion-extension lateral x-rays. All 12 patients underwent posterior decompression, pedicle screw fixation, slip reduction, and posterior lumbar interbody fusion. The slip was anatomically reduced by 100% in 5 patients and between 90% and 95% in 7 (average 95% for the group). X-rays revealed no evidence of instrumentation failure at a mean follow-up of 38 months (range: 18 to 72). Minimal loss of correction (5%) was observed in 2 cases. No neurologic complications were encountered. The mean preoperative ODI of 49 dropped to 12 postoperatively (range: 0 to 20). The mean preoperative VAS for back pain of 7.3 dropped to 1.6 after surgery (range: 0 to 3). The mean preoperative VAS for leg pain of 8 dropped to 1 after surgery (range: 0 to 4). Five patients were followed for more than 3 years: none had evidence of adjacent level disc disease. CONCLUSIONS: Our results may support performing slip reduction in selected adults with isthmic spondylolisthesis.

Failure of the Wallis interspinous implant to lower the incidence of recurrent lumbar disc herniations in patients undergoing primary disc excision.

BACKGROUND: Ipsilateral recurrent disc herniation after lumbar discectomy is a significant problem in the management of lumbar disc disease and may necessitate repeat surgical intervention. A population-based study in Finland found that about 14% of all primary lumbar discectomies required additional surgical interventions. Interspinous devices, which have been shown to unload the posterior anulus, may reduce the occurrence of recurrent herniations. We report our short-term experience with the use of the Wallis device in the management of patients with lumbar disc herniation undergoing primary disc excision. PATIENTS AND METHODS: Thirty-seven consecutive patients (23 males and 14 females, average age 36 y) underwent primary lumbar disc excision followed by fixation of the segment with the Wallis implant during a period of 1 year. Indications for implanting the Wallis device were a voluminous disc herniation and preservation of at least 50% of disc space height. Surgery was performed at level L4-5 in most patients. Average follow-up after surgery was 16 months (range 12 to 24). The last 14 patients were also evaluated by the preoperative and postoperative Oswestry Disability Index (ODI) questionnaire, the SF-36 survey, and by a visual analog scale (VAS) for back and leg pain. RESULTS: The average ODI dropped from 43 to 12.7. The average VAS for back pain dropped from 6.6 to1.4 and the average Vas for leg pain dropped from 8.2 to 1.5. Five patients (4 males and 1 female) with relapsing leg pain were diagnosed by contrast-enhanced magnetic resonance imaging as suffering from recurrent herniation (5/37, 13%). All reherniations occurred at level L4-5 level between 1 and 9 months after the index surgery. Two of the 5 patients subsequently underwent additional discectomy and fusion. SUMMARY: The current Wallis implant is probably incapable of reducing the incidence of recurrent herniations, but it still may be useful in patients with discogenic back pain due to early degenerative disc disease.

Management of deep wound infection after posterior lumbar interbody fusion with cages.

OBJECTIVES: To evaluate long-term treatment outcome of patients with infected posterior lumbar interbody fusion (PLIF) managed with surgical debridement and or prolonged antiobiotic treatment without removal of the interbody cages. METHODS: Between 1996 and 1999, 8 out of 111 patients who underwent PLIF were diagnosed with deep wound infection (7.2%). All infected patients were clinically followed for at least 2 years after completion of the antibiotic treatment. Longer follow-up of at least 6 years duration was performed by a telephone interview. RESULTS: Six patients were managed with surgical debridement, wound irrigation, and primary closure of the wound. None of the patients required removal of the instrumentation. In 2 patients, the PLIF cages were repositioned in the face of infection. All 8 patients received 4 to 6 weeks of intravenous antibiotic therapy followed by another 6 to 9 weeks of oral antibiotic administration. At 2-year follow-up, no clinical or laboratory signs of recurrent infection were evident. Four of the 8 patients reported improved clinical status compared with their prefusion status. At 6-year follow-up, 3 patients had minimal disability according to the Oswestry Disability Index and 2 patients had moderate disability with residual leg pain. CONCLUSIONS: In cases of postoperative deep wound infection after PLIF with cages, removal of the interbody implants is not necessary. Treatment is composed of prolonged antibiotic therapy guided by antimicrobial susceptibility of the isolated bacteria and supplemented with extensive surgical debridement if needed.

Association between sciatica and microbial infection: true infection or culture contamination?

STUDY DESIGN: Discs were cultured during discectomy from patients with back pain, sciatica, and radiologic evidence of disc herniation causing nerve root compression. OBJECTIVE: To investigate the claim of culpability of bacteria in causing the local inflammatory process seen in patients with disc herniation and radiculopathy. SUMMARY OF BACKGROUND DATA: Bacteria have been cultured from intervertebral discs of patients with sciatica. An infectious etiology for sciatica could have a dramatic effect on treatment options for this common problem. METHODS: To minimize the risk of contamination, the surgeon performed processing and culturing procedures intraoperatively under stringent sterile conditions. Immediately following disc excision, the specimens were divided into 4 pieces, and cultured in various aerobic and anaerobic culture mediums that were incubated for 2 weeks. RESULTS: The 120 specimens from 30 patients underwent bacterial culture growth: 116 were sterile, an 4 aerobic cultures (2 patients) grew coagulase-negative staphylococci, suggestive of contamination. CONCLUSIONS: These results refute the hypothesis that microbial infection plays a role in the pathogenesis of sciatica. It is possible that bacterial growth from discs reported in previous studies was at least partly related to contamination, which we painstakingly avoided by application of rigorous aseptic techniques.

Spontaneous ligamentum flavum hematoma in the lumbar spine.

Lumbar or sacral nerve root compression is most commonly caused by intervertebral disc degeneration and/or herniation. Less frequently, other extradural causes may be implicated, such as infection, neoplasm, epidural hematoma, or ligamentum flavum pathology. We present the case of a patient with spontaneous ligamentum flavum hematoma compressing the L4 nerve root, without antecedent trauma. Although exceedingly rare, the diagnosis of ligamentum flavum pathology in general, and that of ligamentum flavum hematoma in particular, should be considered on those rare occasions when the etiology of lumbar or sacral nerve root compressions appears enigmatic on radiological studies. Usually surgical treatment produces excellent clinical outcome.

Anterior decompression combined with corpectomies and discectomies in the management of multilevel cervical myelopathy: a hybrid decompression and fixation technique.

OBJECT: The authors retrospectively evaluated the safety and efficacy of a decompression and fixation technique in the treatment of patients with multilevel cervical spondylotic myelopathy (CSM). METHODS: The authors describe the "hybrid decompression fixation" technique, a procedure involving a combination of corpectomies and discectomies to preserve a vertebra intact within the area of the decompression, thus augmenting mechanical stability. The authors retrospectively reviewed outcomes in 25 patients with multilevel CSM in whom the hybrid technique was performed between 1999 and 2003. Twelve patients underwent a single-level corpectomy and three-level discectomies. In 13 patients a two-level corpectomy and adjacent four-level discectomies were conducted, leaving a vertebral bridge the middle. All patients underwent fusion involving placement of disc and vertebral body cages filled with autogenous local bone and supplemental anterior dynamic plate fixation. The mean preoperative Nurick grade was 3 and improvement in status was reflected by a postoperative decrease to 2.6 (p < 0.05). In one patient neurological deterioration was demonstrated. At the end of the follow-up period (mean 29 months) radiography revealed evidence of osseous fusion in 24 patients; fusion status could not be determined in one patient. No evidence of late-onset instrumentation-related failure was observed in any of the 25 patients. CONCLUSIONS: The authors found the hybrid technique to be safe and efficient for anterior decompression in patients with multilevel CSM. The use of this technique obviates the need for staged circumferential procedures.