Mortality and complications in elderly patients with cervical spine injuries.

PURPOSE: To assess the complications and mortality in elderly individuals with cervical spine injuries. METHODS: This retrospective observational study was conducted in a tertiary care hospital in a rural area in Japan. Data sets from the trauma registry (January 2011 to March 2018) were analyzed. Patients with cervical spine injury were divided into those aged ≥ 65 years (group Y) and > 65 years (group E). We then analyzed age, sex, 30-day mortality, hospital stay, level of cervical spine injury, presence of cervical vertebral fracture, perioperative complications (pneumonia, urinary tract infection, and severe bedsore), neurological deficit (Frankel classification), Abbreviated Injury Scale (AIS) score, and Injury Severity Score (ISS). RESULTS: We evaluated a total of 398 patients; among them, 177 were included in group Y and 221 in group E. The assessed parameters were as follows: age (group Y/E; 48.7/75.9 years), men (78.0/72.3%), 30-day mortality (8.5/10.0%, p = 0.159), hospital stay (17.2/19.1 days, p = 0.36), level of cervical spine injury (C1 [5.7/4.5%], C2 [12.4/15.8%], C3 [10.2/17.2%], C4 [14.1/16.3%], C5 [26.6/22.2%], C6 [22.0/12.2%], and C7 [11.3/10.9%]), vertebral fracture (56.6/61.9%), central cord syndrome (36.2/33%), operation (18.6/13.1%), pneumonia (6.8/11.8%, p = 0.077), urinary tract infection (4.0/6.3%, p = 0.26), severe bedsore (0/1.8%, p = 0.068), Frankel classification (grade A [5.7/6.3%], grade B [6.8/7.7%], grade C [24.9/28.5%], grade D [17.5/11.8%], and grade E [34.5/33.9%]), mean AIS score in the cervical spine (3.3/3.5, p = 0.04), and mean ISS (23.2/22.2, p = 0.38). C3 injuries tended to be higher in group E. CONCLUSION: Mortality and morbidity associated with cervical spine injuries did not differ between younger and older patients. Nevertheless, vigilance is required for the detection of C3 injury in elderly individuals.

Does prophylactic use of topical gelatin-thrombin matrix sealant affect postoperative drainage volume and hematoma formation following microendoscopic spine surgery? A randomized controlled trial.

BACKGROUND CONTEXT: Microendoscopic spinal surgery has demonstrated efficacy and is increasingly utilized as a minimally invasive approach to neural decompression, but there is a theoretical concern that bleeding and postoperative epidural hematoma (PEH) may occur with increased frequency in a contained small surgical field. Hemostatic agents, such as topical gelatin-thrombin matrix sealant (TGTMS), are routinely used in spine surgery procedures, yet there has been no data on whether PEH is suppressed by these agents when administered in microendoscopic spine surgery. PURPOSE: The purpose of this study was to investigate the effect of TGTMS on bleeding and PEH formation in lumbar micoroendoscopic surgery. STUDY DESIGN: This is a randomized controlled trial (RCT) with additional prospective observational cohort. PATIENT SAMPLE: Patients were registered from July 2017 to September 2018 and a hundred and three patients undergoing microendoscopic laminectomy for lumbar spinal stenosis at a single institution were enrolled in this study. OUTCOME MEASURES: The primary outcome was the drainage volume within 48 hours after surgery. Secondary outcomes were the numerical rating scale (NRS) of leg pain on the second (NRS2) and seventh day (NRS7) after surgery and the hematoma area ratio (HAR) in horizontal images on magnetic resonance image (MRI). METHODS: In the RCT, 41 cases that received TGTMS (F group) were compared with 41 control group cases (C group) that did not receive TGTMS at the end of the procedure. Drainage volume, NRS2, NRS7, and HAR on MRI were evaluated. Nineteen cases were excluded from the RCT (I group) due to difficulty of hemostasis during surgery and the intentional use of TGTMS for hemostasis. I group was compared with C group in the drainage volume and NRS of leg pain as a prospective observational study. RESULTS: The RCT demonstrated no statistically significant difference in drainage volume between those receiving TGTMS (117.0±71.7; mean±standard deviation) and controls (125.0±127.0; p=.345). The NRS2 and NRS7 was 3.5±2.6 and 2.8±2.5 in the F group, respectively, and 3.1±2.6 and 2.1±2.3 in the C group, respectively. The HAR on MRI was 0.19±0.19 in the F group and 0.17±0.13 in the C group. There was no significant difference in postoperative leg pain and HAR (p=.644 for NRS2, p=.129 for NRS7, and p=.705 for HAR). In the secondary observational cohort, the drainage volume in the I group was 118.3±151.4, and NRS2 and NRS7 was 3.5±2.0 and 2.6±2.6, respectively. There were no statistically significant differences in drainage volume (p=.386) or postoperative NRS of leg pain between these two groups (p=.981 and .477 for NRS2 and NRS7, respectively). CONCLUSIONS: The prophylactic use of TGTMS in patients undergoing microendoscopic laminotomy for lumbar spinal stenosis did not demonstrate any difference in postoperative bleeding or PEH. Nonetheless, for patients that had active bleeding that required the use of TGTMS, there was no evidence of difference in postoperative clinical outcomes relative to controls.

A short-segment fusion strategy using a wide-foot-plate expandable cage for vertebral pseudarthrosis after an osteoporotic vertebral fracture.

OBJECTIVE: Various surgical treatments have been reported for vertebral pseudarthrosis after osteoporotic vertebral fracture (OVF). However, the outcomes are not always good. The authors now have some experience with combined anterior-posterior short-segment spinal fusion (1 level above and 1 level below the fracture) using a wide-foot-plate expandable cage. Here, they report their surgical outcomes with this procedure. METHODS: Between June 2016 and August 2018, 16 consecutive patients (4 male and 12 female; mean age 75.1 years) underwent short-segment spinal fusion for vertebral pseudarthrosis or delayed collapse after OVF. The mean observation period was 20.1 months. The level of the fractured vertebra was T12 in 4 patients, L1 in 3, L2 in 4, L3 in 3, and L4 in 2. Clinical outcomes were assessed using the lumbar Japanese Orthopaedic Association (JOA) scale and 100-mm visual analog scale for low-back pain. Local kyphotic angle, intervertebral height, bone union rate, and instrumentation-related adverse events were investigated as imaging outcomes. The data were analyzed using the Wilcoxon signed-rank test. RESULTS: The mean operating time was 334.3 minutes (range 256-517 minutes), and the mean blood loss was 424.9 ml (range 30-1320 ml). The only perioperative complication was a superficial infection of the posterior wound that was cured by irrigation. The lumbar JOA score and visual analog scale value improved from 11.2 and 58.8 mm preoperatively to 20.6 and 18.6 mm postoperatively, respectively. The mean local kyphotic angle and mean intervertebral height were 22.6° and 28.0 mm, respectively, before surgery, -1.5° and 40.5 mm immediately after surgery, and 7.0° and 37.1 mm at the final observation. Significant improvement was observed in both parameters immediately after surgery and at the final observation when compared with the preoperative values. Intraoperative endplate injury occurred in 8 cases, and progression of cage subsidence of 5 mm or more was observed in 2 of these cases. Proximal junctional kyphosis was observed in 2 cases. There were no cases of screw loosening. No cases required reoperation due to instrument-related adverse events. Bone union was observed in all 14 cases that had CT evaluation. CONCLUSIONS: This short-segment fusion procedure is relatively minimally invasive, and local reconstruction and bone fusion have been achieved. This procedure is considered to be attempted for the surgical treatment of osteoporotic vertebral pseudarthrosis after OVF.

Efficacy of Posterior Segmental Decompression Surgery for Pincer Mechanism in Cervical Spondylotic Myelopathy: A Retrospective Case-controlled Study Using Propensity Score Matching.

STUDY DESIGN: Retrospective case-controlled study using propensity score matching. OBJECTIVE: We aimed to evaluate the efficacy of cervical microendoscopic laminoplasty (CMEL) of the articular segment in patients with cervical spondylotic myelopathy (CSM) by comparing the clinical results of CMEL with conventional expansive laminoplasty (ELAP) for CSM. SUMMARY OF BACKGROUND DATA: A total of 259 patients undergoing CMEL or ELAP surgery for CSM at authors' institute were reviewed. METHODS: The patients were matched according to calculated propensity scores in a logistic regression model adjusted for age, sex, and preoperative severity of disorders and divided into the CMEL and ELAP groups. All patients were followed postoperatively for more than 2 years. The preoperative and 2-year follow-up evaluations included neurological assessment (Japanese Orthopaedic Association [JOA] score), recovery rates, the JOA Cervical Myelopathy Evaluation Questionnaire (JOACMEQ), axial pain (visual analog scale), and the Short Form 36 questionnaire (SF-36). RESULTS: There were 71 patients in each group (47 males and 24 females each). The mean ages of the CMEL and ELAP groups were 63.8 and 62.8 years, respectively. There was no significant difference in the preoperative JOA score between groups. The mean numbers of surgically affected levels in the ELAP and CMEL groups were 3.2 and 1.8 discs, respectively (P ≤ 0.05). The groups exhibited similar recoveries of JOA, JOACMEQ, and SF-36 scores postoperatively. Sagittal alignment was maintained in both groups. However, postoperative neck axial complaints were significantly reduced in the CMEL group. CONCLUSION: CMEL may be a useful and effective surgical procedure for CSM, providing similar results as ELAP. CMEL for CSM is indicated for posterior decompression of the articular segment along with a pincer mechanism. This minimally invasive technique may have potential advantages compared with conventional ELAP, and may provide an alternative surgical option. LEVEL OF EVIDENCE: 4.

Improved accuracy of diagnosis of lumbar intra and/or extra-foraminal stenosis by use of three-dimensional MR imaging: comparison with conventional MR imaging.

BACKGROUND: The purposes of this study were to assess the reliability of 3-dimensional magnetic resonance (MR) imaging (3D MRI) and conventional MRI (CMRI) for detection of lumbar intra and/or extra-foraminal stenosis (LIEFS) and to compare the diagnostic accuracy of the 2 imaging modalities. METHODS: A total of 60 sets of 3D MR and CMR images from 20 healthy volunteers and 40 LIEFS patients were qualitatively rated according to defined criteria by 3 independent, blinded readers. Kappa statistics were used to characterize intra and inter-reader reliability for qualitative rating of data. Multireader, multicase analysis was used to compare lumbar foraminal stenosis detection between the 2 modalities. RESULTS: Intra-reader agreement for 3D MRI was excellent, with kappa = 0.90; that for CMRI was good, with kappa = 0.78. Average inter-reader agreement for 3D MRI was good, with kappa = 0.79, whereas that for CMRI was moderate, with kappa = 0.41. Average area under the ROC curve values (1st reading/2nd reading) for detection of lumbar foraminal stenosis using 3D MRI and CMRI were 0.99/0.99 and 0.94/0.92, respectively. Detection of LIEFS with 3D MRI was significantly better than with CMRI (P = 0.0408/0.0294). CONCLUSIONS: These results suggest that CMRI was of limited use for detection of the presence of LIEFS. Isolated imaging with CMRI may risk overlooking the presence of LIEFS. In contrast, reliability of 3D MRI for detection of LIEFS was good. Furthermore, readers' performance in the diagnosis of LIEFS can be improved by use of 3D MRI. Therefore, 3D MRI is recommended when using imaging for diagnosis of LIEFS.

Augmentation of motor evoked potentials using multi-train transcranial electrical stimulation in intraoperative neurophysiologic monitoring during spinal surgery.

Transcranial motor evoked potentials (TcMEPs) are widely used to monitor motor function during spinal surgery. Improvements in transcranial stimulation techniques and general anesthesia have made it possible to record reliable and reproducible potentials. However, TcMEPs are much smaller in amplitude compared with compound muscle action potentials (CMAPs) evoked by maximal peripheral nerve stimulation. In this study, multi-train transcranial electrical stimulation (mt-TES) was introduced to enhance TcMEPs, and the optimal setting of mt-TES was investigated. In 30 patients undergoing surgical correction of spinal deformities (4 males and 26 females with normal motor status; age range 11-75 years), TcMEPs from the abductor hallucis (AH) and quadriceps femoris (QF) were analyzed. A multipulse (train) stimulus with an individual pulse width of 0.5 ms and an inter-pulse interval of 2 ms was delivered repeatedly (2-7 times) at different rates (2, 5, and 10 Hz). TcMEP amplitudes increased with the number of train stimuli for AH, with the strongest facilitation observed at 5 Hz. The response amplitude increased 6.1 times on average compared with single-train transcranial electrical stimulation (st-TES). This trend was also observed in the QF. No adverse events (e.g., seizures, cardiac arrhythmias, scalp burns, accidental injury resulting from patient movement) were observed in any patients. Although several facilitative techniques using central or peripheral stimuli, preceding transcranial electrical stimulation, have been recently employed to augment TcMEPs during surgery, responses are still much smaller than CMAPs. Changing from conventional st-TES to mt-TES has potential to greatly enhance TcMEP responses.

Selective vulnerability to ischemia in the rat spinal cord: a comparison between ventral and dorsal horn neurons.

STUDY DESIGN: Whole-cell patch-clamp recordings were performed from ventral horn (VH) and dorsal horn (DH) neurons obtained from the rat spinal cord slices. OBJECTIVE: This study investigated which is more vulnerable to ischemia, spinal VH neurons or DH neurons. SUMMARY OF BACKGROUND DATA: Spinal cord ischemia or injury sometimes causes a greater loss of motor function than of sensory function in patients. However, it is difficult to evaluate whether spinal motor neurons are more vulnerable than sensory neurons because of the anatomic complexity and a variety of physiologic factors in the spinal cord. METHODS: Whole-cell patch-clamp recordings were performed from VH and DH neurons obtained from the spinal cord slices. Ischemia was simulated by superfusing an oxygen- and glucose-deprived medium (ischemia simulating medium [ISM]). RESULTS: Perfusion with ISM generated an agonal depolarization in all VH and DH neurons recorded in current-clamp mode. Following ISM superfusion, an agonal inward current was produced at a holding potential of -70 mV in all VH and DH neurons tested in voltage-clamp mode. The agonal inward current consisted of a slow and subsequent rapid inward current. The average latency of the rapid inward currents after ISM exposures in VH neurons was significantly shorter than that in DH neurons. The average amplitude of the agonal inward currents in VH neurons was significantly bigger than that of DH neurons. Moreover, the recovery ratio by the reintroduction of oxygen and glucose in VH neurons was smaller than that in DH neurons. CONCLUSIONS: These results suggest that VH neurons are more vulnerable to ischemia than DH neurons. This finding may help in achieving a better understanding of the difference between motor and sensory disturbance in spinal cord ischemia or injury patients.

Hypothermia suppresses excitatory synaptic transmission and neuronal death induced by experimental ischemia in spinal ventral horn neurons.

STUDY DESIGN: Whole-cell patch-clamp recordings were performed from the ventral horn neurons obtained from the rat spinal cord slices. OBJECTIVE: This study investigated the effects of hypothermia on excitatory synaptic transmission and ischemia-induced neuronal death. SUMMARY OF BACKGROUND DATA: Hypothermia has long been recognized as a promising physical strategy against both ischemic and traumatic spinal cord injuries. However, the mechanism of hypothermia-mediated neuroprotective action in the spinal cord is still not fully understood at the single cell level. METHODS: Whole-cell patch-clamp recordings were performed from ventral horn neurons obtained from the spinal cord slices. Ischemia was simulated by superfusing an oxygen- and glucose-deprived medium [ischemia simulating medium (ISM)]. RESULTS: When the temperature of the superfusing artificial cerebrospinal fluid solution was changed from normothermia (36 degrees C) to hypothermia (32 degrees C, 28 degrees C, and 24 degrees C), the frequency of spontaneous excitatory postsynaptic currents was significantly decreased in a temperature-dependent manner. Surperfusing the ISM generated an agonal inward current which consisted of a slow and subsequent rapid inward current in all of the neurons tested. The latencies of the slow and rapid inward currents after the ISM exposures were significantly longer at hypothermia than at normothermia. Hypothermia decreased the slope of the ISM-induced slow inward current, although it did not affect the slope of the rapid inward current. Moreover, the glutamate receptor antagonists slightly prolonged the latencies of the slow and rapid inward currents that were induced by ISM and significantly decreased their slopes. CONCLUSION: These results suggest that hypothermia reduces the excitatory synaptic activities and ischemic neuronal death in the spinal ventral horn. This finding may help in achieving a better understanding of the mechanisms of hypothermia-mediated neuroprotection in the spinal cord.

Comparison of neuropathic pain induced by the application of normal and mechanically compressed nucleus pulposus to lumbar nerve roots in the rat.

We studied whether applying nucleus pulposus tissue, obtained from tail intervertebral discs that had been subjected to chronic mechanical compression, to the lumbar nerve roots produces hyperalgesia, which is thought to be a pain-related behavior in the rat. An Ilizarov-type apparatus was used for immobilization and chronically applied compression of the rat tail for eight weeks. Three weeks after application of extracted nucleus pulposus tissue on the lumbar nerve roots, motor function, sensitivity to noxious mechanical stimuli was measured. Eight weeks after application of the apparatus, the instrumented vertebrae were resected and sections were stained with hematoxylin and eosin to evaluate degeneration of the intervertebral disc. Mechanical hyperalgesia observed in rats treated with the compressed nucleus pulposus tissue was greater and of longer duration than in the rats treated with normal and non-compressed discs. The nucleus pulposus in the instrumented vertebrae showed some histological degeneration. In conclusion, chronic mechanical compression of nucleus pulposus, which resulted in degeneration to some extent, enhanced mechanical hyperalgesia, which was induced by application of nucleus pulposus on the nerve root in the rat. Degenerative intervertebral discs might induce more significant pain than normal intervertebral discs.