Risk factors for allogeneic red blood cell transfusion in adult spinal deformity surgery.

STUDY DESIGN: Retrospective study. PURPOSE: To investigate the risk factors for allogeneic red blood cell (RBC) transfusion in adult spinal deformity (ASD) surgery. OVERVIEW OF LITERATURE: Studies have not thoroughly explored the roles of intraoperative hypothermia, autologous blood donation, and hemostatic agent administration, which would provide a better understanding of the risk for perioperative RBC transfusion in ASD surgery. METHODS: The medical records of 151 patients with ASD who underwent correction surgery between 2012 and 2021 were retrospectively reviewed. Estimated blood loss and perioperative allogeneic transfusion were examined. Patients were categorized into two groups based on whether they received perioperative allogeneic blood transfusion. Logistic regression analysis was employed to investigate the effect of age, sex, blood type, body mass index, American Society of Anesthesiologists' physical status, preoperative hemoglobin level, autologous blood donation, global spine alignment parameters, preoperative use of anticoagulants or antiplatelet medicine and nonsteroidal anti-inflammatory drugs, number of instrumented fusion levels, total operative duration, three-column osteotomy, lateral interbody fusion, pelvic fixation, intraoperative hypothermia, use of gelatin-thrombin based hemostatic agents, and intraoperative tranexamic acid (TXA) with simultaneous exposure by two attending surgeons. RESULTS: The estimated blood loss was 994.2±754.5 mL, and 71 patients (47.0%) received allogeneic blood transfusion. In the logistic regression analysis, the absence of intraoperative TXA use and simultaneous exposure (odds ratio [OR], 26.3; 95% confidence interval [CI], 7.6-90.9; p<0.001), lack of autologous blood donation (OR, 21.2; 95% CI, 4.4-100.0; p<0.001), and prolonged operative duration (OR, 1.6; 95% CI, 1.3-1.9; p<0.001) were significant independent factors for perioperative allogeneic blood transfusion in ASD surgery. CONCLUSIONS: Autologous blood storage, intraoperative TXA administration, and simultaneous exposure should be considered to minimize perioperative allogeneic blood transfusion in ASD surgery, particularly in patients with anticipated lengthy surgeries.

Factors influencing the achievement of early surgery in proximal femoral fractures under a Japanese incentive policy.

BACKGROUND: Proximal femoral fractures in geriatric patients are a major challenge in orthopedics, often leading to major functional impairment. Early surgical intervention is crucial for improving patient recovery and overall health outcomes. Thus, Japan's Ministry of Health, Labour and Welfare initiated a reimbursement policy in April 2022 to encourage early surgery for these fractures in patients aged ≥75 years. This study investigated the impact of this policy on early surgery rates in Japan and identified factors influencing the timing of surgical interventions. METHODS: We retrospectively analyzed the data of patients who underwent surgery for proximal femoral fractures at our institution between April 2022 and March 2023. Patients were categorized into two groups based on the timing of surgery relative to the injury: ≤48 h and >48 h. Demographic and clinical data, including age, sex, fracture type, and various health- and admission-related factors, were assessed. RESULTS: Of the 192 patients, 152 were included in the study. Among them, 38% underwent early surgery (≤48 h), and 15% of the patients arrived more than 48 h post-injury. Significant differences were found in admission routes and residence types between the groups. The ≤48 h group had shorter intervals from injury to admission and surgery than the >48 h group. Factors such as the admission process, day of the week, and C-reactive protein levels significantly influenced the timing of surgery. CONCLUSIONS: After introducing incentives for early surgery in Japan, 38% of patients with proximal femoral fractures underwent surgery within 48 h of injury. Factors contributing to patients not receiving early surgery included transport from another hospital, weekend hospitalization, and elevated CRP levels. These findings suggest that achieving surgery within 48 h of injury is challenging through hospital efforts alone, and the time criteria might be more appropriate if changed to "admission to surgery."

Time elapsed from definitive diagnosis to surgery for osteonecrosis of the femoral head: a nationwide observational study in Japan.

OBJECTIVES: This study documents the time elapsed from the diagnosis of osteonecrosis of the femoral head (ONFH) to surgery, exploring the factors that influence ONFH severity. DESIGN: Retrospective observational study of a nationwide database. SETTING: The Kaplan-Meier method with log-rank tests was applied to examine the period from definitive diagnosis of ONFH to surgery using any surgery as the end point. For bilateral cases, the date of the first surgery was the endpoint. PARTICIPANTS: This study included 2074 ONFH cases registered in 34 university hospitals and highly specialised hospitals of the multicentre sentinel monitoring system of the Japanese Investigation Committee between 1997 and 2018. MAIN OUTCOME MEASURE: The primary outcome was the time from diagnosis to surgery. The secondary outcome was the proportion of subjects remaining without surgery at 3, 6 and 9 months, and at 1, 2 and 5 years after diagnosis. RESULTS: The median time to surgery was 9 months (IQR 4-22 months) after diagnosis of ONFH. The time to surgery was significantly shorter in the alcohol alone group and the combined corticosteroid and alcohol group than in the corticosteroid alone group (p=0.018 and p<0.001, respectively), in early stage ONFH with no or mild joint destruction (stages II and III, p<0.001), and with joint preserving surgery (p<0.001). The proportion without surgery was 75.8% at 3 months, 59.6% at 6 months, 48.2% at 9 months, 40.5% at 1 year, 22.2% at 2 years and 8.3% at 5 years. CONCLUSION: ONFH has been considered to be an intractable disease that often requires surgical treatment, but the fact that surgery was performed in more than half of the patients within 9 months from diagnosis suggests severe disease with a significant clinical impact. TRIAL REGISTRATION NUMBER: Chiba University ID1049.

Morphological and functional changes of the geniohyoid muscle in elderly patients after hip fracture surgery: Comparison of ultrasound images with a focus on swallowing function.

OBJECTIVE: The purpose of this study was to clarify, using ultrasound imaging, (1) whether the area and contraction of GH change in elderly patients after hip fracture surgery and (2) whether the changes in the area and contraction of GH are related to decline in swallowing function. METHODS: The participants were 21 female patients over 65 years of age who underwent hip fracture surgery. The patients were divided into two groups based on the results of swallowing assessment by water drinking: One with normal swallowing function (NSF) and the other with suspected decline in swallowing function (DSF). Sagittal cross-sectional area (SA) of GH at rest and the shortening rate (SR) of GH upon contraction during swallowing were compared at two time points: immediately and 2 weeks after surgery. Wilcoxon signed-rank test was used for intra-group comparisons, and Mann-Whitney U-test was used for between-group comparisons. RESULT: SA of GH decreased significantly at 2 weeks after surgery in both groups, regardless of their swallowing function. In the intra-group comparison, SR significantly decreased (worsened) only in DSF group. SR at 2 weeks after surgery was significantly higher in NSF than in the DSF. In the inter-group comparison, DSF showed a significantly smaller (worse) change of SR than NSF in 2 weeks after surgery. CONCLUSION: Decrease in muscle mass, or atrophy, of GH observed in both NSF and DSF, did not coincide with the post-operative change in GH contraction of the two groups. The results suggest the importance of continuous swallowing assessment in the elderly individuals during their perioperative period.

Assessment of the Initial Diagnostic Accuracy of a Fragility Fracture of the Sacrum: A Study of 56 Patients.

STUDY DESIGN: Retrospective study. PURPOSE: To investigate the clinical manifestations of a fragility fracture of the sacrum (FFS) and the factors that may contribute to a misdiagnosis. OVERVIEW OF LITERATURE: The number of patients diagnosed with FFS has increased because of extended life expectancy and osteoporosis. Patients with FFS may report nonspecific symptoms, such as back, buttock, groin, and/or leg pain, leading to a misdiagnosis and a delay in definitive diagnosis. METHODS: Fifty-six patients (13 males and 43 females) with an average age of 80.2±9.2 years admitted to the hospital for FFS between 2006 and 2021 were analyzed retrospectively. The following patient data were collected using medical records: pain regions, a history of trauma, initial diagnoses, and rates of fracture detection using radiography, computed tomography (CT), and magnetic resonance imaging (MRI). RESULTS: Forty-one patients presented with low back and/or buttock pain, nine presented with groin pain, and 17 presented with thigh or leg pain. There was no history of trauma in 18 patients (32%). At the initial visit, 27 patients (48%) were diagnosed with sacral or pelvic fragility fractures. In contrast, 29 patients (52%) were initially misdiagnosed with lumbar spine disease (23 patients), hip joint diseases (three patients), and buttock bruises (three patients). Fracture detection rates for FFS were 2% using radiography, 71% using CT, and 93% using MRI. FFS was diagnosed definitively using an MRI with a coronal short tau inversion recovery (STIR) sequence. CONCLUSIONS: Some patients with FFS have leg pain with no history of trauma and are initially misdiagnosed as having lumbar spine disease, hip joint disease, or simple bruises. When these clinical symptoms are reported, we recommend considering FFS as one of the differential diagnoses and performing lumbar or pelvic MRIs, particularly coronal STIR images, to rule out FFS.

Medical Accidents Related to Ferromagnetic Objects Brought into the MRI Room: Analysis of the National Multicenter Database by Orthopedic Surgeons.

Introduction: Magnetic resonance imaging (MRI) is widely used in orthopedics, but orthopedic surgeons, including spine surgeons, do not have detailed knowledge of MRI-related accidents. We, as orthopedic surgeons, investigated the details of medical accidents related to ferromagnetic objects brought into the MRI room using a national multicenter database. Methods: We conducted an exploratory analysis of accidents involving MRI ferromagnets based on the Japanese database of adverse medical occurrences. From a total of 104,659 accident reports over nine years, 172 involving the presence of ferromagnetic objects in the MRI room were extracted and analyzed. Results: The accident reports frequently involved children and the elderly. Nurses filed the highest number of reports (44.8%) by occupation, which was more than twice as many as physicians (19.8%). The most common ferromagnetic devices brought into the MRI rooms were pacemakers (n = 22). There were also large magnetic objects such as oxygen cylinders (n = 12) and IV stands (n = 7). In the field of orthopedics, ankle weights (n = 4), pedometers (n = 3), and artificial limbs (n = 2) were brought in. "Failure to check" was the most common cause of accidents (69%). Actual harm to patients occurred in 9% of cases, with no fatalities. Conclusions: Manuals and checklists should be developed and continuous education provided to prevent accidents involving magnetic objects brought into the MR scanner room. As orthopedic surgeons, including spine surgeons, we should be cautious with emergency, geriatric, and pediatric patients because their information and medical history may not be accurate. We should not overlook equipment commonly found in orthopedic practice such as ankle weights and pedometers.

Risk factors for celiac artery and superior mesenteric artery stenosis in preoperative lumbar and thoracolumbar spinal surgery patients.

BACKGROUND: Ischemic necrosis of the abdominal organs caused by compression of the celiac artery (CA) and superior mesenteric artery (SMA) by the median arcuate ligament (MAL) after correction surgery has been recognized as acute celiac artery compression syndrome (ACACS). Here, using contrast-enhanced computed tomographic (CT) images, we sought to determine the prevalence and degree of CA and SMA stenosis in spinal patients preoperatively, and the risk factors associated with the stenosis. METHODS: We retrospectively examined contrast-enhanced abdominal CT of 90 patients with preoperative lumbar degenerative disease, lumbar burst fracture, or adult spinal deformity. The trunks of the CA and SMA were detected using three-dimensional reconstructed CT. To investigate their degree of stenosis, we determined the ratio of the narrowest diameter of the stenotic segment to the distal normal lumen's diameter. Patients with a degree of stenosis ≥35% were defined as being in the group with stenosis and the remainder as in the group without. To determine the risk factors for stenosis of these arteries, the relationship between the stenosis and CA and SMA calcification or the median arcuate ligament (MAL) crossing the proximal portion of the celiac axis (MAL overlap) was also investigated. RESULTS: The average degree of stenosis of the CA trunk was 12.1% ± 13.9% and that for the SMA trunk was 8.5% ± 8.8%. There were 8 patients (8.9%) in the group with CA stenosis and 2 patients (2.2%) in the group with SMA stenosis. The number of patients in the group with CA stenosis was significantly greater than the number with MAL overlap or CA calcification (P < 0.05). DISCUSSION: The prevalence of CA or SMA stenosis was 11.2% of preoperative patients due to undergo thoracolumbar fusion surgery. Calcifications of the CA trunk and MAL overlap are risk factors for CA stenosis.

The Optimal Anatomical Position and Threshold Temperature of a Temperature Data Logger for Brace-Wearing Compliance in Patients with Scoliosis.

Introduction: Although strict compliance with brace wearing is important for patients with scoliosis, no study has analyzed the most ideal conditions for temperature logger accuracy. We evaluated the optimal brace position and threshold temperature for the logger and determined the reliability of its measurements in patients with scoliosis. Methods: Five temperature loggers were embedded into holes generated at five different brace positions (right scapula, right chest, left chest, lumbar, and abdomen) within the brace. We compared measurement errors at each position using different threshold temperatures to determine the ideal anatomical position and threshold temperature. Under the ideal conditions determined, we calculated the reliability of the temperature logger readings in three healthy participants. Results: Measurement errors (i.e., differences between the actual and logger-recorded brace wearing times) were the lowest at the 28°C and 30°C threshold temperatures when the logger was positioned at the left chest and at 30°C at the abdomen. Among these three temperature/position combinations, we considered the abdomen to be the least affected by the shape of the brace; thus, the placement of the temperature logger at the abdomen using a threshold temperature of 30°C was the most ideal condition. Conclusions: The placement of the temperature logger at the abdomen using a threshold temperature of 30°C was the most ideal condition, with the reliability of the logger being 97.9%±0.9%. This information might be useful for scoliosis management teams, and this temperature logger provides a valuable clinical tool.

Assessment of locomotive syndrome in patients with visceral cancer, the comparison with non-cancer patients using propensity score matching.

BACKGROUND: When treating cancer patients, the progression of symptoms is accompanied by the deterioration of systemic conditions and motor function. From a risk-benefit perspective, a certain level of physical function must be maintained to continue cancer treatment. Recently, outpatient cancer treatment has become more common. Motor function is important to determine the feasibility of continuing cancer treatment. The study aimed to evaluate the motor function of patients with visceral cancer using locomo tests established by Japanese Orthopaedic Association. METHODS: Locomo tests were performed, and the results were compared with data from non-cancer individuals. Background data were matched by propensity score matching. Data from 53 cancer patients (group C) were compared with that of 75 non-cancer patients (group N). RESULTS: The average score in the two-step test of group C was lower than that of group N (1.27: 1.37, p = 0.004). The average function in the stand-up test of group C was worse than that of group N (p = 0.001). The average score in the 25-question geriatric locomotive function scale (GLFS) of group C was significantly higher than that of group N (19.92: 5.29, SE 2.21, p < 0.001). Higher 25-question GLFS scores indicate reduced mobility. The proportion of the locomo stage 2 in group C was significantly higher than in group N (51%: 13%, p < 0.001). The results of the two field tests revealed a clinically minimal difference between the two groups, but a statistically significant difference. Locomo tests may be detect potential motor dysfunction in outpatient cancer patients with apparently maintained motor function. CONCLUSIONS: Even in cancer patients who attend outpatient clinics, their motor functions could be potentially impaired. Therapeutic interventions to maintain and enhance motor function for cancer patients could be useful for continuing cancer treatment, and furthermore, improving prognosis.

Efficacy of lateral lumbar interbody fusion combined with posterior spinal fusion compared with three-column osteotomy for adult spinal deformity with severe lumbar sagittal deformity.

PURPOSE: The clinical and radiological results of adult spinal deformity (ASD) patients with a severe lumbar sagittal deformity undergoing multilevel lateral lumbar interbody fusion (LLIF) + posterior spinal fusion (PSF) were compared to patients undergoing three-column osteotomy (3CO). METHODS: We defined severe lumbar sagittal deformity as fulcrum backward bending (FBB) pelvic incidence minus lumbar lordosis (PI-LL) ≧ 20 degrees. A total of twenty-five patients with an ASD were enrolled between 2013 and 2018. Fifteen patients were in the LLIF + PSF group, and ten patients were in the 3CO group. We evaluated patient demographics, clinical outcomes, and radiographic parameters such as the Cobb angle and spinopelvic parameters from standing X-ray films in each group. RESULTS: The LLIF + PSF group had a significantly shorter follow-up time than the 3CO group. Postoperatively, the LLIF + PSF group had significantly lower PI-LL and a shorter sagittal vertical axis than the 3CO group. Postoperative PI-LL changes in the LLIF + PSF group were significantly smaller than those in the 3CO group. There were no differences in other patient demographics, radiographic parameters, or clinical outcomes between the groups. CONCLUSION: Multilevel LLIF + PSF improved the PI-LL and SVA more than did 3CO for ASD patients with severe lumbar sagittal deformity. This indicated that the multilevel LLIF with open PSF can provide good clinical outcomes even in cases with severe lumbar sagittal deformity such as large FBB PI-LL in which 3CO techniques usually are needed.

Incidence, Risk Factors, and Prevention Strategy for Proximal Junctional Kyphosis in Adult Spinal Deformity Surgery.

INTRODUCTION: Proximal junctional kyphosis (PJK) is an acute complication of adult spinal deformity (ASD) surgery and may require re-operation because of proximal junctional failure (PJF). PJK causes and prevention strategies remain unknown. This study aimed to investigate the differences in the backgrounds of patients with PJK, compared to those without PJK, in ASD surgery. METHODS: We included data from 86 patients who underwent ASD surgery between 2012 and 2018. There were 40 patients (46.5%) with PJK; 46 patients did not have PJK until the last follow-up. We evaluated patient demographics, clinical outcomes, and radiographic parameters, such as Cobb angle and spinopelvic parameters on standing X-ray films, in each group. RESULTS: There was no significant difference in patient demographics, clinical outcomes, or preoperative radiographic parameters. Postoperative pelvic incidence minus lumbar lordosis (PI-LL) and pelvic tilt (PT) were significantly lower in the PJK group, and thoracic kyphosis (TK) was higher. The cutoff values were 34.5° for TK, 0.5° for PI-LL, and 15.5° for PT. Other radiographic parameters were not significantly different. PJF developed in seven patients (17.5%) in the PJK group. PJF patients had significantly older age, higher postoperative TK, higher postoperative proximal junctional Cobb angle (PJA), more changes between pre- and postoperative PJA, and lower satisfaction scores on the Scoliosis Research Society Outcomes Questionnaire (SRS-22 satisfaction) than non-PJF patients in the PJK group. CONCLUSIONS: One risk factor for PJK was lower postoperative PI-LL that was 0° or less. In ASD surgery, the most critical factor in a PJK prevention strategy is to obtain a postoperative LL adjusted by PI, which is >0°.

Automated classification of hip fractures using deep convolutional neural networks with orthopedic surgeon-level accuracy: ensemble decision-making with antero-posterior and lateral radiographs.

Background and purpose - Deep-learning approaches based on convolutional neural networks (CNNs) are gaining interest in the medical imaging field. We evaluated the diagnostic performance of a CNN to discriminate femoral neck fractures, trochanteric fractures, and non-fracture using antero-posterior (AP) and lateral hip radiographs. Patients and methods - 1,703 plain hip AP radiographs and 1,220 plain hip lateral radiographs were included in the total dataset. 150 images each of the AP and lateral views were separated out and the remainder of the dataset was used for training. The CNN made the diagnosis based on: (1) AP radiographs alone, (2) lateral radiographs alone, or (3) both AP and lateral radiographs combined. The diagnostic performance of the CNN was measured by the accuracy, recall, precision, and F1 score. We further compared the CNN's performance with that of orthopedic surgeons. Results - The average accuracy, recall, precision, and F1 score of the CNN based on both anteroposterior and lateral radiographs were 0.98, 0.98, 0.98, and 0.98, respectively. The accuracy of the CNN was comparable to, or statistically significantly better than, that of the orthopedic surgeons regardless of radiographic view used. In the CNN model, the accuracy of the diagnosis based on both views was significantly better than the lateral view alone and tended to be better than the AP view alone. Interpretation - The CNN exhibited comparable or superior performance to that of orthopedic surgeons to discriminate femoral neck fractures, trochanteric fractures, and non-fracture using both AP and lateral hip radiographs.

Risk Factors for Loosening of S2 Alar Iliac Screw: Surgical Outcomes of Adult Spinal Deformity.

STUDY DESIGN: Retrospective study. PURPOSE: To determine the risk factors for S2 alar iliac (S2AI) screw loosening and its association with lumbosacral fusion in patients with adult spinal deformity (ASD). OVERVIEW OF LITERATURE: S2AI screws have been widely used for ASD surgery in recent years. However, no studies have analyzed the risk factors for loosening of S2AI screws and its association with lumbosacral fusion. METHODS: Cases of 50 patients with ASD who underwent long spinal fusion (>9 levels) with S2AI screws were retrospectively reviewed. Loosening of S2AI screws and S1 pedicle screws and bone fusion at the level of L5-S1 at 2 years after surgery were investigated using computed tomography. In addition, risk factors for loosening of S2AI screws were determined in patients with ASD. RESULTS: At 2 years after surgery, 33 cases (66%) of S2AI screw loosening and six cases (12%) of S1 pedicle screw loosening were observed. In 40 of 47 cases (85%), bone fusion at L5-S1 was found. Pseudarthrosis at L5-S1 was not significantly associated with S2AI screw loosening (19.3% vs. 6.3%, p=0.23), but significantly higher in patients with S1 screw loosening (83.3% vs. 4.9%, p<0.001). On multivariate logistic regression analyses, high upper instrumented vertebra (UIV) level (T5 or above) (odds ratio [OR], 4.4; 95% confidence interval [CI], 1.0-18.6; p=0.045) and obesity (OR, 11.4; 95% CI, 1.2-107.2; p=0.033) were independent risk factors for S2AI screw loosening. CONCLUSIONS: High UIV level (T5 or above) and obesity were independent risk factors for S2AI screw loosening in patients with lumbosacral fixation in surgery for ASD. The incidence of lumbosacral fusion is associated with S1 screw loosening, but not S2AI screw loosening.

Reference values for the locomotive syndrome risk test quantifying mobility of 8681 adults aged 20-89 years: A cross-sectional nationwide study in Japan.

BACKGROUND: The locomotive syndrome risk test was developed to quantify the decrease in mobility among adults, which could eventually lead to disability. The purpose of this study was to establish reference values for the locomotive syndrome risk test for adults and investigate the influence of age and sex. METHODS: We analyzed 8681 independent community dwellers (3607 men, 5074 women). Data pertaining to locomotive syndrome risk test (the two-step test, the stand-up test, and the 25-question geriatric locomotive function scale [GLFS-25]) scores were collected from seven administrative areas of Japan. RESULTS: The reference values of the three test scores were generated and all three test scores gradually decreased among young-to-middle-aged individuals and rapidly decreased in individuals aged over 60 years. The stand-up test score began decreasing significantly from the age of 30 years. The trajectories of decrease in the two-step test score with age was slightly different between men and women especially among the middle-aged individuals. The two physical test scores were more sensitive to aging than the self-reported test score. CONCLUSION: The reference values generated in this study could be employed to determine whether an individual has mobility comparable to independent community dwellers of the same age and sex.

Patients majoring in a healthcare field after scoliosis surgery: Comparison with the national census in Japan.

BACKGROUND: Although scoliosis surgery early in life may affect the career choice of the patient in favor of a healthcare field, no study has analyzed this relationship. We investigated the career paths of patients after scoliosis surgery. METHODS: A total of 212 patients with scoliosis who underwent corrective surgery at 12-17 years of age were mailed a questionnaire, of whom 98 (mean age at survey: 21.0 ± 1.7, years) responded. Choice of study major was determined by the same questions used in the Japanese national census. RESULTS: Of the 98 patients, 35% chose a career in healthcare compared with 11% of the general population of the same age, based on the national census. Healthcare was the most popular career choice of patients, whereas it ranked fourth according to the national census. Furthermore, 87% of patients reported that their decision to pursue a healthcare-related career was affected by their own medical experiences. Among the healthcare-related occupations, nursing ranked first, accounting for 35% of all healthcare professions chosen by the patients. Compared with patients who chose a non-healthcare career, those choosing a healthcare career decided on their study major at a significantly lower age. CONCLUSIONS: One-third of patients with scoliosis who underwent spine surgery chose a career in a healthcare field. Furthermore, an earlier age at the time of making a career decision was a significant factor associated with choosing a healthcare career. These findings suggest that the patients' experiences in the hospital positively affected their future career paths.

Clinical application of intraoperative O-arm navigation in reverse shoulder arthroplasty.

BACKGROUND: Inaccurate fixation and positioning of the glenoid component using conventional techniques are problematic in reversed shoulder arthroplasty (RSA). Our objective was to investigate the accuracy of O-arm navigation of the glenoid component in RSA. METHODS: This retrospective case-control study comprised 2 groups of 25 patients who underwent reversed shoulder arthroplasty with or without intraoperative O-arm navigation. The intraoperative goal was to place the component neutrally in the glenoid in the axial plane and 10° inferiorly tilted in the scapular plane. Glenoid version angle and inclination were measured by computed tomography obtained preoperatively and a year postoperatively. Operative time, intraoperative bleeding, and the presence of postoperative complications were recorded. RESULTS: Compared with the ideal, the range of error for version was 7.3° (SD 3.6°) in the control group and 5.6° (SD 3.6°) in the navigated group (P = 0.278), and the range of error for inclination was 18.3° (SD 11.7°) in the control group and 4.9° (SD 3.8°) in the navigated group (P = 0.0004). The mean operative time was 164.6 (SD 21.2) min in the control group and 192.0 (SD 16.2) min in the navigated group (P = 0.001). The mean intraoperative bleeding was 201.0 (SD 37.0) mL in the control group and 185.3 (SD 35.6) mL in the navigated group (P = 0.300). There were no complications reported related to the intraoperative O-arm navigation. CONCLUSION: O-arm navigation may be a useful tool for the placement with inferior tilt of the glenoid procedure in reversed shoulder arthroplasty.

Accuracy of powered surgical instruments compared with manual instruments for pedicle screw insertion: Evaluation using o-arm-based navigation in scoliosis surgery.

BACKGROUND: Though powered surgical instruments for pedicle screw insertion combined with navigation have been developed to reduce time taken for spine surgery, clinical evidence demonstrating the safety and effectiveness of powered surgical instruments is limited. The goals of the present study were to compare the accuracy of powered instruments and manual instruments using O-arm-based navigation in surgery for scoliosis. METHODS: We retrospectively identified 60 consecutive patients with adolescent idiopathic scoliosis who underwent posterior corrective surgery using O-arm based navigation, collected from Jun 2013 to Feb 2015. Overall, 393 screws were tapped and inserted in 30 patients using manual instruments (group M) and 547 screws were tapped and inserted in 30 patients using powered instruments (group P). Postoperative computed tomography was used to assess screw accuracy using the established Neo classification (Grade 0, no perforation; Grade 1, perforation <2 mm, Grade 2: perforation ≥2 and <4 mm, Grade 3: perforation ≥4 mm). The time to position one screw, including registration, was calculated. RESULTS: In group M, 331 (84%) of the 393 pedicle screw placements were categorized as Grade 0, 49 (13%) were Grade 1, 13 (3.3%) were Grade 2, and 0 were Grade 3. In group P, 459 (84%) of the 547 pedicle screw placements were categorized as Grade 0, 75 (14%) were Grade 1, 13 (2.4%) were Grade 2, and 0 were Grade 3. We found no significant difference in the prevalence of Grade 2-3 perforations between groups. The time to insert one pedicle screw was 5.4 ± 1.4 min in group M, but significantly decreased to 3.4 ± 1.2 min in group P. CONCLUSIONS: Our results demonstrate that powered instruments using O-arm navigation insert pedicle screws as accurately as conventional manual instruments using O-arm navigation. The use of powered instruments requires less time in O-arm surgery for scoliosis.