Trunk orthosis with joints providing resistive force improves dynamic sagittal alignment in postoperative patients with lumbar spinal stenosis

This study aimed to determine whether a trunk orthosis with joints providing resistive force (TORF) modifies sagittal malalignment during level walking in patients with lumbar spinal stenosis (LSS). Fifteen patients, 6 months after undergoing surgery for LSS, performed level walking at a self-selected speed while wearing a TORF. Dynamic sagittal alignment, including sagittal vertical axis, lumbar lordosis, and pelvic tilt, and spatiotemporal data as well as lower limb kinematic and kinetic data were recorded using a three-dimensional motion analysis system and six force plates. Statistical analysis was performed to compare these data with and without the TORF, respectively. Compared to the condition without the TORF, the use of the TORF significantly decreased positive sagittal vertical axis (p < 0.05) and increased the lumbar lordosis and pelvic tilt (p < 0.05). Peak hip flexion angle and extension moment during loading response (LR) significantly increased (p < 0.05), and peak hip extension angle and flexion moment during PS statistically decreased (p < 0.05). There was no difference in spatiotemporal data between the two conditions. Our findings suggest that TORF may modify the dynamic sagittal global alignment and lower limb kinematic and kinetics in postoperative LSS patients during level walking.

Radiographic Outcomes of the Short and Intensive Rehabilitation (SHAiR) Program in Patients with Dropped Head Syndrome

Background

The radiographic outcomes of nonoperative treatment of dropped head syndrome are still unknown. The purpose of the present study was to assess the change in sagittal spinopelvic radiographic parameters after the short and intensive rehabilitation (SHAiR) program in patients with dropped head syndrome.

Methods

This study included 48 consecutive patients with dropped head syndrome who presented with an inability to maintain horizontal gaze and who underwent the SHAiR program during the period of 2018 to 2019. Patients were divided into 2 groups according to their ability to maintain horizontal gaze at the time of final follow-up: those who had regained horizontal gaze (the "effective" group) and those who had not regained horizontal gaze (the "noneffective" group). Sagittal radiographic parameters including the sagittal vertical axis (SVA), the C2-7 angle, the C2-7 SVA, T1 slope, thoracic kyphosis of T1-5 and T5-12, lumbar lordosis, pelvic tilt, pelvic incidence, sacral slope, and curve flexibility, and demographic data and clinical outcomes were compared between the 2 groups using an unpaired t test, chi-square test, and Fisher exact test, as appropriate.

Results

Thirty-five patients in the effective group and 13 patients in the noneffective group were analyzed. The rate of response in regaining horizontal gaze with the SHAiR program was 73%. The C2-7 angle, the C2-7 SVA, T1 slope, and thoracic kyphosis (T1-5) demonstrated significant correction in the effective group (p < 0.05). There were no significant changes in other parameters below the mid-thoracic spine-i.e., the thoracolumbar and lumbar spine and pelvis-following the SHAiR program. Scores of the Neck Disability Index and visual analog scale for pain improved significantly in both groups.

Conclusions

The SHAiR program improved horizontal gaze among a large percentage of our patients and reduced cervical pain among patients overall. The correction of thoracic kyphosis (T1-5) might be an important treatment target to restore the appropriate T1 tilt in patients with dropped head syndrome.

Level of Evidence

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Factors affecting the quality of life in the chronic phase of thoracolumbar osteoporotic vertebral fracture managed conservatively with a brace

BACKGROUND CONTEXT

Although osteoporotic vertebral fractures (OVFs) are the most common type of osteoporotic fracture, few reports have closely investigated the factors contributing to the quality of life (QOL) in the chronic phase after thoracolumbar OVFs using detailed radiographic evaluation.

PURPOSE

This study aimed to identify factors associated with the QOL in the chronic phase after thoracolumbar OVF.

DESIGN

Post hoc analysis of a prospective randomized study.

PATIENT SAMPLE

Participants included 195 patients with fresh thoracolumbar OVF managed conservatively with a brace who were available for radiographic analysis 48 weeks after injury.

OUTCOME MEASURES

The degree of QOL impairment at 48 weeks after thoracolumbar OVF was assessed using the Japanese three-level version of the EuroQol five-dimensional questionnaire (EQ-5D) score.

METHODS

Univariate and multivariate regression analyses were used to evaluate the relationships between the QOL and radiographic factors.

RESULTS

The univariate analysis showed that age, analgesic use, T10/L5 Cobb angle on magnetic resonance imaging (MRI), subsequent vertebral fracture, and nonunion were significantly associated with the EQ-5D score at 48 weeks after thoracolumbar OVF. The multiple regression analysis showed that nonunion, analgesic use, subsequent vertebral fracture, and sacral slope on MRI were independently associated with the EQ-5D score at 48 weeks after thoracolumbar OVF. Receiver operating characteristic analysis for the deterioration of QOL showed that the cutoff value for sacral slope on MRI was 35 degrees.

CONCLUSIONS

This study demonstrated that nonunion, subsequent vertebral fracture, and lower sacral slope were independently associated with poorer QOL in the chronic phase of thoracolumbar OVF managed conservatively with a brace. Therefore, improving or preventing these factors in patients with thoracolumbar OVF in the chronic phase may improve the QOL of the affected patients.

Comparative Study of S2-Alar-Iliac Screw Trajectories between Males and Females Using Three-Dimensional Computed Tomography Analysis: The True Lateral Angulation of the S2-Alar-Iliac Screw in the Axial Plane

The S2 alar-iliac screw (S2AIS) is commonly used for long spinal fusion as a rigid distal foundation in spinal deformity surgeries, and it is also used in percutaneous sacropelvic fixation for providing an in-line connection to the proximal spinal constructs without using offset connectors. Although the pelvic shape is different between males and females, reports on S2AIS trajectories according to gender have been scarce in the literature. In this paper, S2AIS trajectories are compared between males and females using pelvic three-dimensional computed tomography (3D-CT) in a normal Japanese population. After resetting the caudal angulation in CT-imaging plane manipulation, the angulation of S2AIS was more lateral in the axial plane and more horizontal in the coronal plane in females. Mean distances from the midline to starting points of S2AIS tended to be shorter in females, whereas mean distances from the midline to the posterior superior iliac spine was significantly longer in females. We also found that there were positive correlations between the patients’ height and the maximal lengths of S2AISs, and the patients’ height and minimal areas of S2AIS pathways. Our results are useful not only for conventional open spinal surgery, but also for minimally invasive spine surgery.

Association between the Horizontal Gaze Ability and Physical Characteristics of Patients with Dropped Head Syndrome

Background and Objectives: Patients with dropped head syndrome exhibit weakness of the cervical paraspinal muscles. However, the relationship between horizontal gaze disorder and physical function remains unclear. This study aimed to examine and clarify this relationship. Materials and Methods: Ninety-six patients with dropped head syndrome were included. We measured the McGregor’s Slope and investigated physical characteristics, including cervical muscle strength, back muscle strength, and walking ability. Factor analysis was used to classify the characteristics of physical function, and a linear multiple regression analysis was used to evaluate independent variables explaining the variance in the McGregor’s Slope. The physical functions of DHS patients were classified into three categories by factor analysis: limb and trunk muscle strength, walking ability, and neck muscle strength. Results: The average value of the McGregor’s Slope was 22.2 ± 24.0 degrees. As a result of multiple regression analysis, walking speed (β = −0.46) and apex (β = −0.30) were extracted as significant factors influencing the McGregor’s Slope. Conclusions: Horizontal gaze disorders are not associated with cervical muscle strength but with the walking ability and the alignment type of dropped head syndrome.

The Short and Intensive Rehabilitation (SHAiR) Program Improves Dropped Head Syndrome Caused by Amyotrophic Lateral Sclerosis: A Case Report

Background and Objectives: Dropped head syndrome (DHS) is a syndrome that presents with correctable cervical kyphotic deformity as a result of weakening cervical paraspinal muscles. DHS with amyotrophic lateral sclerosis (ALS) is a relatively rare condition, and there is no established treatment. This is the first case report describing the improvement of both dropped head (DH) and cervical pain after the short and intensive rehabilitation (SHAiR) program in an ALS patient with DHS. Case Report: After being diagnosed with ALS in June 2020, a 75-year-old man visited our hospital in October 2020 to receive treatment for DHS. At the initial visit, the patient’s DH was prominent during standing and walking. The pain intensity of the neck was 9 out of 10 on the numerical rating scale (NRS), which was indicative of severe pain. The patient was hospitalized for 2 weeks and admitted into the SHAiR program. DH began to decrease one week after undergoing the SHAiR program and improved two weeks later. Neck pain decreased from 9 to 6 on the NRS. Results: The SHAiR program is a rehabilitation program aimed at improving DH in patients with idiopathic DHS. The program was designed to improve neck extensor and flexor function and global spinal alignment, and the program may have contributed to the improvement of DH and neck pain. Currently, reports of conservative therapies for this disease are limited to the use of cervical orthosis. Although further research is needed on the safety and indications of treatment, the SHAiR program may be a viable treatment option.

Preliminary Clinical Outcome of One-level Mobi-C Total Disc Replacement in Japanese Population

Introduction

In 2018, the first Mobi-C^Ⓡ total disk replacement (TDR) case was performed in Japan. In this study, we examined the preliminary clinical outcome of Mobi-C^Ⓡ for degenerative cervical spine disease.

Methods

We examined 24 consecutive patients who underwent 1-level TDR after 2018 and followed up for more than 6 months after surgery. The evaluation criteria included age, gender, diagnosis, follow-up period, surgical level, implant size, surgery time, intraoperative bleeding volume, complications, revision surgery, imaging findings, JOA score, and various questionnaires.

Results

The mean age was 52.7 years, 13 males and 11 females. There were 15 cases of cervical disk herniation and 9 cases of cervical spondylosis. The mean follow-up period was 17.4 months. Surgical levels were C3/4 in 4 cases, C4/5 in 2 cases, C5/6 in 16 cases, and C6/7 in 2 cases. The mean operation time was 138.5 minutes, the amount of intraoperative bleeding was 32.1 ml, and there were no serious intraoperative complications. The range of motion of the affected level increased significantly, from 6.6 degrees preoperatively to 12.2 degrees at final follow-up. No patients required revision surgery at final follow-up, and there were no cases of heterotopic ossification or adjacent segment disease. One patient exhibited radiculopathy due to mild subsidence 1 year after surgery, and 1 had asymptomatic contact of device plates. Preoperative and final JOA scores improved from 11.7 to 15.8 points, and NRS improved from 4.3 to 1.3 points for neck pain and 4.3 to 1.7 points for arm pain. Preoperative and final NDI improved from 39.7% to 14.0%, and EQ-5D improved from 0.602 to 0.801.

Conclusions

The short-term treatment outcomes of Mobi-C^Ⓡ TDR were generally favorable. Spine surgeons should comply with guidelines when introducing this procedure and strive to adopt this new technology in Japan.

Effect of Early vs Delayed Surgical Treatment on Motor Recovery in Incomplete Cervical Spinal Cord Injury With Preexisting Cervical Stenosis: A Randomized Clinical Trial

IMPORTANCE

The optimal management for acute traumatic cervical spinal cord injury (SCI) is unknown.

OBJECTIVE

To determine whether early surgical decompression results in better motor recovery than delayed surgical treatment in patients with acute traumatic incomplete cervical SCI associated with preexisting canal stenosis but without bone injury.

DESIGN, SETTING, AND PARTICIPANTS

This multicenter randomized clinical trial was conducted in 43 tertiary referral centers in Japan from December 2011 through November 2019. Patients aged 20 to 79 years with motor-incomplete cervical SCI with preexisting canal stenosis (American Spinal Injury Association [ASIA] Impairment Scale C; without fracture or dislocation) were included. Data were analyzed from September to November 2020.

INTERVENTIONS

Patients were randomized to undergo surgical treatment within 24 hours after admission or delayed surgical treatment after at least 2 weeks of conservative treatment.

MAIN OUTCOMES AND MEASURES

The primary end points were improvement in the mean ASIA motor score, total score of the spinal cord independence measure, and the proportion of patients able to walk independently at 1 year after injury.

RESULTS

Among 72 randomized patients, 70 patients (mean [SD] age, 65.1 [9.4] years; age range, 41-79 years; 5 [7%] women and 65 [93%] men) were included in the full analysis population (37 patients assigned to early surgical treatment and 33 patients assigned to delayed surgical treatment). Of these, 56 patients (80%) had data available for at least 1 primary outcome at 1 year. There was no significant difference among primary end points for the early surgical treatment group compared with the delayed surgical treatment group (mean [SD] change in ASIA motor score, 53.7 [14.7] vs 48.5 [19.1]; difference, 5.2; 95% CI, -4.2 to 14.5; P = .27; mean [SD] SCIM total score, 77.9 [22.7] vs 71.3 [27.3]; P = .34; able to walk independently, 21 of 30 patients [70.0%] vs 16 of 26 patients [61.5%]; P = .51). A mixed-design analysis of variance revealed a significant difference in the mean change in ASIA motor scores between the groups (F1,49 = 4.80; P = .03). The early surgical treatment group, compared with the delayed surgical treatment group, had greater motor scores than the delayed surgical treatment group at 2 weeks (mean [SD] score, 34.2 [18.8] vs 18.9 [20.9]), 3 months (mean [SD] score, 49.1 [15.1] vs 37.2 [20.9]), and 6 months (mean [SD] score, 51.5 [13.9] vs 41.3 [23.4]) after injury. Adverse events were common in both groups (eg, worsening of paralysis, 6 patients vs 6 patients; death, 3 patients vs 3 patients).

CONCLUSIONS AND RELEVANCE

These findings suggest that among patients with cervical SCI, early surgical treatment produced similar motor regain at 1 year after injury as delayed surgical treatment but showed accelerated recovery within the first 6 months. These exploratory results suggest that early surgical treatment leads to faster neurological recovery, which requires further validation.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01485458; umin.ac.jp/ctr Identifier: UMIN000006780.

Effect of the short and intensive rehabilitation (SHAiR) program on dynamic alignment in patients with dropped head syndrome during level walking

The purpose of this study was to assess the change of dynamic alignment after the short and intensive rehabilitation (SHAiR) program in patients with dropped head syndrome (DHS). Eighteen patients with DHS patients who complained of their inability to maintain horizontal gaze and underwent the SHAiR program. Patients performed level walking at a self-selected speed. Spatiotemporal, kinematic, and kinetic data were recorded using a three-dimensional motion analysis system. Statistical analysis was performed to compare these data before and after the SHAiR program. Those who underwent the SHAiR program showed a significant increase in the head angle and stride length compared to pre-treatment measurements (p < 0.05). The SHAiR program modifies the malalignment of the head and neck and spatiotemporal parameters in DHS patients during level walking.

Sequential MRI Changes After Lateral Lumbar Interbody Fusion in Spondylolisthesis with Mild and Severe Lumbar Spinal Stenosis

OBJECTIVE

We assessed the sequential magnetic resonance imaging changes of indirect neural decompression after minimally invasive lumbar lateral interbody fusion (LIF) combined with posterior percutaneous pedicle screw (PPS) fixation for degenerative spondylolisthesis (DS) according to the severity of preoperative lumbar spinal stenosis.

METHODS

A total of 43 patients (mean age, 68.7 years; 16 men and 27 women) with DS who had undergone LIF and closed reduction with PPS fixation were enrolled. The intervertebral levels were divided into the moderate stenosis (MS) group (preoperative cross-sectional area [CSA] of the thecal sac >50 mm²) and severe stenosis (SS) group (CSA ≤50 mm²). The CSA, ligamentum flavum thickness, and diameter of the thecal sac at the affected level were measured on cross-sectional magnetic resonance images at baseline, immediately postoperatively, and 2 years postoperatively.

RESULTS

For the 31 and 29 intervertebral levels in the MS and SS groups, the mean CSA at baseline, immediately postoperatively, and 2 years postoperatively was 76.9 mm² and 35.8 mm², 104.3 mm² and 81.4 mm², and 130.9 mm² and 105.7 mm², respectively. The mean ligamentum flavum thicknesses at 2 years postoperatively became thinner than that immediately after surgery in both groups (P < 0.01). The mean diameter of the thecal sac at 2 years was longer than that immediately after surgery in both groups (MS group, P < 0.05; SS group, P < 0.01) The expansion ratio of the CSA at 2 years postoperatively was significantly greater in the SS group than that in the MS group (P < 0.01).

CONCLUSIONS

Sequential enlargement of the spinal canal was obtained by the thinning of the ligamentum flavum after LIF and PPS fixation in patients with DS with both mild and severe stenosis. The effect of indirect neural decompression was equivalent even in those with severe lumbar spinal stenosis.

A Rare Case of Nontraumatic Atlantoaxial Rotatory Fixation in an Adult Patient Treated by a Closed Reduction: A Case Report

CASE

A 42-year-old woman presented with a severe neck pain and torticollis due to uncertain etiology. Because her radiographs and computed tomography revealed atlantoaxial rotatory fixation (AARF) that is an extremely rare condition in the adult population, a nonsurgical treatment was initially applied. Because 3 weeks of indirect traction failed, closed reduction was performed under general anesthesia at 2 months after onset, and her symptoms markedly improved without any complications and recurrence.

CONCLUSION

Closed reduction under general anesthesia for nontraumatic AARF in adult patients might be an effective treatment option, even for chronic cases or intractable cases by traction treatment.

Risk factors for subsequent vertebral fracture after acute osteoporotic vertebral fractures

PURPOSE

To investigate the incidence and characteristics of subsequent vertebral fracture after osteoporotic vertebral fractures (OVFs) and identify risk factors for subsequent vertebral fractures.

METHODS

This post-hoc analysis from a prospective randomized multicenter trial included 225 patients with a 48-week follow-up period. Differences between the subsequent and non-subsequent fracture groups were analyzed.

RESULTS

Of the 225 patients, 15 (6.7%) had a subsequent fracture during the 48-week follow-up. The annual incidence of subsequent vertebral fracture after fresh OVFs in women aged 65-85 years was 68.8 per 1000 person-years. Most patients (73.3%) experienced subsequent vertebral fractures within 6 months. At 48 weeks, European Quality of Life-5 Dimensions, the Japanese Orthopedic Association Back Pain Evaluation Questionnaire pain-related disorder, walking ability, social life function, and lumbar function scores were significantly lower, while the visual analog scale (VAS) for low back pain was higher in patients with subsequent fracture. Cox proportional hazards analysis showed that a VAS score ≥ 70 at 0 weeks was an independent predictor of subsequent vertebral fracture. After adjustment for history of previous fracture, there was a ~ 67% reduction in the risk of subsequent vertebral fracture at the rigid-brace treatment.

CONCLUSION

Women with a fresh OVF were at higher risk for subsequent vertebral fracture within the next year. Severe low back pain and use of soft braces were associated with higher risk of subsequent vertebral fractures. Therefore, when treating patients after OVFs with these risk factors, more attention may be needed for the occurrence of subsequent vertebral fractures.

LEVEL OF EVIDENCE

III.

Predictors for quality of life improvement after acute osteoporotic vertebral fracture: results of post hoc analysis of a prospective randomized study

PURPOSE

No study has investigated the clinical and radiographic risk factors for the deterioration of quality of life (QOL) beyond 6 months after osteoporotic vertebral fractures (OVF). The purpose of this study was to identify the predictors associated with poor QOL improvement after OVF.

METHODS

This post hoc analysis included 166 women aged 65-85 years with acute 1-level OVFs. For the patient-reported outcome measures, scores on the European Quality of Life-5 Dimensions (EQ-5D) scale, and visual analogue scale (VAS) for low back pain were used. Lateral radiography at 0, 12, and 48 weeks and magnetic resonance imaging (MRI) at enrollment and at 48 weeks were performed. The associations between baseline variables with change scores for EQ-5D were investigated using a multiple linear regression model.

RESULTS

Univariate analysis showed that time since fracture, EQ-5D score, and VAS for low back pain at 0 week showed significant association with increased EQ-5D score from 0 to 48 weeks. According to the multiple regression analysis, the following equation was obtained: increased EQ-5D score from 0 to 48 weeks = 1.305 - 0.978 × EQ-5D at 0 week - 0.021 × VAS for low back pain at 0 week - 0.006 × age + (fluid-intensity T2-weighted MR image patterns: - 0.037, except for fluid-intensity T2-weighted MR image patterns: + 0.037).

CONCLUSION

In conclusion, older patients with severe low back pain and fluid-intensity T2-weighted MR image patterns were more likely to have lower QOL improvements after OVFs and may therefore need extra support to improve QOL.

Vertebroplasty with posterior spinal fusion for osteoporotic vertebral fracture using computer-assisted rod contouring system: A new minimally invasive technique

•

Surgical treatment of osteoporotic vertebral fracture (OVF) is challenging.

•

A new minimally invasive technique of posterior spinal fusion was performed for OVF.

•

This technique would be beneficial for elderly or immunocompromised patients.

Introduction

Surgical treatment of osteoporotic vertebral fracture (OVF) has been challenging for spine surgeons, because there are potential risks of instrumentation failure; such as screw loosening, loss of correction, or pseudarthrosis, due to bone fragility in elderly patients with several comorbidities.

Presentation of case

A 68-year-old female presented with a severe low back pain and bilateral thigh pain. She had a history of systemic scleroderma, which was complicated by interstitial lung disease. Although she initially underwent non-surgical treatment with bracing for 7 months, her symptoms had progressively deteriorated, and her radiographs showed non-union at L1 and progressive kyphotic deformity at the thoracolumbar spine. Because an anterior approach was inadvisable due to interstitial lung disease, vertebroplasty with posterior spinal fusion was performed using percutaneous pedicle screws (PPS) at the upper most and lowest instrumented vertebra combined with sublaminar taping and computer-assisted rod contouring system. Good bony union was achieved with no screw loosening at 1-year follow-up.

Discussion

Various surgical procedures have been applied according to the fracture type or medical condition of the patient. Minimally invasive posterior spinal fusion would be a less invasive approach in patients with poor medical condition. PPS can prevent the excessive dissection of paravertebral muscles, and this is especially advantageous at the proximal and distal end of long constructs. A recent computer-assisted rod contouring system accurately matches each screw head resulting in reduced strength of the screw-bone interface.

Conclusion

This technique would be beneficial in the elderly or immunocompromised patients with OVF.

Establishment of a novel rehabilitation program for patients with dropped head syndrome: Short and intensive rehabilitation (SHAiR) program

The pathophysiology of dropped head syndrome (DHS) remains unknown, and its treatment algorithm and indication are not standardized. Here, we established a novel rehabilitation program, short and intensive rehabilitation program for DHS (SHAiR program), consisting of cervical paraspinal muscles exercise, range of motion exercise, cervical and thoracic mobilization, deep cervical flexor muscle exercise, hip lift exercise, anterior pelvic tilt exercise, and walking exercise. The aim of this study was to evaluate the clinical effectiveness of this program. We reviewed clinical outcomes for five consecutive patients with DHS who underwent the SHAiR program (SHAiR group). The outcomes were compared with those of other five patients with DHS who received exercise instruction (control group). Demographic data, the duration from onset of DHS, the apex of sagittal kyphosis on the lateral radiographs, and clinical outcomes including the ability to maintain normal horizontal gaze, chin brow vertical angle, and numerical rating scale (NRS) were evaluated at the initial visit and final follow-up at 7.5 months. There was no significant difference between the two groups in terms of demographic and radiographic data. The ability of horizontal gaze and NRS of cervical pain improved rapidly for all five patients in the SHAiR group as compared to no improvement for all patients in the control group. Rehabilitation for DHS was considered effective not only for localized rehabilitation such as exercise for training cervical extensor muscle function but also exercises for thoracolumbar posture improvement and the psoas muscle.

The Prevalence of the Use of MIS Techniques in the Treatment of Adult Spinal Deformity (ASD) Amongst Members of the Scoliosis Research Society (SRS) in 2016

STUDY DESIGN

Electronic survey administered to Scoliosis Research Society members.

OBJECTIVE

To determine the prevalence of minimally invasive surgery (MIS) techniques for the treatment of adult spinal deformity.

SUMMARY OF BACKGROUND DATA

There is a paucity of data available on the practice pattern, prevalence of minimally invasive spine surgery, and the preferred minimally invasive techniques in the treatment of adult spine deformity.

METHODS

An electronic nine-question survey regarding individual usage pattern of minimally invasive spine surgery techniques was administered in 2016 to the members of the Scoliosis Research Society. Determinants included complexity in condition of patient population, prevalence of use of minimally invasive techniques in the surgeon's practice, prevalence of use of a particular MIS technique, strategy elected during surgery, adoption of staging of procedures and timing between staging of procedures.

RESULTS

A total of 357 surgeons responded (61.3% response rate), and 154 (43.1%) of the respondents said that they use MIS as a part of their surgical treatment of adult spinal deformity. However, of these 154 respondents, 67 (43.5%) said that their MIS usage in deformity practice was between 1% and 20%. Only 11 (7.2%) said that they used MIS 81% to 100% of the time. The top MIS approaches that surgeons chose were MIS lateral lumbar interbody fusion 109 (70.59%) and MIS percutaneous screws 91 (58.8%).

CONCLUSIONS

The low rate of adoption of these techniques among the SRS members may be due to the false perception that there is not enough data to support that MIS techniques are better. This and the fact that a practitioner needs to be facile at different MIS techniques may be the true impediment to the adoption of MIS techniques in the treatment of ASD.

LEVEL OF EVIDENCE

Level IV.

Comparison of Rigid and Soft-Brace Treatments for Acute Osteoporotic Vertebral Compression Fracture: A Prospective, Randomized, Multicenter Study

While bracing is the standard conservative treatment for acute osteoporotic compression fracture, the efficacy of different brace treatments has not been extensively studied. We aimed to clarify and compare the preventive effect of the different brace treatments on the deformity of the vertebral body and other clinical results in this patient cohort. This multicenter nationwide prospective randomized study included female patients aged 65–85 years with acute one-level osteoporotic compression fractures. We assigned patients within four weeks of injury to either a rigid-brace treatment or a soft-brace treatment. The main outcome measure was the anterior vertebral body compression percentage at 48 weeks. Secondary outcome measures included scores on the European Quality of Life-5 Dimensions (EQ-5D), visual analog scale (VAS) for lower back pain, and the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ). A total of 141 patients were assigned to the rigid-brace group, whereas 143 patients were assigned to the soft-brace group. There were no statistically significant differences in the primary outcome and secondary outcome measures between groups. In conclusion, among patients with fresh vertebral compression fractures, the 12-week rigid-brace treatment did not result in a statistically greater prevention of spinal deformity, better quality of life, or lesser back pain than soft-brace.

Safety and Efficacy of Percutaneous Pedicle Screw Placement Using a Power Tool

Introduction

This study compared traditional manual methods and power tool use with regard to the speed and accuracy of percutaneous pedicle screw (PPS) placement and determined the advantages associated with the use of power tools.

Although the indication of PPS placement in minimally invasive spine stabilization (MISt) procedures has been recently expanded, there are no reports on PPS insertion using a power tool.

Methods

We evaluated 35 patients who underwent PPS insertion using a power tool during MISt procedures. On one side, PPS insertion was performed using the manual (M) method, whereas on the contralateral side, insertion was performed using the power tool (P) method. We assessed the number of implanted PPSs, time taken to implant PPSs after guidewire insertion, and accuracy of PPS placement as ranked postoperatively using computed tomography images.

Results

A total of 294 PPSs were inserted (147 using the M method and 147 using the P method). The mean PPS insertion time was 10.5 s using the P method and 27.4 s using the M method. The time required for inserting a screw using the P method remained consistent in the range of 10-15 s, whereas the time using the M method tended to increase from the second screw onward, with a range of 25-30 s. With regard to PPS insertion accuracy, a 2 mm or more pedicle breach was noted in 2 (1.4%) case after the P method and in 2 (1.4%) case after the M method.

Conclusions

PPS placement using power tools has the potential to save the surgical time during MISt procedures.

Quantification of L5 radiculopathy due to foraminal stenosis using three-dimensional magnetic resonance myelography

Introduction

This study aimed to evaluate morphological changes in the L5 nerve roots in control and symptomatic patients using magnetic resonance myelography [MRM]. Moreover, the utility of MRM for the diagnosis of intraforaminal or extraforaminal lesions in patients with L5 radiculopathy was evaluated using healthy subjects as controls.

Methods

Of 270 subjects who underwent MRM of the lumbar spine at our institution between April 2007 and December 2010, 135 patients (78 men and 57 women; average age: 61.3 years) with no history of spinal surgeries and nerve roots without infections, tumors, or malformations were selected for this study.

The end-point measurements included the bifurcation angle of inclination (proximal tilting angle [PTA]) of the L5 nerve root as observed via MRM, lateral angle of inclination (lateral tilting angle [LTA]), bifurcation diameter (proximal nerve root width [PW]), and dorsal root ganglion (DRG) diameter (DRG width [DW]). DW ratio was then calculated for healthy controls and symptomatic subjects. We measured each parameter using the image information unification system ShadeQuest (Yokogawa, Tokyo, Japan). Two spinal surgeons conducted the magnetic resonance imaging evaluation.

Results

Swelling of the L5 DRG was detected in cases with intraforaminal or extraforaminal stenosis. With regard to the cutoff value of 6.5 mm for L5 DW, foraminal stenosis can be confirmed if DW is ≥6.5 mm or more via MRM. In cases where L5 DRG was swollen to ≥1.2 times the size in healthy subjects, L5 radiculopathy with foraminal lesions can be diagnosed.

Conclusions

Our findings indicated that 3D MRM is a noninvasive technique and a useful tool for the diagnosis of intraforaminal or extraforaminal lesions in the lumbar spine. Therefore, it can be combined with other diagnostic methods used for the identification of intraforaminal or extraforaminal L5 nerve root lesion.

Effect of a speech aid prosthesis on reducing muscle fatigue

It has been reported that the levator veli palatini muscles of speakers with velopharyngeal incompetence tend to demonstrate muscle fatigue during speech. This study examined whether a speech aid prosthesis might reduce levator muscle fatigue in such speakers. Eight individuals with post-surgical cleft palates, and who wore a speech aid prosthesis, were studied. Each person was asked to pronounce the syllable [pu] more than 50 times. Mean power frequency (MPF) of one syllable was obtained from electromyographic data from the levator muscle. The MPF regression line was calculated during the course of syllable repetition. The absolute values of the slopes of the regression lines with the prosthesis were significantly smaller than those without the prosthesis. It was shown that the prosthesis reduced the decrease in MPF during speech. These results suggested that speech aid prostheses reduce levator muscle fatigue during speech in persons with velopharyngeal incompetence.

Initial experience of percutaneous vertebroplasty using single-plane C-arm fluoroscopy for guidance

PURPOSE

The purpose of this study was to evaluate the feasibility and safety of percutaneous vertebroplasty (PVP) using single-plane C-arm fluoroscopy.

MATERIALS AND METHODS

Lesions in the present study all comprised compression fractures with intact pedicles. A polymethylmethacrylate (PMMA) mixture was injected by the transpedicular approach under C-arm fluoroscopy using a lateral projection. Before and after PVP, the pain score was determined using visual analog scale methods.

RESULTS

Between June 2002 and May 2004, we performed 31 PVPs in 17 patients during 22 treatment sessions. Underlying pathology comprised neoplasm-related compression fracture (n=9) and fractures attributed to osteoporosis (n=8). Mean pain score was 8.0 (range, 4.5-10) immediately before PVP, and 1.9 (range, 0-7) at 24 h after PVP. Mean time needed to perform PVP was 59 min. Mean time to approach a pedicle was 36 min (range, 20 min for 1 pedicle to 110 min for 3 pedicles). No complications requiring surgical intervention or exacerbating conditions beyond pre-treatment levels were noted.

CONCLUSION

PVP using single-plane C-arm fluoroscopy for guidance is feasible, safe, and quick.

Association analysis using refined microsatellite markers localizes a susceptibility locus for psoriasis vulgaris within a 111 kb segment telomeric to the HLA-C gene

The HLA-Cw6 antigen has been associated with psoriasis vulgaris despite racial and ethnic differences. However, it remains unclear whether it is the HLA-Cw6 antigen itself or a closely linked, hitherto unidentified, locus that predisposes to the disease. Here, in order to map the susceptibility locus for psoriasis vulgaris precisely within the HLA class I region, 11 polymorphic microsatellite markers distributed throughout a 1060 kb segment surrounding the HLA-C locus were subjected to association analysis in Japanese psoriasis vulgaris patients. Statistical analyses of the distribution and deviation from Hardy-Weinberg equilibrium of the allelic frequency at each micro-satellite locus revealed that the pathogenic gene for psoriasis vulgaris is located within a reduced interval of 111 kb spanning 89-200 kb telomeric of the HLA-C gene. In addition to three known genes, POU5F1, TCF19 and S, this 111 kb fragment contains four new, expressed genes identified in the course of our genomic sequencing of the entire HLA class I region. Therefore, these seven genes are the potential candidates for susceptibility to psoriasis vulgaris.

HLA-A33 and -B44 and susceptibility to postherpetic neuralgia (PHN)

HLA class I and class II alleles of 32 Japanese patients with postherpetic neuralgia (PHN) and 136 healthy controls were analyzed by serological (class I) and DNA (class II) typing for any significance in the susceptibility to varicella-zoster virus (VZV). We recognized positive associations of the development of PHN with the HLA class I antigens HLA-A33 and -B44, and the HLA-A33-B44 haplotype. This haplotype is tightly linked to DRB1*1302 in a Japanese healthy population. However, no significant association between PHN and HLA class II alleles was observed with no linkage of the HLA haplotype HLA-A33-B44 to HLA-DRB1*1302 in the patients with PHN. These findings suggest that HLA class I gene may genetically control the immune response against VZV in the pathogenesis of PHN.

Follow-up of clinical efficacy of iontophoresis therapy for postherpetic neuralgia (PHN)

A great variety of therapies have been attempted for PHN, including pharmacotherapy and physical therapy. However, there has been no decisive treatment, and reports of the clinical efficacy of all available therapies have been rather controversial. Almost all studies conducted so far have looked only at short-term therapeutic efficacy, and only a few investigators have conducted long-term observations or studies on long-term outcome. We followed up the clinical efficacy of iontophoresis therapy using lidocaine and methylprednisolone in 197 PHN patients. Monitoring conducted for an average of 4 years after completion of the treatment showed that pain remained unchanged or improved compared to pain observed upon completion of the treatment in 90.4% of patients. Although 42.6% of patients were still continuing some treatment, 90.9% were found to be able to take care of themselves. Findings obtained were reviewed and discussed from various viewpoints. Our findings showed that iontophoresis therapy is not only effective at the end of the treatment, but its efficacy is maintained over a long period of time, indicating that it is clinically very useful for the treatment of PHN.

Role of patellar tendon on the population of muscle fiber types and the contractile properties of single glycerinated muscle fibers in quadriceps muscles of rats

The role of the patellar tendon (PT) in the contractile properties of quadriceps muscle was investigated. After PT resection (partial or complete), PT reconstruction, or a sham operation, rats were forced to run on a rodent treadmill. The histochemical and mechanical characteristics of the vastus medialis (VM) and vastus lateralis (VL) muscles were examined 2, 4, and 8 weeks after treatment. There were no significant changes in either fiber type population or the contractile properties of glycerinated single muscle fibers from VM and VL 2 and 4 weeks after partial PT resection. Complete PT resection caused a decrease in the population of type I fibers in VM, while the running training after PT reconstruction increased the population of type I fibers in VM. For both the PT resection and PT reconstruction groups, the Hill coefficient, an indicator of the Ca2+ sensitivity of myofilaments, was calculated from the pCa-tension relationship of glycerinated single muscle fibers. In the PT reconstruction group, the Hill values for fibers isolated from VM were significantly decreased by running training, but the Hill values for VL were not. The effect of running training on the Ca2+ sensitivity of myofilaments in muscle fibers with PT reconstruction was different from that in muscle fibers without PT treatment. Both resection and partial resection of the PT in this animal model had heterogeneous effects on the contractile properties of quadriceps muscles; we presume that, clinically, we must give careful consideration to PT treatment.

[Ultrastructural alterations of Golgi tendon organs in disuse atrophy induced by muscle immobilization in rats]

In order to investigate changes in the ultrastructure of Golgi tendon organs (GTOs), the leg muscles of Wistar strain rats were immobilized over various periods. The immobilized triceps surae muscles were divided into three categories: a stretched-position group, a relaxed-position group, and Achilles tendon tenotomy group. After 1, 2, 3, 4, 6 and 8 weeks the muscle preparations dissected from the muscle belly and from the muscle-tendon junction were processed for classification of the fiber type histochemically and to find GTOs in plastic embedded-preparations. In the Achilles tenotomy group, an early fiber transformation from type I to type II fiber was observed, but in the other two groups a low rate of transition of fiber type occurred. At the end of 8 weeks, similar tendencies were observed in all groups. The ultrastructures of GTOs were not significantly different among three groups in basic and general structure when compared with the control group. However, swollen mitochondria in axons and axon terminals and damage in the lamina structure of the myelin sheath were seen in the capsule, axon terminal, and myelinated nerve fiber of GTOs. Although some differences were observed with shorter periods of immobilization, several structural changes were observed over longer periods, indicating the more profound effect of the length of the period rather than the type of immobilization.

Alteration of catalytic properties of chymosin by site-directed mutagenesis

Artificial mutations of chymosin by recombinant DNA techniques were generated to analyze the structure--function relationship in this characteristic aspartic proteinase. In order to prepare the mutant enzymes in their active form, we established procedures for purification of correctly refolded prochymosin from inclusion bodies produced in Escherichia coli transformants and for its subsequent activation. Mutagenesis by linker insertion into cDNA produced several mutants with an altered ratio of milk clotting activity to proteolytic activity and a different extent of stability. In addition to these mutants, several mutants with a single amino acid exchange were also constructed by site-directed mutagenesis and kinetic parameters of these mutant enzymes were determined by using synthetic hexa- and octa-peptides as substrates. Exchange of Tyr75 on the flap of the enzyme to Phe caused a marked change of substrate specificity due to the change of kcat or Km, depending on the substrate used. Exchange of Val110 and Phe111 also caused a change of kinetic parameters, which indicates functional involvement of these hydrophobic residues in both the catalytic function and substrate binding. The mutant Lys220----Leu showed a marked shift of the optimum pH to the acidic side for hydrolysis of acid-denatured haemoglobin along with a distinct increase in kcat for the octa-peptide in a wide pH range.