Exoscopic Minimally Invasive Open-Door Laminoplasty for Cervical Myelopathy: A Technical Note and Preliminary Analysis of Clinical Outcomes during the Acute Postoperative Period.

Background/Objectives: Expansive open-door laminoplasty results in favorable clinical outcomes for cervical myelopathy. However, some postoperative complications associated with surgical invasiveness, such as axial neck pain and kyphosis, have not been resolved. The use of an exoscope, which is a recently introduced novel magnification tool, allows for traditional open-door laminoplasty with minimal invasiveness. Therefore, we propose the use of exoscopic minimally invasive open-door laminoplasty (exLAP) and present its clinical outcomes during the acute postoperative period. Methods: A total of 28 patients who underwent open-door laminoplasty at C3-C6 were reviewed. Of these patients, 17 underwent exLAP (group M) and 11 underwent conventional Hirabayashi open-door laminoplasty (group H). Outcomes were evaluated using numerical rating scale (NRS) scores for neck pain and the frequency of oral analgesic use from postoperative day 1 to 7. Results: The NRS score for neck pain was significantly lower for patients in group M than for those in group H. Conclusions: ExLAP is a novel, practical, and minimally invasive surgical technique that may alleviate the postoperative axial pain of patients with cervical myelopathy.

Grade of Subchondral Insufficiency Fracture of the Knee and the Presence of a Posterior Shiny-Corner Lesion are Correlated with Duration of Medial Meniscus Posterior Root Tear in Women.

Bone marrow edema (BME) after meniscus injury and risk factors for subchondral insufficiency fracture of the knee (SIFK) have been reported. However, their association with medial meniscus posterior root tear (MMPRT) remains unknown. We investigated the association of BME volume (BME-V), posterior shinycorner lesion (PSCL), and SIFK with MMPRT to examine the correlations between BME-V and medial meniscus extrusion (MME), PSCL and duration from injury to the time of magnetic resonance imaging (duration), and SIFK and duration. Twenty-nine patients who underwent surgery for MMPRT were included (mean age, 59.2; range, 39-84). The presence of PSCL, femoral BME-V (cm3), and SIFK grade (1-4) were evaluated. Preoperative factors, such as MME (mm) and duration (weeks), were investigated using multivariate linear/ logistic regression analyses. Multivariate linear regression analysis revealed duration as a significant factor for high-grade SIFK (p<0.01). Multivariate logistic regression analysis revealed duration as a significant factor for the presence of PSCL (odds ratio=0.94, p<0.05). A long duration of MMPRT leads to severe MME and highgrade SIFK (3 and 4), often resulting in knee arthroplasty. Early diagnosis of MMPRT and pullout repair can prevent severe MME and high-grade SIFK.

The Effects of the Combination of Mesenchymal Stromal Cells and Nanofiber-Hydrogel Composite on Repair of the Contused Spinal Cord.

A bone marrow-derived mesenchymal stromal cell (MSC) transplant and a bioengineered nanofiber-hydrogel composite (NHC) have been shown to stimulate nervous tissue repair in the contused spinal cord in rodent models. Here, these two modalities were combined to assess their repair effects in the contused spinal cord in adult rats. Cohorts of contused rats were treated with MSC in NHC (MSC-NHC), MSC in phosphate-buffered saline (MSC-PBS), NHC, or PBS injected into the contusion site at 3 days post-injury. One week after injury, there were significantly fewer CD68+ cells in the contusion with MSC-NHC and NHC, but not MSC-PBS. The reduction in CD86+ cells in the injury site with MSC-NHC was mainly attributed to NHC. One and eight weeks after injury, we found a greater CD206+/CD86+ cell ratio with MSC-NHC or NHC, but not MSC-PBS, indicating a shift from a pro-inflammatory towards an anti-inflammatory milieu in the injury site. Eight weeks after injury, the injury size was significantly reduced with MSC-NHC, NHC, and MSC-PBS. At this time, astrocyte, and axon presence in the injury site was greater with MSC-NHC compared with MSC-PBS. We did not find a significant effect of NHC on MSC transplant survival, and hind limb function was similar across all groups. However, we did find fewer macrophages at 1 week post-injury, more macrophages polarized towards a pro-regenerative phenotype at 1 and 8 weeks after injury, and reduced injury volume, more astrocytes, and more axons at 8 weeks after injury in rats with MSC-NHC and NHC alone compared with MSC-PBS; these findings were especially significant between rats with MSC-NHC and MSC-PBS. The data support further study in the use of an NHC-MSC combination transplant in the contused spinal cord.

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.

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.

A "fully upper extremity" bailout of direct transaxillary large bore arterial access: A refinement within arm's reach?

Contemporary direct ("fully percutaneous") transaxillary (TAx) large-bore arterial access technique advocates for a 0.018" wire to be passed from femoral arterial access to axillary artery to serve percutaneous bailout options. However, in certain patients, avoiding femoral arterial access entirely may be desired. We describe the merits of a "fully upper extremity" (FUE) bailout approach, as a refinement to previously described direct TAx technique.

Maximal Resection of Intramedullary Lipoma Using Intraoperative Ultrasonography: A Technical Note.

One of the problems during surgery for intramedullary lipoma is the ambiguous boundary between the lipoma and the spinal cord, resulting in either incomplete resection or damage to the spinal cord. We report a case of intramedullary lipoma resection on a 61-year-old man in which the boundary between the tumor and spinal cord was repeatedly visualized with intraoperative ultrasonography. We focused on the distinctive features of fat as hyperechoic, in contrast to low-echo neural tissue. Subtotal resection of the tumor was achieved without any aggravation of neurological symptoms. Intraoperative ultrasonography may be useful for confirming tumor boundaries during intramedullary lipoma resection.

Navigated Lateral Osteotomy for Adult Spinal Deformity: A Technical Note.

BACKGROUND: Minimally invasive surgery is receiving considerable attention as a technique for reducing the complications of adult spinal deformity (ASD) surgery. For this technique, a new lateral osteotomy plays an important role to release fused vertebrae. We describe herein a novel navigated lateral osteotomy technique not requiring C-arm fluoroscopy to correct adult spinal deformities. CASE DESCRIPTION: A 68-year-old woman with symptomatic ASD and a 4-year history of severe low back pain affecting daily life was referred to our hospital. Surgery was performed without C-arm fluoroscopy. A navigated osteotome was used to release the fused L1/2 mass. The patient was successfully treated with surgery, and low back pain was well controlled. In terms of clinical outcomes, Oswestry Disability Index improved from 64%-19% and Visual Analog Scale score for low back pain improved from 74 mm-19 mm on final follow-up at 2 years. CONCLUSIONS: This novel navigated lateral osteotomy for ASD is a useful technique that enables minimally invasive surgery for fixed deformity. With this new technique, surgeons and operating room staff can avoid adverse effects of intraoperative radiation.

Quantification of patellar tendon reflex using portable mechanomyography and electromyography devices.

Deep tendon reflexes are one of the main components of the clinical nervous system examinations. These assessments are inexpensive and quick. However, evaluation can be subjective and qualitative. This study aimed to objectively evaluate hyperreflexia of the patellar tendon reflex using portable mechanomyography (MMG) and electromyography (EMG) devices. This study included 10 preoperative patients (20 legs) who had a pathology that could cause bilateral patellar tendon hyperreflexia and 12 healthy volunteers (24 legs) with no prior history of neurological disorders. We attached MMG/EMG sensors onto the quadriceps and tapped the patellar tendon with maximal and constant force. Our results showed a significantly high amplitude of the root mean square (RMS) and low frequency of the mean power frequency (MPF) in the rectus femoris, vastus medialis, and vastus lateralis muscles in both EMG and MMG with both maximal and constant force. Especially in the patients with cervical and thoracic myelopathy, the receiver operating characteristic (ROC) curve for diagnosing hyperreflexia of the patellar tendon showed a moderate to very high area under the curve for all EMG-RMS, EMG-MPF, MMG-RMS, and MMG-MPF values. The use of EMG and MMG for objectively quantifying the patellar tendon reflex is simple and desirable for future clinical applications and could help diagnose neurological disorders.

Dexmedetomidine Is an Equal Cost Alternative to Propofol in Transcatheter Aortic Valve Replacement, With Equivalent In-Hospital and 30-Day Outcomes.

OBJECTIVE: Transcatheter aortic valve replacement (TAVR) with monitored anesthesia care (MAC) is well-tolerated and is growing in popularity. Differences in outcomes based on anesthetic agent choice with MAC has received less attention. The authors sought to determine whether differences in outcomes and cost exist based on whether patients receive dexmedetomidine or propofol when undergoing TAVR with MAC. DESIGN: Retrospective cohort study. SETTING: The Penn State Milton S. Hershey Medical Center, Hershey, Pennsylvania. PARTICIPANTS: The study comprised 161 patients who underwent TAVR with MAC between May 2014 and March 2019. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: A propofol-only (n = 58) group and dexmedetomidine-only (n = 103) group were identified. No differences in in-hospital mortality or complication rate were identified when evaluating for stroke, transfusion, new arrhythmia, cardiac arrest, or bleeding and vascular complications (p > 0.05, all). Thirty-day outcomes were also equivalent, with no differences in mortality, stroke, vascular complication, new arrhythmia, or myocardial infarction (p > 0.05, all). The average amount of epinephrine, norepinephrine, or phenylephrine used intraoperatively was not significantly different. Overall median hospitalization costs were equivalent ($57,554.31 with dexmedetomidine v $58,538.08 with propofol, p = 0.97). CONCLUSIONS: There were no significant differences in in-hospital outcomes, 30-day outcomes, or total cost of the patient's hospitalization, based on the use of dexmedetomidine versus propofol in patients undergoing TAVR.

Short-term outcomes of mirogabalin in patients with peripheral neuropathic pain: a retrospective study.

BACKGROUND: Mirogabalin, which is approved for the treatment of peripheral neuropathic pain in Japan, is a ligand for the α2δ subunit of voltage-gated calcium channels. Both pregabalin and mirogabalin act as nonselective ligands at the α2δ-1 and α2δ-2 subunits. Mirogabalin has a unique binding profile and long duration of action. Pregabalin has been reported to produce intolerable adverse effects in some patients. This study investigated outcomes associated with mirogabalin administration in patients with peripheral neuropathic pain who ceased treatment with pregabalin. METHODS: We retrospectively assessed peripheral neuropathic pain using the neuropathic pain screening questionnaire (NeP score) in 187 patients (58 men, 129 women) who were treated with mirogabalin. All patients had switched from pregabalin to mirogabalin due to lack of efficacy or adverse events. Differences in the treatment course (i.e., numeric rating scale (NRS) scores) were compared using one-way analysis of variance with Bonferroni post hoc tests. RESULTS: The mean age of the patients was 72.3 years (range, 30-94 years), and the mean duration of disease was 37 months (range, 3-252 months). After treatment with mirogabalin for 1 week, NRS scores significantly decreased compared with baseline and continued to decrease over time. After 8 weeks, NRS scores improved by ≥ 30% from baseline in 113 patients (69.3%). Twenty-four patients (12.8%) stopped mirogabalin treatment due to adverse events. Somnolence (26.7%), dizziness (12.3%), edema (5.9%), and weight gain (0.5%) were noted as adverse events of mirogabalin. CONCLUSIONS: The results of this investigation indicate that mirogabalin is safe and effective for reducing peripheral neuropathic pain.

The effect of a nanofiber-hydrogel composite on neural tissue repair and regeneration in the contused spinal cord.

An injury to the spinal cord causes long-lasting loss of nervous tissue because endogenous nervous tissue repair and regeneration at the site of injury is limited. We engineered an injectable nanofiber-hydrogel composite (NHC) with interfacial bonding to provide mechanical strength and porosity and examined its effect on repair and neural tissue regeneration in an adult rat model of spinal cord contusion. At 28 days after treatment with NHC, the width of the contused spinal cord segment was 2-fold larger than in controls. With NHC treatment, tissue in the injury had a 2-fold higher M2/M1 macrophage ratio, 5-fold higher blood vessel density, 2.6-fold higher immature neuron presence, 2.4-fold higher axon density, and a similar glial scar presence compared with controls. Spared nervous tissue volume in the contused segment and hind limb function was similar between groups. Our findings indicated that NHC provided mechanical support to the contused spinal cord and supported pro-regenerative macrophage polarization, angiogenesis, axon growth, and neurogenesis in the injured tissue without any exogenous factors or cells. These results motivate further optimization of the NHC and delivery protocol to fully translate the potential of the unique properties of the NHC for treating spinal cord injury.

Multipotent Neurotrophic Effects of Hepatocyte Growth Factor in Spinal Cord Injury.

Spinal cord injury (SCI) results in neural tissue loss and so far untreatable functional impairment. In addition, at the initial injury site, inflammation induces secondary damage, and glial scar formation occurs to limit inflammation-mediated tissue damage. Consequently, it obstructs neural regeneration. Many studies have been conducted in the field of SCI; however, no satisfactory treatment has been established to date. Hepatocyte growth factor (HGF) is one of the neurotrophic growth factors and has been listed as a candidate medicine for SCI treatment. The highlighted effects of HGF on neural regeneration are associated with its anti-inflammatory and anti-fibrotic activities. Moreover, HGF exerts positive effects on transplanted stem cell differentiation into neurons. This paper reviews the mechanisms underlying the therapeutic effects of HGF in SCI recovery, and introduces recent advances in the clinical applications of HGF therapy.

High-Throughput Screening and Characterization of a High-Density Soybean Mutant Library Elucidate the Biosynthesis Pathway of Triterpenoid Saponins.

Triterpenes (C30) constitute one of the diverse class of natural products with potential applications in food, cosmetic and pharmaceutical industries. Soyasaponins are oleanane-type triterpenoids widespread among legumes and particularly abundant in soybean seeds. They have associated with various pharmacological implications and undesirable taste properties of soybean-based food products. Uncovering the biosynthetic genes of soyasaponins will provide new opportunities to control the pathway for human benefits. However, the pathway of soyasaponin biosynthesis has not been fully elucidated in part because of a paucity of natural mutants. Here, we applied a structured high-density soybean mutant library for the forward genetic screening of triterpenoid biosynthesis. The seed soyasaponin polymorphism in the mutant library was evaluated using a high-throughput thin-layer chromatography and liquid chromatography tandem mass spectrometry analysis. This screening identified 35 mutants (3.85% of 909 mutant lines) with seven unusual soyasaponin phenotypes (Categories 1-7), which was greater than the number of natural mutants reported previously (22 mutants, 0.18% of ∼12,428 accessions). Nine unique intermediates of soyasaponin biosynthesis were identified and their chemical structures were estimated based on their MS/MS fragment patterns. Based on published information, 19 mutants could be associated with loss of function of four individual soyasaponin biosynthesis genes identified through expressed sequence tag mining or positional cloning, whereas the remaining 16 mutants were novel and may facilitate discovery of the unknown biosynthetic genes of soyasaponins. Our approach and library may help to identify new phenotype materials and causative genes associated with specialized metabolite production and other traits.

Effectiveness of using low rate fluoroscopy to reduce an examiner's radiation dose during lumbar nerve root block.

BACKGROUND: Long-term exposure to radiation can lead to gene mutations and increase the risk of cancer. Low rate fluoroscopy has the potential to reduce the radiation exposure for both the examiner and the patient during various fluoroscopic procedures. The purpose of this study was to evaluate the impact of low rate fluoroscopy on reducing an examiner's radiation dose during nerve root block. METHODS: A total of 101 lumbar nerve root block examinations were performed at our institute during a 6-month period. During the first 3 months, low rate fluoroscopy was performed at 7.5 frames/s (FPS) in 54 examinations, while 47 were performed at 15 FPS during the last 3 months. The examiner wore a torso protector, a neck protector, radiation protection gloves, and radiation protection glasses. Optically stimulated luminescence (OSL) dosimeter badges were placed on both the inside and the outside of each protector. The dosimeters were exchanged every month. Radiation doses (mSv) were measured as the integrated radiation quantity every month from the OSL dosimeters. The effective and equivalent doses for the hands, skin, and eyes were investigated. RESULTS: The mean monthly equivalent doses were significantly lower both inside and outside the hand protector for the 7.5 FPS versus 15 FPS (inside; P = 0.021, outside; P = 0.024). There were no significant differences between the two groups for the mean monthly calculated effective dose for each protector's condition. CONCLUSIONS: Radiation exposure was significantly reduced for the skin on the examiner's hand when using low rate fluoroscopy at 7.5 FPS, with no noticeable decrease in image quality or prolonged fluoroscopy time.

Anterior cervical arthrodesis for chronic hangman's fracture in a patient with osteopetrosis: a case report.

INTRODUCTION: Osteopetrosis is a clinical syndrome characterized by the failure of osteoclasts to resorb bone. Affected patients usually suffer from repetitive fractures due to this pathological state. Surgical treatment of these fractures is often complicated by the difficulty of working with the extremely hard and brittle bones. The purpose of this study was to report a case of chronic hangman's fracture in a patient with osteopetrosis who underwent surgery for cervical anterior interbody fusion. MATERIALS AND METHODS: A 76-year-old woman visited our institute 1 month after injury. Radiographs revealed a type II hangman's fracture with severe translation according to the Levine-Edwards classification. We performed anterior spinal arthrodesis from C2 to C3. RESULTS: We obtained successful anterior C2-C3 arthrodesis without major complications, but encountered some surgical difficulties in treatment due to hard and brittle bones. CONCLUSIONS: Anterior cervical arthrodesis can be considered an effective treatment for chronic unstable hangman's fracture in patients with osteopetrosis. However, great care must be taken when performing surgery and continued follow-up is warranted.

Collagen-Binding Hepatocyte Growth Factor (HGF) alone or with a Gelatin- furfurylamine Hydrogel Enhances Functional Recovery in Mice after Spinal Cord Injury.

The treatment of spinal cord injury (SCI) is currently a significant challenge. Hepatocyte growth factor (HGF) is a multipotent neurotrophic and neuroregenerative factor that can be beneficial for the treatment of SCI. However, immobilized HGF targeted to extracellular matrix may be more effective than diffusible, unmodified HGF. In this study, we evaluated the neurorestorative effects of an engineered HGF with a collagen biding domain (CBD-HGF). CBD-HGF remained in the spinal cord for 7 days after a single administration, while unmodified HGF was barely seen at 1 day. When a gelatin-furfurylamine (FA) hydrogel was applied on damaged spinal cord as a scaffold, CBD-HGF was retained in gelatin-FA hydrogel for 7 days, whereas HGF had faded by 1 day. A single administration of CBD-HGF enhanced recovery from spinal cord compression injury compared with HGF, as determined by motor recovery, and electrophysiological and immunohistochemical analyses. CBD-HGF alone failed to improve recovery from a complete transection injury, however CBD-HGF combined with gelatin-FA hydrogel promoted endogenous repair and recovery more effectively than HGF with hydrogel. These results suggest that engineered CBD-HGF has superior therapeutic effects than naïve HGF. CBD-HGF combined with hydrogel scaffold may be promising for the treatment of serious SCI.

Exposure of the examiner to radiation during myelography versus radiculography and root block: A comparative study.

BACKGROUND: Exposure to radiation over many years prompts concerns regarding potential health-related effects, particularly the incidence of cataracts and the development of cancer. The purpose of this study was to examine and compare the exposure of the examiner to radiation during myelography versus radiculography and root block. METHODS: A total of 114 examinations were performed in our institute in the 6 months. Sixty-two examinations were performed during myelography in the first 3 months (MG group), while 52 were performed during radiculography and root block in the last 3 months (RB group). The examiner wore a torso protector, a neck protector, radiation protection gloves, and radiation protection glasses. Optically stimulated luminescence (OSL) dosimeter badges were placed on both the inside and the outside of each protector. The dosimeters were exchanged every month. Radiation doses (mSv) were measured as the integrated radiation quantity every month from the OSL dosimeters. The effective dose and the equivalent doses of hand, skin, and eyes were investigated. RESULTS: The mean equivalent doses were significantly lower outside the neck, torso, eye protectors, and inside the torso protector in the RB group than in the MG group. Conversely, the mean equivalent dose was significantly lower outside the hand protector in the MG group than in the RB group. The use of a neck protector significantly decreased the effective dose compared to the non-use of a neck protector in the RB group. CONCLUSIONS: The present study showed the standard radiation exposure to the examiner during myelography, radiculography, and root block. Receiving full protection including a neck protector and protection gloves is an easy and reliable means to reduce radiation exposure.

Quality of Life and Mid-Term Survival of Patients Bridged with Extracorporeal Membrane Oxygenation to Left Ventricular Assist Device.

Insertion of a left ventricular assist device (LVAD) improves survival and quality of life (QOL) in patients with class IV heart failure failing medical management. However, QOL and survival of patients bridged to LVAD with extracorporeal membrane oxygenation (ECMO) is unknown. Between July 2008 and June 2014, 213 patients underwent insertion of HeartMate II LVAD at two VAD centers without a bridge with a temporary VAD. Extracorporeal membrane oxygenation was used as a bridge before LVAD insertion in 22 Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) 1 patients (ECMO-VAD group). No bridge was used in 21 INTERMACS 1 patients and 170 INTERMACS 2-4 patients (primary LVAD group). Survival was compared between the ECMO-VAD group and INTERMACS 1 patients who underwent a primary LVAD insertion (INTERMACS 1 group). Quality of life was compared between the ECMO-VAD group and the primary LVAD group as a whole. The in-hospital mortality of the ECMO-VAD and INTERMACS1 groups was 23% and 14%, respectively (P = 0.38). The postimplant QOL scores of the ECMO-VAD group were not different compared with the primary LVAD group. Although the ECMO-VAD group consists of critically ill patients, the QOL and survival after discharge were not significantly different compared with patients who were not bridged with ECMO.

Impact of Rotation Correction after Brace Treatment on Prognosis in Adolescent Idiopathic Scoliosis.

STUDY DESIGN: Level 4 retrospective review. PURPOSE: Brace treatment is the standard nonoperative treatment for adolescent idiopathic scoliosis (AIS). Rotation correction is also important, because AIS involves a rotation deformity. The purpose of this study was to evaluate the impact of rotation correction after Osaka Medical College (OMC) brace treatment on clinical outcomes in AIS. OVERVIEW OF LITERATURE: Brace treatment has a significant effect on the progression of AIS. However, few reports have examined rotation correction after brace treatment. METHODS: A total of 46 patients who wore the OMC brace were retrospectively reviewed. The curve magnitude was determined according to the Cobb method, and the rotation angle of the apical vertebrae was measured by the modified Nash-Moe method. Based on the difference in the rotation angle before and after the initial brace treatment, patients were divided into two groups. Group A (n=33) was defined as no change or improvement of the rotation angle; group B (n=13) was defined as deterioration of the rotation angle. If the patients had curve or rotation progression of 5° or more at skeletal maturity, or had undergone surgery, the treatment was considered a failure. RESULTS: Differences of rotation angle between before and after the initial brace treatment were 2°±2° in group A and -3°±2° in group B (p<0.001). The rates of treatment failure were 42% in group A and 77% in group B (p<0.05). This study included 25 patients with Lenke type 1 (54%). Group A (24%) with Lenke type 1 also had a significantly better success rate of brace treatment than group B (75%) (p<0.05). CONCLUSIONS: Insufficient rotation correction increased brace treatment failure. Better rotation correction resulted in a higher success rate of brace treatment in patients with Lenke type 1.