Biomedical subjects
Publications and source records attributed to A Wild.
Scars around the neural structures after opening the spinal canal are common and severe problems in spine surgery. This paper presents the use of a special membrane to avoid epidural scarring in two cases.
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Sacral insufficiency fractures (SIF) usually occur in elderly women and are secondary to various conditions, mainly postmenopausal or steroid-induced osteoporosis and radiation therapy. They are often overlooked or confused clinically and radiographically with metastatic disease. We report a case of a 72-year-old woman who presented to our department with severe low-back pain. She was thoroughly investigated for the cause of her back pain. Plain X-rays did not reveal any abnormality, but magnetic resonance (MR) scan revealed marked oedema within both sides of the sacrum, suggesting a neoplastic lesion. Bone scintigraphy did show a hyperfixation pattern forming an 'H' in the sacrum which is a characteristic sign of SIF. Computed tomography (CT) confirmed sclerotic changes interpreted as insufficiency fractures through both sacral alae. Increased awareness of these fractures may help to avoid unnecessary investigations and treatment. Bed rest and analgesia followed by rehabilitation provide good relief of symptoms.
A 44 year old male patient presented with severe hypertension. The diagnostic work-up revealed elevated levels of plasma renin activity (about 10 times the upper limit of normal) in the presence of normal plasma aldosterone levels and serum potassium concentrations. Renovascular disease was excluded by angiography. Selective renal vein sampling did not show any renin gradient. CT-scans of the abdomen demonstrated normal morphology of the kidneys and adrenals but revealed a big mass in the pancreatic corpus and tail with infiltration of the splenic vein and the presence of enlarged local lymph nodes. The endocrine nature of the pancreatic mass was further supported by a positive octreotide scintigraphy scan. Surgical removal of the tumor by left sided pancreatectomy combined with splenectomy resulted in rapid normalization of elevated renin concentrations as well as blood pressure. Histological examination of the tumor tissue revealed the presence of a neuroendocrine pancreatic carcinoma. Highly (x 70) elevated renin levels were detected by radioimmunoassay in the tumor tissue. To our knowledge this is the first renin-producing neuroendocrine pancreatic carcinoma described in the literature. The present paper describes the case in detail and reviews the available literature on clinical symptomatology, diagnosis and treatment of renin-producing tumors.
Primary adrenal hyperplasia, which may occur as a familial disorder, is a rare cause of ACTH-independent Cushing's syndrome. In most of these cases the underlying pathology is primary adrenocortical micronodular dysplasia. Very few cases of familial Cushing's syndrome due to primary macronodular adrenal hyperplasia have been described. We report a family with seven affected family members. The pedigree indicates an autosomal dominantly inherited disorder. Interestingly only female family members developed the clinically apparent syndrome. The only available obligatory male gene carrier failed to adequately suppress his plasma cortisol level on overnight dexamethasone suppression test. His adrenal glands showed nodular enlargement on abdominal computed tomographic imaging. Screening of the MEN 1 gene and genetic analysis of the hot spot regions of the GNAS 1 (codons 201 and 227) and GNAI 2 (codons 179 and 205) genes did not show any mutations in the constitutional DNA or the adrenal tissue DNA of the index patient. In conclusion, this family is the largest kindred reported in the literature with ACTH-independent Cushing's syndrome due to autosomal dominant inherited macronodular adrenocortical hyperplasia. Four currently alive and affected family members in two generations and further careful observation of the yet unaffected members of the third available generation might offer the opportunity to identify the still unknown gene defect in the future.
The Luque procedure was developed to correct the deformity without the need of bracing and maintaining that correction with growth. However many authors are disappointed by their results and the complications which appear in the management of infantile scoliosis with Luque trolley alone. Besides failed implants, pseudarthrosis, modest spinal growth and protuberant rods and wires, the major problem of the Luque systems is the high incidence of loss of correction by postoperative rotation. Therefore a new application technique is recommended. A standard posterior extraperiostal approach is chosen. Sublaminar titanium cables are passed at each level except the caudal lamina. Then the rods are precontoured in shape of the planed curve correction. We use a low profile titanium instrumentation with 5.0 mm diameter rods and 4.2 mm pedicle screws. In contrast to the conventional use of two antiparallel "L"-rods we recommend the use of one reversed "U"-rod securing the laminae with sublaminar titanium cables of the upper end vertebrae. For fixation of the lower spine a dual-opening pedicle screw system is used. Using a holding forceps the distal rods are introduced and fixed into the side opening of the screws then secured by sublaminar wires. In addition both single rods are stabilized by a low profile cross link bar. This technique allows to correct pelvic obliquity and a stable anchorage of two screws reduces risk of postoperatively rotation or caudal rod slippage due to gravity forces.
The good biomechanical and tribological properties, together with the excellent biocompatibility, of ceramic-on-ceramic components, make them a preferential choice for total hip replacement surgery, at least in Europe. We report on a man admitted as an outpatient with painless grating in the hip one year after replacement of a ceramic femoral head, but not of the ceramic inlay. Clinical and radiological findings were indicative of a broken liner. This was confirmed during revision surgery, during which it was replaced by a polyethylene inlay; although the ceramic head appeared intact, it was replaced by a metal head. Inspection of the surface of the broken liner in the scanning electron microscope (SEM) revealed signs of material failure. We recommend careful inspection of ceramic-on-ceramic articulating components during total hip revision surgery and if there is any uncertainty, replacement of both so as to avoid premature failure.
INTRODUCTION: There is a controversial discussion about the adequate surgical procedure for degenerative lumbar spinal stenosis. Due to the observation that the degenerative lumbar spinal stenosis takes place predominantly at the interlaminar region on the level of the disc involving facets and bulging of the ligamentum flavum, resection of the whole lamina might not be necessary. A biomechanical study was designed to assess the effect of different decompression techniques using cadaver lumbar spine models. METHODS: Twelve cadaver spines with CT verified degenerative lumbar spinal stenosis were dissected in order to measure the volume of the dural sac at different flexion and extension angles. Each segment (L3/4, L4/5) was decompressed first by limited interlaminar decompression and second by complete laminectomy. Intrathecal volume measurements were taken initially, after limited interlaminar decompression and after complete laminectomy. RESULTS: Before surgical procedure, the cadaver spines showed an increase of the intrathecal volume in flexion and decrease in extension. After limited interlaminar decompression, there was a significant reduction of volume loss in extension. There was no significant additional reduction of volume loss in extension after complete laminectomy in comparison to limited interlaminar decompression. CONCLUSION: The results allow to conclude that limited interlaminar decompression is efficient for decompression in degenerative lumbar spinal stenosis.
We report a case of intra-articular migration of the proximal part of a broken polylactic acid screw from the tibial site of anterior cruciate ligament-reconstruction with quadrupled semi-tendinosus tendon. Five months after initially successful ACL surgery the patient felt a sudden locking of the knee without another injury. MRI showed intra-articular migration of one-half of the polylactic acid screw, and standard radiographs a widening of the proximal tibial tunnel. At revision arthroscopy the broken part was easily removed. The patient had full recovery. This case demonstrates the problem of "bioscrew" breakage in ACL surgery.
STUDY DESIGN: Case report. OBJECTIVES: To present the case of a patient with congenital spondyloptosis treated and followed over 10 years. SUMMARY OF BACKGROUND DATA: The surgical management of spondyloptosis in children is variably reported in the literature. Some authors propose that posterior fusion in situ is a safe and reliable procedure, whereas others suggest that reduction of the slipped vertebra may prevent some of the adverse sequelae of in situ fusion, which include nonunion, bending of the fusion mass, and persistent lumbosacral deformity. Many investigators advocate a combined anterior and posterior fusion using instrumentation. METHODS: At the time of the first symptoms an 18-month-old boy with congenital spondyloptosis of L5-S1 was referred to the authors' institution. Because of the progression of pain, neurologic disturbance, mild foot deformity, muscle contractures, and lumbosacral kyphosis, surgical intervention was undertaken. Operative intervention began with a resection of the L5 lamina and wide bilateral L5 nerve root decompression. This was followed by anterior subtotal resection of L5 and interbody bone graft of the morcelized vertebral body for fusion from L5 to S1. The next step was reduction of the spondyloptosis and stabilization by posterior instrumentation L2-S1 with a sacral Cotrel-agraffe device. RESULTS: The procedure achieved almost complete reduction of the spondyloptosis with near-normal restoration of lumbar lordosis allowing more physiologic lumbar spinal biomechanics. There were no neurologic complications. After surgery there was no suggestion of back pain or gait disturbance and no progression of any deformity. CONCLUSION: In the treatment of severe congenital spondylolisthesis a staged procedure of decompression, reduction, and instrumented fusion is recommended for those cases in which intervention is indicated.
STUDY DESIGN: Prospective study. OBJECTIVE: To evaluate the functional outcome of two-stage anterior and posterior instrumented fusion without fixation to the sacrum on 11 patients with neuromuscular scoliosis from thoracolumbar myelomeningocele. SUMMARY OF BACKGROUND DATA: To our knowledge, there are no published results of combined anterior and posterior correction and fusion without inclusion of the sacrum in neuromuscular scoliosis from thoracolumbar myelomeningocele. In this article we present our experience and critically evaluate the functional outcome on 11 patients with neuromuscular scoliosis. PATIENTS AND METHODS: From July 1, 1992 through June 30, 1995, 11 consecutive patients with severe thoracolumbar scoliosis were admitted at our hospital. The mean age at operation was 12 years 9 months (range 9 years 9 months to 14 years 6 months). All patients underwent a two-stage anterior and posterior spinal reconstruction. The patients were evaluated before surgery and after surgery. RESULTS: All patients were observed for a mean of 4 years 11 months (range 42-88 months) from the time of second stage procedure. Before treatment the mean scoliosis was 81 degrees (range 55-110 degrees ); this was reduced to a mean of 31 degrees (range 8-70 degrees ), and at the final follow-up the correction had deteriorated slightly to a mean of 35 degrees (range 12-80 degrees ). No patient had increased neurologic deficit or showed other major complication. CONCLUSIONS: Pelvic obliquity in thoracolumbar neuromuscular scoliosis from lumbosacral myelomeningocele spontaneously corrected when the scoliotic deformity is adequately addressed with instrumented fusion without inclusion of the sacrum. The correction obtained remained stable at follow-up. In the absence of a control group we believe that sparing lumbar segments from primary fusion offers these patients a better freedom of mobility.
Germline mutations of the MEN1 gene have been identified as the causative genetic defect of multiple endocrine neoplasia type I (MEN-I), an autosomal dominantly inherited condition. To establish the basis for predictive family screening we evaluated the spectrum of MEN1 gene mutations in MEN-I patients treated at our institution. Relatives at risk were subjected to predictive genetic screening after genetic counseling. Gene carriers were subjected to extensive clinical screening for MEN-I, including biochemical tests for basal hormone concentrations in blood and urine, a standardized meal stimulation test and imaging procedures (ultrasonography, computed tomography, magnetic resonance imaging). Among index patients of 15 independent MEN-I kindreds, 14 heterozygous MEN1 germline mutations were identified by single-strand conformational variant analysis (SSCV) and direct DNA sequence analysis. Of 51 individuals at risk, 26 predictively tested relatives with the wild-type MEN1 gene could be excluded from further screening procedures because they had not inherited the disease. In all previously presumed unaffected relatives with the mutant gene, our extensive clinical screening program revealed at least one manifestation of MEN-I. Furthermore, 22 additional diagnoses could be established in identified MEN-I patients. We show that mutation analysis enables predictive genetic screening for MEN-I families, providing a valuable tool for genetic counseling and clinical management. An extensive clinical screening program focusing on genetically proven individuals at risk allows detection of MEN-I manifestations at an early, asymptomatic stage of the disease. Controlled, prospective studies are now required to prove whether timely appropriate treatment on the basis of predictive screening might help improve disease-related quality of life and prolong life expectancy in MEN-I kindreds.
UNLABELLED: The management of leg length difference (LLD) and angular deformities of the leg remains controversial. Numerous treatment options have been proposed over the past years depending on the patient's general condition, skeletal age, function, and degree and configuration of the deformity. Our retrospective study consisted of 48 patients with 58 legs treated between 1970 and 1991 by Blount's epiphyseal stapling to equalise length or correct angular deformity. After an average follow-up of 16.5 years, all patients with idiopathic bow-legs or knock-knees (n=12) and 71% of LLD caused by overgrowth (e.g. Klippel-Trenaunay syndrome) showed good and excellent results at skeletal maturity, whereas the results of the treatment of LLD with undergrowth of the leg and angular deformities due to trauma, infection or general dysplasia and malformation were fair to poor because of the difficulty in prediction of growth development and growth potential, allowing only for partial correction of the deformity. Besides the restriction of the stapling procedure due to the aetiology of the deformity, the age of the patients at the time of surgery is important, as it determines the complication rate of this technique (loosening or dislocation of staples). Thus Blount's epiphyseodesis should not be performed before the age of 9 years in girls and 11 years in boys. CONCLUSION: Blount's epiphyseal stapling can be recommended as a safe procedure with predictably good results in idiopathic angular deformities of the leg and leg length difference caused by overgrowth.
Gordon's Syndrome is described as an autosomal dominant condition with the characteristics of short stature, a stiff spine, camptodactyly (89%), cleft palate (27%) and club feet (73%). The authors present a case report of a patient with this rare entity complicated by an unusual complex spinal deformity. There are no prior reports in the literature concerning operative or nonoperative management of deformity in this patient population. Scoliosis in Gordon's Syndrome shares the characteristics of an arthrogrypotic neuromuscular curve and demands extensive soft tissue release for optimal correction.
BACKGROUND: Use of a standardized meal stimulation test has been recommended for the early diagnosis of pancreaticoduodenal endocrine tumours (PETs) in patients with multiple endocrine neoplasia type 1 (MEN 1). The diagnostic value of this test was re-evaluated. METHODS: In a prospective, controlled trial 58 standardized meal stimulation tests (563 kcal) were performed in 12 patients with MEN 1 and histologically, biochemically and/or radiologically confirmed PETs (group 1), 11 carriers of an MEN 1 mutation with no evidence of PETs (group 2) and in 27 healthy controls (group 3). Serum pancreatic polypeptide (PP) and gastrin concentrations were measured before and during the test meal. RESULTS: Patients in group 1 had significantly higher mean basal serum PP and gastrin concentrations than patients in group 2 and controls (P < 0.05). In all three groups an increase in serum PP was observed after meal stimulation, but there was no significant difference between the groups. No increase in gastrin level was found in any of the groups after meal stimulation. CONCLUSION: The standardized meal stimulation test does not reliably indicate the presence of PETs in patients with MEN 1, whereas raised basal serum PP and gastrin levels do. The expensive and time-consuming meal test can be excluded from MEN 1 screening programmes.
There are only very few data available about the morbidity of elite fencers athletes. The aim of this study was to elucidate the nature and history of the morbidity in high-performance fencers. The injury profile over 15 years of 93 fencers at a highly competitive level was analysed by clinical assessment and examination. We found a positive correlation between the injured upper extremity with the dominant fencing side while the lower extremity showed no side preference with regard to vulnerability. Achillodynia occurred more frequently at the contralateral side. The joint most affected was the knee. The dominating symptom was patellofemoral pain which occurred in 39.8 %.
BACKGROUND: p16(INK4a) alterations are considered to be an early event in pancreatic tumorigenesis and have been described in duct lesions adjacent to pancreatic cancers. This study evaluates whether duct lesions in chronic pancreatitis tissues of patients without pancreatic cancer also harbor genetic alterations in the p16(INK4a) tumor-suppressor gene, and thus represent high-risk precursors for pancreatic cancer. METHODS: Tissues were obtained from 20 pancreatic specimens taken from patients operated on for histologically verified chronic pancreatitis. Pancreatic intraductal neoplasias (PanIN) were identified in hematoxylin-and-eosin-stained slides. p16 protein expression was investigated immunohistochemically in all specimens. DNA from PanIN and non-PanIN tissue was analyzed genetically for p16(INK4a) mutations by single-strand conformation variation analysis and direct sequencing of the encoding region. Additionally, p16(INK4a) promoter methylation was analyzed by a methylation specific polymerase test. RESULTS: PanIN-1a lesions were identified in 10 of the 20 chronic pancreatitis specimens. Four of these 10 PanIN specimens (40%), but none of the 20 non-PanIN tissues, revealed a loss of p16 expression in immunohistochemistry. The mutational analysis of the p16(INK4a) gene showed 1 known polymorphism (c.442G > A; A148T) but no mutations. Two of the 10 specimens with PanIN revealed an inactivating hypermethylation of the p16(INK4a) promoter. CONCLUSIONS: This study shows for the first time that p16(INK4a) alterations can be observed in a considerable number of PanIN1 in chronic pancreatitis tissues not associated with pancreatic cancer. Therefore, p16(INK4a) alterations, especially promoter methylation, might indicate high-risk precursors in chronic pancreatitis that might progress to cancer.
In the UK, policy changes in primary health care research and development have led to the establishment of primary care research networks. These organizations aim to increase research culture, capacity and evidence base in primary care. As publicly funded bodies, these networks need to be accountable. Organizational science has studied network organizations including why and how they develop and how they function most effectively. This paper draws on organizational science to reflect on why primary care research networks appear to be appropriate for primary care research and how their structures and processes can best enable the achievement of their aims.