Association of phase angle with sarcopenia in chronic musculoskeletal pain patients: a retrospective study

BACKGROUND

In chronic musculoskeletal pain patients, detection of sarcopenia is of significant clinical interest. Phase angle, which can be measured through bioelectrical impedance analysis (BIA), can detect sarcopenia; however, the evidence in chronic musculoskeletal pain patients is limited. This study aimed to assess the relationship between phase angle and sarcopenia in patients with chronic musculoskeletal pain. Our hypothesis was that phase angle would be a useful indicator to identify sarcopenia in patients with chronic musculoskeletal pain.

METHODS

A total of 190 patients (51 men and 139 women) with chronic musculoskeletal pain were included in this retrospective cross-sectional study. Patient data of backgrounds, numeric rating scale score for pain, skeletal muscle index, and phase angle assessed using BIA were retrospectively reviewed. Sarcopenia was diagnosed using the Asian Working Group for Sarcopenia criteria 2019.

RESULTS

A total of 51 patients (26.7%), including 10 men (19.6%) and 41 women (29.5%), were diagnosed with sarcopenia. Phase angle, sarcopenia-related factors, age, and body mass index (BMI) differed significantly in patients with and without sarcopenia. On multiple logistic regression analysis, the prevalence of sarcopenia was significantly correlated with phase angle and BMI. The areas under the curve exhibited high accuracy in discriminating sarcopenia in men and moderate accuracy in both sexes and in women.

CONCLUSIONS

Phase angle may be a valid discriminator of sarcopenia in patients with chronic musculoskeletal pain.

Three-Dimensional Analysis of the Ideal Entry Point for Sacral Alar Iliac Screws

STUDY DESIGN

This is a virtual three-dimensional (3D) imaging study examining computed tomography (CT) data to investigate instrumentation placement.

PURPOSE

In this study, we aim to clarify the ideal entry point and trajectory of the sacral alar iliac (SAI) screw in relationship to the dorsal foramen at S1 and the respective nerve root.

OVERVIEW OF LITERATURE

To the best of our knowledge, there is yet no detailed 3D imaging study on the ideal entry point of the SAI screw. Despite the evidence suggesting that the dorsal foramen at S1 is a landmark on the sacrum, the S1 nerve root disruption is a general concern during the insertion of SAI screws. No other study has been published examining the nerve root location at the S1and SAI screw insertions.

METHODS

Preoperative CT data from 26 patients pertaining to adult spinal deformities were investigated in this study. We applied a 3D image processing method for a detailed investigation. Virtual cylinders were used to mimic SAI screws. These were placed to penetrate the sacral iliac joint without violating the other cortex. We then assessed the trajectory of the longest SAI screw and the ideal entry point of SAI using a color mapping method on the surface of the sacrum. We measured the location of the nerve root at S1 in relation to the foramen at S1 and the sacral surface.

RESULTS

As per the results of our color mapping, it was determined that areas that received high scores are located medially and caudally to the dorsal foramen of S1. The mean angle between a horizontal line and a line connecting the medial edge of the foramen and nerve root at S1 was 93.5°. The mean distances from the dorsal medial edge of the foramen and sacral surface to S1 nerve root were 21.8 mm and 13.9 mm, respectively.

CONCLUSIONS

The ideal entry point of the SAI screw is located medially and caudally to the S1 dorsal foramen based on 3D digital mapping. It is also shown that this entry point spares the S1 nerve root from possible iatrogenic injuries.

Posterolateral Floating Technique for the Thoracic Ossification of the Posterior Longitudinal Ligament with Navigation: A Technical Note

We describe a floating technique via a posterolateral approach with intraoperative O-arm navigation to facilitate decompression of the spinal cord in thoracic myelopathy due to severe ossification of the posterior longitudinal ligament (OPLL). A 62-year-old man with myelopathy due to thoracic OPLL had left-leg muscle weakness, urinary disturbance, and spastic gait. Bilateral leg pain and gait disturbance had persisted for 2 years. He was successfully treated by the posterolateral OPLL floating procedure and posterior pedicle fixation under O-arm navigation. At a 2-year follow-up, manual muscle testing results and sensory function of the left leg had recovered fully. His cervical Japanese Orthopedic Association score had improved from 5/12 to 11/12. The novel intraoperative O-arm navigation-guided posterolateral floating procedure for thoracic OPLL is effective for achieving precise decompression and strong fixation with a posterior approach only and can provide an excellent result for severe thoracic OPLL without the risk of adverse events from intraoperative radiation.

Factors influencing caregiver burden in chronic pain patients: A retrospective study

Chronic pain coexists with disability, anxiety, depression, and sleep disturbances, which are factors of pain chronicity in the fear-avoidance model. Self-efficacy for managing pain plays a protective role against pain chronicity. For chronic pain sufferers, social support from caregivers is important. However, such caregivers face enormous physical and mental burdens. This study aimed to assess how self-efficacy and factors related to the fear-avoidance model affect caregiver burden. Participants were 135 chronic pain patients and their caregivers who visited our outpatient pain special clinic. In clinical assessments, numeric rating scale (NRS), pain catastrophizing scale (PCS), hospital anxiety and depression scale (HADS), Athens insomnia scale (AIS), pain disability assessment scale (PDAS), pain self-efficacy questionnaire (PSEQ) for the patients and Zarit Burden Interview (ZBI) for their caregivers were evaluated. Participants were divided into 2 groups (L group ZBI < 24 points and H group ZBI ≥ 24 points) and compared. Regression analyses were conducted to identify factors correlated with the ZBI scores. Compared to L group, H group showed significantly higher NRS and HADs depression scores, and lower PSEQ scores. In univariate regression analysis, ZBI scores were significantly correlated with NRS, PCS, HADS anxiety, HADS depression, PDAS and PSEQ. Multiple linear regression analysis revealed that ZBI scores were significantly correlated with PSEQ. The caregivers who perceived high caregiver burden had significantly higher patients' pain intensity, depression, and lower self-efficacy than those who perceived low caregiver burden. Caregiver burden correlated with the pain intensity, pain catastrophizing, anxiety, depression, disability, and self-efficacy of chronic pain patients. Among these factors, self-efficacy was the most negatively correlated with caregiver burden. Treatments focused on increasing self-efficacy for managing pain have the potential to reduce caregiver burden.

Evaluation of SARC-F and SARC-CalF for sarcopenia screening in patients with chronic musculoskeletal pain: A prospective cross-sectional study

OBJECTIVES

Early sarcopenia detection using screening tools, such as SARC-F and SARC-CalF, has been proven reliable. However, the relationship between chronic musculoskeletal pain with sarcopenia is unknown. This study assessed sarcopenia morbidity as well as the reliability of sarcopenia screening with SARC-F and SARC-CalF in patients with chronic musculoskeletal pain.

METHODS

Overall, 172 patients with chronic musculoskeletal pain were included in this cross-sectional study. All participants completed the SARC-F, SARC-CalF, numeric rating scale (NRS), and pain disability assessment scale (PDAS) assessments. Sarcopenia was diagnosed using the Asian Working Group for Sarcopenia criteria 2019. Correlations between SARC-F and SARC-CalF scores and each measured variable were evaluated using univariate and multiple linear regression analyses. A receiver operating characteristic curve analysis was conducted, and reliabilities of SARC-F and SARC-CalF scores for diagnosing sarcopenia were compared.

RESULTS

Thirty-nine patients were diagnosed with sarcopenia. Among these, 10 patients were <65 years old, and 29 were >65 years old. Both SARC-F and SARC-CalF scores significantly correlated with grip power, gait speed, skeletal mass index, numeric rating scale score, and PDAS score. In multiple linear regression analysis, SALC-F and SALC-CalF scores significantly correlated with PDAS score, skeletal mass index, and gait speed. The area under the curve were 0.70 for SARC-F and 0.88 for SARC-CalF; SARC-CalF had a significantly higher area under the curve than SARC-F.

DISCUSSION

Sarcopenia was diagnosed in patients aged <65 years with chronic musculoskeletal pain. SALC-F and SARC-CalF scores showed a significant correlation with disability due to pain and were reliable sarcopenia screening tools for chronic musculoskeletal pain. SARC-CalF was more reliable than SARC-F.

Mechanical Study of Various Pedicle Screw Systems including Percutaneous Pedicle Screw in Trauma Treatment

Background and Objectives: Spine surgery using a percutaneous pedicle screw placement (PPSP) is widely implemented for spinal trauma. However, percutaneous systems have been reported to have weak screw-rod connections. In this study, conventional open and percutaneous systems were biomechanically evaluated and compared. Material and Methods: The experiments were performed in two stages: the first stage was a break test, whereas the second stage was a fatigue test. Four systems were used for the experiments. System 1 was intended for conventional open surgery (titanium rod with a 6.0 mm diameter, using a clamp connecting mechanism). System 2 was a percutaneous pedicle screw (PPS) system for trauma (titanium alloy rod with a 6.0 mm diameter, using ball ring connections). System 3 was a PPS system for trauma (cobalt-chromium alloy rod with a 6.0 mm diameter, using sagittal adjusting screw connections). System 4 was a general-purpose PPS system (titanium alloy rod with a 5.5 mm diameter, using a mechanism where the adapter in the head holds down the screw). Results: Stiffness values of 54.8 N/mm, 43.1 N/mm, 90.9 N/mm, and 39.3 N/mm were reported for systems 1, 2, 3, and 4, respectively. The average number of load cycles in the fatigue test was 134,393, 40,980, 1,550,389, and 147,724 for systems 1 to 4, respectively. At the end of the test, the displacements were 0.2 mm, 16.9 mm, 1.2 mm, and 8.6 mm, respectively. System 1, with a locking mechanism, showed the least displacement at the end of the test. Conclusion: A few PPS systems showed better results in terms on stiffness and life than the open system. The experiments showed that mechanical strength varies depending on the spinal implant. The experiments conducted are essential and significant to provide the mechanical strength required for surgical reconstruction.

C-arm Free O-arm Navigated Posterior Atlantoaxial Fixation in Down Syndrome: A Technical Note

The surgical treatment of pediatric atlantoaxial subluxation (AAS) in Down syndrome (DS) remains technically challenging due to radiation exposure and complications such as vertebral artery injury and nonunion. The established treatment is fixation with a C1 lateral mass screw and C2 pedicle screw (modified Goel technique). However, this technique requires fluoroscopy for C1 screw insertion. To avoid exposing the operating team to radiation we present here a new C-arm free O-arm navigated surgical procedure for pediatric AAS in DS. A 5-year-old male DS patient had neck pain and unsteady gait. Radiograms showed AAS with an atlantodental interval of 10 mm, and irreducible subluxation on extension. CT scan showed Os odontoideum and AAS. MRI demonstrated spinal cord compression between the C1 posterior arch and odontoid process. We performed a C-arm free O-arm navigated modified Goel procedure with postoperative halo-vest immobilization. At oneyear follow-up, good neurological recovery and solid bone fusion were observed. The patient had no complications such as epidural hematoma, infection, or nerve or vessel injury. This novel procedure is a useful and safe technique that protects surgeons and staff from radiation risk.

Comparative Study of Bilateral Dual Sacral-Alar-Iliac Screws versus Bilateral Single Sacral-Alar-Iliac Screw for Adult Spine Deformities

OBJECTIVE

To evaluate the feasibility of O-arm navigation of bilateral dual sacral-alar-iliac (SAI) screws compared with conventional bilateral single SAI and S1 pedicle screws for pelvic anchors in cases of adult spinal deformity.

METHODS

This retrospective, comparative study included 39 patients who underwent corrective fusion using SAI screws from T10 to the pelvis. Patients were divided into 2 groups according to the number of SAI screws placed during adult spinal deformity surgery: single SAI screw (group S, 17 cases) and dual SAI screws (group D, 22 cases). The incidence of rod breakage, proximal junctional kyphosis, screw loosening, reoperation, and global alignment in each group was estimated. Postoperative patient-reported outcomes were measured using the Oswestry Disability Index, Japanese Orthopaedic Association Back Pain Evaluation Questionnaire, and visual analog scale.

RESULTS

The incidence of SAI screw loosening was significantly lower in group D than in group S (23% vs. 65%, P = 0.011). The rod breakage incidence was 0% and 12% in groups D and S, respectively (P = 0.17). There were no significant differences in the postoperative global alignment and clinical outcomes between the 2 groups.

CONCLUSIONS

Dual SAI screws were associated with a significantly reduced incidence of screw loosening compared with single SAI screws. The bilateral dual SAI screws technique for pelvic anchors is feasible for the treatment of patients with adult spinal deformity.

Minimally Invasive L5 Corpectomy with Navigated Expandable Vertebral Cage: A Technical Note

Background: Conventional L5 corpectomy requires a large incision and an extended period of intraoperative fluoroscopy. We describe herein a new L5 corpectomy technique. Methods: A 79-year-old woman was referred to our hospital for leg pain and lower back pain due to an L5 vertebral fracture. Her daily life had been affected by severe lower back pain and sciatica for more than 2 months. We initially performed simple decompression surgery, but this proved effective for only 10 months. Results: For revision surgery, the patient underwent minimally invasive L5 corpectomy with a navigated expandable cage without fluoroscopy. The second surgery took 215 min, and estimated blood loss was 750 mL. The revision surgery proved successful, and the patient could then walk using a cane. In terms of clinical outcomes, the Oswestry Disability Index improved from 66% to 24%, and the visual analog scale score for lower back pain improved from 84 to 31 mm at the 1-year follow-up. Conclusions: Minimally invasive L5 corpectomy with a navigated expandable vertebral cage is effective for reducing cage misplacement and surgical invasiveness. With this new technique, surgeons and operating room staff can avoid the risk of adverse events due to intraoperative radiation exposure.

Assessment of the Concordance Rate between Intraoperative Pathological Diagnosis and the Final Pathological Diagnosis of Spinal Cord Tumors

The intraoperative pathological diagnosis (IPD) plays an important role in determining the optimal surgical treatment for spinal cord tumors. The final pathological diagnosis (FPD) is sometimes different from the IPD. Here, we sought to identify the accuracy of the IPD of spinal cord tumors compared to the FPD. We retrospec-tively analyzed the cases of 108 patients with spinal cord tumors treated surgically in our institute; the IPD, FPD, mismatched cases, and concordance rate between the IPD and FPD were investigated. Five cases involved a mismatch between the IPD and FPD. The overall concordance rate was 95.4%, with 90.9% for extra-dural lesions, 98.5% for intradural extramedullary lesions, 84.2% for intramedullary lesions, and 100% for dumbbell-type tumors. The concordance rate of intramedullary lesions tended to be lower than that of other lesions (p = 0.096). A lower concordance rate was revealed for intramedullary lesions compared to the other lesions. Despite the IPD clearly remaining a valuable tool during operative procedures, surgeons should recog-nize the limitations of IPDs and make comprehensive decisions about surgical treatments.

Psoas muscle index predicts osteoporosis and fracture risk in individuals with degenerative spinal disease

OBJECTIVES

Skeletal muscle loss and osteoporosis are major medical and socioeconomic concerns as the global population ages. Studies have reported that skeletal muscle mass correlates to bone mineral density (BMD). The psoas muscle index (PMI), measured as the L3 cross-sectional areas of the right and left psoas divided by the square of height, has a positive correlation with the total volume of skeletal muscle in the body. This study aimed to evaluate relationships between PMI and BMD and fracture risk estimated by the Fracture Risk Assessment Tool (FRAX).

METHODS

Preoperatively acquired, plain computed tomography images at the L3 level were used to measure PMI in 87 people with degenerative spinal diseases. We evaluated the correlation between PMI and BMD and fracture risk estimated by FRAX.

RESULTS

PMI was significantly correlated with BMD in the entire lumbar spine and femoral neck (r = 0.413 and 0.525, both P < 0.001). People with osteoporosis showed significantly lower PMI than those without (P < 0.05). PMI was also significantly correlated with FRAX score (r = -0.545, P < 0.001). Furthermore, based on the recommendation of osteoporosis treatment, participants were divided into two groups: FRAX ≥15% (R group) and FRAX <15% (C group). The R group showed significantly lower PMI than the C group (P < 0.001). Receiver operating characteristic curve analysis revealed that PMI has moderate accuracy in diagnosing osteoporosis and FRAX ≥15%.

CONCLUSIONS

PMI was significantly associated with BMD and fracture risk. PMI measurement is straightforward and may increase the diagnosis rate of osteoporosis and fracture risk.

Cognitive factors associated with locomotive syndrome in chronic pain patients: A retrospective study

BACKGROUND

Prevention and treatment for locomotive syndrome (LS) are important for extending healthy life expectancy. The 25-question geriatric locomotive function scale (GLFS-25) was developed to diagnose LS. The Fear-Avoidance model was proposed to explain pain chronicity. LS and chronic pain decrease activities of daily living; however, the relationships between LS and factors related to chronic pain in the Fear-Avoidance model are unknown. Objective of the current study was to assess the prevalence of LS and examine the factors of the Fear-Avoidance model and the GLFS-25 that affect the prevalence of LS in patients with chronic pain.

METHODS

Participants included 281 patients (99 men, 182 women) aged over 40 years with chronic pain who visited our outpatient clinic for chronic pain. All participants completed the GLFS-25, numeric rating scale (NRS), pain catastrophizing scale (PCS), hospital anxiety and depression scale (HADS), and Athene insomnia scale (AIS). According to a GLFS-25 cutoff point, participants were divided into three groups (LS-2; GLFS-25 ≥ 16, LS-1; 7 ≤ GLFS-25 < 16, and non-LS; GLFS-25 < 7 points) and each parameter was compared among the groups, followed by multiple logistic regression analysis. Next, multiple linear regression analysis was performed to determine the factors associated with the GLFS-25.

RESULTS

Of all 281 patients, 241 (85.8%) patients were diagnosed with LS-2. Univariate analysis revealed there were significant differences in NRS, PCS, HADS anxiety, HADS depression, and AIS among groups. Multiple logistic regression analyses showed PCS was significantly associated with LS-2 prevalence. The GLFS-25 was positively correlated with NRS, HADS depression, AIS in multiple linear regression analysis.

CONCLUSIONS

We found that patients with chronic pain in our outpatient clinic had a significant rate of LS-2. The prevalence of LS-2 was significantly correlate with pain catastrophizing, and the GLFS-25 was significantly correlated with higher pain intensity, depression, and insomnia.

Cobalt-chromium versus titanium alloy rods for correction of adolescent idiopathic scoliosis based on 1-year follow-up: a multicenter randomized controlled clinical trial

OBJECTIVE

For instrumented correction surgery for adolescent idiopathic scoliosis (AIS), surgeons are increasingly switching from titanium (Ti) alloy rods to stiffer cobalt-chromium (CoCr) rods. The authors conducted the first multicenter randomized controlled clinical trial to investigate whether these materials affect the outcomes in terms of spine correction and quality of life (QOL). This trial was registered at UMIN Clinical Trials Registry on September 3, 2012, under the identifier UMIN000008838 (level of evidence 1).

METHODS

Female AIS patients (Lenke types 1-3, patient age 10-19 years) were recruited at 5 Japanese institutions and randomized into two cohorts: 6.0-mm-diameter Ti rods were placed in one group, and 6.0-mm-diameter CoCr rods were placed in the other. Patients were followed up at 2 weeks and 3, 6, and 12 months with radiographic examination to quantify the sagittal and coronal correction (Cobb angle, thoracic kyphosis, rib hump, and apical vertebral rotation). Patients completed questionnaires (Scoliosis Research Society-22r, 12-Item Short-Form Health Survey, and Scoliosis Japanese Questionnaire-27) at 6 and 12 months to assess QOL.

RESULTS

A total of 69 AIS patients were randomized to the demographically similar Ti (n = 37) or CoCr (n = 32) cohort. Four adverse events were recorded, two in each cohort, but these were not related to the rod material. At the final follow-up, both Ti and CoCr cohorts showed significant improvement in spinal correction, including the Cobb angle, thoracic kyphosis, and rib hump size. The correction rates were 68.4% and 67.1% for the Ti and CoCr cohorts, respectively. No parameters differed significantly between the cohorts at any time. Survey data showed improved but similar outcomes in both cohorts.

CONCLUSIONS

Both treatments (Ti and CoCr) produced similar results and were efficient in engendering clinically significant spine corrections. Clinical trial registration no.: UMIN000008838 (UMIN Clinical Trials Registry).

The factors driving self-efficacy in intractable chronic pain patients: a retrospective study

Background

The fear-avoidance model is a theoretical paradigm for explaining acute and chronic pain. In this model, pain catastrophizing plays an important role. On the other hand, self-efficacy influences whether patients view their pain optimistically, ultimately preventing the conversion of pain into intractable pain. The aim of the present study was to evaluate the factors that influence self-efficacy in patients with chronic pain.

Methods

Study participants included 147 outpatients (35 men, 112 women) with intractable chronic pain who visited our hospital between September 2014 and July 2015. Their mean age was 71.0 (range 32–92) years. Pain sites were as follows: low back, 97 patients; knee, 71 patients; shoulder, 34 patients; and hip, 15 patients. All patients were assessed using the following measures: Numeric Rating Scale (NRS), Pain Catastrophizing Scale (PCS), Hospital Anxiety and Depression Scale (HADS), Pain Disability Assessment Scale (PDAS), and Pain Self-Efficacy Questionnaire (PSEQ). All participants were further divided into two groups based on median PSEQ scores (group L: PSEQ of 35 points or less, n = 74; group H: PSEQ greater than 35 points, n = 73). The factors that influenced self-efficacy in these patients were analyzed using univariate and multiple linear regression analyses.

Results

Significant differences were observed in gender; pain duration; and NRS, PDAS, HADS, and PCS scores between group L and group H. Multiple linear regression analysis revealed that self-efficacy was correlated with PDAS score, HADS depression score, and pain duration.

Conclusions

Patients with longer pain duration indicated greater self-efficacy and patients with higher pain disability and depression exhibited lower self-efficacy.

Drug dependence in patients with chronic pain: A retrospective study

Drug dependence, which can exist concurrently with chronic pain, is seen as one of the major causes of rapidly increasing medical expenses. However, drug dependence in patients with chronic pain has not been evaluated. The aim of this study was to identify the risk factors for drug dependence in patients with chronic noncancer pain.This retrospective study included 151 patients with chronic noncancer pain (43 males, 108 females; mean age, 72 years). Low back pain (LBP) occurred in 96 patients, whereas 22 had shoulder pain, 8 had hip pain, and 77 had knee pain. Patients were divided into drug dependence and nondrug dependence groups based on the Severity of Dependence Scale (SDS) scores. Patients with SDS scores ≥5 and <5 were classified into drug dependence and nondrug dependence groups, respectively. All patients completed self-report questionnaires. Factors that predict drug dependence were identified by performing univariate and multivariate analyses.Sixty (40%) of the 151 patients met the SDS criteria for drug dependence. Significant differences were found between patients with and without drug dependence for the LBP, hip pain, number of medications, and for the Numerical Rating Scale, Pain Disability Assessment Scale (PDAS), Hospital Anxiety and Depression Scale, and Pain Catastrophizing Scale (PCS) scores. Multiple regression analysis identified LBP, hip pain, PCS, and PDAS scores as factors related to drug dependence in patients with chronic noncancer pain.Drug dependence tends to differ in patients based on the location of their chronic pain. Pain catastrophizing and disability indicated a greater tendency for drug dependence. Thus, PCS and PDAS scores are useful screening tools for predicting drug dependence in patients with chronic pain.

An evaluation of anesthetic fade in motor evoked potential monitoring in spinal deformity surgeries

Background

Intraoperative neuromonitoring using motor evoked potentials (MEP) satisfactorily detects motor tract integrity changes during spinal surgery. However, monitoring is affected by “anesthetic fade,” in which the stimulation threshold increases because the waveform amplitude decreases with the accumulation of propofol. Therefore, the purpose of this study was to clarify the effect of anesthetic fade on transcranial MEPs by investigating the time-dependent changes of amplitude during spinal deformity surgeries.

Methods

We retrospectively reviewed medical records of 142 spinal deformity patients (66 patients with idiopathic scoliosis, 28 with adult spinal deformities, 19 with neuromuscular scoliosis, 17 with syndromic scoliosis, and 12 with congenital scoliosis). The average age was 28 years (range, 5 to 81 years). MEPs were recorded bilaterally from the abductor digiti minimi (ADM) and abductor hallucis (AH) muscles during spinal deformity surgeries. The Wilcoxon signed-rank test was used to investigate the time-dependent changes of amplitude after propofol infusion to evaluate anesthetic fade effects.

Results

The average time to baseline from initial propofol infusion was 113 min (range, 45 to 182 min). In the ADM, the amplitude was 52% at 1 h after initial propofol infusion, 102% at 2 h, 105% at 3 h, 101% at 4 h, 86% at 5 h, and 81% at 6 h. Compared to the 2-h time point, MEP decreased significantly by 16% at 5 h (P < 0.0005) and by 21% at 6 h (P < 0.05). In the AH, the amplitude was 49% at 1 h after initial infusion of propofol, 102% at 2 h, 102% at 3 h, 92% at 4 h, 71% at 5 h, and 63% at 6 h. Compared to the 2-h time point, MEP decreased significantly by 10% at 4 h (P < 0.005), by 31% at 5 h (P < 0.0000005), and by 39% at 6 h (P < 0.05).

Conclusions

MEP amplitude significantly decreased in the upper limbs at 5 and 6 h and in the lower limbs at 4, 5, and 6 h after the initial infusion of propofol, respectively. The influence of anesthetic fade could influence false positive MEPs during long spinal surgeries.

Venous Thromboembolism in Patients with Acute Thoracolumbar Spinal Cord Injury

Venous thromboembolism (VTE) is a major complication in patients with acute spinal cord injury. There are few reports of VTE with acute thoracolumbar spinal cord injury (TLSCI). We assessed the incidence of VTE with acute TLSCI using color Doppler ultrasonography. We retrospectively assessed 75 patients with acute TLSCI (T1 to L1). All patients were surgically treated. VTE of the lower extremity and pelvis was assessed using color Doppler ultrasound regardless of whether symptoms were present. This retrospective study included patients who were assessed between 6 and 10 days (mean 8.1 days) after injury. VTE was detected in 27 of the 75 patients (35.7%) with or without paralysis. Of the 13 patients who had complete motor paralysis, 8 (62%) had VTE; of the 31 patients with incomplete motor paralysis, 10 (32%) had VTE, and of the 31 patients without motor paralysis, 9 (29%) had VTE. Among the patients with TLSCI, those with VTE had a significantly higher mean age than those without. The incidence of VTE in TLSCI patients is not related to the severity of paralysis in a Japanese population. The incidence appears to be related primarily to age.

Amelioration of Diabetes in Mice after Single-Donor Islet Transplantation Using the Controlled Release of Gelatinized FGF-2

Fibroblast growth factor (FGF)-2 has been recognized to be a key element involved in angiogenesis and a putative factor involved in stem cell-mediated islet regeneration. However, the usefulness of FGF-2 in an islet transplantation setting has not yet been explored. We therefore evaluated the effect of FGF-2 on both islet culture and islet transplantation. Isolated islets were cultured in the presence of 100 ng/ml FGF-2 for a week and then the glucose-responding insulin secretion and insulin contents were measured. Gelatinized FGF-2 (100 ng), which allowed the controlled release of FGF-2, was used for islet transplantation of streptozotocin-induced diabetic mice. Islets (150 IEQ), obtained from a single donor, mixed with gelatinized FGF-2, were transplanted into the subrenal capsule of the mice and the animals were observed for 30 days. Revascularization around the islet grafts was examined. The blood glucose levels were measured and the intraperitoneal glucose tolerance test (IPGTT) was performed. The supplementation of FGF-2 maintained proper insulin secretion and insulin contents in an in vitro culture. The use of gelatinized FGF-2 facilitated revascularization and favorable islet engraftment, thus resulting in an amelioration of the blood glucose levels in diabetic mice. The utilization of FGF-2 showed increased contents of insulin in the islet grafts and revealed a similar pattern as that of normal healthy mice in IPGTT. In contrast, the transplantation of islets without FGF-2 supplementation showed poor revascularization and failed to control the blood glucose levels in the diabetic mice.

Visualization of cerebrospinal fluid flow in syringomyelia through noninvasive magnetic resonance imaging with a time-spatial labeling inversion pulse (Time-SLIP)

CONTEXT

We report a case of syringomyelia assessed by magnetic resonance imaging (MRI) with a time-spatial labeling inversion pulse (Time-SLIP), which is a non-contrast MRI technique that uses the cerebrospinal fluid (CSF) as an intrinsic tracer, thus removing the need to administer a contrast agent. Time-SLIP permits investigation of flow movement for over 3 seconds without any limitations associated with the cardiac phase, and it is a clinically accessible method for flow analysis.

FINDINGS

We investigated an 85-year-old male experiencing progressive gait disturbance, with leg numbness and muscle weakness. Conventional MRI revealed syringomyelia from C7 to T12, with multiple webs of cavities. We then applied the Time-SLIP approach to characterize CSF flow in the syringomyelic cavities. Time-SLIP detected several unique CSF flow patterns that could not be observed by conventional imaging. The basic CSF flow pattern in the subarachnoid space was pulsatile and was harmonious with the heartbeat. Several unique flow patterns, such as bubbles, jumping, and fast flow, were observed within syringomyelic cavities by Time-SLIP imaging. These patterns likely reflect the complex flow paths through the septum and/or webs of cavities.

CONCLUSION/CLINICAL RELEVANCE

Time-SLIP permits observation of CSF motion over a long period of time and detects patterns of flow velocity and direction. Thus, this novel approach to CSF flow analysis can be used to gain a more extensive understanding of spinal disease pathology and to optimize surgical access in the treatment of spinal lesions. Additionally, Time-SLIP has broad applicability in the field of spinal research.

Scoliosis correction surgery for patients with McCune-Albright syndrome using pedicle screws: a report of two cases with different characteristics and a review of the literature

PURPOSE

Scoliosis can occur secondary to McCune-Albright syndrome (MAS); it can be progressive and sometimes requires surgical treatment. It is still unclear if pedicle screw (PS) fixation in these patients with poor bone quality can be considered an effective treatment for scoliosis. The purpose of this study is to report two MAS patients with spinal fibrous dysplasia (FD) who underwent scoliosis surgeries with the PS system.

METHODS

Case 1: a 12-year-old girl. Standing posteroanterior radiographs revealed a 58° right curve from T7 to L2. Computed tomography (CT) showed small areas of FD throughout the spine. A posterior spinal arthrodesis from T4 to L3 using PS fixation was performed with a CT-based navigation system. Case 2: a 26-year-old woman. Radiographs in the standing position revealed a right 87° curve from T8 to L2 and a 55° kyphosis from T8 to T12. CT images showed multiple areas of severe spinal FD causing angular deformity and collapse of vertebral bodies. The patient underwent posterior spinal arthrodesis from T8 to her pelvis using a CT-based navigation system for PS fixation.

RESULTS

Superior scoliosis corrections were obtained using PS instrumentation, attaining complete bony union in both cases without major complications. However, Case 2 had some technical difficulties in treating due to the multiple large FD lesions.

CONCLUSIONS

PS fixation can be considered an effective treatment for correcting scoliosis and maintaining the correction at follow-up in MAS patients with poor bone quality. However, great care must be taken when performing correction and follow-up.

Plasmon modes in single gold nanodiscs

Optical properties of single gold nanodiscs were studied by scanning near-field optical microscopy. Near-field transmission spectra of a single nanodisc exhibited multiple plasmon resonances in the visible to near-infrared region. Near-field transmission images observed at these resonance wavelengths show wavy spatial features depending on the wavelength of observation. To clarify physical pictures of the images, theoretical simulations based on spatial correlation between electromagnetic fundamental modes inside and outside of the disc were performed. Simulated images reproduced the observed spatial structures excited in the disc. Mode-analysis of the simulated images indicates that the spatial features observed in the transmission images originate mainly from a few fundamental plasmon modes of the disc.

A prospective study of the incidence and outcomes of incidental dural tears in microendoscopic lumbar decompressive surgery

Little information is available about the incidence and outcome of incidental dural tears associated with microendoscopic lumbar decompressive surgery. We prospectively examined the incidence of dural tears and their influence on the outcome six months post-operatively in 555 consecutive patients (mean age 47.4 years (13 to 89)) who underwent this form of surgery. The incidence of dural tears was 5.05% (28/555). The risk factors were the age of the patient and the procedure of bilateral decompression via a unilateral approach. The rate of recovery of the Japanese Orthopaedic Association score in patients with dural tears was significantly lower than that in those without a tear (77.7% vs 87.6%; p < 0.02), although there were no significant differences in the improvement of the Oswestry Disability Index between the two groups. Most dural tears were small, managed by taking adequate care of symptoms of low cerebrospinal fluid pressure, and did not require direct dural repair. Routine MRI scans were undertaken six months post-operatively; four patients with a dural tear had recurrent or residual disc herniation and two had further stenosis, possibly because the dural tear prevented adequate decompression and removal of the fragments of disc during surgery; as yet, none of these patients have undergone further surgery.

Cite this article: Bone Joint J 2014;96-B:641–5.

Management of lumbar artery injury related to pedicle screw insertion

We report on 2 patients who experienced injury to one of their lumbar arteries related to pedicle screw misplacement. In this report, the lumbar pedicle screw holes were made laterally with resultant injury to the lumbar artery. During surgery, arterial bleeding was controlled with pressure and gauze; however, the patients experienced vital shock after surgery. Vital shock ensued and they were rescued by catheter embolization. If patients receiving lumbar instrumentation surgery experience severe anemia or vital shock postoperatively, the surgeon should assume lumbar artery injury as a differential diagnosis.

Development of dysphagia and trismus developed after c1-2 posterior fusion in extended position

Cervical misalignment after upper cervical fusion including the occipital bone may cause trismus or dysphagia, because the occipito-atlanto joint is associated with most of the flex and extended motion of the cervical spine. There are no reports of dysphagia and trismus after C1-2 fusion. The purpose of this paper is to demonstrate the potential risk of dysphagia and trismus even after upper cervical short fusion without the occipital bone. The patient was a 69-year-old man with myelopathy caused by os odontoideum and Klippel-Feil syndrome, who developed dysphagia and trismus immediately after C1-2 fusion and C3-6 laminoplasty. Radiographs and CT revealed that his neck posture was extended, but his symptoms still existed a week after surgery. The fixation angle was hyperextended 12 days after the first surgery. His symptoms disappeared immediately after revision surgery. The fixation in the neck-flexed position is thought to be the main cause of the patient's post-operative dysphagia and trismus. Dysphagia and trismus may occur even after short upper cervical fusion without the occipital bone or cervical fusion in the neck-extended position. The pre-operative cervical alignment and range of motion of each segment should be thoroughly evaluated.

The clinical manifestations of lumbar disease are correlated with self-rating depression scale scores

BACKGROUND

Depression can exacerbate symptoms of chronic pain and worsen disability. The symptoms of lumbar disease may be particularly sensitive to psychological state, but statistical associations between low back pain (LBP) severity and mental health status have not been established.

METHODS

Of the 151 patients with LBP, 122 completed questionnaires probing depressive symptoms, LBP severity, and degree of disability. In addition to completing self-report questionnaires, patients provided demographic and clinical information. A self-rating depression scale (SDS) was used to screen for depression. Pain and disability were assessed by the visual analog scale (VAS) and the Roland-Morris disability questionnaire (RDQ), respectively. Overall clinical severity was assessed using the Japanese Orthopaedic Association (JOA) score. Kendall's tau correlation coefficients were calculated to examine the relationships among these variables.

RESULTS

Ninety-four patients (77 %) were in a depressive state as indicated by SDS score ≥40, including mild depression group (47 patients, SDS score from 40 to 49) and depression group (47 patients, SDS score ≥50). There were only 28 patients in the no depression group (SDS score ≤39). There was no significant difference in both age and pain duration among the three groups. The mean VAS score in the depression group (70 ± 19 mm) was higher than both no depression (41 ± 24 mm) and mild depression groups (52 ± 21 mm). The mean JOA score in the no depression group (14 ± 5.0 points) was higher than both mild depression (12 ± 4.0 points) and depression groups (10 ± 6.0 points). The mean RDQ in the depression group (15.1 ± 6.0 points) was higher than both no depression (6.4 ± 5.0 points) and mild depression groups (10.9 ± 5.4 points). Factors significantly correlated with SDS score included VAS, JOA score, and RDQ score. In contrast, SDS did not correlate with patient age or pain duration.

CONCLUSIONS

The majority of chronic LBP patients examined were in a depressed state and the severity of depression correlated with pain severity, degree of self-rated disability, and clinical severity.

Relationship between coronary artery disease and retinopathy in patients with type 2 diabetes mellitus

OBJECTIVE

To examine risk factors for coronary artery disease (CAD) and retinopathy in patients with type 2 diabetes mellitus (DM) and assess the relationship between CAD and retinopathy.

METHODS

A total of 1,003 outpatients with type 2 DM (578 men and 425 women) were classified into two groups according to the presence (based on ischemic findings on a resting electrocardiogram or a history of angina or myocardial infarction) or absence of CAD and four retinopathy stages based on the International Clinical Classification of Diabetic Retinopathy.

RESULTS

Stepwise multiple regression analyses showed that independent risk factors for CAD were age, the triglyceride (TG) level and smoking, while those for retinopathy included age, age of DM diagnosis, the HbA1c level and a female gender. The prevalence of CAD increased in association with the progression of retinopathy (p<0.01).

CONCLUSION

Since it is difficult to distinguish macrovascular and microvascular diseases, diabetic vascular disorders require comprehensive approaches to assessment and treatment.

Surgical treatment for congenital kyphosis correction using both spinal navigation and a 3-dimensional model

An 11 year-old girl had 66 degrees of kyphosis in the thoracolumbar junction. For the purpose of planning for kyphosis correction, we created a 3-D, full-scale model of the spine and consulted spinal navigation. Three-dimensional models are generally used as tactile guides to verify the surgical approach and portray the anatomic relations specific to a given patient. We performed posterior fusion from Th10 to L3, and vertebral column resection of Th12 and L1. Screw entry points, directions, lengths and diameters were determined by reference to navigation. Both tools were useful in the bone resection. We could easily detect the posterior element to be resected using the 3D model. During the anterior bony resection, navigation helped us to check the disc level and anterior wall of the vertebrae, which were otherwise difficult to detect due to their depth in the surgical field. Thus, the combination of navigation and 3D models helped us to safely perform surgery for a patient with complex spinal deformity.

Transplantation of osteogenically differentiated mouse iPS cells for bone repair

Induced pluripotent stem (iPS) cells are a type of undifferentiated cell that can be obtained from differentiated cells and have the pluripotent potential to differentiate into the musculoskeletal system, the myocardium, vascular endothelial cells, neurons, and hepatocytes. We therefore cultured mouse iPS cells in a DMEM containing 15% FBS, 10(-7) M dexamethasone, 10 mM β-glycerophosphate, and 50 μg/ml ascorbic acid for 3 weeks, in order to induce bone differentiation, and studied the expression of the bone differentiation markers Runx2 and osteocalcin using RT-PCR in a time-dependent manner. Osteocalcin, a bone differentiation marker in bone formation, exhibited the highest expression in the third week. In addition, the deposition of calcium nodules was observed using Alizarin red S staining. iPS cells cultured for bone differentiation were transplanted into severe combined immunodeficiency (SCID) mice, and the osteogenic potential exhibited after 4 weeks was studied. When bone differentiation-induced iPS cells were transplanted into SCID mice, bone formation was confirmed in soft X-ray images and tissue specimens. However, teratoma formation was confirmed in 20% of the transplanted models. When mouse iPS cells were treated with irradiation of 2 Gray (Gy) prior to transplantation, teratoma formation was inhibited. When mouse iPS cells treated in a likewise manner were xenotransplanted into rats, bone formation was confirmed but teratoma formation was not observed. It is believed that irradiation before transplantation is an effective way to inhibit teratoma formation.

Statistical analysis of prognostic factors for survival in patients with spinal metastasis

There are a variety of treatment options for patients with spinal metastasis, and predicting prognosis is essential for selecting the proper treatment. The purpose of the present study was to identify the significant prognostic factors for the survival of patients with spinal metastasis. We retrospectively reviewed 143 patients with spinal metastasis. The median age was 61 years. Eleven factors reported previously were analyzed using the Cox proportional hazards model:gender, age, performance status, neurological deficits, pain, type of primary tumor, metastasis to major organs, previous chemotherapy, disease-free interval before spinal metastasis, multiple spinal metastases, and extra-spinal bone metastasis. The average survival of study patients after the first visit to our clinic was 22 months. Multivariate survival analysis demonstrated that type of primary tumor (hazard ratio [HR] = 6.80, p < 0.001), metastasis to major organs (HR = 2.01, p = 0.005), disease-free interval before spinal metastasis (HR = 1.77, p = 0.028), and extra-spinal bone metastasis (HR = 1.75, p = 0.017) were significant prognostic factors. Type of primary tumor was the most powerful prognostic factor. Other prognostic factors may differ among the types of primary tumor and may also be closely associated with primary disease activity. Further analysis of factors predicting prognosis should be conducted with respect to each type of primary tumor to help accurately predict prognosis.

Segmental pedicle screw fixation for a scoliosis patient with post-laminectomy and post-irradiation thoracic kyphoscoliosis of spinal astrocytoma

Spinal deformity is an important clinical manifestation after surgery for spinal cord tumors. One-third of patients who receive laminectomies and irradiation of the spinal column develop scoliosis, kyphosis, or kyphoscoliosis. Recent reports indicate good results after scoliosis surgery using segmental pedicle screws and a navigation system, but these reported studies have not included surgery for post-laminectomy kyphosis. Hooks and wires are ineffective in such patients who undergo laminectomy, and there are also high perioperative risks with insertion of pedicle screws because landmarks have been lost. Here, we report on the 5-year follow-up of a 13-year-old male patient with post-laminectomy and post-irradiation thoracic kyphoscoliosis after surgical treatment of spinal astrocytoma. Posterior segmental pedicle screw fixation was performed safely using a computer-assisted technique. The authors present the first case report for treatment of this condition using a navigation system.

The natural history of asymptomatic lumbar canal stenosis in patients undergoing surgery for cervical myelopathy

We retrospectively examined the prevalence and natural history of asymptomatic lumbar canal stenosis in patients treated surgically for cervical compressive myelopathy in order to assess the influence of latent lumbar canal stenosis on the recovery after surgery. Of 214 patients who had undergone cervical laminoplasty for cervical myelopathy, we identified 69 (32%) with myelographically documented lumbar canal stenosis. Of these, 28 (13%) patients with symptomatic lumbar canal stenosis underwent simultaneous cervical and lumbar decompression. Of the remaining 41 (19%) patients with asymptomatic lumbar canal stenosis who underwent only cervical surgery, 39 were followed up for ≥ 1 year (mean 4.9 years (1 to 12)) and were included in the analysis (study group). Patients without myelographic evidence of lumbar canal stenosis, who had been followed up for ≥ 1 year after the cervical surgery, served as controls (135 patients; mean follow-up period 6.5 years (1 to 17)). Among the 39 patients with asymptomatic lumbar canal stenosis, seven had lumbar-related leg symptoms after the cervical surgery.

Kaplan–Meier analysis showed that 89.6% (95% confidence interval (CI) 75.3 to 96.0) and 76.7% (95% CI 53.7 to 90.3) of the patients with asymptomatic lumbar canal stenosis were free from leg symptoms for three and five years, respectively. There were no significant differences between the study and control groups in the recovery rate measured by the Japanese Orthopaedic Association score or improvement in the Nurick score at one year after surgery or at the final follow-up.

These results suggest that latent lumbar canal stenosis does not influence recovery following surgery for cervical myelopathy; moreover, prophylactic lumbar decompression does not appear to be warranted as a routine procedure for coexistent asymptomatic lumbar canal stenosis in patients with cervical myelopathy, when planning cervical surgery.

Dominant vertebral artery injury during posterior atlantoaxial transarticular screw fixation in a juvenile rheumatoid arthritis patient with atlantoaxial subluxation

Many authors have reported on iatrogenic vertebral artery (VA) injury, but, to our knowledge, this is the first report of a dominant VA injury with compensatory blood flow from the hypoplastic VA. A 23-year-old woman with juvenile rheumatoid arthritis and atlantoaxial subluxation sustained injury to her dominant VA after occipitocervical fusion using transarticular screws. This did not result in lethal consequences due to compensation from her hypoplastic contralateral VA. Postoperative angiography, however, illustrated occlusion of the dominant left side, while the hypoplastic VA of the right side was enlarged. The patient experienced vertigo and loss of consciousness several times during rehabilitation. At the 4-year follow-up exam, bony fusion was observed, with no neurological deficits or correction loss. She had had no episodes of unconsciousness and no recurrence of any symptoms over the previous 3 years.

A case of surgery for kyphosis of the thoracolumbar spine in an elderly patient with dysphagia

Here we report a case of surgery for kyphosis of the thoracolumbar spine in an elderly patient, in whom surgery was performed because the patient had developed intractable digestive symptoms. The case was that of a 76-year-old female with complaints of back pain and dysphagia. When videofluoroscopic examination (VF) of swallowing was performed in the cardia of the stomach, images that indicated stagnation and the reflux of food were observed. It was easier for the patient to swallow food in the extension position. We performed corrective fusion of the posterior spine. After the surgery, the kyphosis angle was improved to 27°, the patient's back pain was alleviated, and it became easier for the patient to swallow food. VF also showed that the patient's difficulties with the passage of food had improved. We believe that surgery is a good treatment option for cases of kyphosis with digestive symptoms and deteriorating activities of daily living (ADL), even in the absence of pain and paralysis. VF is also useful for performing evaluations before and after surgery.

Photo and Scanning Probe Lithography Using Alkylsilane Self-Assembled Monolayers

An organic film of a few nm in thickness was applied as a resist for photolithography and scanning probe lithography. This resist film was prepared on an oxide-covered Si substrate through chemisorption and spontaneous organization of organosilane molecules, e.g., n-octadecyltrimethoxysilane. The film belongs to a class of materials referred to as self-assembled monolayer (SAM). A SAM/Si sample was irradiated through a photomask with vacuum ultraviolet (VUV) light at a wavelength of 172 nm. The photomask image was transferred to the SAM through the decomposition of the SAM. Furthermore, we demonstrate nano-scale patterning of the SAM using an atomic force microscope (AFM) with an electrically conductive probe. The SAM was electrochemically degraded in the region where the AFM probe had been scanned. Both the photo-printed and AFM-genereated patterns were successfully transferred into the Si substrates based on wet chemical etching or on dry plasma etching. At present, using these VUV and AFM-based lithographies, we have succeeded in fabricating minute features of 2 μm and 20 nm in width, respectively.

A 5-HT(4)-receptor activation-induced neural plasticity enhances in vivo reconstructs of enteric nerve circuit insult

BACKGROUND

It was recently reported that some 5-HT(4)-receptor agonists increased neuronal numbers and length of neurites in enteric neurons developing in vitro from immunoselected neural crest-derived precursors. We aimed to explore a novel approach in vivo to reconstruct the enteric neural circuitry that mediates a fundamental distal gut reflex.

METHODS

The neural circuit insult was performed in guinea pigs by rectal transection and subsequent end-to-end one layer anastomosis. A 5-HT(4)-receptor agonist, mosapride citrate (10-100 micromol L(-1)) (applied for a patent) was applied locally at the anastomotic site.

KEY RESULTS

Mosapride promoted the regeneration of the neural circuit in the impaired myenteric plexus and the recovery of the defecation reflex in the distal gut. Furthermore, mosapride generated neurofilament (NF)-, 5-HT(4)-receptor- and 5-bromo-2'-deoxyuridine (BrdU)-positive cells and surprisingly formed neural network in the newly formed granulation tissue at the anastomotic site 2 weeks after enteric nerve circuit insult. Possible neural stem cell markers, anti-distal less homeobox 2 (DLX2)- and p75-positive and NF-positive cells increased during the same time period. All actions by mosapride were inhibited by the specific 5-HT(4)-receptor antagonist, GR113808 (10 micromol L(-1)).

CONCLUSIONS & INFERENCES

These results indicate that activation of enteric neural 5-HT(4)-receptors promotes reconstruction of an enteric neural circuit leading to the recovery of the defecation reflex in the distal gut, and that this reconstruction involves possibly neural stem cells. These findings indicate that treatment with 5-HT(4) agonists could be a novel therapy for generating new enteric neurons to rescue aganglionic gut disorders.

Bone repair using a hybrid scaffold of self-assembling peptide PuraMatrix and polyetheretherketone cage in rats

Self-assembling peptide scaffold (SAPS) is well known to have very good bone conduction properties. However, the intensity of SAPS is too weak to actually use it for a clinical bone regeneration. Therefore, we have produced a hybrid scaffold system that involves fabricating a cage from polyetheretherketone (PEEK) that has high intensity, filling the interior of this cage with SAPS, and then transplanted this hybrid scaffold to bone defects in rat femurs. After 28 days, soft X-ray radiographs and histological assessment revealed that good new bone formation was clearly observed in the defects transplanted the PEEK cage with SAPS, but not in the PEEK cage only. The PEEK cage maintained a form and osteoconduction ability of internal SAPS, and SAPS promoted bone formation inside the PEEK; therefore, each was in charge of intensity and bone regeneration separately. The present study suggests that hybrid scaffolds made from PEEK cages and SAPS can be useful tools for the regeneration of load-bearing bones, based on the idea that it should be possible to develop ideal bone filler materials by combining the strength of artificial bone with the bone regeneration and bone conduction properties of SAPS.

Computer navigation-assisted spinal fusion with segmental pedicle screw instrumentation for scoliosis with Rett syndrome: a case report

Scoliosis is a common clinical manifestation of Rett syndrome, a neurodevelopmental disorder that almost exclusively affects females. The spinal curve in patients with Rett syndrome is typically a long C curve of a neuromuscular type. As the onset of the scoliosis is very early and shows rapid progression, early surgical intervention has been recommended to prevent a life-threatening collapsing spine syndrome. However, there are high perioperative risks in Rett syndrome patients who undergo spinal surgery, such as neurological compromise and respiratory dysfunction due to rigid spinal curve. We herein report the surgical result of treating severe rapid progressive thoracic scoliosis in a 16-year-old girl with Rett syndrome. Posterior segmental pedicle screw fixation was performed from T1 to L3 using a computer-assisted technique. Post-operative radiography demonstrated a good correction of the curve in both the sagittal and coronal alignment. There were no postoperative complications such as neurological compromise. The patient had maintained satisfactory spinal balance as of the 3-year follow-up examination.

Vibrations of microspheres probed with ultrashort optical pulses

We use ultrashort optical pulses to excite and detect vibrations of single silica spheres with a diameter of 5 microm placed at the surface of an acoustically mismatched substrate. In addition to the photoelastic detection of picosecond longitudinal acoustic pulses propagating inside the bulk, we detect gigahertz acoustic resonances of the sphere through probe beam defocusing. The mode frequencies are in close accord with those calculated from the elastic vibrations of a free sphere. We also record a resonant enhancement in the amplitude of specific modes of two touching spheres.

Bone repair by transplantation of hTERT-immortalized human mesenchymal stem cells in mice

BACKGROUND

Human mesenchymal stem cells (hMSCs) are multipotent stem cells found in the adult bone marrow that have the capacity to differentiate into various mesenchymal cell types. The hMSCs may provide a potential therapy to restore damaged tissues or organs of mesenchymal origin; however, a drawback is their limited life span in vitro.

METHODS

We immortalized normal hMSCs with retrovirally transmitted human telomerase reverse transcriptase cDNA. One of the immortalized clones (YKNK-12) was established, and the biological characteristics were investigated in vitro and in vivo.

RESULTS

YKNK-12 cells were capable of differentiating adipocytes, osetoblasts, and chondrocytes. Osteogenically differentiated YKNK-12 cells produced significant levels of growth factors BMP4, BMP6, FGF6, FGF7, transforming growth factor-beta1, and transforming growth factor-beta3.. Microcomputer tomography T and soft X-ray assays showed an excellent calvarial bone healing in mice after transplantation of osteogenically differentiated YKNK-12 cells. These cells expressed human-specific osteocalcin and increased the gene expression of runt-related transcription factor 2, alkaline phosphatase, osteocalcin, and osterix in the bone regenerating area. YKNK-12 cell transplant corrected the bone defect without inducing any adverse effects.

CONCLUSIONS

We conclude that hMSCs immortalized by transduction with human telomerase reverse transcriptase may provide an unlimited source of cells for therapeutic use in bone regeneration.

Usefulness of a navigation system in surgery for scoliosis: segmental pedicle screw fixation in the treatment

STUDY DESIGN

Postoperative outcomes of segmental pedicle screw fixation were evaluated in posterior scoliosis surgery with the use of navigation system.

OBJECTIVES

We report the usefulness of a navigation system and a segmental pedicle screw fixation in surgery for scoliosis.

SUMMARY OF BACKGROUND DATA

Few reports on a segmental pedicle screw fixation method for scoliosis surgery using a navigation system have been published. This is the report on the usefulness of a navigation system in segmental pedicle screw fixation.

METHODS

We targeted 16 cases in which segmental pedicle screw fixation had been performed using a navigation system at our hospital. We inserted 264 pedicle screws in total, and we did not perform registration for each corpus vertebrate in order to shorten the duration of the surgery. We reviewed screw deviation among the items for review using Neo classification with postoperative CT images (1.25 mm). For screw deviation in this case, grade 2 or higher in the Neo classification system was designated as total deviation. Furthermore, we evaluated the registration period per corpus vertebrae, the complications, duration of surgery, blood loss, Cobb angle, and the correction rate.

RESULTS

In terms of screw deviation, 11 (4.2%) of the 264 inserted screws were classified as total deviation. However, there were no neurovascular complications during or after surgery in any cases, and all cases maintained strong internal fixation. In the relationship between the use or nonuse of registration and the deviation, four screws (3.2%) in the corpus vertebrae for which registration was performed and seven screws (5.0%) in the adjacent corpus vertebrae for which registration was not performed had deviated. The duration of registration per corpus vertebrate averaged 4 min and 24 s (58-791 s), but registration also requires a learning curve, so the duration of registration per corpus vertebrae averaged 1 min and 14 s in more recent cases, thus marking a significant shortening.

CONCLUSION

Segmental pedicle screw fixation are excellent in regard to their fixing and correction force and have been clinically applied even in surgery for scoliosis, but the potential risk of neurovascular complications is unavoidable. The adoption of a navigation system in surgery for scoliosis is useful to increase the safety and certainty of the insertion of pedicle screws.

Surgical treatment of metastatic vertebral tumors

Surgical treatment of metastatic spinal cord compression is controversial. The purpose of this study was to investigate the effectiveness of our current surgical treatments and the use of spinal instrumentation. In this retrospective study covering the years between 1990 and 2006, 100 patients with spinal metastases which were secondary to various cancers underwent posterior and/or anterior decompression with spinal stabilization for the purposes of reduction of pain, and/or to help correct or improve neurological deficits. The group was made up of 60 men and 40 women whose ages ranged from 16 to 83 years (average of 60 years), and the average follow-up period was 14 months. The effect of treatment upon pain relief and neural deficits was assessed, and the cumulative survival rate was calculated by the Kaplan-Meier method. The average surgical time was 185 min. This was calculated based on the following times, listed here with the surgery type: 178 min for posterior surgery; 245 min for anterior surgery;465 min for combined surgery;and 475 min for total en bloc spondylectomy. Average blood loss during surgery was 1,630 ml for posterior surgery, 1,760 ml for anterior surgery, 1,930 ml for combined surgery, and 3,640 ml for total en bloc spondylectomy. Preoperative pain and paralysis were improved by 88% and 53%, respectively. In regards to surgical complications, postoperative epidural hematoma was observed in 2 patients, and instrumentation-related infection was observed in 1. Only 2 patients died within 2 months of surgery. In conclusion, posterior and/or anterior decompression with spinal stabilization is a safe and effective treatment for patients with spinal metastases, and can improve their quality of life.

Posterior spinal fusion using a pedicle nail system with polymethylmethacrylate in a paraplegic patient after vertebral collapse caused by osteoporosis

BACKGROUND CONTEXT

Because posterior decompression and fusion for vertebral collapse in an osteoporotic spine sometimes results in a pullout of the pedicle screw. Several authors reported that fixation of pedicle screws in severely osteoporotic bone could be improved by inserting polymethylmethacrylate (PMMA) into the hole before inserting the screw. However, pedicle screws were not designed to be used with PMMA.

PURPOSE

To report a patient with vertebral collapse who were treated using a novel-concept, pedicle nail using with PMMA.

STUDY DESIGN

Case report.

METHODS

The patient was a 74-year-old female who experienced back pain after some heavy lifting 3 months before. She was laid up for 2 months because of the back pain and weakness of her lower legs. Radiographs and magnetic resonance imaging showed vertebral collapse and neural severe compression from the posterior wall of vertebra T12. The pedicle nail consists of an outer sheath with evenly spaced holes and an internal, removable, threaded component. The outer sheath and the internal component were connected before insertion. The pedicle nail attaches to and is bound by the PMMA through the holes of the outer sheath. We performed a T11-L1 posterior fusion and laminectomy using the pedicle nail, and we used a hydroxyapatite block to perform a transpedicular vertebroplasty of T12.

RESULTS

Bone union was observed on a lateral radiograph without pedicle nail loosening.

CONCLUSIONS

The authors speculate that posterior spinal fusion and vertebroplasty using the pedicle nail will be a reasonable choice for delayed paraplegia after osteoporotic vertebral fracture.

Safety of atlantoaxial fusion using laminar and transarticular screws combined with an atlas hook in a patient with unilateral vertebral artery occlusion (case report)

OBJECTIVE AND IMPORTANCE

A disadvantage of transarticular and C2 pedicle screws is vertebral artery (VA) injury as a result of screw misplacement. If unilateral occlusion of the VA is present, VA injury of the dominant side will cause fatal complications as a result of collateral flow insufficiency. Several authors have recently reported the usefulness of C2 laminar screws because of their safety on VA injury. We used transarticular and C2 laminar screws combined with the atlas hook in a patient with C1-2 instability and unilateral VA occlusion, in order to reduce the risk of further VA injury.

CLINICAL PRESENTATION

A 64-year-old woman with rheumatoid atlantoaxial subluxation complained of cervical myelopathy and neck pain. Preoperative MR angiography showed a left side VA occlusion.

TECHNIQUE

The patient underwent atlantoaxial, posterior fusion using a transarticular screw on the side of the occlusion and a C2 laminar screw on the dominant side combined with a bilateral atlas hook. The transarticular screw was inserted using a navigation system and image intensifier, and the laminar screw was inserted free hand. Bone grafting from the iliac crest was performed.

CONCLUSION

Transarticular and C2 laminar screws fixation combined with the atlas hook in a patient with unilateral VA occlusion is a useful technique, in order to reduce the risk of further VA injury.