Kyeong Hwan Kim

Prevalence and Morphologic Features of Ponticulus Posticus in Koreans: Analysis of 312 Radiographs and 225 Three-dimensional CT Scans

Study Design A retrospective review of three-dimensional CT scan images and radiographs. Purpose To investigate the prevalence and morphologic features of ponticulus posticus in Koreans. Overview of Literature There has been little reported on the prevalence or morphologic characteristics of ponticulus posticus in Asians, predisposing them to vertebral artery injury during screw placement in the lateral mass of the atlas. Methods The presence and types of ponticulus posticus were investigated on 225 consecutive cervical three-dimensional CT scans and 312 consecutive digital lateral cephalometric head radiographs. Results Various spectra of ponticulus posticus were found in 26% of the CT scans and 14% of the radiographs. Conclusions Ponticulus posticus is a relatively common anomaly in Koreans. Therefore, the presence of this anomaly should be carefully examined for on radiographs before lateral mass screw placement. If ponticulus posticus is suspected or confirmed on radiographs, three-dimensional CT scanning should be considered before placement of lateral mass screws into the posterior arch, especially given its wide variation of size and shape.

Adjacent Segment Disease After Interbody Fusion and Pedicle Screw Fixations for Isolated L4-L5 Spondylolisthesis : A Minimum Five-Year Follow-up

Study Design. A retrospective study. Objective. The purpose of this study are (1) to analyze prevalence of clinical and radiologic adjacent segment diseases (ASD), (2) to find precipitating factor of clinical ASD in each isthmic and degenerative spondylolisthesis groups, and (3) to compare clinical and radiologic change in isthmic and degenerative spondylolisthesis. Summary of Background Data. There is no clinical report regarding the use of magnetic resonance imaging (MRI) for evaluating ASD in patient who underwent 360° fusion with single-level spondylolisthesis with healthy adjacent segment. Methods. A total of 69 patients who underwent instrumented single-level interbody fusion at the L4–L5 level and showed no definitive degenerated disc in adjacent segments on preoperative MRI and plain radiographs were evaluated at more than 5 years after surgery. The patients were divided into 2 groups: group I was isthmic spondylolisthesis patients and group II was degenerative spondylolisthesis patients. The radiologic ASD was diagnosed by plain radiographs and MRI. Clinical ASD is defined as symptomatic spinal stenosis, intractable back pain, and subsequent sagittal or coronal imbalance with accompanying radiographic changes. Symptomatic spinal stenosis was defined as stenosis diagnosed by MRI and combined with neurologic claudication. Results. The prevalence of radiologic ASD on group I and group II was 72.7% and 84.0%, respectively. About 7 (15.9%) patients showed clinical ASD in group I and 6 (24.0%) patients showed clinical ASD in group II. MRI showed significant reliability for diagnosis of clinical ASD. Compared with patients with asymptomatic ASD, patients with clinical ASD showed significantly less postoperative lordotic angle at the L4–L5 level (i.e., less than 20°) in both groups. Conclusion. Maintaining postoperative L4–L5 segmental lordotic angle at about 20° or more is important for prevention of clinical ASD in single-level 360° fusion operation. MRI is reliable method for diagnosing clinical ASD.

Anterior bone cement augmentation in anterior lumbar interbody fusion and percutaneous pedicle screw fixation in patients with osteoporosis.

OBJECT The purpose of the present study was to evaluate the efficacy of anterior polymethylmethacrylate (PMMA) cement augmentation in instrumented anterior lumbar interbody fusion (ALIF) for patients with osteoporosis. METHODS Sixty-two patients with osteoporosis who had undergone single-level instrumented ALIF for spondylolisthesis and were followed for more than 2 years were included in the study. The patients were divided into 2 groups: instrumented ALIF alone (Group I) and instrumented ALIF with anterior PMMA augmentation (Group II). Sixty-one patients were interviewed to evaluate the clinical results, and plain radiographs and 3D CT scans were obtained at the last follow-up in 46 patients. RESULTS The mean degree of cage subsidence was significantly higher in Group I (19.6%) than in Group II (5.2%) (p = 0.001). The mean decrease of vertebral body height at the index level was also significantly higher in Group I (10.7%) than in Group II (3.9%) (p = 0.001). No significant intergroup differences were observed in the incidence of radiographic adjacent-segment degeneration (ASD) or in terms of pain and functional improvement. The incidences of clinical ASD (23% in Group I and 10% in Group II) were not significantly different. There was 1 case of nonunion and 3 cases of screw migration in Group I, but none resulted in implant failure. CONCLUSIONS Anterior PMMA augmentation during instrumented ALIF in patients with osteoporosis was useful to prevent cage subsidence and vertebral body collapse. In addition, PMMA augmentation did not increase the nonunion rate and incidence of ASD.

MRI versus CT for the diagnosis of lumbar spinal stenosis

OBJECTIVE The purpose of the study was to compare the effectiveness of CT and MRI in visualizing soft tissues in lumbar spinal stenosis (LSS), and to correlate the images with preoperative symptoms. MATERIALS AND METHODS A total of 163 patients who had undergone unilateral laminotomy for bilateral decompression to treat LSS at L4-5 were retrospectively analyzed. The narrowed spinal canal area was measured on axial images with CT and MRI, and compared with the acquired dimensions from preoperative Visual Analog Scale (VAS) and Oswestry Disability Index (ODI) scores. RESULTS The mean compromised spinal canal areas were 75.08 mm(2) on MRI and 63.13 mm(2) on CT, which were significantly different. Mean VAS for back pain was 5.37, and 7.94 for leg pain. Mean ODI was 55.17%. There was no significant correlation noted between clinical parameters and narrowed spinal canal area. CONCLUSION Spinal canal area was more narrowed on CT than on MRI in axial cuts. This finding can be explained by the superior ability of multidetector CT to discriminate cortical bone from soft tissue such as the ligamentum flavum. Our study highlights the value of CT examination in combination with MRI prior to LSS surgery.

A minimally invasive technique for L5-S1 intraforaminal disc herniations: microdiscectomy with a tubular retractor via a contralateral approach.

Surgical treatment of intraforaminal disc herniations at the L5-S1 level is technically demanding. The 2 most commonly used procedures involve either a medial or lateral ipsilateral approach and often require a partial or even complete facet resection, which may in turn result in vertebral instability and/or back pain, as well as, in some cases, a fusion or stabilization procedure. In this report, the authors present a new minimally invasive technique for the treatment of L5-S1 intraforaminal disc herniations. Using this technique, which involves tubular retractors and an operative microscope to approach the neural foramen from the contralateral side, the authors could easily visualize and remove the herniated disc material and perform a thorough microdiscectomy with minimal resection of osseous and ligamentous structures. To illustrate this new minimally invasive technique for the treatment of intraforaminal disc herniations at L5-S1, they describe the cases of 2 patients who underwent the procedure and in whom successful results were achieved.

Effect of Age and Early Intervention with a Systemic Steroid, Intravenous Immunoglobulin or Amniotic Membrane Transplantation on the Ocular Outcomes of Patients with Stevens-Johnson Syndrome

Purpose This retrospective observational case series of fifty-one consecutive patients referred to the eye clinic with acute-stage Stevens-Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN) from 1995 to 2011 examines the effect of early treatment with a systemic corticosteroid or intravenous immunoglobulin (IVIG) on the ocular outcomes in patients with SJS or TEN. Methods All patients were classified by age (≤18 years vs. >18 years) and analyzed by treatment modality and early intervention with systemic corticosteroids (≤5 days), IVIG (≤6 days), or amniotic membrane graft transplantation (AMT) (≤15 days). The main outcomes were best-corrected visual acuity (BCVA) in logarithm of the minimum angle of resolution (logMAR) and ocular involvement scores (OIS, 0-12), which were calculated based on the presence of superficial punctate keratitis, epithelial defect, conjunctivalization, neovascularization, corneal opacity, keratinization, hyperemia, symblepharon, trichiasis, mucocutaneous junction involvement, meibomian gland involvement, and punctal damage. Results The mean logMAR and OIS scores at the initial visit were not significantly different in the pediatric group (logMAR = 0.44, OIS = 2.76, n = 17) or the adult group (logMAR = 0.60, OIS = 2.21, n = 34). At the final follow-up, the logMAR and OIS had improved significantly in the adult group (p = 0.0002, p = 0.023, respectively), but not in the pediatric group. Early intervention with IVIG or corticosteroids significantly improved the mean BCVA and OIS in the adult group (p = 0.043 and p = 0.024, respectively for IVIG; p = 0.002 and p = 0.034, respectively for corticosteroid). AMT was found to be associated with a significantly improved BCVA or OIS in the late treatment group or the group with a better initial OIS (p = 0.043 and p = 0.043, respectively for BCVA; p = 0.042 and p = 0.041, respectively for OIS). Conclusions Our findings suggest that patients with SJS or TEN who are aged 18 years or less have poorer ocular outcomes than older patients and that early treatment with steroid or immunoglobulin therapy improves ocular outcomes.

A Comparative Study of the Effect of Fibrin Glue versus Sutures on Clinical Outcome in Patients Undergoing Pterygium Excision and Conjunctival Autografts

Purpose To compare the effect of using fibrin glue or 10-0 nylon sutures on the clinical outcome of patients undergoing pterygium excision and conjunctival autografting. Methods We retrospectively reviewed the medical records of 52 eyes from 46 patients who underwent pterygium excision and conjunctival autografting and were followed up for more than 3 months. The operation duration, postoperative inflammation, complications, and recurrence rates were compared between groups of 20 patients (22 eyes) for whom fibrin glue was used (fibrin glue group) and 26 patients (30 eyes) for whom suturing was performed with 10-0 nylon (suture group) in pterygium excision and conjunctival autografting. Results The operation duration was 27.71 (5.22) minutes in the fibrin glue group and 43.30 (8.18) minutes in the suture group (p = 0.000). Seven days after the operation, the fibrin glue group showed milder conjunctival inflammation than the suture group (p = 0.000). Postoperative complications and corneal recurrence rates were not statistically different between the two groups. Conclusions The use of fibrin glue in pterygium excision with conjunctival autografting is likely to be a more effective, safer procedure than suturing.

Asymptomatic Cervical or Thoracic Lesions in Elderly Patients who Have Undergone Decompressive Lumbar Surgery for Stenosis

Study Design A retrospective study. Purpose To evaluate the prevalence and risk factors of asymptomatic cervical or thoracic lesions in elderly patients who have undergone surgery for lumbar spinal stenosis. Overview of Literature Concurrent multiple spinal lesions have been reported in many studies with a varied prevalence, and described the characteristics of the disease and its treatment options. However, the cervical or thoracic lesions without apparent symptoms in patients with symptomatic lumbar stenosis had not been evaluated. Methods A total of 101 elderly patients (aged 65 or more), who had undergone surgery for lumbar spinal stenosis from January 2005 to December 2005, were enrolled in this study. All patients underwent lumbar magnetic resonance imaging (MRI) along with T2-weighted cervical and thoracic sagittal MRI prior to surgery. The concurrent cervical or thoracic lesions were classified according to the disease entity, and the severity of the lesions was graded from grade 0 (no lesion) to grade 4 (any lesion compressing the cord with a signal change). The prevalence of concurrent cervical and thoracic lesions was then analyzed. In addition, the risk factors for the development of concurrent lesions were evaluated, and the risk factors affecting the severity of the concurrent lesion were analyzed individually. Results Seventy-seven (76.2%) and 30 (29.7%) patients had a concurrent cervical and thoracic lesion, respectively. Twenty-six patients (25.7%) had both a cervical and thoracic lesion. There was a positive correlation between the symptom duration of lumbar stenosis and the prevalence of both cervical (p = 0.044) and thoracic (p = 0.022) lesions. Conclusions The incidence of asymptomatic cervical or thoracic lesions is apparently high in elderly patients who have undergone surgery for lumbar spinal stenosis, particularly in those with longer symptom duration. This highlights the need for a preoperative evaluation of the cervical and thoracic spine in these patients.

Indirect decompression for a prior severe C1-2 dislocation causing progressive quadriparesis

Combined anterior and posterior surgery is frequently chosen for the treatment of prior, severe C1-2 dislocations that occurred during early childhood because of the difficulty in achieving reduction and satisfactory decompression. The authors treated a prior, severe C1-2 dislocation that was causing progressive quadriparesis. The patient was a 14-year-old boy who had suffered a C1-2 fracture-dislocation at 3 years of age and had been treated with a Minerva body jacket cast. The treatment involved posterior C1-2 segmental screw fixation, without direct bone decompression or additional surgery. Satisfactory neural decompression was achieved with the techniques used, and complete bone union was confirmed. The patient showed satisfactory neurological recovery at the 5-year follow-up assessment.

Effects of subconjunctival administration of anti-high mobility group box 1 on dry eye in a mouse model of Sjӧgren’s syndrome

Purpose Extracellular high mobility group box 1 (HMGB1) acts as a damage associated molecular pattern molecule through the Toll-like receptor to promote autoreactive B cell activation, which may be involved in the pathogenesis of Sjӧgren’s syndrome. The aim of this study was to investigate the effect of subconjunctival administration of anti-HMGB1 on dry eye in a mouse model of Sjӧgren’s syndrome. Methods Ten weeks-old NOD.B10.H2b mice were subconjunctivally injected with 0.02 to 2 μg of anti-HMGB1 antibodies or PBS twice a week for two consecutive weeks. Tear volume and corneal staining scores were measured and compared between before- and after-treatment. Goblet cell density was counted in PAS stained forniceal conjunctiva and inflammatory foci score (>50 cells/focus) was measured in extraorbital glands. Flow cytometry was performed to evaluate the changes in BrdU+ cells, IL-17-, IL-10-, or IFNγ-secreting cells, functional B cells, and IL-22 secreting innate lymphoid cells (ILC3s) in cervical lymph nodes. The level of IL-22 in intraorbital glands was measured by ELISA. Results Injection of 2 μg or 0.02 μg anti-HMGB1 attenuated corneal epithelial erosions and increased tear secretion (p<0.05). Goblet cell density was increased in 0.2 μg and 2 μg anti-HMGB1-treated-mice with marginal significance. The inflammatory foci score, and the number of BrdU+ cells, IL-17-, IL-10-, IFNγ-secreting cells, and functional B cells did not significantly change following anti-HMGB1 treatment. Surprisingly, the percentage of ILC3s was significantly increased in the draining lymph nodes (p<0.05), and the expression of IL-22 was significantly increased in the intraorbital glands (p<0.05) after administration of 2 μg anti-HMGB1. Conclusion This study shows that subconjunctival administration of anti-HMGB1 attenuates clinical manifestations of dry eye. The improvement of dry eye may involve an increase of ILC3s, rather than modulation of B or plasma cells, as shown using a mouse model of Sjӧgren’s syndrome.