Role of growth plate (apophyseal ring fracture) in causing modic type changes in pediatric low back pain patients.

PURPOSE: We investigated the prevalence of Modic changes (MCs) and associated pathologies in pediatric patients. METHODS: A total of 368 MRI obtained for 240 male and 128 female patients under the age of 18 years with complaints of low back/leg pain were retrospectively examined. All changes in signal intensity in the vertebral endplate and subchondral bone on MRI were defined as MCs. We investigated the relationship between MCs and underlying diseases, including lumbar spondylolysis/spondylolisthesis, and conditions of the growth plate in cases with MCs. The degree of disc degeneration in patients with MCs was evaluated using the Pfirrmann grading system. RESULTS: MCs were identified in six patients (1.6%). In five of the six patients, the signal intensity changes were localized to the anterosuperior endplate of the affected vertebra; the MCs were associated with anterior apophyseal ring fracture and an open growth plate in all these cases. Disc degeneration was classified as Pfirrmann grade I in three patients and grade II and III in one patient each. One patient had type I changes associated with grade IV disc degeneration and herniation and no sign of an open growth plate. CONCLUSION: The prevalence of MCs in pediatrics patients was much lower than the rates reported in adults. Most MCs were associated with an anterior apophyseal ring fracture. If Modic type changes are seen in immature vertebrae of pediatric patients, growth plate lesions such as apophyseal ring fractures should be considered. LEVEL OF EVIDENCE: Diagnostic: individual l cross-sectional studies with consistently applied reference standard and blinding.

Clinical indications for the use of computed tomography in children who underwent frequent computed tomography: a near-13-year follow-up retrospective study at a single institution in Japan.

Recent studies suggest a causal link of childhood leukemia and brain tumor with repeated computed tomography (CT) scans. The reasons why frequent CT scans are taken in a specific child remain unclear. The present study aimed to clarify the medical reasons why frequent CT examinations in children, and the characteristics of the diseases of those children that required multiple CT scans. A long-term follow-up retrospective study was conducted over a 12.75-year period at a single institution. Radiological reports were investigated that contained the indications for the CT scans. The clinical indications were classified for the examination of children under 16 years of age who underwent more than three CT scans into trauma, tumor, inflammation, and others. This study showed that 8.5% of CT examinations were done three times or more. The numbers of patients by indication were 23.3% for trauma, 5.3% for hydrocephalus, and 2.3% for appendicitis. The frequencies of trauma and inflammation decreased rapidly with an increasing number of CT scans. In particular, hydrocephalus brought high frequency more than ten scans. Regarding the frequencies of clinical indications by age groups, there was a significant difference (p<0.05). The near-13-year follow-up study indicated the main clinical indications for frequent CT scans in children were trauma and hydrocephalus. Multiple follow-up CT scans in children with hydrocephalus would be traded off against the resultant increase in brain tumor risk associated with CT exposure.

Transcription factor scleraxis vitally contributes to progenitor lineage direction in wound healing of adult tendon in mice.

Tendon is a dense connective tissue that transmits high mechanical forces from skeletal muscle to bone. The transcription factor scleraxis (Scx) is a highly specific marker of both precursor and mature tendon cells (tenocytes). Mice lacking scx exhibit a specific and virtually complete loss of tendons during development. However, the functional contribution of Scx to wound healing in adult tendon has not yet been fully characterized. Here, using ScxGFP-tracking and loss-of-function systems, we show in an adult mouse model of Achilles tendon injury that paratenon cells, representing a stem cell antigen-1 (Sca-1)-positive and Scx-negative progenitor subpopulation, display Scx induction, migrate to the wound site, and produce extracellular matrix (ECM) to bridge the defect, whereas resident tenocytes exhibit a delayed response. Scx induction in the progenitors is initiated by transforming growth factor ß (TGF-ß) signaling. scx-deficient mice had migration of Sca-1-positive progenitor cell to the lesion site but impaired ECM assembly to bridge the defect. Mechanistically, scx-null progenitors displayed higher chondrogenic potential with up-regulation of SRY-box 9 (Sox9) coactivator PPAR-γ coactivator-1α (PGC-1α) in vitro, and knock-in analysis revealed that forced expression of full-length scx significantly inhibited Sox9 expression. Accordingly, scx-null wounds formed cartilage-like tissues that developed ectopic ossification. Our findings indicate a critical role of Scx in a progenitor-cell lineage in wound healing of adult mouse tendon. These progenitor cells could represent targets in strategies to facilitate tendon repair. We propose that this lineage-regulatory mechanism in tissue progenitors could apply to a broader set of tissues or biological systems in the body.

The scab-like sign: A CT finding indicative of haemoptysis in patients with chronic pulmonary aspergillosis?

OBJECTIVES: The aim of this study was to assess the CT findings that characterise haemoptysis in patients with chronic pulmonary aspergillosis (CPA). METHODS: We retrospectively identified 120 consecutive patients with CPA (84 men and 36 women, 17-89 years of age, mean age 68.4 years) who had undergone a total of 829 CT examinations between January 2007 and February 2017. In the 11 patients who underwent surgical resection, CT images were compared with the pathological results. RESULTS: The scab-like sign was seen on 142 of the 829 CT scans, specifically, in 87 of the 90 CT scans for haemoptysis and in 55 of the 739 CT scans obtained during therapy evaluation. In 48 of those 55 patients, haemoptysis occurred within 55 days (mean 12.0 days) after the CT scan. In the 687 CT scans with no scab-like sign, there were only three instances of subsequent haemoptysis in the respective patients over the following 6 months. Patients with and without scab-like sign differed significantly in the frequency of haemoptysis occurring after a CT scan (p<0.0001). Pathologically, the scab-like sign corresponded to a fibrinopurulent mass or blood crust. CONCLUSIONS: The scab-like sign should be considered as a CT finding indicative of haemoptysis. KEY POINTS: • Haemoptysis is commonly found in patients with CPA. • A CT finding indicative of haemoptysis in CPA patients is described. • Scab-like sign may identify CPA patients at higher risk of haemoptysis.

The correlation between clinical radiological outcome and contact state of implant and femur using three-dimensional templating software in cementless total hip arthroplasty.

BACKGROUND: Initial fixation is a key factor in the success of cementless THA using a tapered wedge stem. The purpose of this study was to use three-dimensional templating software to examine the correlation between quantitative contact state and important clinical radiological outcomes, specifically stem subsidence, stress shielding, and cortical hypertrophy. METHODS: We conducted a retrospective consecutive review of 75 hips in 70 patients over a minimum 3-year follow-up period. X-rays and CT scans were investigated to assess preoperative planning, quantify the contact state of implant and femur, and assess stem alignment, stem subsidence, stress shielding, and cortical hypertrophy. We evaluated the correlation between radiological outcomes and three-dimensional quantitative contact state according to Gruen Zone in each Dorr classification. RESULTS: Density mapping indicated that stem subsidence increased postoperatively if the stem had less cortical contact in the middle to distal portion of the implant in terms of initial fixation. Cases having too much cortical contact in the distal portion of the implant tended to have increased stress shielding. We found no correlation between cortical hypertrophy and the contact state of implant and femur. CONCLUSIONS: Density mapping with three-dimensional templating software can be useful in predicting stem subsidence and stress shielding following cementless THA with a tapered wedge stem. Further analysis is required to accurately depict the correlation between cortical hypertrophy and the contact state.

The paracrine effect of adipose-derived stem cells inhibits osteoarthritis progression.

BACKGROUND: This study aimed to determine whether intra-articularly injected adipose-derived stem cells (ADSCs) inhibited articular cartilage degeneration during osteoarthritis (OA) development in a rabbit anterior cruciate ligament transection (ACLT) model. The paracrine effects of ADSCs on chondrocytes were investigated using a co-culture system. METHODS: ACLT was performed on both knee joints of 12 rabbits. ADSCs were isolated from the subcutaneous adipose tissue. ADSCs with hyaluronic acid were intra-articularly injected into the left knee, and hyaluronic acid was injected into the right knee. The knees were compared macroscopically, histologically, and immunohistochemically at 8 and 12 weeks. In addition, cell viability was determined using co-culture system of ADSCs and chondrocytes. RESULTS: Macroscopically, osteoarthritis progression was milder in the ADSC-treated knees than in the control knees 8 weeks after ACLT. Histologically, control knees showed obvious erosions in both the medial and lateral condyles at 8 weeks, while cartilage was predominantly retained in the ADSC-treated knees. At 12 weeks, the ADSC-treated knees showed a slight suppression of cartilage degeneration, unlike the control knees. Immunohistochemically, MMP-13 expression was less in the ADSC-treated cartilage than in the control knees. The cell viability of chondrocytes co-cultured with ADSCs was higher than that of chondrocytes cultured alone. TNF-alpha-induced apoptotic stimulation was similar between the two groups. CONCLUSIONS: Intra-articularly injected ADSCs inhibited cartilage degeneration progression by homing to the synovium and secreting a liquid factor having chondro-protective effects such as chondrocyte proliferation and cartilage matrix protection.

Value of computed tomography-based three-dimensional surgical preoperative planning software in total hip arthroplasty with developmental dysplasia of the hip.

INTRODUCTION: Preoperative planning with computed tomography (CT)-based three-dimensional templating has been expanded to achieve more precise placement of hip components. However, few reports have addressed the utility of three-dimensional surgical planning software for secondary osteoarthritis cases. This study therefore investigated the value of CT-based three-dimensional templating software for preoperative planning in primary total hip arthroplasty (THA), with an emphasis on developmental dysplasia of the hip. MATERIALS AND METHODS: We performed a retrospective review of 65 hips in 57 patients who underwent cementless primary THA. The preoperative diagnosis was secondary osteoarthritis in all cases due to developmental dysplasia of the hip. All preoperative planning and postoperative evaluations were completed using CT-based three-dimensional templating software. We analyzed the accuracy of stem size prediction and cup size prediction, the reproducibility of preoperative and postoperative stem anteversion, and the absolute error in preoperative and postoperative stem anteversion using CT-based three-dimensional templating software. RESULTS: The sizes of 65 % of the femoral stems (42/65) were estimated exactly, and 98 % (63/65) were accurately estimated to within one stem size. The final acetabular cup sizes corresponded exactly to the preoperatively planned size in 92 % of all cases (62/65). 100 % of the cup size estimates were accurate to within one cup size. There was strong reproducibility of preoperative and postoperative stem anteversion (r = 0.88, P < 0.05). The absolute error in stem anteversion was 4.0° ± 3.6°. CONCLUSIONS: Using CT-based three-dimensional templating software made it possible to achieve reproducible stem anteversion and choose accurate stem and cup sizes in patients with developmental dysplasia of the hip.

The value of bulk femoral head allograft in acetabular reconstruction using Kerboull-type plate.

PURPOSE: This study investigated the mid- and long-term results of acetabular reconstruction using a KT plate with an allograft and showed the utility of filling the bony defect with bulk femoral head allograft rather than morselised allograft. METHODS: We retrospectively investigated a consecutive series of 31 hips in 30 patients who underwent primary THA or revision THA between March 2002 and March 2012. Bulk grafts from femoral head allografts were used in 16 hips and morselised grafts were used in 15 hips. The mean follow-up period was 7.2 years (3-13 years). The acetabular bone defects were classified according to the American Academy of Orthopedic Surgeons grading system. Type II defects were present in five hips; 26 hips were type III. RESULTS: Radiological failure, defined as absolute error of the inclination of the KT plate >3°, breakage of the KT plate or screw, and/or absolute error of the vertical or horizontal migration of the femoral head >3 mm was found in 12 cases. All these complications appeared in the morselized group; there were no complications in the bulk group. The eight-year survival rate of morselised grafts was 52.5% and that of bulk grafts was 100%, using radiological loosening as an end point. CONCLUSIONS: We conclude that using bulk graft from femoral head allografts is necessary to achieve mechanically stable reconstruction for large acetabular bone defects.

Usefullness of three-dimensional templating software to quantify the contact state between implant and femur in total hip arthroplasty.

BACKGROUND: It would be ideal if surgeons could precisely confirm whether the planned femoral component achieves the best fit and fill of implant and femur. However, the cortico-cancellous interfaces can be difficult to standardize using plain radiography, and therefore, determining the contact state is a subjective decision by the examiner. Few reports have described the use of CT-based three-dimensional templating software to quantify the contact state of stem and femur in detail. The purpose of this study was to use three-dimensional templating software to quantify the implant-femur contact state and develop a technique to analyze the initial fixation pattern of a cementless femoral stem. METHODS: We conducted a retrospective review of 55 hips in 53 patients using a short proximal fit-and-fill anatomical stem (APS Natural-Hip™ System). All femurs were examined by density mapping which can visualize and digitize the contact state. We evaluated the contact state of implant and femur by using density mapping. RESULTS: The varus group (cases that had changed varus 2° by 3 months after surgery) consisted of 11 hips. The varus group showed no significant difference with regard to cortical contact in the proximal medial portion (Gruen 7), but the contact area in the distal portion (Gruen 3 and Gruen 5) was significantly lower than that of non-varus group. Density mapping showed that the stem only has to be press-fit to the medial calcar, but also must fill the distal portion of the implant in order to achieve the ideal contact state. CONCLUSIONS: Our results indicated that quantifying the contact state of implant and femur by using density mapping is a useful technique to accurately analyze the fixation pattern of a cementless femoral stem.

Neuronal projections and putative interaction of multimodal inputs in the subesophageal ganglion in the blowfly, Phormia regina.

In flies, the maxillary palp possesses olfactory sensilla housing olfactory receptor neurons (ORNs), which project to the primary olfactory center, the antennal lobes (ALs). The labellum possesses gustatory sensilla housing gustatory receptor neurons (GRNs), which project to the primary gustatory center, the subesophageal ganglion (SOG). Using an anterograde staining method, we investigated the axonal projections of sensory receptor neurons from the maxillary palp and labellum to the SOG or other parts of brain in the blowfly, Phormia regina. We show that maxillary mechanoreceptor neurons and some maxillary ORNs project to the SOG where they establish synapses, whereas other maxillary ORNs terminate in the ipsi- and contralateral ALs. The labellar GRNs project to the SOG, and some of these neural projections partially overlap with ORN terminals from the maxillary palp. Based on these anterograde staining data and 3D models of the observed axonal projections, we suggest that interactions occur between GRNs from the labellum and ORNs from the maxillary palp. These observations strongly suggest that olfactory information from the maxillary palp directly interacts with the processing of gustatory information within the SOG of flies.

Three-dimensional kinetic simulation before and after rotational acetabular osteotomy.

BACKGROUND: Some reports indicate that one of major causes of clinical failure after periacetabular osteotomy is development of secondary femoroacetabular impingement (FAI). To assess the impact of range of motion (ROM) on the increase in FAI following rotational acetabular osteotomy (RAO), we performed FAI simulations before and after RAO. METHODS: We evaluated 12 hips that had undergone RAO (study group), and 12 normal hips (control group). The study group was evaluated before and after surgery. Morphological parameters were evaluated to assess acetabular coverage. The acetabular anteversion angle, anterior CE angle, alpha angle, and combined anteversion angle were also measured. Impingement simulations were performed using 3D-CT. The ROM which causes bone-to-bone impingement was evaluated in flexion (flex), abduction, external rotation at 0° flexion, and internal rotation at 90° flexion. The lesions caused by impingement were evaluated. RESULTS: Radiographic measurements indicated improved postoperative acetabular coverage in the study group. The crossover sign was recognized pre- and postoperatively in every case in the study group and in no cases in the control group. In the simulation study, flexion, abduction, and internal rotation at 90° flexion decreased postoperatively. Impingement occurred within 45° internal rotation at 90° flexion in two preoperative and nine postoperative cases. The impingement lesions were anterosuperior of the acetabulum in all cases. There were correlations between anterior CE angle, CE angle, acetabular anteversion angle, and hip flexion angle. There were also correlations between the anterior CE angle, combined anteversion angle, and angle of internal rotation at 90° flexion. CONCLUSIONS: In the postoperative simulation, there was a tendency to reduce the ROM in flexion, abduction, and internal rotation at 90° flexion due to impingement. Since there were more cases which caused impingement within 45° internal rotation at 90° flexion after RAO, we consider there is a potential for increased FAI after RAO.

The value of computed tomography based navigation in revision total hip arthroplasty.

PURPOSE: This study investigates the accuracy of a computed tomography (CT)-based navigation system for accurate acetabular component placement during revision total hip arthroplasty (THA). METHODS: We performed a retrospective review of 30 hips in 26 patients who underwent cementless revision THA using a CT-based navigation system; the control group consisted of 25 hips in 25 patients who underwent cementless primary THA using the same system. We analysed the deviation of anteversion and inclination angles among the pre-operative plan, intra-operative records from the navigation system and data from postoperative CT scans. RESULTS: There were no significant differences between groups (P < 0.05) in terms of mean deviation between pre-operative planning and postoperative measurements or between intraoperative records and postoperative measurements. CONCLUSION: CT-based navigation in revision THA is a useful tool that enables the surgeon to implant the acetabular component at the precise angle determined in pre-operative planning.

Do we need intraoperative radiographs for positioning the femoral component in total hip arthroplasty?

INTRODUCTION: Poor long-term results of total hip arthroplasty (THA) can result from femoral component misalignment. There are few reports that discuss the effectiveness of intraoperative radiographs for placing femoral components. This study is a retrospective review to find out the usefulness of intraoperative radiographs in detecting and improving the femoral component misalignment in posterior-approached primary THA. MATERIALS AND METHODS: The study group included 150 primary THAs performed between September 2009 and April 2012. After the trial component insertion in lateral decubitus position, intraoperative radiography was performed. The surgeon assessed the femoral component position in three aspects: alignment, leg length, and offset. If it is not following the preoperative template, the surgeon makes the intraoperative adjustments to change the femoral component position. After the operation, postoperative radiograph was taken; the same parameters were measured and were compared to intraoperative findings. The changes in each parameter were classified into three categories: satisfactory, no change, and unsatisfactory. Among the three parameters, if one is satisfactory and the others are not unsatisfactory, we defined it as accurate positioning of the femoral component. RESULTS: Intraoperative adjustments were made in 122 cases (81.3 %). The adjustments included changes in the component size (35.3 %), component alignment (38.6 %), femoral offset (14.0 %), and additional femoral neck cuts (56.0 %). As a result, accurate positioning was successfully achieved in 112 cases (91.8 %) by taking intraoperative radiographs. CONCLUSION: Our data suggest that intraoperative radiography is a useful method for detecting the errors of placing the femoral components, and the success of a surgeon to correct those errors after detecting them intraoperatively.

Transforaminal Full-Endoscopic Ventral Facetectomy: Midterm Results and Factors Associated with Poor Surgical Outcomes.

BACKGROUND: Full-endoscopic spine surgery (FESS) is a well-established procedure for herniated nucleus pulposus. It is a minimally invasive surgery that can be performed under local anesthesia through only an 8-mm skin incision. With improvements in surgical equipment such as high-speed drills, the indications for FESS have expanded to include lumbar spinal stenosis (LSS). We perform a transforaminal full-endoscopic ventral facetectomy (TF-FEVF) for unilateral nerve root-type lateral recess stenosis (LRS) using a transforaminal approach under local anesthesia.The aim of this study was to examine the postoperative results of TF-FEVF for LRS and to identify factors associated with poor surgical outcomes. 85 patients who underwent TF-FEVF for LRS under local anesthesia. Clinical outcomes were determined by visual analog scale (VAS) and the modified MacNab criteria. Evaluation was performed using magnetic resonance imaging (MRI), computed tomography (CT), and flexion-extension radiographs. METHODS: This study involved 85 patients (47 males and 38 females) who underwent TF-FEVF for LRS. The mean age was 70.5 years and the mean follow-up duration was 14.8 months. Data were collected on sex, age, level of operation, diagnosis, history of spine surgery at the same level, and duration of follow-up. The diagnosis was categorized as LSS with or without disk bulging. Clinical evaluation was performed using the VAS and modified MacNab criteria. MRI was used to evaluate the degree of disk degeneration, vertebral endplate degeneration, disk height, thickening of the ligamentum flavum, and stenosis. Bony stenosis was evaluated using CT. Sagittal translation and sagittal angulation were also measured by flexion-extension radiographs, and the Cobb angle was measured using a standing front view radiograph. All variables were compared between patients with excellent/good outcomes (E/G group) and those with fair/poor outcomes (F/P group) using the modified MacNab criteria. RESULTS: Postoperative VAS showed that leg pain decreased from 59.0 ± 28.6 preoperatively to 17.9 ± 27.2 at the final follow-up (p < 0.01) and that lower back pain also decreased from 60.7 ± 26.6 preoperatively to 27.3 ± 28.6 at final follow-up (p < 0.01). According to the modified MacNab criteria, the results during the final follow-up were excellent in 39 cases, good in 21 cases, fair in 13 cases, and poor in 12 cases. There were no significant differences in sex, age, diagnosis, history of spine surgery, and duration of follow-up periods between the 60 cases (70.6%) in the E/G group and the 25 cases (29.4%) in the F/P group. Imaging evaluation revealed statistically significant differences between the E/G group and the F/P group in intervertebral angle flexion (3.2 vs. 0.4 degrees; p < 0.05), sagittal angulation (4.3 vs. 8.1 degrees; p < 0.05), slip in flexion (0.9 vs. 2.8 mm; p < 0.05), sagittal translation (0.7 vs. 1.6 mm; p < 0.05), and Cobb angle (-0.5 vs. -1.9 degrees; p < 0.05). CONCLUSION: Midterm results of TF-FEVF were generally favorable; factors contributing to good or poor TF-FEVF outcomes were large sagittal angulation, large sagittal translation, and concave side.

Full-endoscopic spine surgery in oldest old patients aged over 90 years:A case report.

BACKGROUND: Transforaminal full-endoscopic spine surgery (FESS) is the least invasive spinal surgery and can be performed under local anesthesia. In Japan, the population is rapidly aging and the number of spinal surgeries performed in the elderly is also increasing. OBJECT: In this report, we describe 3 patients aged 90 years or older in whom we performed FESS under local anesthesia. CASE: The first case was a 90-year-old man who presented with severe leg pain. He had multiple medical comorbidities and was unsuitable for general anesthesia. We performed FESS. After surgery, the leg pain resolved with full recovery of muscle strength. He was discharged with no perioperative complications. The second case was a 90-year-old man who presented with severe leg pain. MRI showed a herniated nucleus pulposus and foraminal stenosis at L4/5. We performed FESS. The leg pain improved immediately after surgery. The third case was a 91-year-old woman in whom we diagnosed left L5 radiculopathy due to foraminal stenosis at L5/S1. After surgery, her leg pain was relieved. CONCLUSION: FESS is a good surgical procedure for elderly patients who are in a poor general condition because it is minimally invasive and can be performed under local anesthesia with early mobilization. J. Med. Invest. 71 : 169-173, February, 2024.

Comparison of Percutaneous Endoscopic Transforaminal Discectomy, Chemonucleolysis, Microdiscectomy, and Microendoscopic Discectomy for Symptomatic Lumbar Disc Herniation: One-year Follow-up Clinical Results and Disc Degeneration.

This study compared the 1-year clinical outcomes and disc degeneration rates after transforaminal full-endoscopic lumbar discectomy (TF-FED), condoliase injection, open discectomy (OD), and microendoscopic discectomy (MED) for lumbar disc herniation (LDH). In total, 279 patients with LDH were divided into four treatment groups: TF-FED, OD, MED, and condoliase injection. Outcomes were evaluated on the basis of the complication rate, Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ), visual analog scale (VAS) scores, and the modified MacNab criteria. Surgical and hospital costs were assessed. Disc degeneration and endplate bone marrow edema were evaluated using magnetic resonance images. The mean postoperative JOABPEQ, VAS, or modified MacNab scores among the four groups had no significant differences. Additionally, the nerve injury or reoperation rate among the TF-FED, OD, and MED groups had no significant difference. However, the reoperation rate with condoliase injection was high because of residual disc herniation. Surgical and hospital costs were lower with condoliase injection and higher with OD and MED than those with TF-FED. With TF-FED and condoliase injection, the Pfirrmann grade progressed, and the disc height was significantly smaller than that with OD and MED. Endplate bone marrow edema was more common with condoliase injection and TF-FED. All groups had good outcomes. TF-FED and condoliase injection may reduce the burden of surgery because they can be performed under local anesthesia with little blood loss and low medical costs but tend to be associated with disc degeneration and endplate bone marrow edema. A randomized controlled study with a larger sample is needed.

Strict component positioning is necessary in hip resurfacing.

BACKGROUND: Hip resurfacing arthroplasty has some advantages, including improved metal-on-metal articulation, a lower dislocation rate and preserved femoral bone. This procedure is a surgical option for younger and more active patients with osteoarthritis and osteonecrosis of the femoral head. Although there have been some reports about the efficacy of this technique, others report serious complications caused by metal debris. Additionally, femoral neck preservation adversely decreases the head-neck ratio and results in postoperative impingement. METHODS: We evaluated the range of motion after hip resurfacing with various component orientations and optimal component orientations to avoid postoperative impingement using computer simulations in 10 male patients with osteonecrosis. RESULTS: The mean ranges of motion in flexion, extension, abduction, adduction and internal rotation at 90° of flexion were 92.4° ± 13.8°, 25.7° ± 13.8°, 38.0° ± 11.1°, 29.1° ± 10.0° and 20.9° ± 11.5°, respectively. The oscillation angle in flexion and extension motion was 118.1° ± 10.3°. More than 100° of flexion was acquired in 79 of 240 simulations (32.9 %), and more than 20° extension was acquired in 142 simulations (59.2 %). Combined anteversion was significantly correlated with maximal flexion and extension angles. The component safe zone to fulfill the range of motion criteria varied among patients, and 4 of 10 patients had no safe zone. CONCLUSIONS: Postoperative impingement occurs relatively frequently in hip resurfacing because of preservation of the femoral neck and component malpositioning. The safe zone of the acetabular component to avoid postoperative impingement is very narrow. Greater care should be taken regarding patient selection, rigorous preoperative planning and accurate component positioning.

[Establishment of "Anaphylaxis Scoring Aichi (ASCA)," a new symptom scoring system to be used in an oral food challenge (OFC)].

BACKGROUND: An original symptom score sheet named "Anaphylaxis Scoring Aichi (ASCA)" was created to quantitatively determine the severity of allergic symptoms provoked in an oral food challenge. METHODS: ASCA lists and sorts subjective and objective symptoms into five organs (respiratory, skin-mucosal, gastrointestinal, psycho-neurological and cardiovascular). The organ scores were given (0 to 60 points) in accordance with the severity of each symptom. The total score was defined as the sum of the highest 5 organ scores (maximum 240 points) observed throughout the course of an OFC. This study evaluated the ASCA score in 253 cases of a positive food challenge (age 1-16 years, mean 5.3±3.2 years) conducted from April to August 2011 in our institute. The results were compared to the modified anaphylaxis grading presented in the Japanese Pediatric Guideline for Oral Food Challenge Test in Food Allergy 2009. At the same time, we evaluated the indications of symptomatic treatment using ASCA score. RESULTS: The total score closely correlated with the anaphylaxis grading, but there was a wide range of overlap between grade 2 and grade 3. All cases with a total score≥60 points were equivalent to grade 4 or 5, and that were consisted of three or more organ symptoms. These severe cases contained respiratory or skin/mucosal symptoms, and despite the early induction of initial therapy, the symptoms became worse. CONCLUSION: ASCA is therefore considered to be a useful tool for use in an oral food challenge test.

Contralateral lower limb radiculopathy by extraforaminal disc herniation following oblique lumbar interbody fusion in degenerative lumbar disorder: illustrative cases.

BACKGROUND: Contralateral lower limb radiculopathy is a potential early complication of oblique lumbar interbody fusion (OLIF) in degenerative lumbar disorders. Among several pathologies related to contralateral radiculopathy following OLIF, extraforaminal disc herniation during the OLIF procedure is very rare. OBSERVATIONS: Case 1 is a 68-year-old male underwent L4-5 and L5-6 OLIF for recurrent lumbar canal stenosis-expressed right leg pain and muscle weakness after surgery. Case 2 is a 76-year-old female on whom L4-5 OLIF was performed for L4 degenerative spondylolisthesis and who presented right leg pain and numbness postoperatively. In both patients, OLIF cages were inserted into the posterior part of the disc space or obliquely and the extraforaminal extruded disc compressed opposite exiting nerve roots (L5 root in case 1 and L4 root in case 2) as shown on magnetic resonance imaging (MRI). Surgical decompression with discectomy was required for pain relief and neurological improvement in both cases. LESSONS: When emerging from new-onset opposite limb radiculopathy attributed to the OLIF procedure, extraforaminal disc herniation should be considered a potential pathology and MRI is useful for early diagnosis and selecting a subsequent management, including surgery.