Trend differences in cervical spinal cord injuries before and after the coronavirus disease 2019 pandemic

STUDY DESIGN

Cross-Sectional Study.

OBJECTIVES

To investigate the changes in the characteristics of cervical spinal cord injuries (CSCI) before and after the coronavirus disease 2019 (COVID-19) pandemic among patients transported to our hospital in Japan.

SETTING

Hospital with an emergency center in Chiba, Japan.

METHODS

Patients eligible for the study were those transported within 24 h of injury and diagnosed with cervical spinal cord injury between January 2018 and December 2021 at our hospital. Medical records were retrospectively examined to investigate the number and characteristics of patients with CSCI. The clinical variables of patients with CSCI were compared according to the time of admission as related to the COVID-19 pandemic: 2018-19 (before) or 2020-21 (after).

RESULTS

The total number of patients with CSCI from 2018 to 2021 was 108, with 57 before the COVID-19 pandemic and 51 after the COVID-19 pandemic. The number of severe cases with an injury severity score (ISS) of >16 decreased after COVID-19 (p < 0.05). Falls on level surfaces were the most common cause of injury both before and after COVID-19. Although the ranking of traffic accidents decreased after COVID-19, among those, the number of bicycle injuries tended to increase.

CONCLUSIONS

The number of serious cases with an ISS > 16 decreased, presumably because of the decline in high-energy trauma due to the background decrease in the number of traffic accidents.

Cervical kyphosis surgery using a cervical pedicle screw placed with a U-shaped wire that enables observation of the lateral edge of the cortical bone of the spinal canal: A case report and literature review

RATIONALE

A cervical pedicle screw (CPS) serves as an important anchor for cervical surgeries. Its placement requires the development of a highly safe and easy-to-handle method. Considering that the lateral end of the cortical bone of the spinal canal (LE point) is the most crucial for CPS placement, we devised a U-shaped wire capable of identifying LE points under direct vision and reliably confirming the site with C-arm lateral fluoroscopy.

PATIENT CONCERNS

A 65-year-old male, who had been aware of numbness in both hands, mild finger dexterity disorder, and gait disturbance for half a year, visited our hospital due to the progression of his symptoms in the previous 2 months.

DIAGNOSIS

The patient presented with mild muscle weakness and tendon hyperreflexia in the upper and lower extremities on both sides, and magnetic resonance imaging revealed moderate spinal canal stenosis at the C4/5 and 5/6 levels. Based on the local third cervical vertebra (C3)/4 angle of -10 degrees and the C2/7 angle of -15 degrees, the patient was diagnosed with cervical myelopathy with cervical kyphosis. He had a Japanese Orthopaedic Association score for cervical myelopathy of 10.

INTERVENTIONS

We placed CPSs at C3 using a U-shaped wire. After placing an anchor in the range of C3-T1, laminectomy from C4 to C7 was performed. Subsequently, corrective fixation was performed to reduce kyphosis, followed by bone grafting in the range of C3-T1 and complete posterior cervical decompression fixation.

OUTCOMES

The CPSs were placed at C3 without deviation and intra- or postoperative complications. The surgery resulted in improvement in kyphosis with a C2/7 angle of -5 degrees and recovery in spinal cord disorder with a Japanese Orthopedic Association score for cervical myelopathy of 13.

LESSONS

A U-shaped wire, which can be prepared inexpensively and easily, is a useful tool, especially for inexperienced surgeons, for safe CPS placement by capture of LE points accurately.

Risk factors of AIS C incomplete cervical spinal cord injury for poor prognosis-The significance of anorectal evaluation

BACKGROUND

Although the prognosis of incomplete cervical spinal cord injury (SCI) diagnosed as American Spinal Injury Association Impairment Scale grade C (AIS C) is generally favorable, some patients remain non-ambulatory. The present study explored the clinical factors associated with the non-ambulatory state of AIS C patients.

METHODS

This study was a single-center retrospective observational study. Seventy-three participants with AIS C on admission were enrolled and divided into two groups according to ambulatory ability after one year. Prognostic factors of SCI were compared in ambulatory (A-group) and non-ambulatory participants (NA-group). Univariable and multivariable logistic regression analyses were performed on demographic information, medical history, mechanism of injury, presence of fracture, ASIA motor scores (MS) of the extremities, neurological findings, including an anorectal examination on admission, and imaging findings.

RESULTS

Forty-one patients were included in the A-group and 32 in the NA-group. Univariable analysis revealed that the following factors were related to poor outcomes (p < 0.05): older age, history of cerebrovascular disorder, impairment/absence of S4-5 sensory score, deep anal pressure (DAP) (-), voluntary anal contraction (VAC) (-), anorectal tone (-), anal wink reflex (-), and low MS of the upper and lower extremities. In the multivariable analysis using age, presence or absence of sacral abnormality, and history of cerebrovascular disorders (adjusted for these three factors), older age and presence of sacral abnormality on admission were independent risk factors for a non-ambulatory state at the 1-year follow-up.

CONCLUSIONS

Incomplete AIS C SCI individuals with older age and/or impairment of anorectal examination could remain non-ambulatory at 1-year follow-up.

Incidence and Risk Factors for Pneumonia in the Chronic Phase of Cervical Spinal Cord Injury with Complete Motor Paralysis

Introduction

Pneumonia is one of the leading causes of acute- and chronic-phase mortality in patients with cervical spinal cord injury (CSCI) with quadriplegia. The risk factors for chronic-phase pneumonia recurrence in CSCI are still unknown. This study aimed to investigate the incidence of pneumonia in the chronic phase after injury and to identify its risk factors.

Methods

This retrospective clinical observational study included patients with CSCI with American Spinal Injury Association Impairment Scale grades of A or B admitted to our center within 72 h of CSCI injury who started treatment and were available for follow-up for at least 90 days. The patients were assessed for incidences of pneumonia and its associations with clinical characteristics, including risk factors at the time of injury. Patients in whom pneumonia developed within 30 days postadmission and those after 30 days of hospitalization were comparatively examined using univariate and multivariate analyses.

Results

Pneumonia occurred in 36% of the 69 enrolled patients throughout the study period and in 20% of all patients after 30 days of hospitalization. Multivariate analysis of risk factors for pneumonia showed that atelectasis (adjusted OR [aOR], 95% confidence interval [CI]: 4.9, 1.2-20.0), enteral feeding (aOR [95% CI]: 13.3 [3.0-58.9]), mechanical ventilation (aOR [95% CI]: 4.0 [1.0-15.0]), and tracheotomy (aOR [95% CI]: 14.6 [2.3-94.6]) within 30 days of admission were significantly associated with the occurrence of pneumonia even after 30 days of hospitalization.

Conclusions

The risk factors for developing pneumonia in the chronic phase were atelectasis, enteral feeding, mechanical ventilation, and tracheotomy within 30 days of hospitalization. This study suggests that treatment of atelectasis, long-term respiratory muscle rehabilitation, and training to improve swallowing function are essential to prevent the recurrence of pneumonia after 30 days of hospitalization.

Clinical study of preoperative skeletal muscle mass as a predictor of physical performance recovery following palliative surgery for spinal metastases

BACKGROUND

Surgical treatment of spinal metastases has been associated with high morbidity and mortality in patients with sarcopenia based on low skeletal muscle mass. We assessed physical performance using the Eastern Cooperative Oncology Group performance status scale and the Barthel Index on the 30th day after palliative surgery for spinal metastases and investigated the effectiveness of surgery according to sarcopenia assessed by skeletal muscle mass.

METHODS

We retrospectively analyzed 78 consecutive patients with thoracic and lumbar spinal metastases who underwent palliative surgery. The value of the area of the psoas major muscle at the L3 level normalized by the vertebral area was divided into first, middle, and third tertiles. Clinical variables were compared by tertile. Variables affecting the 30-day good performance status were investigated with univariate and multivariate analyses.

RESULTS

The 30-day morbidity rates were 50%, 38.5%, and 15.4% by tertile. The 30-day mortality rate was 2%; all were in the first tertile. Good preoperative performance status scores were seen in 15.4% of first and 50% of third tertile patients. Postoperatively, the performance status improved in all groups, with 30.8%, 65.4%, and 92.3% by tertile. Multivariate regression analysis revealed that a good preoperative performance status (OR: 15.50, 95% CI: 1.610-149.00, P < 0.05) and the value of the area of the psoas major muscle at the L3 level normalized by the vertebral area not in the first tertile (OR: 0.22, 95% CI: 0.06-0.82, P < 0.05) were significant predictors of a good postoperative 30-day performance status.

CONCLUSIONS

A good preoperative performance status and exclusion from the first tertile were clinical factors predicting a good postoperative 30-day performance status. In patients with large psoas muscle mass (third tertile), a good 30-day performance status can be expected after surgery, suggesting that surgery in this population should be pursued aggressively.

Rare case of real-time observation of paralytic deterioration after cervical dislocation in the hyperacute phase

Background

There have been no prior reports of real-time detailed records leading to complete quadriplegia immediately after fracture dislocation in high-energy trauma. Here, we report a case of cervical dislocation in which the deterioration to complete motor paralysis (modified Frankel B1) and complete recovery (Frankel E) could be monitored in real time after reduction in the hyperacute phase.

Case presentation

A 65-year-old man was involved in a car accident and sustained a dislocation at the C5/6 level (Allen–Ferguson classification: distractive flexion injury stage IV). His paralysis gradually deteriorated from Frankel D to C 2 hours after the injury and from Frankl C to B 5 hours after the injury. His final neurological status immediately before reduction was Frankel B1 (complete motor paralysis with sensation only in the perianal region). Reduction was completed within 6 h and 5 min after injury, and spinal fusion was subsequently performed. The patient exhibited rapid motor recovery immediately after surgery, and was able to walk independently on postoperative day 14.

Conclusions

This case suggests that there is a mixture of cases in which the spinal cord has not been catastrophically damaged, even if the patient has complete motor paralysis. Prompt reduction has the potential to improve neurological function in such cases.

The position of the vertebral artery V1 segment relative to the C7 vertebra

BACKGROUND

The vertebral artery (VA) usually enters the transverse foramen at the C6 level. Thus, surgeons prefer to insert pedicle screws (PSs) at C7, but this does not eliminate the risk of VA injury. We aimed to clarify anatomical features of the VA V1 segment at the C7 pedicle level, based on computed tomographic angiography (CTA) of 81 consecutive patients.

METHODS

We examined the course of the VA V1 segment on axial CTA images. VA position was classified according to its alignment with the anterior (A), middle (M), or posterior (P) third of the C7 vertebral body at the pedicle level. We also assessed the prevalence of hypoplastic VA (HVA). We measured the distance (VED) from the optimum C7 PS entry point (Ep) to the center of the VA. We also measured the angles formed by the vertebral midline and a line from the inner edge of the VA to the Ep (the VEA), and by the vertebral midline and a line from the inner edge of the pedicle to the Ep (the PEA).

RESULTS

The variant location of the VA to the C7 vertebra was A in 13 courses (8.1%), M in 123 (76.9%), and P in 20 (12.5%). HVA was present in the contralateral side in 7 of 20 courses (35%) in the P group, and in 8 of 127 courses (6.3%) in the M group (p < 0.05). The mean VED was 20.2 mm, the mean VEA 6.9°, and the mean PEA angle was 36.3°.

CONCLUSION

The 20 VA courses in the P group (12.5% of the total VA courses) were relatively close to the C7 Ep. HVA was present contralateral to the VA in 7 of 20 courses in the P group. CTA should be considered before proceeding with, even if, C7 PS instrumentation, to avoid unexpected pitfall.

Time Course of Respiratory Dysfunction and Motor Paralysis for 12 Weeks in Cervical Spinal Cord Injury without Bone Injury

Introduction

Cervical spinal cord injury without bone injury (SCIWOBI) is a common cervical injury in the elderly population and is most likely to occur at the C3/C4 level. Respiratory dysfunction (RD) related to the damage of the spinal respiratory center, which is close to the C4 segment, is one of the greatest obstacles in improving the activities of daily living of patients with severe paralysis. We evaluated the time course of RD and motor function in cervical SCIWOBI to identify effective medical strategies.

Methods

We followed 54 patients (49 men, 5 women; mean age: 65 years old) who were treated for SCIWOBI at our medical center from 2011 to 2014. The patients were evaluated within 72 hours of injury and were monitored for at least 12 weeks. All patients began respiratory-muscle training the day after admission regardless of whether they were treated conservatively or surgically. The percent vital capacity (%VC), forced expiratory volume (FEV) in one second/forced vital capacity ratio (FEV 1.0%), and American Spinal Injury Association motor score (MS) were recorded at admission and again at weeks 4 and 12. We calculated the %VC rate of change and the MS improvement rate over the entire period.

Results

Fifty patients (92.6%) had restrictive ventilatory impairment at admission. The %VC correlated with the upper- and lower-limb MSs at admission, and the %VC and upper- and lower-limb MSs had improved by weeks 4 and 12 after the injury. The %VC rate of change was significantly correlated with the rate of improvement in lower-limb MS throughout the entire period.

Conclusions

Lung capacity decreased in SCIWOBI owing to respiratory-muscle paralysis and upper- and lower-limb motor paralyses. Lung capacity improved as the lower limbs recovered their motor function. Respiratory rehabilitation should be continued for at least 12 weeks after SCIWOBI.

Delayed bilateral vertebral artery occlusion after cervical spine injury: a case report

INTRODUCTION

There are considerable risks for the secondary spinal cord injury and the initial and/or delayed vertebral artery occlusion in cases of cervical fracture dislocation.

CASE PRESENTATION

An 86-year-old man was injured in a car accident and was diagnosed with no fracture or dislocation of the cervical spine by the emergency physician. However, he was transferred to our hospital 3 days later because he had motor weakness that was evaluated to be 32 points (out of 50 points) on the upper limb American Spinal Injury Association (ASIA) motor score and was diagnosed with spontaneously reduced fracture dislocation at C5/6. Magnetic resonance images revealed that the bilateral vertebral arteries were occluded, and there were some microinfarction lesions in the brain. On the first visit to his previous doctor, he was found to have a flow void in the right vertebral artery. This indicated that it was occluded during the waiting period at his previous doctor. On the day of his arrival at our hospital, the patient underwent a C5/6 posterior spinal fusion. Three months after surgery, he recovered to 46 points on the upper extremity ASIA motor score, and blood flow in the left vertebral artery was resumed.

DISCUSSION

Early reduction and stabilization are necessary for cervical spine fracture dislocation; however, it is important not only for the prevention of the secondary injury but also for the reduction of the risk of vertebral artery occlusion.

Changes in the contents of enzymatic immature, mature, and non-enzymatic senescent cross-links of collagen after once-weekly treatment with human parathyroid hormone (1-34) for 18 months contribute to improvement of bone strength in ovariectomized monkeys

Improvements in total content of enzymatic cross-linking, the ratio of hydroxylysine-derived enzymatic cross-links, and non-enzymatic advanced glycation end product cross-link formation from once-weekly administration of hPTH(1-34) for 18 months in OVX cynomolgus monkeys contributed to the improvement of bone strength.

INTRODUCTION

Parathyroid hormone (PTH) is used for the treatment of osteoporosis. To elucidate the contribution of material properties to bone strength after once-weekly treatment with hPTH(1-34) in an ovariectomized (OVX) primate model, the content of collagen and enzymatic immature, mature, and non-enzymatic cross-links, collagen maturity, trabecular architecture, and mineralization in vertebrae were simultaneously estimated.

METHODS

Adult female cynomolgus monkeys were divided into four groups (n = 18-20 each) as follows: SHAM group, OVX group, and OVX monkeys given once-weekly subcutaneous injections of hPTH(1-34) either at 1.2 or 6.0 μg/kg (low- or high-PTH groups) for 18 months. The content of collagen, enzymatic and non-enzymatic cross-linking pentosidine, collagen maturity, trabecular architecture, mineralization, and cancellous bone strength of vertebrae were analyzed.

RESULTS

Low-PTH and high-hPTH treatments increased the content of enzymatic immature and mature cross-links, bone volume (BV/TV), and trabecular thickness, and decreased pentosidine, compared with the OVX group. Stepwise logistic regression analysis revealed that BV/TV, the content of total enzymatic cross-links, and calcium content independently affected ultimate load (model R (2) = 0.748, p < 0.001) and breaking energy (model R (2) = 0.702, p < 0.001). BV/TV was the most powerful and enzymatic cross-link content was the second powerful determinant of both ultimate load and breaking energy. The most powerful determinant of stiffness was the enzymatic cross-link content (model R (2) = 0.270, p < 0.001).

CONCLUSION

Once-weekly preventive administration of hPTH(1-34) increased the total contents of immature and mature enzymatic cross-links, which contributed significantly to vertebral cancellous bone strength.

Effects of alfacalcidol on mechanical properties and collagen cross-links of the femoral diaphysis in glucocorticoid-treated rats

Bone fragility is increased in glucocorticoid (GC)-induced osteopenia even though GC-treated patients have higher bone mineral density (BMD), suggesting that the impaired bone quality may affect bone strength. This study was conducted to clarify the effects of GC on bone strength and collagen cross-links of adult rats and the effect of coadministration of alfacalcidol (ALF), a prodrug of active vitamin D(3). Six-month-old male Wistar-Imamichi rats (n = 32) were divided into the following four groups with equal average body weight: (1) 4-week age-matched controls, (2) 4-week GC (prednisolone, 10 mg/kg daily, i.m.) with concomitant administration of vehicle, (3) 4-week GC with concomitant administration of ALF (0.05 μg/kg daily, p.o.), and (4) 4-week GC with concomitant administration of ALF (0.1 μg/kg daily, p.o.). At the end of treatment, BMD, collagen cross-links, mechanical properties of the femoral midshaft, bone metabolic markers, and biochemical parameters were analyzed. In the GC group, femoral bone strength decreased without any change of BMD. This was accompanied by a decrease in the content of enzymatic cross-links. ALF (0.1 μg/kg) inhibited the GC-induced reduction in bone strength. The content of mature cross-links in the 0.1-μg/kg ALF group was significantly higher than that in the GC group. GC treatment caused a decrease in bone metabolic markers and serum calcium levels, which was counteracted by ALF coadministration. Preventive treatment with ALF inhibited the deterioration of bone mechanical properties primarily in association with the restoration of enzymatic cross-link formation and amelioration of the adverse effects of GC treatment on calcium metabolism.

Long bone fracture repair in mice harboring GFP reporters for cells within the osteoblastic lineage

GFP reporter mice previously developed to assess levels of osteoblast differentiation were employed in a tibial long bone fracture model using a histological method that preserves fluorescent signals in non-decalcified sections of bone. Two reporters, based on Col1A1 (Col3.6GFPcyan) and osteocalcin (OcGFPtpz) promoter fragments, were bred into the same mice to reflect an early and late stage of osteoblast differentiation. Three observations were apparent from this examination. First, the osteoprogenitor cells that arise from the flanking periosteum proliferate and progress to fill the fracture zone. These cells differentiate to osteoblasts, chondrocytes, to from the outer cortical shell. Second, the hypertrophic chondrocytes are dispersed and the cartilage matrix mineralized by the advancing Col3.6+ osteoblasts. The endochondral matrix is removed by the following osteoclasts. Third, a new cortical shell develops over the cartilage core and undergoes a remodeling process of bone formation on the inner surface and resorption on the outer surface. The original fractured cortex undergoes resorption as the outer cortical shell remodels inward to become the new diaphyseal bone. The fluorescent microscopy and GFP reporter mice used in this study provide a powerful tool for appreciating the molecular and cellular processes that control these fundamental steps in fracture repair, and may provide a basis for understanding fracture nonunion.

Raloxifene ameliorates detrimental enzymatic and nonenzymatic collagen cross-links and bone strength in rabbits with hyperhomocysteinemia

We demonstrate a reduction in enzymatic divalent immature and trivalent pyridinium cross-links and an increase in the nonenzymatic cross-link, pentosidine (Pen), in rabbits with methionine (Met)-induced hyperhomocysteinemia. Such detrimental cross-link formation in bone was ameliorated by raloxifene (RLX) treatment.

INTRODUCTION

Collagen cross-links are determinants of bone quality. Homocysteine (Hcys) interferes with collagen cross-linking. Because RLX is thought to ameliorate bone quality, we investigated whether RLX ameliorated hyperhomocysteinemia-induced cross-link abnormalities using a Met-rich diet rabbit model.

METHODS

We divided New Zealand white rabbits into six groups (n = 6 per group): baseline control, sham operation, sham + 1% Met diet, ovariectomy (OVX), 1% Met diet + OVX, OVX + RLX (10 mg/kg/day), and 1% Met diet + OVX + RLX. RLX was administered for 16 weeks. We measured the amount of enzymatic immature and mature pyridinium cross-links and the nonenzymatic cross-link, Pen, and correlated the cross-link content to bone strength.

RESULTS

Hcys levels were significantly higher in the Met diet groups than in the normal diet groups. Met-fed rabbits with or without OVX showed a significant reduction of enzymatic cross-links, whereas an increase in Pen was observed in Met-fed rabbits with OVX. The cross-link content of the RLX-treated Met-fed rabbits with OVX was restored to similar levels as the sham group, accompanied by an improvement of bone strength.

CONCLUSION

These results demonstrate that hyperhomocysteinemia reduced bone strength via a reduction of enzymatic cross-links and an increase of nonenzymatic cross-links. RLX may ameliorate hyperhomocysteinemia-induced detrimental cross-linking in rabbits with OVX and may improve bone strength via the amelioration of collagen cross-links.

Anatomical considerations for cervical pedicle screw insertion: the use of multiplanar computerized tomography reconstruction measurements

OBJECT

The purpose of this study was to evaluate the linear and angular parameters of the vertebral body (VB) required for cervical pedicle screw (CPS) insertion by using multiplanar computerized tomography (CT) reconstructions.

METHODS

Three hundred fifteen vertebrae from C-3 to C-7 in 63 patients were studied. Pedicle dimensions such as pedicle transverse angle (PTA), pedicle sagittal angle (PSA), and pedicle outer width (POW) were measured on axial CT reconstructions, as were linear parameters including the lateral mass thickness (LMT), the anteroposterior (AP) and mediolateral distances between spinal canal and transverse foramen, and spinal canal longitudinal and transverse diameter. In addition, the correlations between PTA and other parameters were calculated using univariate linear regression analysis. The overall mean LMT ranged from 10.7 to 12.6 mm. The smallest mean AP spinal canal-transverse foramen distance was found at C-7 (1.1 mm),whereas the largest mean distance was at C-4 (3.1 mm). The smallest mean mediolateral spinal canal-transverse foramen distance was found at C-4 (1.2 mm), whereas the largest mean distance was at C-7 (4.7 mm). There were significant intergroup differences between male and female patients except for PTA and spinal canal longitudinal diameter. The PTA had a direct linear correlation with AP and mediolateral spinal canal-transverse foramen distances. The largest Pearson coefficient was 0.71 between the PTA and AP spinal canal-transverse foramen distance and the inverse one was -0.73 between the PTA and mediolateral spinal canal-transverse foramen distance.

CONCLUSIONS

Analysis of the data obtained in this study suggests that not only pedicle dimensions but also linear and angular parameters of the VB can be useful data when inserting a CPS.