Biomedical subjects

Kee D Kim

Publications and source records attributed to Kee D Kim.

8 recordsLinked to original sources

PubMed2007

Three-dimensional finite-element analysis of maxillary protraction with and without rapid palatal expansion.

The aims of this study were to determine the reaction of the craniofacial bones on the protraction force transferred to the maxillary body, and whether or not the midpalatal suture had opened during skeletal Class III treatment. A computerized tomograph was obtained from a dry skull with a normal occlusion to construct a three-dimensional finite-element model (3D.FEM) of the craniofacial bones and the maxillary teeth to simulate actual bone reactions. A protraction force of 500 g was applied at the first premolar region, directed 20 degrees inferior to the occlusal plane. The displacement and the stress distribution of the craniofacial bones and sutures were then calculated using the ANSYS 5.3 program dividing the analysis into two simulations, based on whether or not the midpalatal suture was opened. The results showed that there was less compressive stress and greater tensile stress in the circumaxillary suture areas when the midpalatal suture was opened. The amount of displacement and deformation when the midpalatal suture was opened also demonstrated a decrease in upward-forward rotation of the maxilla and zygomatic arch and greater amounts of displacement in the frontal, vertical, and lateral directions compared with no opening of the midpalatal suture. Analysis of these results showed that maxillary protraction produce similar changes to normal downward and forward growth of the maxilla and was achieved with accompanying opening of the midpalatal suture.

Cephalometry↗

PubMed2006

Comparison of minimally invasive and conventional open posterolateral lumbar fusion using magnetic resonance imaging and retraction pressure studies.

OBJECTIVE: To determine whether minimally invasive lumbar spinal fusion results in less paraspinal muscle damage than conventional open posterior fusion. METHODS: The maximum intramuscular pressure (IMP) generated by a minimally invasive and standard open retractor was compared in cadavers using an ultra-miniature pressure transducer. In a second clinical study, eight patients with either minimally invasive or open posterolateral lumbar spinal fusion underwent magnetic resonance imaging (MRI) scanning approximately 6 months post surgery. MRI was used to estimate edema and atrophy within multifidus, with T2 mapping and diffusion-weighted imaging allowing quantification of differences between the two surgical techniques. RESULTS: IMP measured with the minimally invasive retractor was 1.4 versus 4.7 kPa with the open retractor (P < 0.001). The minimally invasive retractor produced a transient maximal IMP only on initial expansion. Maximum IMP was constant throughout open retractor deployment. Striking visual differences in muscle edema were seen between open and minimally invasive groups on MRI. The mean T2 relaxation time at the level of fusion was 47 milliseconds in the minimally invasive and 90 milliseconds in the open group (P = 0.013). The mean apparent diffusion coefficient was 1357 x 10(-6) mm/s and 1626 x 10(-6) mm(2)/s (P = 0.0184), respectively. CONCLUSIONS: The peak IMP generated by the minimally invasive retractor was significantly less than with the open retractor. Postoperatively, less muscle edema was demonstrated after the minimally invasive lumbar spinal fusion, with lower mean T2 and apparent diffusion coefficient measurements supporting the hypothesis that less damage occurs using a minimally invasive approach.

Adult↗

PubMed2005

Neurocysticercosis: a review.

BACKGROUND: In North America, the largest number of neurosurgical cases stemming from parasitic infections involves the larval form of Taenia solium, the infectious organism causing neurocysticercosis. This infection of the central nervous system (CNS) is most commonly seen in areas with significant immigrant populations and can often present particular challenges to treating physicians. METHODS: A review of the literature was performed, highlighting the epidemiology, parasitology, and clinical manifestations of neurocysticercosis. Particular attention was paid to 4 locations of neurocysticercosis lesions: parenchymal, subarachnoid/cisternal, intraventricular, and spinal. RESULTS: Both medical and surgical interventions may be necessary for adequate treatment of neurocysticercosis, depending on various factors, including location of lesion. CONCLUSIONS: A review of neurocysticercosis, with particular attention paid to location of disease involvement in the CNS, provides important information to the clinical management of this disease.

Humans↗

PubMed2005

Parasitic central nervous system infections: echinococcus and schistosoma.

Central nervous system (CNS) manifestations of Echinococcus and Schistosoma infections occur throughout the world, with incidence increasing in developed regions. A detailed literature review generated a current summary on epidemiology, parasitology, pathology, clinical manifestations, imaging studies, diagnosis, and treatment of neuroechinococcosis and neuroschistosomiasis. Recent advancements have been made in diagnosis, treatment, and prevention of these parasitic CNS infections. Ongoing advancements in neuroimaging and diagnostic studies, as well as efforts to better understand the parasite genome and host-parasite relationships, will likely continue to improve patient management.

Animals↗

PubMed2004

Reduction of leg pain and lower-extremity weakness for 1 year with Oxiplex/SP gel following laminectomy, laminotomy, and discectomy.

OBJECT: Although good surgical technique is effective in reducing postoperative epidural fibrosis, compression or tethering of the nerve root may cause recurrent radicular pain and physical impairment. The implantation of a bioresorbable gel on the dura may further decrease the amount of scar formation after surgery and thus improve the patient's ability to perform activities of daily living (ADL). This study is a 12-month evaluation of the safety and effectiveness of Oxiplex/SP Gel (FzioMed, Inc., San Luis Obispo, CA) in the reduction of pain and radiculopathy after lumbar discectomy. METHODS: A pilot randomized single-blind multicenter clinical trial was conducted to evaluate the performance of Oxiplex/SP Gel in patients who underwent surgery for unilateral herniation of the lumbar disc at L4-5 or L5-S1. Eighteen patients with severe leg pain and lower-extremity weakness (11 women and seven men) were randomly assigned intraoperatively to receive the gel at the conclusion of surgery (treatment group) or to undergo surgery alone (control group). Self-assessment questionnaires (Lumbar Spine Outcomes Questionnaire) to assess pain, symptoms, and ADL were completed preoperatively and at scheduled postoperative intervals (30 days, 90 days, 6 months, and 12 months). The authors examined the spine and lower extremities of patients scheduled for discectomy to assess neurological function and pain. Treated patients received sufficient Oxiplex/SP Gel (1-3 ml) to coat the nerve root and fill the epidural space. Postoperative clinical evaluations were performed at 30 and 90 days. Patients completed the self-assessment questionnaires at baseline and were contacted by telephone or mail for the completion of the postoperative self-assessment questionnaires. Surgical procedures were well tolerated; no device-related adverse events and no clinically significant laboratory results were reported. The 11 patients with severe leg pain and lower-extremity weakness who were treated with Oxiplex/SP Gel had a reduction in those symptoms at 30 days, 90 days, 6 months, and 12 months after discectomy, compared with the seven control patients who underwent surgery only. CONCLUSIONS: Oxiplex/SP Gel was easy to use and safe in patients who underwent unilateral discectomy. A greater benefit in clinical outcome measures was seen over the 12-month follow-up period in gel-treated patients.

Activities of Daily Living↗

PubMed2004

Trevor disease of the spine. Case report.

The authors report the case of a 15-year-old boy who presented with left shoulder pain and paresthesia of the left hand. Imaging studies revealed an osseous lesion compressing the C-8 nerve root. The patient underwent tumor resection followed by instrumentation-augmented fusion. Histological findings were consistent with osteochondroma. The tumor most likely originated from the articular cartilage between the first rib and T-1 or between C-7 and T-1. The correct diagnosis, therefore, was dysplasia epiphysialis hemimelica (DEH), also known as Trevor disease. To the authors' knowledge, this is the first report of DEH involving the spine.

Adolescent↗

PubMed2004

Peridural fibrosis.

Explore the source record for details and available documents.

Decompression, Surgical↗

PubMed2003

Reduction of radiculopathy and pain with Oxiplex/SP gel after laminectomy, laminotomy, and discectomy: a pilot clinical study.

STUDY DESIGN: Safety using Oxiplex/SP Gel during single-level discectomy for reduction of symptoms associated with unilateral herniation of the lumbar disc was investigated by self-assessment questionnaire and magnetic resonance imaging. OBJECTIVE: To evaluate the safety and assess the efficacy parameters of Oxiplex/SP Gel. SUMMARY OF BACKGROUND DATA: Animal studies demonstrated that Oxiplex/SP Gel (CMC/PEO) reduced epidural fibrosis after lumbar surgery. METHODS: Surgeons examined spine and lower extremities of patients scheduled for discectomy to assess neurologic function and pain. Treated patients received sufficient Oxiplex/SP Gel (1-3 mL) to coat the nerve root and fill the epidural space. The control condition was surgery alone. At baseline, then 30 days, 90 days, and 6 months after surgery, patients completed self-assessment questionnaires concerning leg pain, lower extremity weakness, functional disability, daily living activities, symptoms, and radiculopathy. Magnetic resonance imaging was performed at baseline and 90 days after surgery. At 30 and 90 days after surgery, patients underwent physical examination, wound inspection, and laboratory tests. RESULTS: The surgical procedures were well tolerated by the 23 patients treated with Oxiplex/SP Gel and the 11 control patients. There were no unanticipated adverse events, no clinically significant laboratory results, and no significant differences detected by magnetic resonance imaging. Treated patients had greater reduction in outcome measures at 30 days. The differences in scores were attenuated at 90 days and 6 months. A subgroup, the patients with significant leg pain and weakness at baseline (11 patients treated with Oxiplex/SP Gel and 7 control patients), had greater reduction in outcome measures than the control patients throughout the study. CONCLUSIONS: Oxiplex/SP Gel was easy to use and safe for patients undergoing unilateral discectomy. Greater benefit in clinical outcome measures was seen in gel-treated patients, especially those with severe leg pain and weakness at baseline.

Adult↗