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Biomedical subjects

F Hefti

Publications and source records attributed to F Hefti.

At least 19 recordsLinked to original sources
PubMed2005

Extraanatomic lateral reconstruction to the popliteal vessels.

OBJECTIVES: To describe the lateral approach to the popliteal artery in reconstructions after soft tissue sarcoma resection in the thigh. DESIGN: Case reports. Subjects Four patients with soft tissue sarcoma. METHODS: Extraanatomic reconstruction of the resected artery and vein in the medial part of the thigh was performed. Vessel reconstruction was performed before tumor resection to avoid leg ischemia. RESULTS: In all four patients the artery was replaced by using the contralateral saphenous vein, while the femoral vein was replaced in two cases using e-PTFE. Post-operative complications included one large lymphatic collection and a deep wound infection. Arterial primary graft patency was 100% after 1-7 years. Patency of the e-PTFE-venous graft was 0% without further consequences. CONCLUSIONS: The extraanatomic lateral replacement of the vessels in the thigh is an elegant method in difficult vascular reconstructions after soft tissue sarcoma resection or debridement for deep vascular infections.

Adult↗
PubMed2004

[Treatment of congenital scoliosis with the vertical expandable prosthetic titanium rib implant].

Children with congenital thoracic scoliosis associated with fused ribs and unilateral unsegmented bars adjacent to convex hemivertebrae will invariably have curve progression without treatment. It is assumed that the unilateral unsegmented bars do not grow and therefore early spinal fusion has been performed in the past with consecutive short thoracic spines and loss of lung volume. A new surgical technique is based on an indirect deformity correction and enlargement of the thorax via a longitudinal implant, the vertical expandable prosthetic titanium rib (VEPTR). The length of the thoracic spine after VEPTR implantation was analyzed in 21 children with an average follow-up of 4.2 years. Eighteen children did not have any prior surgery while three had already undergone spinal fusion. Using a 3-D analysis of computed tomography, a significant growth of the concave (7.9 mm/7.1% increase per year) and convex (8.3 mm/6.4%) side of the thoracic spine was found with no significant difference between sides. Unilateral unsegmented bars showed significant growth as well. Contrary to common knowledge, we were able to demonstrate the growth of the concave side of the thoracic spine and of the unilateral unsegmented bars after expansion thoracoplasty and VEPTR implantation.

Child↗
PubMed2002

[Idiopathic scoliosis and Scheuermann's kyphosis. Historical and current aspects of conservative treatment].

Although in practice since antiquity the nonoperative treatment of spinal deformities is still controversial. Giving preference to orthotic treatment and physiotherapy the historical development of nonoperative treatment will be demonstrated by the examples of idiopathic scoliosis and Scheuermann's kyphosis. It is surprising how early essential and still valuable principles of nonoperative treatment had been acquired and how many of the present-day concepts have remarkable forerunners in the 19th century. In the light of previous knowledge and personal experience the indication, practice and realistic capabilities of modern nonoperative treatment of idiopathic scoliosis and Scheuermann's kyphosis are pointed out.

Adolescent↗
PubMed2002

[Congenital anomalies of the spine].

Congenital anomalies of the spine usually originate in (toxic) disturbances during pregnancy. There are occasional hereditary types. These are characterized by the presence of multiple anomalies. Congenital scolioses are often associated with other anomalies like spinal dysraphy (20-30%) and fusion of the ribs. Furthermore heart defects, Sprengel's deformity, cleft palates, hemimelias, clubfeet or congenital vertical talus are frequently associated with congenital scoliosis. We classify in failures of formation, segmentation and combined types. The type of malformation determines the prognosis. One hemivertebra is associated with a risk of progression of 0-2 degrees/year, 2 ipsilateral hemivertebra with 2-3 degrees/year, a unilateral unsegmented bar with 5 degrees/year and a combination of a unilateral unsegmented bar with a contralateral hemivertebra with approximately 10 degrees/year. Conservative treatment is usually ineffective. The indication for operative treatment should be made before the deformity becomes unacceptable, as a correction is difficult and dangerous. The following operations can be carried out: Anterior and/or posterior fusion with or without instrumentation, epiphyseodesis, (hemi)vertebrectomies (with anterior and/or posterior approach), distraction with a halo, osteotomies, separation of the fused ribs and gradual distraction (Campbell's expansion thoracoplasty). The operations carry significant risks and the indication to the various treatment modalities is difficult. Operations should be made under monitoring of sensory and motor evoked potentials. From 498 patients with congenital anomalies of the spine in our observation we have operated on 143. Hemivertebrectomies were the most frequent interventions (56).

Abnormalities, Multiple↗
PubMed2002

[Intraspinal malformations. Tethered cord syndrome].

The importance of intraspinal malformations associated with "tethered cord" (attachment of the spinal cord) has increased in recent years, because of better imaging methods using nuclear magnet resonance (MRI). Orthopedic malformations such as club feet, equinus deformity, lordosis, hip dislocation, kyphosis, and differences of leg lengths, which up till now have been mostly treated by orthopedic surgeons, are usually first examined for congenital anomalies. According to the results of this examination, a neurosurgical operation for untethering is performed. The aim of our study is to define spinal malformations more exactly and to elucidate their importance for orthopedics. In addition, indications for operating, operative aims, diagnosis, therapy and follow-up are discussed. Examples of our results are shown, and the significance for interdisciplinary cooperation is emphasized.

Adolescent↗
PubMed2001

[Palliative surgery for bone metastases].

Advances in the treatment of patients who have bone metastases are an issue of high importance to the orthopaedic surgeon. Early diagnosis requires knowledge of the pathogenesis of bone metastases. A primary route of metastatic cells is via Batson's vertebral vein plexus. An understanding of the pathophysiology enables the surgeon to plan effective treatment. As many patients continue to survive for prolonged periods following the detection of bone metastases, it is important to plan treatment that relieves pain and is functional. In long bones non-operative treatment with radiotherapy, patient education to avoid excessive torsional loads and systemic chemotherapy or hormonal therapy as well as diphosphonates are utilized for small lesions with less than 25 percent of the cortical diameter. The indications for surgical treatment include lesions with elevated fracture risk according to Mirels score. Special emphasis is led on the surgical treatment of spinal metastasis. Early and effective treatment improves the remaining quality of life in patients with metastatic bone disease. However a firm knowledge of the pathogenesis and pathophysiology helps the clinician in making an early diagnosis. Nevertheless the orthopaedic surgeon must recognize the need to approach management of these patients from a multidisciplinary perspective in cooperation with the oncologist, radiotherapist, rehabilitation medicine specialist, radiologist, and pathologist. The cooperation among all members of the team will assure the best possible care for the patient who has metastatic bone disease.

Bone Neoplasms↗
PubMed2001

The non-peptidyl fungal metabolite L-783,281 activates TRK neurotrophin receptors.

Neurotrophin binding to the extracellular surface of the Trk family of tyrosine kinase receptors leads to the activation of multiple signalling cascades, culminating in neuroregenerative effects, including neuronal survival and neurite outgrowth. Since neurotrophins themselves are not ideal drug candidates due to their poor pharmacokinetic behaviour and bioavailability, small molecule neurotrophin mimetics may be beneficial in treating a number of neurodegenerative disorders. The present study demonstrates that L-783,281, a non-peptidyl fungal metabolite, is capable of stimulating TrkA, B and C phosphorylation to various extents in CHO cells stably expressing human Trk receptors. L-783,281 also stimulated Trk phosphorylation in a number of rat and human primary neuronal cultures, whereas the highly similar compound, L-767,827, was without effect. Mechanistic studies utilizing transiently transfected PDGF/TrkA and TrkA/PDGF chimeras, demonstrated that L-783,281 is likely to interact with the intracellular domain of the TrkA receptor. Further investigations suggested that L-783,281 was nevertheless able to instigate receptor dimerization by binding in a non-covalent manner. Although the cytotoxicity of the compound was shown to preclude its effects in neuronal survival and neurite outgrowth assays, it is a prototype for a small molecule neurotrophin mimetic that activates Trk by interacting at a site different from the neurotrophin-binding site.

Animals↗
PubMed2000

CEP-1347 increases ChAT activity in culture and promotes cholinergic neurone survival following fimbria-fornix lesion.

Recent evidence suggests that the activation of the Jun N-terminal kinase (JNK) signal transduction pathway may be important in neuronal responses to stresses such as trophic factor deprivation. Preventing the activation of JNK and expression of c-Jun may, therefore, be neuroprotective. Here, we report that the small molecule CEP-1347, which has been shown to inhibit the JNK signalling pathway, promotes cholinergic activity in cultured embryonic septal neurones. In vivo, we have shown that CEP-1347, administered either by sub-cutaneous (s.c.) injection or by continuous infusion, is partially neuroprotective, for cholinergic neurones in the medial septum, following fimbria-fornix transection. These data suggest that small molecules such as CEP-1347 may have beneficial effects in treating neurodegenerative diseases.

Animals↗
PubMed2000

[Deviations in the axes of the lower extremities].

Deviations in the axes can be physiological or pathological. During growth, the axes of the lower extremities undergo significant changes. The femoral neck-shaft-angle decreases from 150 degrees on average at birth to 120 degrees on average at the end of growth. The lower leg is bowed in a varus direction at birth. After a child begins to walk, the knee axis deviates to a slight valgus. This goes back to normal before the age of ten. Pathologic deviations of the axis are rare. They occur in congenital deformations, after trauma or infection, or as a result of metabolic diseases. In association with coxa vara pseudarthrosis of the femoral neck usually develops. Therefore this deformation has to be treated. Correction is best made with a Y-shaped osteotomy according to Pauwels. At the lower leg, a deviation of 15 degrees from the normal axis is usually an indication for operative treatment. In children and adolescents, corrections are best made with (monolateral) external fixators. They allow early weight bearing, which is especially desirable in bilateral corrections.

Adolescent↗
PubMed2000

Congenital pseudarthrosis of the tibia: history, etiology, classification, and epidemiologic data.

Congenital pseudarthrosis of the tibia is a rare disease with a variable history. The pseudarthrosis is usually not present at birth (and therefore is not truly congenital) but occurs during the first decade of life. Paget in 1891 was the first to describe a case. The etiology is unknown. Neurofibromatosis plays a role in approximately 50% of patients. In the others, hereditary and mechanical factors are debated. Various (morphologic) classification systems have been proposed (Andersen, Boyd, Crawford). Because the appearance changes during the course of the disease, all classification systems have limited value: the determining factor is the stage of the disease at which it was classified. Because of the rarity of the disease and the variability of its history, the European Pediatric Orthopaedic Society decided to carry out a multicenter study on this disease. This paper presents the epidemiologic data on the patients involved. Data have been gathered on 340 patients from 13 countries. Two hundred patients were male (58.8%), 140 were female (41.2%). The right side was affected in 165 patients (48.5%) and the left side in 172 (50.6%); 3 patients had bilateral disease. Symptoms of neurofibromatosis were present in 54.7%. Histologic examinations in 192 patients showed a nonspecific appearance in 45.3%; in 15.6% the ultrastructure resembled fibrous dysplasia, and in 39% there was histologic evidence of neurofibromatosis. Most of the lesions were initially localized in the middle or distal third of the tibia. In 29% the localization changed during the course of the disease.

Child↗
PubMed2000

The fibula in congenital pseudoarthrosis of the tibia: the EPOS multicenter study. European Paediatric Orthopaedic Society (EPOS).

Fibular involvement in congenital pseudoarthrosis of the tibia (CPT) can be either a rare isolated pathology or is in association with the tibial changes. Out of 282 patients with CPT who had complete radiographic work-up, 62% (almost two thirds) demonstrated fibular pathology: 36% had true fibular pseudoarthrosis and the rest, i.e., 26% had fibular hypoplasia or dysplastic fibula. Neurofibromatosis was found in 62% of the patients with fibular pathology. The typical radiological features of tibial pseudoarthrosis are often missing in patients with fibular pathology. It is most probably because fibular changes precede the tibial involvement. In 250 patients with tibial surgical treatment, the highest rate of fusion occurred in patients with fibular involvement compared with those with normal fibula.

Child↗
PubMed2000

Treatment approaches for congenital pseudarthrosis of tibia: results of the EPOS multicenter study. European Paediatric Orthopaedic Society (EPOS).

This study was designed to analyze the different therapeutic methods used by European Paediatric Orthopaedic Society members from 13 countries for congenital pseudarthrosis of tibia. The treatment data of 340 patients who underwent 1287 procedures for this condition were analyzed. The essential findings were that the method of choice needed to approach the biological problem with the aims of: (1) resecting the pseudarthrosis to provide stability, the basic requirement for bony consolidation; (2) correcting length discrepancy and axial deformity; (3) achieving fusion; and (4) solving the additional problems around the main deformity such as alignment, leg length discrepancy and ankle valgus. The Ilizarov technique emerged as being the optimal method, having the highest rate of fusion (75.5%) of pseudarthrosis and rate of success in correction of the additional deformities. There was also consensus that surgery should be avoided before the third year of life.

Adolescent↗
PubMed2000

Free vascular fibular transfer in congenital pseudoarthrosis of the tibia: results of the EPOS multicenter study. European Paediatric Orthopaedic Society (EPOS).

This paper presents a review of the literature, describes the principal author's (B.R.) personal experience and provides the results of the European Paediatric Orthopaedic Society (EPOS) multicenter study. The objective is to evaluate the present status and future role of free vascular fibular transfer in treating congenital pseudoarthrosis of the tibia. Variables such as the selection of cases, age at operation, technical surgical details and postoperative results will be considered. The data on the EPOS study were incomplete at the time of writing, but the considerable amount of information already amassed is a valuable contribution to this updated report.

Child↗
PubMed2000

Functional results at the end of skeletal growth in 30 patients affected by congenital pseudoarthrosis of the tibia.

From a multicentric study on Congenital Pseudoarthrosis of the tibia (CPT) conducted on 340 patients, we evaluated the functional results on a group of thirty patients who were at the end of skeletal growth (age < or = 16 years). The prognosis of CPT is very much related to the radiologic classification. Crawford type 2 and Crawford type 4 pseudoarthrosis have a worse prognosis, with a lower percentage of fusion at the site of pseudoarthrosis. Crawford 4 patients have the worst functional results. Most of them showed a severe leg length discrepancy, needed a permanent brace, with an ankle joint function fair or poor. The presence of fibula pseudoarthrosis seems to be responsible for most of the worst functional results. The level of deformity caused by either the natural course of the disease or its treatment, is decisive in the evaluation of the functional results.

Adolescent↗