Hyaluronic Acid and Platelet-Rich Plasma Injections in Foot and Ankle Disorders / 대한족부족관절학회지

Numerous nonoperative treatments have been used to reduce pain and improve the clinical outcomes of patients with foot and ankle disorders. Among these treatments, hyaluronic acid and platelet-rich plasma (PRP) injections have been used increasingly. This review analyzes the recent literature reporting the efficacy and indications for hyaluronic acid and PRP injections. Hyaluronic acid and PRP can be used safely as adjuncts. Hyaluronic acid injections have shown efficacy and have a promising role as an adjuvant treatment method.In addition, its indication has expanded to various foot and ankle diseases over osteoarthritis. On the other hand, the efficacy of PRP injection has not yet been clarified, and the lack of standardization of procedures for the preparation and administration of PRP makes it difficult to establish definitive treatment indications.

Predictors of Vertebral Endplate Fractures after Oblique Lumbar Interbody Fusion

Background@#Cage subsidence after oblique lumbar interbody fusion (OLIF) induces restenosis and adversely affects patient outcomes. Many studies have investigated the causes of subsidence, one of which is endplate fracture (EF). This study aimed to identify predictors of EF after OLIF. @*Methods@#This retrospective study reviewed consecutive patients who underwent OLIF at a single institute between August 2019 and February 2022. A total of 104 patients were enrolled. The patients’ demographic data and surgical details were collected through chart reviews. Radiographic variables were measured. Related variables were also analyzed using binomial logistic regression, dividing each group into those with versus without EF. @*Results@#EF occurred at 30 of 164 levels (18.3%), and the binary logistic analysis revealed that sex (odds ratio [OR], 11.07), inferior endplate concave depth (OR, 1.95), disc wedge angle (OR, 1.22), lumbar lordosis (OR, 1.09), pelvic incidence (OR, 1.07), sagittal vertical axis (OR, 1.02), sacral slope (OR, 0.9), L3–4 level (OR, 0.005), and L4–5 level (OR, 0.004) were significantly related to EF. @*Conclusions@#OLIF in older Asian patients should be performed carefully after recognizing the high possibility of EF and confirming the factors that should be considered preoperatively.

Current Management of Talar Fractures

Talar fracture management is one of the most challenging tasks for orthopedic surgeons. High complication rates and functional impairments after talar fractures have been well documented, and thus, surgical strategies capable of perfect anatomic reduction and stable fixation are important. The current review was undertaken to provide recommendations regarding updated surgical strategies that include surgical timing, approach, fixation methods, and the prevention and treatment of possible complications.

Comparison of the Size of the Posterior Malleolar Fragment in Trimalleolar Ankle Fractures Measured Using Lateral Plain Radiography and Three-Dimensional Computed Tomography

Purpose@#This study aimed to evaluate and compare the accuracy of the size of the posterior malleolar fragment measured using lateral plain radiography and three-dimensional computed tomography (3DCT) in patients with ankle trimalleolar fractures. @*Materials and Methods@#This study enrolled 80 patients (80 ankles) with ankle trimalleolar fractures and analyzed the size of the posterior malleolar fragments using plain radiography and 3D-CT. The articular involvement of the posterior malleolar fragments was measured as a percentage of the articular surface in the sagittal length of the tibial plafond using lateral plain radiography, and the articular surface area was directly measured using 3D-CT. In addition, we classified the patients into three groups based on the morphology of the posterior malleolar fracture, according to the Haraguchi classification method, and evaluated and compared the accuracy of the size of the posterior malleolar fragments. @*Results@#The mean articular involvement of the posterior malleolar fragments on plain radiography was 27.6% (range, 6.0%-53.1%), which was significantly higher than the mean of 21.9% (range, 4.7%-47.1%) measured using 3D-CT (p=0.004). In the analysis, according to the fracture morphology, the mean difference between the two methods was the largest for type I fractures at 9.1% (range, 1.8%-19.5%) and the smallest for type II fractures at 1.1% (range, –7.7% to 8.8%). @*Conclusion@#The articular involvement of posterior malleolar fragments measured using plain radiography showed low accuracy and significantly higher values than the actual articular involvement. Therefore, careful evaluation using 3D-CT is crucial for accurate analysis and optimal treatment in patients with ankle trimalleolar fractures.

Isolation and Characterization of Extracellular Vesicle from Mesenchymal Stem Cells of the Epidural Fat of the Spine

Methods@#In this study, we isolated the exosomes using the tangential flow filtration (TFF) system with exosome-depleted fetal bovine serum and performed the characterization tests via western blotting, reverse transcription–polymerase chain reaction, nanoparticle tracking analysis (NTA), and transmission electron microscopy. @*Results@#In transmission electron microscopy, the exosome had a diameter of approximately 100–200 nm and had a spherical shape, whereas in the NTA, the exosome had an average diameter of 142.8 nm with a concentration of 1.27×1010 particles/mL. The flow cytometry analysis showed the expression of CD63 and CD81. The western blotting analysis showed the positive markers. @*Conclusions@#These findings showed that isolating the exosomes via TFF resulted in high-quality EF-MSC exosome yield. Further studies with exosomes from EF-MSC are needed to evaluate the function and role of the EF tissue.

The impact of novel COVID-19 initial pandemic on orthopedic healthcare: an experience from a single institution of South Korea

Background@#This study was to investigate the cancellation rate and trend of orthopedic surgeries during the novel coronavirus disease 2019 (COVID-19) pandemic. Moreover, we assessed the psychologic status of orthopedic healthcare workers, and investigated the details of the preventive surgeries underwent in COVID-19-positive patients. @*Methods@#For 3 months after January 20, 2020, cancellation rates of elective surgeries were investigated, and the number of elective surgeries conducted in the same period over the last two years was compared. Four different questionnaires were used to investigate psychologic status among the orthopedic health care workers. We compared the outcomes according to occupation (physician or nurse), and type of work (faculty staff or resident physician). Outcomes according to occupation and type of work were compared. Preventive surgeries underwent in patients who could not wait for the results of the COVID-19 diagnosis were investigated. @*Results@#Spine and hip surgery had relatively lower cancellation rates, and elective surgeries were significantly reduced. During the initial pandemic, the cancellation rate of orthopedic elective surgeries was significantly higher than in the same period of the previous year and was different for each subdivision depending on the degree of pain or disability. The psychological outcomes were within the normal range and there were no significant differences between groups. After preventive surgery, all medical staff involved in the operation tested negative. @*Conclusion@#During the COVID-19 pandemic, the cancellation rate of orthopedic elective surgeries was significantly higher than in the same period of the previous year. Orthopedic health care workers did not seem to have significant psychological distress. As a result of the preventive surgery in specialized facilities, all the medical staff who participated in the operation tested negative.

Comparing Outcomes of Screw Fixation and Non-Fixation for Small-Sized Posterior Malleolar Fragment in Ankle Trimalleolar Fractures

Purpose@#This study was undertaken to compare outcomes of screw fixation and non-fixation of a small-sized posterior malleolar fragment involving less than 25% articular surface in ankle trimalleolar fractures. @*Materials and Methods@#A total of 32 consecutive ankles (32 patients), with posterior malleolar fragment involving 15%-25% of the joint surface, were enrolled in the study. Patients were divided into 2 groups according to whether the fragment was fixed or not (fixed: 20 ankles, non-fixed: 12 ankles).The minimum follow-up period was 12 months. Median size of the posterior malleolar fragment in the fixed and non-fixed groups were 24.6% (range, 22.3%-25.0%) and 22.1% (range, 17.4%-24.3%), respectively. Complications as well as clinical and radiographic outcomes were compared and analyzed between the two groups. @*Results@#Clinical outcomes, including American Orthopaedic Foot & Ankle Society (p=0.501), visual analogue scale (p=0.578), and ankle range of motion (p=0.552), showed no difference between groups at the final follow-up. No differences were obtained in the radiographic outcomes, including joint stepoff (p=0.289) and fragment gap (p=0.289). Complications, including 1 case of delayed union and 1 case of wound infection, were reported in the fixed group. @*Conclusion@#Clinical outcomes and radiographic outcomes of the non-fixation group were satisfactory and comparable to the fixation group. Our results indicate that anatomical reduction with small-sized posterior malleolar fragment in ankle trimalleolar fractures is sufficient for satisfactory outcomes, without the need for additional internal fixation.

Diagnostic Modality in Spine Disease: A Review

Spine diseases are common and exhibit several causes, including degeneration, trauma, congenital issues, and other specific factors. Most people experience a variety of symptoms of spine diseases during their lifetime that are occasionally managed with conservative or surgical treatments. Accurate diagnosis of the spine pathology is essential for the appropriate management of spine disease, and various imaging modalities can be used for the diagnosis, including radiography, computed tomography (CT), magnetic resonance imaging (MRI), and other studies such as EOS, bone scan, single photon emission CT/CT, and electrophysiologic test. Patient (or case)-specific selection of the diagnostic modality is crucial; thus, we should be aware of basic information and approaches of the diagnostic modalities. In this review, we discuss in detail, about diagnostic modalities (radiography, CT, MRI, electrophysiologic study, and others) that are widely used for spine disease.

Mesenchymal Stem Cells Decrease Oxidative Stress in the Bowels of Interleukin-10 Knockout Mice

Background/Aims@#Inflammatory bowel disease (IBD) is an autoimmune disease characterized by chronic inflammation mainly in the large intestine. The interleukin-10 knockout (IL-10 KO) mouse is a well-known animal model of IBD that develops spontaneous intestinal inflammation resembling Crohn’s disease. Oxidative stress is considered to be the leading cause of cell and tissue damage. Reactive oxygen species (ROS) can cause direct cell injury and/or indirect cell injury by inducing the secretion of cytokines from damaged cells. This study evaluated the effects of mesenchymal stem cell (MSC) on the progression of IBD. @*Methods@#In this study, human bone marrow-derived MSCs were injected into IL-10 KO mice (MSC). Oxidative stress and inflammation levels were evaluated in the large intestine and compared with those in control IL-10 KO mice (CON) and normal wild-type control mice (Wild). @*Results@#The levels of ROS (superoxide and hydrogen peroxidase) and a secondary end-product of lipid peroxidation (malondialdehyde) were considerably higher in the CON, while superoxide dismutase and catalase levels were lower in the MSC. Inflammation-related marker (interferon-γ, tumor necrosis factor-α, IL-4, and CD8) expression and inflammatory histological changes were much less pronounced in MSC than in CON. @*Conclusions@#MSCs affect the redox balance, leading to the suppression of IBD.

Diagnostic Modality in Spine Disease: A Review

Spine diseases are common and exhibit several causes, including degeneration, trauma, congenital issues, and other specific factors. Most people experience a variety of symptoms of spine diseases during their lifetime that are occasionally managed with conservative or surgical treatments. Accurate diagnosis of the spine pathology is essential for the appropriate management of spine disease, and various imaging modalities can be used for the diagnosis, including radiography, computed tomography (CT), magnetic resonance imaging (MRI), and other studies such as EOS, bone scan, single photon emission CT/CT, and electrophysiologic test. Patient (or case)-specific selection of the diagnostic modality is crucial; thus, we should be aware of basic information and approaches of the diagnostic modalities. In this review, we discuss in detail, about diagnostic modalities (radiography, CT, MRI, electrophysiologic study, and others) that are widely used for spine disease.

When is the Optimal Time Point for Predicting the 1-Year Follow-up Outcome of Selective Nerve Root Block for Cervical Radiculopathy?

OBJECTIVES@#In the current study, we aimed to (1) evaluate the early and late therapeutic effects of selective nerve root block (SNRB) for cervical radiculopathy, and (2) to determine the optimal time point for predicting the long-term effectiveness of cervical SNRB.SUMMARY OF LITERATURE REVIEW: Although SNRB is an important option for cervical radiculopathy, various studies of cervical SNRB have failed to specify its efficacy, especially long-term effectiveness.@*MATERIALS AND METHODS@#We retrospectively enrolled 35 patients with cervical radiculopathy who were regularly followed-up for at least 1 year after SNRB. Clinical outcomes were evaluated using a visual analogue scale (VAS) for pain intensity and the modified Kim's method for patient satisfaction at regular follow-up intervals. In the correlation analysis, stepwise multiple linear regression was used to identify selected and unselected factors.@*RESULTS@#The average VAS score decreased over time (p<0.05); the values just before the injection and at 1 week, 3 weeks, and 1 year of follow-up were 6.11, 3.29, 2.89, and 1.37, respectively. In the stepwise multiple regression analysis, the 1-week VAS score was related to the initial VAS score, the 3-week VAS score was related to the 1-week VAS score, and the last VAS score was related to the 3-week VAS score and symptom duration before the injection. The degree of satisfaction at the 1-year follow-up point was significantly associated with the 3-week VAS score (p=0.011).@*CONCLUSIONS@#The current study showed that pain intensity at the 3-week time point after cervical SNRB might be the optimal time point for predicting long-term effectiveness.

Epidural Fat-Derived Mesenchymal Stem Cell: First Report of Epidural Fat-Derived Mesenchymal Stem Cell

STUDY DESIGN: Experimental study. PURPOSE: To determine whether epidural fat (EF) tissue contains mesenchymal stem cells (MSC). OVERVIEW OF LITERATURE: Spine surgeons are unaware of the contents of EF tissue and the reason for its presence between the ligamentum flavum and the dura mater; therefore, EF tissues are routinely eliminated during surgical procedures. However, EF removal causes certain postoperative problems, such as post-laminectomy syndrome. We hypothesized that the EF tissue may play a significant supportive role for the neural structures and other nearby conditions. METHODS: EF tissues were obtained from consenting patients (n=3) during posterior decompression surgery of the lumbar spine. The primary cells were isolated and cultured as per previously described methods with some modifications, and the cell morphology and cumulation were examined. Thereafter, reverse transcription–polymerase chain reaction (RT-PCR), a fluorescence-activated cell sorting (FACS) analysis, and differentiation potency for differentiation into osteoblasts, chondroblasts, and adipocytes were investigated to identify whether the cells derived from EF are MSC. RESULTS: The cells from the EF tissue had a fibroblast or neuron-like morphology that persisted until the senescence at p18. MSC-specific genes, such as OCT4, SOX2, KLF4, MYC, and GAPDH were expressed in the RT-PCR study, while MSC-specific surface markers such as CD105, CD90, and CD73 were exhibited in the FACS analysis. The differentiation properties of EF-MSC for differentiation into the three types of cells (osteoblast, chondroblast, and adipocyte) were also confirmed. CONCLUSIONS: Based on the cell culture, FACS analysis, RT-PCR analysis, and differentiation potent outcomes, all the features of the cells corresponded to MSC. This is the first study to identify EF-MSC derived from the EF tissue.

When is the Optimal Time Point for Predicting the 1-Year Follow-up Outcome of Selective Nerve Root Block for Cervical Radiculopathy?

STUDY DESIGN: Retrospective study. OBJECTIVES: In the current study, we aimed to (1) evaluate the early and late therapeutic effects of selective nerve root block (SNRB) for cervical radiculopathy, and (2) to determine the optimal time point for predicting the long-term effectiveness of cervical SNRB. SUMMARY OF LITERATURE REVIEW: Although SNRB is an important option for cervical radiculopathy, various studies of cervical SNRB have failed to specify its efficacy, especially long-term effectiveness. MATERIALS AND METHODS: We retrospectively enrolled 35 patients with cervical radiculopathy who were regularly followed-up for at least 1 year after SNRB. Clinical outcomes were evaluated using a visual analogue scale (VAS) for pain intensity and the modified Kim's method for patient satisfaction at regular follow-up intervals. In the correlation analysis, stepwise multiple linear regression was used to identify selected and unselected factors. RESULTS: The average VAS score decreased over time (p<0.05); the values just before the injection and at 1 week, 3 weeks, and 1 year of follow-up were 6.11, 3.29, 2.89, and 1.37, respectively. In the stepwise multiple regression analysis, the 1-week VAS score was related to the initial VAS score, the 3-week VAS score was related to the 1-week VAS score, and the last VAS score was related to the 3-week VAS score and symptom duration before the injection. The degree of satisfaction at the 1-year follow-up point was significantly associated with the 3-week VAS score (p=0.011). CONCLUSIONS: The current study showed that pain intensity at the 3-week time point after cervical SNRB might be the optimal time point for predicting long-term effectiveness.

Relevance of emergency level assessment by the Korean Triage and Acuity Scale for adult patients in a local emergency medical center

OBJECTIVE: The Korean Triage and Acuity Scale (KTAS), which was implemented in 2016, needs to be assessed for its validity and reliability. Here we evaluate the relevance of emergency level assessment by analyzing the validity of KTAS as a Korean standardized triage system. METHODS: We retrospectively analyzed the medical records of adults who presented to a local emergency room (ER) during an 18-month period. We compared medical resources used, life-saving interventions performed, length of stay (LOS) in ER, admission rate, and mortality at each KTAS level. RESULTS: Among a total of 40,339 patients, most patients were at KTAS 4 (n=19,532, 48.4%) and the longest median LOS in ER was 450 minutes at KTAS 2. As the KTAS level increased, the percentage of medical resources used and life-saving interventions performed increased significantly. The odds of total admission and intensive care unit admission were significantly higher at KTAS 1 through 4 compared to those at KTAS 5. The odds related to admission and mortality were also significantly higher at KTAS 3 than at KTAS 4. CONCLUSION: We concluded that the KTAS, as a Korean standardized triage system of emergency level assessment, is relevant. Further, KTAS 1-3 and KTAS 4-5 are appropriate criteria to distinguish emergency and non-emergency patients.

A Sternum-Disk Distance Method to Identify the Skin Level for Approaching a Surgical Segment without Fluoroscopy Guidance during Anterior Cervical Discectomy And Fusion

STUDY DESIGN: A retrospective review of prospectively collected data. PURPOSE: To introduce the sternum-disk distance (SDD) method for approaching the exact surgical level without C-arm guidance during anterior cervical discectomy and fusion (ACDF) surgery and to evaluate its accuracy and reliability. OVERVIEW OF LITERATURE: Although spine surgeons have tried to optimize methods for identifying the skin level for accessing the operative disk level without C-arm guidance during ACDF, success has rarely been reported. METHODS: In total, 103 patients who underwent single-level ACDF surgery with the SDD method were enrolled. The primary outcome measure was the accuracy of the SDD method. The secondary outcome measures were the mean SDD value at each cervical level from the cranial margin of the sternum in the neutral and extension positions of the cervical spine and the inter- and intra-observer reliability of the SDD outcome determined using repeated measurements by three orthopedic spine surgeons. RESULTS: The SDD accuracy (primary outcome measure) was indicated in 99% of the patients (102/103). The mean SDD values in the neutral-position magnetic resonance imaging (MRI) were 108.8 mm at C3–C4, 85.3 mm at C4–C5, 64.4 mm at C5–C6, 44.3 mm at C6–C7, and 24.1 mm at C7–T1; and those in the extension-position MRI were 112.9 mm at C3–C4, 88.7 mm at C4–C5, 67.3 mm at C5–C6, 46.5 mm at C6–C7, and 24.3 mm at C7–T1. The Cohen kappa coefficient value for intra-observer reliability was 0.88 (excellent reliability), and the Fleiss kappa coefficient value for inter-observer reliability as reported by three surgeons was 0.89 (excellent reliability). CONCLUSIONS: Based on the results of the present study, we recommend performing ACDF surgery using the SDD method to determine the skin level for approaching the surgical cervical segment without fluoroscopic guidance.

Comparison of Outcomes of Total Hip Arthroplasty between Patients with Ankylosing Spondylitis and Avascular Necrosis of the Femoral Head

BACKGROUND: The objective of this study was to compare clinical and radiological outcomes of total hip arthroplasty (THA) between ankylosing spondylitis (AS) of the hip joint and avascular necrosis (AVN) of the femoral head. METHODS: Thirty patients (30 hips) underwent cementless THA for AS between 2003 and 2012. They were compared to 30 patients (30 hips) who underwent the same procedure for AVN of the femoral head. Each group was matched for age and gender, and both groups had similar preoperative demographic characteristics. All cases were followed for minimum 4 postoperative years. Clinical evaluation was based on operation time, intraoperative blood loss, quantity of postoperative drainage, Harris Hip Score (HHS), and range of motion (ROM). Radiological results were evaluated by acetabular cup anteversion and inclination, femoral stem orientation, pre- and postoperative leg length discrepancy, and postoperative complications. RESULTS: The operation time was significantly longer in the AS group (120.2 ± 26.2 min) than in the AVN group (79.5 ± 11.1 min). The volume of postoperative drainage was significantly greater in the AS group (764.5 ± 355.4 mL vs. 510.5 ± 195.6 mL). Preoperative HHS was lower in the AS group (55.6 ± 13.8 vs. 59.2 ± 2.8). Similarly, postoperative HHS was significantly lower in the AS group (92.8 ± 2.7 vs. 97.4 ± 2.6). The arc of ROM was improved from 146.5°± 13.2° preoperatively to 254.7°± 17.2° postoperatively in the AS group and from 182.6°± 15.5° to 260.4°± 13.7° in the AVN group. Implant position and postoperative leg length discrepancy were not different between the groups. However, three cases of heterotopic ossification was observed in the AS group, whereas only 1 case was found in the AVN group. One deep infection and one aseptic stem loosening were found in the AS group, whereas none was observed in the AVN group. CONCLUSIONS: Cementless THA showed satisfactory clinical and radiological results in both groups, despite the longer operation time, larger blood loss volume, and lower HHS score of the AS group. Our findings suggest that cementless THA is an effective and reliable treatment for both AS and AVN.

The Efficacy of Vitamin C on Postoperative Outcomes after Posterior Lumbar Interbody Fusion: A Randomized, Placebo-Controlled Trial

BACKGROUND: Vitamin C has critical features relavant to postoperative pain management and functional improvement; however, no study has yet evaluated the effectiveness of vitamin C on improving the surgical outcomes for spine pathologies. Thus, this study aimed to explore the impact of vitamin C on postoperative outcomes after single-level posterior lumbar interbody fusion (PLIF) for lumbar spinal stenosis in prospectively randomized design. We conducted a 1-year prospective, randomized, placebo-controlled, double-blind study to evaluate the impact of vitamin C on the postoperative outcomes after PLIF surgery. METHODS: A total of 123 eligible patients were randomly assigned to either group A (62 patients with vitamin C) or group B (61 patients with placebo). Patient follow-up was continued for at least 1 year after surgery. The primary outcome measure was pain intensity in the lower back using a visual analogue scale. The secondary outcome measures were: (1) the clinical outcome assessed using the Oswestry Disability Index (ODI); (2) the fusion rate assessed using dynamic radiographs and computed tomography scans; and (3) complications. RESULTS: Pain intensity in the lower back was significantly improved in both groups compared with preoperative pain intensity, but no significant difference was observed between the 2 groups over the follow-up period. The ODI score of group A at the third postoperative month was significantly higher than the score of group B. After the sixth postoperative month, the ODI score of group A was slightly higher than the score of group B; however, this difference was not significant. The fusion rates at 1 year after surgery and the complication rates were not significantly different between the 2 groups. CONCLUSIONS: Postoperative pain intensity, the primary outcome measure, was not significantly different at 1 year after surgery between the 2 groups. However, vitamin C may be associated with improving functional status after PLIF surgery, especially during the first 3 postoperative months.

A Fatal Case of Colchicine Poisoning

Colchicine is a drug that has long been used to treat a variety of illnesses; however, it reportedly has adverse effects at apparent toxic doses as well as at lower and therapeutically recommended doses. The typical therapeutic dose of colchicine is up to 2.4 mg daily, although it is sometimes as high as 8–10 mg daily. Here, we describe a case in which the patient showed sudden deterioration and died because of unintentional colchicine poisoning with a relatively small dose. When a colchicine poisoned patient visits the hospital, the physician should identify the patient's colchicine poisoning dose and concomitant drugs. Moreover, the patients should be monitored intensively for 24 to 72 hours and managed with various supportive treatment methods early and actively.

Feasibility Study of Free-Hand Technique for Pedicle Screw Insertion at C7 without Fluoroscopy-Guidance

STUDY DESIGN: Retrospective interventional study. PURPOSE: To introduce a free-hand pedicle screw (PS) insertion technique without fluoroscopic guidance in the C7 vertebra and evaluate the procedure's feasibility and radiologic outcomes. OVERVIEW OF LITERATURE: Although PS insertion at C7 has been recognized as a critical procedure in posterior cervical fusion surgery, conventional techniques for C7 PS have several limitations. METHODS: Thirty two patients (64 screws) who underwent PS insertion in C7 with the novel technique were included in this study. Postoperative clinical and radiological outcomes were evaluated. Special attention was paid to the presence of any problems in the screw position including cortical breaches of the PS and encroachment of the PS into the spinal canal or the vertebral foramen. This novel technique for PS insertion in C7 without fluoroscopy guidance had three key elements. First, the ideal PS entry point was chosen near the C6-7 facet joint using preoperative images. Second, the convergent angle distance was measured at axial computed tomography (CT) imaging, which defined the distance between the tip of C7 spinous process and the extended line passing through the pedicle axis from the ideal entry point. Third, the cranial-caudal angle distance was measured in sagittal CT images, which defined the distance between the tip of the C7 spinous process and the extended line passing through the pedicle axis. RESULTS: Cortical breach on postoperative CT images was observed in three screws. All violated only the lateral wall of the affected pedicle. The breached screws occurred in the initial five cases. Postoperative neurologic deterioration was not observed in any patient, regardless of cortical breaching. CONCLUSIONS: The novel technique successfully allows for C7 PS to be placed and is associated with a low rate of cortical breach.

Significance of Coronal Proset Magnetic Resonance Imaging to Detect Hidden Zone of the Mid-Zone Stenosis in the Lumbar Spine and Morphometric Analysis of the Mid-Zone Stenosis

STUDY DESIGN: Retrospective exploratory imaging study. PURPOSE: To investigate the significance of the coronal magnetic resonance imaging (MRI) using Proset technique to detect the hidden zone in patients with mid-zone stenosis by comparing with conventional axial and sagittal MRI and to explore the morphologic characteristic patterns of the mid-zone stenosis. OVERVIEW OF LITERATURE: Despite advancements in diagnostic modalities such as computed tomography and MRI, stenotic lesions under the pedicle and pars interarticularis, also called the mid-zone, are still difficult to definitely detect with the conventional axial and sagittal MRI due to its inherited anatomical peculiarity. METHODS: Of 180 patients scheduled to undergo selective nerve root block, 20 patients with mid-zone stenosis were analyzed using MRI. Characteristic group patterns were also explored morphologically by comparing MRI views of each group after verifying statistical differences between them. Hierarchical cluster analysis was performed to classify morphological characteristic groups based on three-dimensional radiologic grade for stenosis at all three zones. RESULTS: At the mid-zone, the stenosis of grade 2 or more was found in 14 cases in the coronal image,13 cases in the sagittal image, and 9 cases in the axial image (p<0.05). Especially, mid-zone stenosis was not detected in six of 20 cases at the axial images. At the entrance and exit-zone, coronal image was also associated with more accurate detection of hidden zone compared to other views such as axial and sagittal images. After repeated statistical verification, the morphological patterns of hidden zone were classified into 5 groups: 6 cases in group I; 1 case in group II; 4 cases in group III; 7 cases in group IV; and 2 cases in group V. CONCLUSIONS: Coronal MRI using the Proset technique more accurately detected hidden zone of the mid-zone stenosis compared to conventional axial and sagittal images.