Comparison of osteoanabolic agents (teriparatide and romosozumab) with bisphosphonates in prevention of subsequent vertebral fractures in patients treated for osteoporotic vertebral fracture for 12 months: An observational cohort study

Introduction

Domino osteoporotic vertebral fracture (OVF) is as a subsequent fracture that develops within 3 months before the initial OVF heals. There is limited evidence regarding the efficacy of osteoanabolic agents on its treatment. This study evaluated the effects of bisphosphonates and anabolic agents teriparatide and romosozumab on subsequent domino OVF.

Methods

This was post hoc analysis of a prospective, multicenter, observational study conducted across 8 hospitals, enrolling 144 patients with conservatively treated OVF, grouped into patients receiving bisphosphonate (BP, n = 55), teriparatide (TPTD, n = 62), and romosozumab (Romo, n = 27). The primary outcome was the incidence of subsequent OVF at 3 and 12 months, whereas the secondary outcomes included the incidence of pseudoarthrosis and progression of vertebral collapse (VC). Pseudoarthrosis was classified as stable or unstable based on vertebral instability.

Results

The use of osteoanabolic agents did not reduce the incidence of subsequent OVF at 3 and 12 months. There were no significant differences in the background data or type of conservative treatment among the three groups. However, the TPTD and Romo groups had significantly lower rates of unstable pseudarthrosis (p = 0.03). Additionally, there were no significant differences in VC progression between groups, but it tended to be higher in the BP group than the TPTD and Romo group (p = 0.07).

Conclusion

Osteoanabolic agents were beneficial in reducing unstable pseudoarthrosis, but were not more effective than bisphosphonates in the development of subsequent domino OVF. A more comprehensive approach to the treatment of osteoporosis is needed to prevent domino OVFs.

Optogenetic inhibition of spinal inhibitory neurons facilitates mechanical responses of spinal wide dynamic range neurons and causes mechanical hypersensitivity

Inhibitory interneurons in the spinal dorsal horn (DH) play a major role in regulating innocuous and noxious information. Reduction in inhibitory synaptic transmission is thought to contribute to the development of touch-evoked pain (allodynia), a common symptom of neuropathic pain. However, it is not fully understood how inhibitory neurons in the DH regulate sensory responses in surrounding neurons and modulate sensory transmission. In this study, we established a novel experimental method to analyze temporal activity of DH neurons during the optogenetically induced disinhibition state by combining extracellular recording and optogenetics. We investigated how specific and temporally restricted dysfunction of DH inhibitory neurons affected spinal neuronal activities evoked by cutaneous mechanical stimulation. In behavioral experiments, the specific and temporally restricted spinal optogenetic suppression of DH inhibitory neurons induced mechanical hypersensitivity. Furthermore, this manipulation enhanced the mechanical responses of wide dynamic range (WDR) neurons, which are important for pain transmission, in response to brush and von Frey stimulation but not in response to nociceptive pinch stimulation. In addition, we examined whether a neuropathic pain medication, mirogabalin, suppressed these optogenetically induced abnormal pain responses. We found that mirogabalin treatment attenuated the abnormal firing responses of WDR neurons and mechanical hypersensitivity. These results suggest that temporally restricted and specific reduction of spinal inhibitory neuronal activity facilitates the mechanical responses of WDR neurons, resulting in neuropathic-like mechanical allodynia which can be suppressed by mirogabalin. Our optogenetic methods could be useful for developing novel therapeutics for neuropathic pain.

Patient-specific guide systems decrease the major perforation rate of pedicle screw placement in comparison to the freehand technique for adolescent idiopathic scoliosis

PURPOSE

This study aimed to compare the accuracy of pedicle screw (PS) placement between a low-profile three-dimensional (3D) printed patient-specific guide system and freehand technique for adolescent idiopathic scoliosis (AIS) surgery.

METHODS

Patients with AIS who underwent surgery between 2018 and 2023 at our hospital were included in the study. The 3D-printed patient-specific guide was used since 2021 (guide group). PS perforation was classified using Rao and Neo's classification (grade 0, no violation; grade 1, < 2 mm; grade 2, 2-4 mm; grade 3, > 4 mm). Major perforations were defined as grades 2 or 3. The major perforation rate of PS, operative time, estimated blood loss (EBL), and correction rate were compared between the two groups.

RESULTS

A total of 576 PSs were inserted in 32 patients (20 patients in the freehand (FH) group and 12 patients in the guide group). The major perforation rate was significantly lower in the guide group than in the FH group (2.1% vs. 9.1%, p < 0.001). Significantly fewer major perforations were observed in the guide group than in the FH group in the upper thoracic (T2-4) region (3.2% vs. 20%, p < 0.001) and lower thoracic (T10-12) region (0% vs. 13.8%, p = 0.001). The operative time, EBL, and correction rate were equivalent between the two groups.

CONCLUSION

The 3D-printed patient-specific guide notably reduced the major perforation rate of PS without increasing EBL and operative time. Our findings indicate that this guide system is reliable and effective for AIS surgery.

Effects of Perioperative Teriparatide Treatment on the Hounsfield Unit Values at the Upper Instrumented Vertebra in Adult Spinal Deformity Surgery

STUDY DESIGN

Retrospective single-center study.

OBJECTIVE

This study aimed to assess the effects of pre and postoperative teriparatide (TPTD) treatment on Hounsfield units (HU) after surgery for adult spinal deformity (ASD).

SUMMARY OF BACKGROUND DATA

The most commonly used method for assessing bone mineral density is dual-energy x-ray absorptiometry. HU values at the upper instrumented vertebra (UIV) have been proposed as a surrogate method for assessing bone quality, particularly in patients with ASD. However, the effect of TPTD treatment on vertebral HU values remains unclear.

MATERIALS AND METHODS

We identified 57 consecutive patients with ASD who underwent long-instrumented fusion surgery (>5 vertebrae) between 2014 and 2020. Patients were retrospectively divided into a non-TPTD group (n = 31) and a TPTD group (n = 26). HU measurements were obtained at a level above the UIV (UIV + 1). Changes in the HU value at 1-year postoperatively were compared between the TPTD and non-TPTD groups. The duration of preoperative TPTD was compared between the proximal junctional proximal junctional failure (PJF) and non-PJF groups.

RESULTS

Preoperative HU values were significantly lower in the TPTD group than in the non-TPTD group, despite no significant difference in preoperative bone mineral density of the proximal femur between the two groups. Changes in HU values were significantly higher in the TPTD group than in the non-TPTD group (20.8 ± 15.7% vs -2 ± 10.2%, P < 0.001). In the subanalysis of the TPTD group, the duration of preoperative TPTD treatment was significantly shorter in the PJF group than in the non-PJF group (34.7 ± 16.8 days vs 86.9 ± 34.7 days, P = 0.004).

CONCLUSIONS

Pre and post-operative TPTD treatment increased the average HU value at UIV + 1 by 20.8%. Therefore, more prolonged preoperative TPTD treatment improves bone quality and may help prevent osteoporosis-related complications.

The Relationship between the Hounsfield Units Value of the Upper Instrumented Vertebra and the Severity of Proximal Junctional Fracture after Adult Spinal Deformity Surgery

Background and Objectives: In this retrospective cohort study, we investigate associations between the Hounsfield units (HU) value of upper instrumented vertebra (UIV) and proximal junctional kyphosis (PJK) after adult spinal deformity (ASD) surgery. Materials and Methods: The cohort consisted of 60 patients (mean age 71.7 years) who underwent long instrumented fusion surgery (≥6 vertebrae) for ASD with at least 1 year of follow-up. The preoperative bone mineral density (BMD) measured on DXA scans, the HU values at UIV and UIV+1, and the radiographic parameters were compared between the PJK and non-PJK groups. The severity of UIV fracture was assessed using a semiquantitative (SQ) grade. Results: PJK occurred in 43% of patients. No significant differences in patient age, sex, BMD, and preoperative radiographic parameters were observed between the PJK and non-PJK groups. The HU values of the UIV (103.4 vs. 149.0, p < 0.001) and UIV+1 (102.0 vs. 145.7, p < 0.001) were significantly lower in the PJK group. The cutoff values of HU at UIV and UIV+1 were 122.8 and 114.9, respectively. Lower HU values at UIV (Grade 1: 134.2, Grade 2: 109.6, Grade 3: 81.1, p < 0.001) and UIV+1 (Grade 1: 131.5, Grade 2: 107.1, Grade 3: 82.1, p < 0.001) were associated with severe SQ grade. Conclusions: Lower HU values at UIV and UIV+1 had a negative impact on signal incidence of PJK and were correlated with the severity of UIV fractures. Preoperative treatment of osteoporosis seems necessary for preoperative UIV HU values less than 120.

Occupational Fall Risk Assessment Tool for older workers

BACKGROUND

No easy-to-use fall risk assessment tools have been devised to assess occupational fall risk in older workers.

AIMS

To develop an Occupational Fall Risk Assessment Tool (OFRAT) and report its predictive validity and reliability in older workers.

METHODS

The baseline fall risk assessment was completed by 1113 participants aged ≥60 years who worked ≥4 days/month in Saitama, Japan. Participants were followed up for falls during occupational activities for 1 year, and 30 participants were assessed twice for test-retest reliability. The following assessment measures were summed to form the OFRAT risk score: older age, male sex, history of falls, physical work participation, diabetes, use of medications increasing fall risk, reduced vision, poor hearing, executive dysfunction and slow stepping. The scores were then classified into four grades (0-2 points: very low, 3 points: low, 4 points: moderate and ≥5 points: high).

RESULTS

During follow-up, 112 participants fell 214 times during work. The negative binomial regression model showed that participants with higher grades had a higher incidence rate ratio [95% confidence interval] for falls than those with very low grades (low: 1.64 [1.08-2.47], moderate: 4.23 [2.82-6.34] and high: 6.12 [3.83-9.76]). The intraclass correlation coefficient for risk score was 0.86 [0.72-0.93], and the weighted kappa coefficient for grade assessment was 0.74 [0.52-0.95].

CONCLUSIONS

The OFRAT is a valid and reliable tool for estimating the occupational fall risk in older workers. It may assist occupational physicians implement strategies to prevent falls in this group.

Subsequent Domino Osteoporotic Vertebral Fractures Adversely Affect Short-Term Health-Related Quality of Life: A Prospective Multicenter Study

Background and Objectives: Conservative treatment is the gold standard for acute osteoporotic vertebral fractures (AOVFs). However, the treatment strategy for multiple AOVFs remains unknown. We conducted a prospective study using magnetic resonance imaging (MRI) to investigate how rapidly subsequent osteoporotic vertebral fractures (OVFs) occur as domino OVFs within 3 months. This study aimed to assess the incidence and impact of domino OVFs on quality of life (QOL) following conservative treatment for initial AOVFs. Materials and Methods: A prospective multicenter cohort study was conducted at eight hospitals. The included patients were those with AOVFs occurring within 3 weeks, aged >60 years, and diagnosed using MRI. All patients were treated conservatively and underwent MRI after 3 months. Subsequent domino OVFs were defined as newly occurring OVFs within 3 months. Patient characteristics, types of conservative treatment, and patient-reported outcomes, including a visual analogue scale (VAS), the Oswestry disability index (ODI), and the Japanese Orthopaedic Association back pain evaluation questionnaire (JOABPEQ), were evaluated and compared between the domino OVF and non-domino OVF groups. Results: A total of 227 patients were analyzed. The mean age was 80.1 ± 7.3 years and 78% were female. Subsequent domino OVFs were observed in 31 (13.6%) patients within 3 months. An increasing number of prevalent OVFs were significantly associated with domino OVFs (p = 0.01). No significant differences in bone mineral density, type of brace, and anti-osteoporosis medications were found between the two groups. The JOABPEQ (excluding social function), ODI, and VAS were significantly improved after 3 months. Patients with domino OVFs at 3 months had poorer JOABPEQ social life function, ODI, and VAS than those with non-domino OVFs. Conclusions: In this study, the incidence of domino OVFs was 13.6% within 3 months. Domino OVFs had a negative impact on QOL at 3 months and were associated with prevalent OVFs.

The Impact of Controlling Nutritional Status (CONUT) score on functional prognosis in hospitalized elderly patients with acute osteoporotic vertebral fractures

BACKGROUND

Nutritional status, which is associated with osteoporosis and muscle weakness is considered an important factor in the management of acute osteoporotic vertebral fracture (AOVF). However, few reports have investigated the nutritional status of hospitalized patients with AOVF and the impact of malnutrition on their functional prognosis. This study aimed to evaluate the nutritional status of hospitalized elderly patients with AOVF using the Controlling Nutritional Status (CONUT) score and to determine the usefulness of the CONUT score in predicting their functional prognosis.

METHODS

The CONUT score on admission was retrospectively calculated for 134 hospitalized elderly patients (mean age 83 ± 7.6 years, 66% female) with AOVF who received conservative treatment between 2017 and 2020. Functional outcome was assessed by comparing ambulatory ability before the onset of AOVF and upon discharge. Patients were divided into two groups: CONUT-high ( ≥ 4) and CONUT-low ( ≤ 3), according to receiver operating characteristic (ROC) analysis to predict decline in ambulatory ability upon discharge. Logistic regression analysis was performed to obtain odds ratios (OR) and 95% confidence intervals (CI) of the relationships between the nutritional status and ambulatory ability. The discriminative power of the CONUT score was then compared with other nutritional assessment tools such as the Geriatric Nutritional Risk Index (GNRI) and prognostic nutritional index (PNI) by ROC analysis.

RESULTS

81% of hospitalized patients with an AOVF were malnourished at the time of admission. The CONUT-high group had a significantly higher rate of decline in ambulatory ability (P < 0.001) than the CONUT-low group. Logistic regression analysis revealed the CONUT score ( ≥ 4) as an independent risk factor for a decline in ambulatory ability (OR 3.44, 95% CI 1.61-7.37, P = 0.0014). ROC analysis showed that the area under the curve (AUC) for the CONUT score (AUC = 0.724) was significantly greater than that for the GNRI (AUC = 0.624, P = 0.021) and PNI (AUC = 0.636, P = 0.0008).

CONCLUSIONS

This study showed that 81% of hospitalized elderly patients with AOVFs were malnourished and that the CONUT score was a useful predictive factor of functional prognosis.

The impact of diabetes mellitus on spinal fracture with diffuse idiopathic skeletal hyperostosis: A multicenter retrospective study

BACKGROUND

Patients with diffuse idiopathic skeletal hyperostosis (DISH) are susceptible to spinal column injuries with neurological deterioration. Previous studies indicated that the prevalence of diabetes mellitus (DM) in patients with DISH was higher than that in patients without DISH. This study investigates the impact of DM on surgical outcomes for spinal fractures in patients with DISH.

METHODS

We retrospectively evaluated 177 spinal fractures in patients with DISH (132 men and 45 women; mean age, 75 ± 10 years) who underwent surgery from a multicenter database. The subjects were classified into two groups according to the presence of DM. Perioperative complications, neurological status by Frankel grade, mortality rate, and status of surgical site infection (SSI) were compared between the two groups.

RESULTS

DM was present in 28.2% (50/177) of the patients. The proportion of men was significantly higher in the DM group (DM group: 86.0% vs. non-DM group: 70.1%) (p = 0.03). The overall complication rate was 22.0% in the DM group and 19.7% in the non-DM group (p = 0.60). Poisson regression model revealed that SSI was significantly associated with DM (DM group: 10.0% vs. non-DM group: 2.4%, Relative risk: 4.5) (p = 0.048). Change in neurological status, mortality rate, instrumentation failure, and nonunion were similar between both groups. HbA1c and fasting blood glucose level (SSI group: 7.2% ± 1.2%, 201 ± 67 mg/dL vs. non-SSI group: 6.6% ± 1.1%, 167 ± 47 mg/dL) tended to be higher in patients with SSI; however, there was no significant difference.

CONCLUSIONS

In spinal fracture in patients with DISH, although DM was an associated factor for SSI with a relative risk of 4.5, DM did not negatively impact neurological recovery. Perioperative glycemic control may be useful for preventing SSI because fasting blood glucose level was high in patients with SSI.

Adjacent vertebral Hounsfield unit value of acute osteoporotic vertebral fracture is a risk factor for concomitant domino osteoporotic vertebral fractures

BACKGROUND

Most patients with acute osteoporotic vertebral fracture (AOVF) are successfully treated conservatively. However, the optimal management method and prognosis for multiple AOVFs are unclear. This study aimed to investigate the prevalence of multiple AOVFs and identify the associated risk factors.

METHODS

This study enrolled 134 hospitalized patients (mean age 83 ± 7.6 years, 66% women) with AOVF treated conservatively between 2017 and 2020. The fractures were diagnosed by magnetic resonance imaging (MRI). The AOVFs were divided into two groups; single osteoporotic vertebral fractures (OVF) and domino OVFs (at least two OVFs). The adjacent vertebral Hounsfield unit values (HU) of the OVF and dual x-ray absorptiometry (DXA) of the lumbar spine or hip were used to evaluate the bone mineral density (BMD). Logistic regression analysis was performed to identify the risk factors for domino OVFs.

RESULTS

Domino OVFs were noted in 21 (15.7%) of 134 patients. There were 10 cases of adjacent level and 11 cases of remote level. The BMI (18.5 ± 4.2 vs. 21.2 ± 4.6, p = 0.025) and adjacent vertebral HU value of OVF (57.3 ± 17.5 vs. 76.6 ± 24.1, p = 0.008) were significantly lower in the domino OVFs group than in the single OVF group. Logistic regression analysis revealed the adjacent vertebral HU value of the OVF as an independent risk factor for domino OVFs, (odds ratios (OR) 0.96, p = 0.012). The domino OVF group had a significantly higher decline in gait ability (76% vs. 48%, p = 0.017).

CONCLUSIONS

The adjacent vertebral HU value of AOVF is a useful tool for evaluating BMD for domino OVFs. The optimal treatment for osteoporosis should be considered to prevent subsequent domino OVFs.

Risk factors for delayed diagnosis of spinal fracture associated with diffuse idiopathic skeletal hyperostosis: A nationwide multiinstitution survey

BACKGROUND

Patients with DISH are susceptible to spinal fractures and subsequent neurological impairment, including after minor trauma. However, DISH is often asymptomatic and fractures may have minimal symptoms, which may lead to delayed diagnosis. The purpose of this study was to identify risk factors for delayed diagnosis of spinal fractures in patients with diffuse idiopathic skeletal hyperostosis (DISH).

METHODS

The subjects were 285 patients with DISH surgically treated at 18 medical centers from 2005 to 2015. Cause of injury, imaging findings, neurological status at the times of injury and first hospital examination, and the time from injury to diagnosis were recorded. A delayed diagnosis was defined as that made >24 h after injury.

RESULTS

Main causes of injury were minor trauma due to a fall from a standing or sitting position (51%) and high-energy trauma due to a fall from a high place (29%) or a traffic accident (12%). Delayed diagnosis occurred in 115 patients (40%; 35 females, 80 males; mean age 76.0 ± 10.4 years), while 170 (60%; 29 females, 141 males; mean age 74.6 ± 12.8 years) had early diagnosis. Delayed group had a significantly higher rate of minor trauma (n = 73, 63% vs. n = 73, 43%), significantly more Frankel grade E (intact neurological status) cases at the time of injury (n = 79, 69% vs. n = 73, 43%), and greater deterioration of Frankel grade from injury to diagnosis (34% vs. 8%, p < 0.01). In multivariate analysis, a minor trauma fall (OR 2.08; P < 0.05) and Frankel grade E at the time of injury (OR 2.29; P < 0.01) were significantly associated with delayed diagnosis.

CONCLUSION

In patients with DISH, it is important to keep in mind the possibility of spinal fracture, even in a situation in which patient sustained only minor trauma and shows no neurological deficit. This is because delayed diagnosis of spinal fracture can cause subsequent neurological deterioration.

Comparison of Clinical Outcomes After Transforaminal Interbody Fusion Using Cortical Bone Trajectory versus Percutaneous Pedicle Screw Fixation

OBJECTIVE

The study aim was to compare clinical outcomes between patients undergoing transforaminal lumbar interbody fusion (TLIF) using percutaneous pedicle screw (PPS) and cortical bone trajectory (CBT) by a single surgeon.

METHODS

This was a retrospective matched-cohort study of 77 patients (mean age, 71.7 years; 56% female) who underwent TLIF using CBT or PPS. Thirty-nine consecutive patients in the CBT group and 38 patients in the PPS group were matched for age, sex, and fused levels. All CBT screws were inserted by using a three-dimensional patient-specific guide (MySpine MC, Medacta). Perioperative outcomes of operative time, estimated blood loss, numeric rating scale scores, and serum concentration of creatine kinase were compared between the 2 groups. At 1 year postoperatively, clinical outcomes and radiographic outcomes, including cage subsidence, screw loosening, and fusion rates, were compared between the 2 groups.

RESULTS

The numeric rating scale scores on postoperative days 3 and 7 and serum creatine kinase levels on postoperative days 1 and 3 were significantly lower in the CBT group than in the PPS group (all P < 0.005). There were no significant intergroup differences in operation time and estimated blood loss. At postoperative 1 year, there were no significant differences in cage subsidence, screw loosening, and fusion rates between the CBT group and PPS group. Clinical outcomes were equivalent between the 2 groups.

CONCLUSIONS

The CBT technique using three-dimensional patient-specific guides resulted in lower perioperative pain and quicker recovery after surgery, which suggests that CBT is a less invasive procedure than PPS.

Role of Rho-associated coiled-coil containing protein kinase in the spinal cord injury induced neuropathic pain

BACKGROUND CONTEXT

Spinal cord injury (SCI) can lead to increased phosphorylation of p38 in spinal cord microglia. This is one of the main causes for the development of persistent pain. Recently, we reported our study on the activation of p38 mitogen-activated protein kinases (MAPK) in spinal microglia, which has been considered the key molecule for the onset and maintenance of neuropathic pain after peripheral nerve injury, using a rat model. We also reported that the RhoA/Rho-associated coiled-coil containing protein kinase (ROCK) pathway mediates p38 activation in spinal microglia in peripheral nerve injury. But the precise mechanisms of neuropathic pain induced by SCI are still unclear.

PURPOSE

This study aimed to examine the activation of microglia and the p38 MAPK expression in the lumbar spinal cord after thoracic SCI in rats, and the correlation to the therapeutic effect of ROCK inhibitor ripasudil in rats with SCI.

STUDY DESIGN

Male Sprague-Dawley rats underwent thoracic (T10) spinal cord contusion injury using an Infinite Horizon impactor device. SCI rats received ROCK inhibitor ripasudil (24 nmol/day or 240 nmol/day) from just before SCI to 3 days after SCI.

METHODS

The mechanical threshold in the rat's hind paws was measured over four weeks. Morphology of microglia and phosphorylation of p38 (p-p38) in the lumbar spinal cord and were analyzed using immunohistochemistry.

RESULTS

The p-p38 positive cell and Iba1 (a maker of microglia) positive area were significantly increased at the lumbar spinal dorsal horn (L4-5) 3 days and 7 days after SCI compared with the sham-control (p<.05), whereas phosphorylated p38 was co-localized with microglia. Three days after SCI, the intensity of phosphorylated p38 and Iba1 immunoreactive cells in the dorsal horn was significantly lower in the ripasudil treated groups than in the saline group. However, administration of ROCK inhibitor did not affect the numbers of microglia. Moreover, the withdrawal threshold of the ripasudil-treated rats was significantly higher than that of the saline-injected rats on 14 days and 28 days after SCI.

CONCLUSIONS

Our results suggest that activation of ROCK in spinal cord microglia is likely to have an important role in the activation of p38 MAPK, which has been considered as a key molecule that switches on neuropathic pain after SCI. Inhibition of ROCK signaling may offer a means in developing a novel neuropathic pain treatment after SCI. It may help patients with neuropathic pain after SCI.

CLINICAL SIGNIFICANCE

The findings in the present study regarding intracellular mechanisms suggest that modulation of ROCK signaling may be a focus for novel treatment for neuropathic pain after SCI.

Low back pain is closely associated with frailty but not with sarcopenia: Cross-sectional study of rural Japanese community-dwelling older adults

AIM

We speculated that low back pain, which is the most common ailment in older adults, is associated with frailty and/or sarcopenia and contributes to the progression of either condition. Our objective was to evaluate the relationship between low back pain, sarcopenia and frailty in rural Japanese community-dwelling older adults.

METHODS

We recruited 730 participants aged ≥65 years who underwent a comprehensive health examination between November 2016 and December 2018. The Oswestry Disability Index (ODI) was used to assess low back pain quantitatively, and scores were compared for the frail groups determined by the Japanese version of Cardiovascular Health Study, and the sarcopenia groups as determined by the Asian Working Group for Sarcopenia 2019.

RESULTS

Among 730 participants, the prevalence of low back pain was 57.8%. There were significant differences in the ODI scores between the robust, prefrail and frail groups (P < 0.001). In contrast, there were no significant differences in the ODI scores among the robust, low appendicular skeletal muscle and sarcopenia groups. Logistic regression analysis showed that the prevalence of low back pain and the ODI scores were significantly associated with frailty after adjustment for age, sex and body mass index (odds ratio 3.41, 95% confidence interval 1.39-8.39, P = 0.008, and odds ratio 1.06, 95% confidence interval 1.04-1.09, P < 0.001, respectively).

CONCLUSIONS

To the best of our knowledge, this study is the first to show the close association between low back pain and frailty, and suggests that not only the decline in physical function but also neuropsychiatric factors, including chronic pain, constitute a vicious cycle of frailty in community-dwelling older adults. Geriatr Gerontol Int 2021; 21: 54-59.

Efficacy of Intervention for Prevention of Postoperative Delirium after Spine Surgery

Introduction

Delirium after spine surgery is an important complication; identification of risk factors associated with postoperative delirium (PD) is essential for reducing its incidence. Prophylactic intervention for PD has been reported to be effective. This study aimed to identify risk factors for PD and determine the efficacy of a prevention program using a delirium risk scoring system for PD after spine surgery.

Methods

This study was conducted in two stages. First, 294 patients (167 males, 127 females) who underwent spine surgery from 2013 to 2014 were assessed to examine the incidence and risk factors of PD and to establish a novel PD screening tool (Group A). Second, preoperative intervention was performed on 265 patients who underwent surgery from 2016 to 2017 (Group B) for the purpose of preventing PD using a delirium risk scoring system. Outcomes, including PD incidence and rates of adverse events, were compared between Group A and Group B.

Results

A logistic regression analysis revealed that psychiatric disorders (odds ratio [OR] = 10.3, P < 0.001), benzodiazepine use (OR = 4.9, P < 0.001), age > 70 years (OR = 4.2, P < 0.001), hearing loss (OR = 3.7, P = 0.001), and admission to intensive care unit (ICU) (OR = 3.7, P = 0.006) were independent risk factors associated with PD. Based on these results, we established a novel delirium screening tool after spine surgery. PD incidence was significantly higher in Group A than in Group B (22% vs. 13%, P = 0.0008). The occurrence of dangerous behavioral symptoms was significantly higher in Group A than in Group B (66% vs. 40%, P = 0.02). The catheter problem tended to be higher in Group A than in Group B (19% vs. 9%, P = 0.245).

Conclusions

In this study, psychiatric disorders, benzodiazepine use, age > 70 years, hearing loss, and admission to ICU were independent risk factors associated with PD. With the introduction of the delirium risk score, the onset of delirium was delayed, and adverse outcomes of delirium were reduced.

Trajectory of criterion symptoms of major depression under newly started antidepressant treatment: sleep disturbances and anergia linger on while suicidal ideas and psychomotor symptoms disappear early

OBJECTIVE

In modern psychiatry, depression is diagnosed with the diagnostic criteria; however, the trajectory of each of the criterion symptoms is unknown. This study aims to examine this.

METHODS

We made repeated assessments of the nine diagnostic criterion symptoms with the Patient Health Questionnaire-9 (PHQ-9) among 2011 participants of a 25-week pragmatic randomised controlled trial of sertraline and/or mirtazapine for hitherto untreated major depressive episodes. The changes from baseline were estimated with the mixed-effects model with repeated measures. The time to disappearance of each symptom was modeled using the Kaplan-Meier survival analysis.

RESULTS

The total score on PHQ-9 was 18.5 (SD = 3.9, n = 2011) at baseline, which decreased to 15.3 (5.2, n = 2011) at week 1, to 11.5 (5.9, n = 1953) at week 3, to 7.8 (6.0, n = 1927) at week 9, and to 6.0 (5.9, n = 1910) at week 25. Suicidal ideas, psychomotor symptoms decreased rapidly, while anergia and sleep disturbance also decreased but only slowly. The survival analyses confirmed the primary analyses.

CONCLUSIONS

Upon initiation of antidepressant treatment, patients with newly treated major depressive episodes can expect their suicidal ideas and psychomotor symptoms to disappear first but sleep disturbances and anergia to linger on.

Spinal fractures in patients with Diffuse idiopathic skeletal hyperostosis:A nationwide multi-institution survey

BACKGROUND

Diffuse idiopathic skeletal hyperostosis (DISH) increases the spine's susceptibility to unstable fractures that can cause neurological deterioration. However, the detail of injury is still unclear. A nationwide multicenter retrospective study was conducted to assess the clinical characteristics and radiographic features of spinal fractures in patients with DISH.

METHODS

Patients were eligible for this study if they 1) had DISH, defined as flowing ossification along the anterolateral aspect of at least four contiguous vertebral bodies, and 2) had an injury in the ankylosing spine. This study included 285 patients with DISH (221 males, 64 females; mean age 75.2 ± 9.5 years).

RESULTS

The major cause of injury was falling from a standing or sitting position; this affected 146 patients (51.2%). Diagnosis of the fracture was delayed in 115 patients (40.4%). Later neurological deterioration by one or more Frankel grade was seen in 87 patients (30.5%). The following factors were significantly associated with neurological deficits: delayed diagnosis (p = 0.033), injury of the posterior column (p = 0.021), and the presence of ossification of the posterior longitudinal ligament (OPLL) (p < 0.001). The majority of patients (n = 241, 84.6%) were treated surgically, most commonly by conventional open posterior fixation (n = 199, 69.8%). Neurological improvement was seen in 20.0% of the conservatively treated patients, and in 47.0% of the patients treated surgically.

CONCLUSIONS

Minor trauma could cause spinal fractures in DISH patients. Delayed diagnosis, injury of the posterior column, and the presence of OPLL were significantly associated with neurological deterioration. Patients with neurological deficits or unstable fractures should be treated by fixation surgery.

Comparison of the AOSpine subaxial cervical spine injury classification system and the Allen classification

The AOSpine group has launched a new subaxial cervical spine injury system (AOSCIS) based on morphology. The objective of this study was to use the AOSCIS and compare it to the widely used Allen classification (AC) based on mechanics for subaxial cervical spine injury. Twenty-two consecutive patients with subaxial cervical spine injury who received posterior cervical fixation in our hospital were included in this study. Medical records were evaluated retrospectively. The evaluated factors were as follows: preoperative ASIA impaired scale (AIS), AOSCIS, AC, and diffuse idiopathic skeletal hyperostosis (DISH). There was AIS A in nine patients, AIS C in four patients, AIS D in four patients, and AIS E in five patients. Two patients with AOSCIS B2 were classified as AC DF1. Two AOSCIS F3 patients were classified as AC CE1. Eighteen AOSCIS C patients were classified into multiple categories: five as AC DF2, three as DF3, one as CF4, one as CF5, four as DE2, three as CE3 + DE1, and one as CE3 + VC2. All of the AOSCIS A0 (F) or B patients were classified as AC stage 1, and all of the AOSCIS C patients were classified as AC stage 2 and higher (P < 0.05). All of six patients with DISH were classified as AOSCIS C and CE3, DE2, or DF3. AOSCIS and AC are correlated. Conducting an evaluation using both systems helps us to better comprehend subaxial cervical spine injuries.

Influence of Spinopelvic Alignment on Pelvic Tilt after Total Hip Arthroplasty

Objective

To evaluate the impact of spinopelvic parameters and hip contracture on change in the pelvic tilt (PT) after Total hip arthroplasty (THA).

Methods

One hundred patients (15 male and 85 female) who underwent THA were included in this prospective study. Radiographic data were obtained preoperatively and 1 year after THA. Radiographic parameters included sagittal anterior pelvic plane (APP), sagittal vertical axis (SVA), sacral slope (SS), pelvic inclination (PI), and lumbar lordosis angle (LL). The APP was defined as the angle between the anterior pelvic plane and the vertical plane. A positive value indicates pelvic retroversion. Postoperative changes in PT were divided into three groups: the PA group (pelvic anteversion, ΔAPP < −5°), the PR group (pelvic retroversion, ΔAPP > 5°), and the PT group (minimal change, ΔAPP ≤ ± 5°). The Kruskal–Wallis test and the Steel–Dwass test were used to compare the preoperative and postoperative spinopelvic parameters among the three groups. The Spearman's rank correlation coefficient was used to evaluate the correlation between ΔAPP and spinopelvic parameters.

Results

Minimal change in pelvic tilt was observed in 59% of patients, while pelvic anteversion was observed in 16% of patients and pelvic retroversion was observed in 25% of patients. There were no significant changes in the spinopelvic parameters, including TK, LL, SVA, LL, SS, and APP after THA. The Femoral angle (FA) was significantly decreased after THA (P < 0.001). Preoperative APP was significantly more retroverted in the PA group than the PR group, and the PT group (6.8 ± 12.2, 0.2 ± 9.9, −8.3 ± 8.3, P < 0.001). Preoperative SS, PI‐LL, and PI were significantly smaller in the PA group than the PT group and the PR group. A significant negative correlation was identified between preoperative APP and ΔAPP (r = −0.418, P < 0.001).

Conclusion

Approximately 60% of the patients did not have any marked change in PT after THA. Preoperative APP was the only predictive factor associated with marked anterior or posterior change in PT.

Clinical outcomes after posterior cervical decompression and fusion surgery for destructive spondyloarthropathy in patients undergoing long-term hemodialysis: A matched case-control study

BACKGROUND

Cervical destructive spondyloarthropathy (DSA) often leads to cervical myelopathy in long-term hemodialysis patients. However, the surgical outcomes after instrumented fusion surgery for cervical DSA are still unclear. The objective of this study was to investigate the clinical outcomes of cervical DSA in comparison with a control group.

MATERIALS AND METHODS

A consecutive series of 20 undergoing long-term hemodialysis patients who underwent instrumented fusion surgery for cervical DSA between 2010 and 2016 were included in this study (DSA group). The mean age at surgery was 65 years, and there were 11 men and 9 women. The average length of hemodialysis was 23 years. The age- and sex-matched control group consisted of 20 patients (degenerative conditions). The Japanese Orthopedic Association (JOA) score, recovery rate, complications, and loss of correction of fused level were compared between the groups.

RESULTS

Two of the 20 patients died due to perioperative complications. More than 1 year of follow-up data after surgery was available for 18 patients. The mean JOA score significantly increased from 5.4 before surgery to 9.7 at 1 year after surgery and 8.3 at the final follow-up (mean: 33.2 ± 21.3 months, P = 0.019). There were no significant differences in the mean recovery rate (41% vs. 37%, P = 0.44) between the DSA group and control group. Loss of correction of more than 5°was significantly higher in the DSA group (44% vs. 10%, P = 0.027). The rate of pseudarthrosis (17% vs. 5%, P = 0.328) and adjacent segment disease (22% vs. 10%, P = 0.17) tended to be higher in the DSA group.

DISCUSSION

The clinical outcomes showed significant recovery in both groups. Therefore, posterior cervical decompression and fusion surgery was effective for treating cervical DSA.

Effect of Teriparatide on Subsequent Vertebral Fractures after Instrumented Fusion Surgery for Osteoporotic Vertebral Fractures with Neurological Deficits

STUDY DESIGN

Retrospective case review.

PURPOSE

To assess the incidence and effect of teriparatide (TP) on subsequent vertebral fractures following a long-instrumented fusion surgery for osteoporotic vertebral fractures (OVFs).

OVERVIEW OF LITERATURE

TP treatment may be a useful strategy for patients with OVFs treated with a long-instrumented surgery.

METHODS

Overall, 47 patients who underwent long-instrumented fusion surgery (≥3 levels) for OVFs with neurological deficits between 2010 and 2013 were enrolled. The mean age of the subjects was 76 years; the study population comprised 20 males and 27 females. The mean follow-up duration was 23 months. The average of fused vertebrae was 4.9. TP was used for 19 patients who comprised the TP group. The incidence of subsequent VFs was estimated with Kaplan-Meier analyses and compared between the TP and non-TP groups using the log-rank test. Risk factors were evaluated using a Cox proportional hazards model.

RESULTS

A total of 38% (18/47 cases) of the subjects were identified with subsequent VFs. There were no significant differences in the age, sex, fused levels, presence of prevalent fractures, and correction loss of the two groups. The occurrence of subsequent VFs was lower in the TP group than in the non-TP group (16% vs. 54%, p=0.014). The log-rank test revealed that the TP treatment significantly reduced the risk of subsequent VFs (p=0.048). A Cox proportional hazards model revealed that preoperative TP treatment is only a protective factor of subsequent VFs after instrumented fusion surgery for OVFs (hazard ratio, 0.281; p=0.047).

CONCLUSIONS

In this retrospective study, pre- and postoperative TP treatment significantly reduced the incidence of subsequent VFs after instrumented fusion surgery for OVFs. A prospective randomized study is warranted to determine the efficacy of TP treatments.

Initial severity of major depression and efficacy of new generation antidepressants: individual participant data meta-analysis

OBJECTIVE

The role of baseline severity as effect modifier in various psychiatric disorders is a topic of controversy and of clinical import. This study aims to examine whether baseline severity modifies the efficacy of various antidepressants for major depression through individual participant data (IPD) meta-analysis.

METHOD

We identified all placebo-controlled, double-blind randomised trials of new generation antidepressants in the acute phase treatment of major depression conducted in Japan and requested their IPD through the public-private partnerships (PPPs) between the relevant academic societies and the pharmaceutical companies. The effect modification by baseline depression severity was examined through six increasingly complex competing mixed-effects models for repeated measures.

RESULTS

We identified eleven eligible trials and obtained IPD from six, which compared duloxetine, escitalopram, mirtazapine, paroxetine or bupropion against placebo (total n = 2464). The best-fitting model revealed that the interaction between baseline severity and treatment was not statistically significant (coefficient = -0.04, 95% confidence interval: -0.16 to 0.08, P = 0.49). Several sensitivity analyses confirmed the robustness of the findings.

CONCLUSION

We may expect as much benefit from antidepressant treatments for mild, moderate or severe major depression. Clinical practice guidelines will need to take these findings into consideration.

Interpretable inference on the mixed effect model with the Box-Cox transformation

We derived results for inference on parameters of the marginal model of the mixed effect model with the Box-Cox transformation based on the asymptotic theory approach. We also provided a robust variance estimator of the maximum likelihood estimator of the parameters of this model in consideration of the model misspecifications. Using these results, we developed an inference procedure for the difference of the model median between treatment groups at the specified occasion in the context of mixed effects models for repeated measures analysis for randomized clinical trials, which provided interpretable estimates of the treatment effect. From simulation studies, it was shown that our proposed method controlled type I error of the statistical test for the model median difference in almost all the situations and had moderate or high performance for power compared with the existing methods. We illustrated our method with cluster of differentiation 4 (CD4) data in an AIDS clinical trial, where the interpretability of the analysis results based on our proposed method is demonstrated. Copyright © 2017 John Wiley & Sons, Ltd.

Prognosis and adjacent segment disease after lumbar spinal fusion surgery for destructive spondyloarthropathy in long-term hemodialysis patients

BACKGROUND

Lumbar destructive spondyloarthropathy (DSA) is a serious complication in long-term hemodialysis patients. There have not been many reports regarding the surgical management for lumbar DSA. In addition, the adjacent segment pathology after lumbar fusion surgery for DSA is unclear. The objective of this study was to assess the clinical outcome and occurrence of adjacent segmental disease (ASD) after lumbar instrumented fusion surgery for DSA in long-term hemodialysis patients.

MATERIALS AND METHODS

A consecutive series of 36 long-term hemodialysis patients who underwent lumbar instrumented fusion surgery for DSA were included in this study. The mean age at surgery was 65 years. The mean follow-up period was 4 years. Symptomatic ASD was defined as symptomatic spinal stenosis or back pain with radiographic ASD. The Japanese Orthopedic Association score (JOA score), recovery rate (Hirabayashi method), complications, and reoperation were reviewed.

RESULTS

The mean JOA score significantly increased from 13.5 before surgery to 21.3 at the final follow-up. The mean recovery rate was 51.4%. Six of the 36 patients died within 1 year after index surgery. One patient died due to perioperative complication. Symptomatic ASD occurred in 43% (13 of 30) of the cases. Of these 13 cases, 5 had adjacent segment disc degeneration and 8 had adjacent segment spinal stenosis. Three cases (10%) required reoperation due to proximal ASD. Multi-level fusion surgery increased the risk of ASD compared with single-level fusion surgery (59% vs. 23%). The recovery rate was significantly lower in the ASD group than the non-ASD group (38% vs. 61%).

DISCUSSION

This study demonstrated that symptomatic ASD occurred in 43% of patients after surgery for lumbar DSA. A high mortality rate and complication rate were observed in long-term hemodialysis patients. Therefore, care should be taken for preoperative planning for surgical management of DSA.

Localized Cutaneous Cryptococcosis: Summary of Reported Cases in Japan

A 68-year-old male plasterer with no history of trauma presented to our clinic in March 2012 with a 16×14-mm ulcer that developed following a crushed small papule on the right anterior chest. In April 2012, the patient was referred to another hospital, where cutaneous cryptococcosis was diagnosed based on discharge culture results. The patient was treated with oral itraconazole at a dose of 150 mg/day for 10 weeks; however, the ulcer remained unchanged and he discontinued the treatment. In May 2014, when he revisited our clinic, the ulcer with crust had grown to 29×13 mm. No regional lymph node swelling was noted. India ink staining showed a yeast-like fungus with a thick, clear capsule. A cream-colored, viscous yeast-like colony was observed on Sabouraud dextrose agar. Genetic testing identified the isolate as Cryptococcus neoformans serotype A. The patient was negative for serum cryptococcal antigen. Neither chest radiography nor computed tomography revealed any abnormalities. The patient had no underlying disease. Oral fluconazole (400 mg/day for 12 weeks) was prescribed, resulting in scar formation. The patient has remained free of relapse for one year to date, since the end of treatment. Localized cutaneous cryptococcosis is not a commonly used disease name overseas. However, 36 cases of this disease have been reported in Japan (since in 1968). We herein report a new case with localized cutaneous cryptococcosis and summarize previously reported cases in Japan.

Use of pain drawing as an assessment tool of sciatica for patients with single level lumbar disc herniation

The objectives of this study were to examine the diagnostic accuracy of pain drawing (PD) in determining the level of involvement and to investigate how the quantitative evaluation results of PD using a grid score (GS) correlates with the results of other clinical evaluation measures in diagnosis and assessment of patients with lumber disc herniation (LDH) involving a single nerve root. Thirty-one patients with single level LDH who were diagnosed and conservatively treated by the first author constituted the study population. In order to assess the diagnostic accuracy of PD, the level of involvement as determined by PD was compared to the final diagnosis. In 26 of the 31 patients who could be followed for more than 6 months of conservative treatment, the GS in PD evaluation was compared to the score assessed by the Japanese Orthopaedic Association scoring system for low back pain (JOA score) and the visual analog scale (VAS) both before and after the treatment. The overall diagnostic accuracy of PD for the determination of the affected level averaged 68.8 %, and the accuracy was higher at the L4/5 and L5/S levels than the L2/3 and L3/4 levels. The average values of VAS and GS significantly decreased and the JOA score significantly improved after the treatment. Moreover, a significant correlation was demonstrated between the scores derived from these three evaluation measures. The present study indicated the potential usefulness of PD in clinical assessment during the treatment course.

Hemothorax caused by the trocar tip of the rod inserter after minimally invasive transforaminal lumbar interbody fusion: case report

Minimally invasive surgery (MIS) for transforaminal lumbar interbody fusion (MIS-TLIF) is widely used for lumbar degenerative diseases. In the paper the authors report a unique case of a hemothorax caused by the trocar tip of the rod inserter after MIS-TLIF. A 61-year-old woman presented with thigh pain and gait disturbance due to weakness in her lower right extremity. She was diagnosed with a lumbar disc herniation at L1-2 and the MIS-TLIF procedure was performed. Immediately after surgery, the patient's thigh pain resolved and she remained stable with normal vital signs. The next day after surgery, she developed severe anemia and her hemoglobin level decreased to 7.6 g/dl, which required blood transfusions. A chest radiograph revealed a hemothorax. A CT scan confirmed a hematoma of the left paravertebral muscle. A chest tube was placed to treat the hemothorax. After 3 days of drainage, there was no active bleeding. The patient was discharged 14 days after surgery without leg pain or any respiratory problems. This complication may have occurred due to injury of the intercostal artery by the trocar tip of the rod inserter. A hemothorax after spine surgery is a rare complication, especially in the posterior approach. The rod should be caudally inserted in the setting of the thoracolumbar spine.

Post-Traumatic Torticollis Due to Odontoid Fracture in a Patient With Diffuse Idiopathic Skeletal Hyperostosis: A Case Report

Descriptive case report.To report a rare case of post-traumatic torticollis by odontoid fracture in a patient with diffuse idiopathic skeletal hyperostosis (DISH).Cervical fractures in DISH can result from minor trauma, and a delay in presentation often prevents their timely diagnosis. Cervical fractures in patients with spinal DISH usually occur in extension injuries, and almost always occur in the lower cervical spine. Reports of odontoid fractures with torticollis in patients with spinal DISH are rare.A 73-year-old man with DISH presented with severe neck pain and a cervical deformity presenting as torticollis without neurological deficits. He gave a history of a fall while riding a bicycle at a low speed 3 months ago. X-ray showed torticollis in the right side, and computed tomography (CT) showed a type-II odontoid fracture and subluxation at the C1-2 level.We performed a staged treatment because this patient had severe neck pain associated with a chronic course. Initially, the fracture dislocation was reduced under general anesthesia and was stabilized with a halo vest. We then performed posterior occipitocervical in situ fusion after confirming the correction of the cervical deformity by CT. The patient showed significant amelioration of neck symptoms postoperatively, and bony fusion was achieved 1 year after surgery.For post-traumatic torticollis due to an odontoid fracture, plain CT is useful for diagnosis and posterior occipitocervical in situ fusion following correction and immobilization with a halo vest is a safe and an effective treatment.

Ossified Posterior Longitudinal Ligament With Massive Ossification of the Anterior Longitudinal Ligament Causing Dysphagia in a Diffuse Idiopathic Skeletal Hyperostosis Patient

Descriptive case report.To report a case of a diffuse idiopathic skeletal hyperostosis (DISH) patient with both massive ossification of the anterior longitudinal ligament (OALL) leading to severe dysphagia as well as ossification of the posterior longitudinal ligament (OPLL) causing mild cervical myelopathy, warranting not only an anterior approach but also a posterior one.Although DISH can cause massive OALL in the cervical spine, severe dysphagia resulting from DISH is a rare occurrence. OALLs are frequently associated with OPLL. Treatment for a DISH patient with OPLL in setting of OALL-caused dysphagia is largely unknown.A 70-year-old man presented with severe dysphagia with mild cervical myelopathy. Neurological examination showed mild spastic paralysis and hyper reflex in his lower extremities. Plane radiographs and computed tomography of the cervical spine revealed a discontinuous massive OALL at C4-5 and continuous type OPLL at C2-6. Magnetic resonance imaging revealed pronounced spinal cord compression due to OPLL at C4-5. Esophagram demonstrated extrinsic compression secondary to OALL at C4-5.We performed posterior decompressive laminectomy with posterior lateral mass screw fixation, as well as both resection of OALL and interbody fusion at C4-5 by the anterior approach. We performed posterior decompressive laminectomy with posterior lateral mass screw fixation, as well as both resection of OALL and interbody fusion at C4-5 by the anterior approach. Severe dysphagia markedly improved without any complications.We considered that this patient not only required osteophytectomy and fusion by the anterior approach but also required decompression and spinal fusion by the posterior approach to prevent both deterioration of cervical myelopathy and recurrence of OALL after surgery.

Erosion in the occipital bone caused by the fixation instrument used for posterior atlantoaxial fusion -report of 4 cases

Introduction

Conventionally, posterior C1-C2 fusion has been performed using a sublaminar wiring technique with a structural bone graft. Subsequent advent of newer fixation devices, such as the C1 lateral mass screw and C1 hook, has achieved more solid fixation with improved surgical outcome; however, in these fixation systems, the protruding end of the metal implant above the level of the atlas may result in a complication due to contact with the surrounding structures.

Case description

Two men and two women whose ages at the time of surgery ranged from 14 to 72 years. A supralaminar hook was used as a fixation device for C1 in two cases, whereas a lateral mass screw (Tan’s method) and an atlas claw hook were employed for one each of the remaining 2 cases. We retrospectively reviewed the clinical features and postoperative course of these patients using the clinical records. Moreover, we measured the protruding height of the instrument above the atlas as well as the Redlund-Johnell (R-J) value on postoperative radiographs. All patients complained of crepitus and/or pain on neck extension. Erosion in the occipital bone was detected on multiplanar reconstruction computed tomography (MPR-CT), whereas plain radiographs failed to reveal the bony change. In those cases, protruding instruments used for C1 fixation contacted the occipital bone resulting in an erosive change at the impingement point. We removed the implant in all four cases after confirmation of solid bony union.

Discussion and evaluation

Two of the four patients complained of occipital crepitus alone without pain. The management options for this condition may be controversial; however, progression of bony erosion may result in perforation of the occipital bone. This may possibly be associated with the serious complication of cerebrospinal fluid leakage. Considering this potential sequela, we removed the implants from all our reported cases after confirmation of solid bony union.

Conclusions

We treated four cases that developed erosion in the occipital bone after posterior spinal instrumentation was performed for upper cervical lesions including C1. MPR-CT was useful in detecting the erosive changes in the occipital bone.

Development of low-fluorescence thick photoresist for high-aspect-ratio microstructure in bio-application

In this study, we propose and evaluate a novel low-auto-fluorescence photoresist (SJI photoresist) for bio-application, e.g., in gene analysis and cell assay. The spin-coated SJI photoresist has a wide thickness range of ten to several hundred micrometers, and photoresist microstructures with an aspect ratio of over 7 and micropatterns of less than 2 μm are successfully fabricated. The emission spectrum intensity of the SJI photoresist is found to be over 80% less than that of the widely used SU-8 photoresist. To evaluate the validity of using the proposed photoresist in bio-application for fluorescence observation, we demonstrate a chromosome extension device composed of the SJI photoresist. The normalized contrast ratio of the SJI photoresist exhibits a 50% improvement over that of the SU-8 photoresist; thus, the SJI photoresist is a versatile tool for bio-application.

Inference of median difference based on the Box-Cox model in randomized clinical trials

In randomized clinical trials, many medical and biological measurements are not normally distributed and are often skewed. The Box-Cox transformation is a powerful procedure for comparing two treatment groups for skewed continuous variables in terms of a statistical test. However, it is difficult to directly estimate and interpret the location difference between the two groups on the original scale of the measurement. We propose a helpful method that infers the difference of the treatment effect on the original scale in a more easily interpretable form. We also provide statistical analysis packages that consistently include an estimate of the treatment effect, covariance adjustments, standard errors, and statistical hypothesis tests. The simulation study that focuses on randomized parallel group clinical trials with two treatment groups indicates that the performance of the proposed method is equivalent to or better than that of the existing non-parametric approaches in terms of the type-I error rate and power. We illustrate our method with cluster of differentiation 4 data in an acquired immune deficiency syndrome clinical trial.

The impact of dynamic factors on surgical outcomes after double-door laminoplasty for ossification of the posterior longitudinal ligament of the cervical spine

OBJECT

Laminoplasty is the preferred operation for most patients with cervical myelopathy due to multilevel ossification of the posterior longitudinal ligament (OPLL). Recent studies have demonstrated several significant risk factors for poor clinical outcomes after laminoplasty, including older age, lower preoperative Japanese Orthopaedic Association (JOA) score, postoperative change in cervical alignment, cervical kyphosis, and high occupying ratio of the OPLL (that is, the ratio of the greatest anteroposterior thickness of the OPLL to the anteroposterior diameter of the spinal canal at the same level on a lateral image). However, the impact of dynamic factors on clinical outcomes is unclear. The purpose of this study is to assess the impact of dynamic factors on the clinical outcome after laminoplasty for cervical myelopathy due to OPLL.

METHODS

A consecutive series of patients who underwent laminoplasty for cervical myelopathy due to OPLL between 2003 and 2009 was retrospectively reviewed. The indication for laminoplasty at the authors' hospital included preoperative straight or lordotic alignment of the cervical spine and an occupying ratio of OPLL less than 60%. The JOA score and recovery rate were used to evaluate clinical outcomes. A poor clinical outcome was defined as a recovery rate of less than 50%. Patient factors examined along with outcome included age, preoperative JOA score, preoperative somatosensory evoked potentials, preoperative motor evoked potentials, body mass index, and presence of high intensity on MRI. Radiographic measures included the preoperative C2-7 lordotic angle, preoperative C2-7 range of motion (ROM), preoperative segmental ROM at the level of myelopathy, and the occupying ratio of OPLL.

RESULTS

There were 45 patients (33 males and 12 females). The mean follow-up period was 4 years (range 2-6.8 years). The mean patient age was 66.9 years (range 50-85 years). The mean JOA score significantly increased from 9.1 before surgery to 13.1 at the final follow-up. The mean recovery rate was 51.2%. Nineteen patients (42%) had a recovery rate of less than 50%. Patient factors were not associated with surgical outcomes. Only the preoperative C2-7 ROM was significantly greater in the poor surgical outcome group (23.1° vs 14.1°). Receiver operating characteristic curve analysis showed that the optimal preoperative C2-7 ROM cutoff was 20°. Logistic regression analysis revealed that patients with a preoperative C2-7 ROM of greater than 20° had a 4.6 times higher risk (p = 0.021) of a poor clinical outcome, indicating that dynamic factors may have an impact on the surgical outcome of laminoplasty.

CONCLUSIONS

Fusion surgery may be a useful strategy in patients with preoperative hypermobility of the cervical spine.

Subarachnoid-subarachnoid bypass for spinal adhesive arachnoiditis

The authors report a case of adhesive arachnoiditis (AA) and arachnoid cyst successfully treated by subarachnoid to subarachnoid bypass (S-S bypass). Arachnoid cysts or syringes sometimes compress the spinal cord and cause compressive myelopathy that requires surgical treatment. However, surgical treatment for AA is challenging. A 57-year-old woman developed leg pain and gait disturbance. A dorsal arachnoid cyst compressed the spinal cord at T7-9, the spinal cord was swollen, and a small syrinx was present at T9-10. An S-S bypass was performed from T6-7 to T11-12. The patient's gait disturbance resolved immediately after surgery. Two years later, a small arachnoid cyst developed. However, there was no neurological deterioration. The myelopathy associated with thoracic spinal AA, subarachnoid cyst, and syrinx improved after S-S bypass.

Outcome and treatment of postoperative spine surgical site infections: predictors of treatment success and failure

BACKGROUND

Surgical site infection (SSI) is an important complication after spine surgery. The management of SSI is characterized by significant variability, and there is little guidance regarding an evidence-based approach. The objective of this study was to identify risk factors associated with treatment failure of SSI after spine surgery.

PATIENTS AND METHODS

A total of 225 consecutive patients with SSI after spine surgery between July 2005 and July 2010 were studied retrospectively. Patients were treated with aggressive surgical debridement and prolonged antibiotic therapy. Outcome and risk factors were analyzed in 197 patients having 1 year of follow-up. Treatment success was defined as resolution within 90 days.

RESULTS

A total of 126 (76 %) cases were treated with retention of implants. Forty-three (22 %) cases had treatment failure with five (2.5 %) cases resulting in death. Lower rates of treatment success were observed with late infection (38 %), fusion with fixation to the ilium (67 %), Propionibacterium acnes (43 %), poly microbial infection (68 %), >6 operated spinal levels (67 %), and instrumented cases (73 %). Higher rates of early resolution were observed with superficial infection (93 %), methicillin-sensitive Staphylococcus aureus (95 %), and <3 operated spinal levels (88 %). Multivariate logistic regression revealed late infection was the most significant independent risk factor associated with treatment failure. Superficial infection and methicillin-sensitive Staphylococcus aureus were predictors of early resolution.

CONCLUSION

Postoperative spine infections were treated with aggressive surgical debridement and antibiotic therapy. High rates of treatment failure occurred in cases with late infection, long instrumented fusions, polymicrobial infections, and Propionibacterium acnes. Removal of implants and direct or staged re-implantation may be a useful strategy in cases with high risk of treatment failure.

Therapeutic impact of organism isolation in management of patients with pyogenic vertebral osteomyelitis

In management of patients with pyogenic vertebral osteomyelitis, organism isolation by biopsy is generally considered to be of primary importance when constructing a treatment plan. In our clinical practice, however, patients can be successfully treated even without identifying the organisms. The objective of this study is to review our clinical experiences and clarify the therapeutic impact of organism isolation. Forty patients who were conservatively managed in our institution constituted the base of this study. The average follow-up period was 16.7 months. Among the study subjects, 13 patients underwent percutaneous needle biopsy and the organism was identified in 6 patients. Additionally, the organism was isolated from the sample obtained from blood and possible foci in 10 patients. In total, the causative organism was identified in 15 of the 40 patients (37.5%). Patients were divided into two groups based on whether the organism was identified by culture (Groups A and B, with and without organism isolation respectively). The duration of antibiotic therapy was not significantly different between the groups (Group A: 4.8 ± 1.6 months, Group B: 4.3 ± 2.1 months), while subsequent mortalities in Group A and B were 13.3% and 8% without significant intergroup difference. Organism isolation did not productively help select the effective antibiotics and reduce the treatment period or mortality rate in treatment of patients with pyogenic vertebral osteomyelitis. Therefore, current strategic antibiotic therapy may be effective in eradicating infection even without identification of the causative organism in treatment of patients with pyogenic vertebral osteomyelitis.