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Biomedical subjects

G U Exner

Publications and source records attributed to G U Exner.

At least 37 records · Page 2Linked to original sources

[Abnormalities of the foot].

A few selected++ metric and numeric malformations of the foot (Fibular deficiency, vertical talus, coalition, syndactylism, macrodactylism, metatarsal malformation, cleft foot, overriding fifth toe) are discussed to demonstrate, that concepts for their treatment should be developed as early as possible in order to allow for bringing those structures that are developed in optimum use. Besides function cosmetic aspects of the foot also deserve being respected.

Adolescent↗

Reconstruction of the first and second metatarsals with free microvascular fibular bone graft after resection of a Ewing sarcoma.

We report the case of a 12-year-old girl with a Ewing sarcoma originating from the first metatarsal of one foot. Because the girl and her parents refused amputation of the foot, we resorted to complete local resection and to reconstruction of the first and second metatarsals with a free microvascular fibular bone graft. At 3 1/2 years after surgery, the patient continues to walk without a limp, and the mechanical function of the forefoot has been largely restored, although considerable loss of function of the big toe is apparent. Details of the surgical technique and tumor management are described.

Bone Neoplasms↗

Slipped capital femoral epiphysis: a long-term follow-up study after open reduction of the femoral head combined with subcapital wedge resection.

Sixty-six hips of 65 patients with moderate to severe slipped capital femoral epiphysis were treated by open reduction of the femoral head. In 60 hips this procedure was combined with a cuneiform subcapital wedge resection of the femoral neck according to the technique described by Dunn (14). Avascular necrosis occurred in seven cases, and chondrolysis was evident in eight hips. In the 48 hips with a follow-up time of more than 10 years (M = 20.6), the results were classified as good (normal hip) in 22, moderate in 16, and poor in 10 hips. Compared with the natural disease course, the long-term outcome appears to be improved by open reduction of the femoral head, with 60% of the hips free of degenerative changes and 19% with mild osteoarthrosis. Analysis of individual gliding angles and subcapital correction depending on the direction of the slip should lead to restoration of near-normal anatomic conditions or a normal hip function.

Adolescent↗

Limb salvage with osteoarticular allografts after resection of proximal tibia bone tumors.

A retrospective study was performed between 1980 and 1995 on 38 recipients of proximal tibial allografts after wide resection of benign and malignant tumors. Twenty-one (55%) patients experienced one or more complications. Of the 26 patients who received chemotherapy, 15 (58%) experienced one or more complications, whereas of the 12 patients who did not receive chemotherapy, six (50%) experienced one or more complications. In the chemotherapy group, there were 12 (46%) fractures, four (15%) infections, three (12%) nonunions, and four (15%) instabilities. In the nonchemotherapy group there were three (25%) infections, two (17%) fractures, one (8%) instability, and one (8%) nonunion. These complications were managed adequately with multiple subsequent surgical procedures. Three patients underwent amputations for deep wound infections. Twelve (32%) patients underwent removal of the allograft, and the limb was salvaged by reallografting or by total knee arthroplasty. The results of both groups were 66% (25 of 38 patients) satisfactory (good or excellent). The chemotherapy group had a significantly higher incidence of fractures. All other complication rates and functional outcomes were not significantly different between these groups.

Adult↗

[Magnetic resonance tomography in osteoid osteoma: more confusion than benefit?].

The purpose of this evaluation was the description of potentially misleading MR appearances of osteoid osteoma. The MR images of 10 patients with osteoid osteoma were retrospectively evaluated and compared to radiographic, intraoperative and histologic findings. 4 of the 10 abnormalities were located in the proximal femur, two in the lumbar spine, and one each in the tibial plateau, in the cervical spine, in the sacrum and in the first metacarpal. 8 of the 9 nidi visible on standard radiographs and/or CT scans were demonstrated on MR images. Edema was visible within the bone marrow in 3, within soft tissue in 2 and in both locations in 4 MR examinations. The soft tissue abnormalities were circumscribed in 3 patients and could be misdiagnosed as soft tissue tumors or an abscess in these patients. One of 5 osteoid osteomas located in the proximity of a joint mimicked septic arthritis. The MR appearance of osteoid osteoma may be misleading. However, false diagnoses usually can be avoided with a careful search of a nidus. MR imaging in osteoid osteoma is important for differential diagnosis.

Adolescent↗

[Hip dysplasia in infancy. Proton spin tomography and computerized tomography].

Magnetic resonance imaging (MRI) and computed tomography (CT) are useful techniques for the objective documentation of the relation between the femoral head and the acetabulum after closed or open reduction of a developmental dislocation of the hip joint. Before the ossification nucleus of the femoral head is sufficiently developed, MRI is preferred. For the evaluation of reduction from the 2nd year on, MRI and CT are equivalent. However, in older children MRI may also be indicated for the evaluation of cartilaginous structures or the diagnosis of femoral head necrosis. CT in older patients may also be useful for 30 analysis of bony structures, e.g. for planning complex osteotomies.

Child, Preschool↗

[Garré sclerosing osteomyelitis].

Osteomyelitis sclerosans Garré is still not completely understood. In spite of the fact that it is caused by bacterial infection, in most cases no bacterial growth can be discovered in culture. Furthermore, it remains open whether the chronic process is maintained by low-grade persistent infection or is maintained by itself after sterilization of the infection. Newer studies that may prove the presence of bacteria, e.g., by PCR, may elucidate the causes in the future. Sclerosing bone disease, sometimes multifocal, which present the same clinical, radiographic and histological features as chronic sclerosing osteomyelitis may be associated with diseases such as palmoplantar pustulosis, colitis ulcerosa, Crohn's disease, etc. and are reported as SAPHO (synovitis acne pustulosis hyperostosis osteitis) syndrome. In these diseases bacterial growth is almost always negative. However, temporary improvement under antibiotic therapy may be observed. A relationship between typical isolated chronic sclerosing osteomyelitis and SAPHO syndrome may exist, but the diseases should at present be differentiated. Neoplasms such as osteoid osteoma, Ewing sarcoma, or eosinophilic granuloma may simulate primary sclerosing osteomyelitis, and pathological examination of peripherally taken specimens may appear to be compatible with the diagnosis of sclerosing osteomyelitis. It should be appreciated that malignant tumors--even though this is the exception--can present a chronic, mild picture. Treatment of osteomyelitis sclerosans Garré needs be determined on an individual basis. A conservative approach with antibiotics usually leads only to temporary pain relief. The biopsy with opening of the medullary canal is sometimes sufficient for healing, while in extreme situations only segmental or even complete resection of the diseased bone case result in a permanent cure.

Adolescent↗

[Osteosarcoma and Ewing's sarcoma. Improved recovery chances in the past 25 years according to the experience of Balgrist Hospital].

At the Balgrist hospital 38 patients with osteosarcoma and 18 patients with Ewing sarcoma were treated from 1970 through 1992; a follow-up of at least three years is available for all patients. Disease-free survival in this period of time has increased from 20% (Ewing sarcoma) and 30% (osteosarcoma) to over 75%. While systemic tumor control was improved by systematic chemotherapy, local tumor control was improved by appropriate biopsy techniques, and amputations have been replaced by local resections, in most cases with reconstruction (arthrodesis, rotation plasty, endoprosthesis, allografts), which require further improvements. With respect to cure of the neoplastic disease, the currently available methods have been used to their maximum potential, and a steady state has been reached regarding survival. Further improvement of survival will therefore depend on the introduction of completely new modalities.

Adolescent↗

Metaphyseal peg in geroderma osteodysplasticum: a new genetic bone marker and a specific finding?

We describe two sibs with geroderma osteodysplasticum (GO) who, in addition to the known clinical and radiologic manifestations of the disorder, presented a metaphyseal peg indenting the epiphysis of the long bones, particularly at the knees. The peg was visible only at the age of 4 to 5 years but was invisible in infancy and following physeal closure. This may explain why this anomaly was not described in previous reports of 23 patients in 11 families with GO. The metaphyseal peg is an abnormality of bone development so far unknown to us. We speculate that it represents a primary, agedependent alteration of bone shape and hence a new genetic bone marker apparently specific to GO.

Abnormalities, Multiple↗

Prevention of secondary coxarthrosis in slipped capital femoral epiphysis: a long-term follow-up study after corrective intertrochanteric osteotomy.

Fifty-one patients with unilateral severe (gliding angles 30 degrees-60 degrees) slipped capital femoral epiphysis (SCFE) treated by intertrochanteric corrective osteotomy were reexamined after 20-29 years (average 24 years) of follow-up; 55% of the patients showed neither radiographic signs of degenerative hip disease nor clinical symptoms, whereas 28% had moderate and 17% had severe osteoarthritis. These results are definitely superior to those reported in other series of patients with comparable slips treated by bed rest or in situ fixation only. Analysis of individual gliding angles and directions of the slips shows that results can probably be further improved by correct assessment of the gliding process to allow for best use of the potentials of intertrochanteric corrective osteotomies. Correction should also be performed as early as possible to allow for maximum remodeling.

Adolescent↗

Titanium implant for the osteosynthesis of massive allograft reconstruction to improve follow-up by magnetic resonance imaging.

In twelve patients with local aggressive or malignant bone tumors allograft reconstruction after limb sparing procedures were performed using titanium implants for osteosynthesis. In eleven of these patients magnetic resonance imaging studies could be completed. Distortions of the images were limited to the vicinity of the implants and did not preclude detailed analysis of the gross anatomy and of fine articular structures involving and adjacent to the allografts used. Titanium implants therefore can be recommended whenever magnetic resonance imaging can be anticipated to be of importance for follow-up studies, such as after limb saving procedures for malignant musculoskeletal tumors. Aspects of high interest and importance in such cases include early recognition of local recurrence, bone fusion and healing of soft tissue structures, incorporation of allografts, and viability of cartilage.

Adolescent↗

[The lax juvenile flexible flatfoot--disease or normal variant?].

The spectrum of normal variations of children's feet is extremely broad and often difficult to separate from pathological conditions. Especially the flexible flatfoot normally disappears during growth, and even if it persists up to adult life, it hardly has any pathological significance. The natural course taken even by severe flexible flatfoot in children leads to results that are as good, if not even better than when surgery had been performed; therefore, more reticence with surgical treatment in such cases is advocated.

Child↗

[Epiphysiolysis of the femoral head--can surgery prevent later arthritis?].

Slipped capital femoral epiphysis is one of the few orthopaedic emergencies. All orthopaedic surgeons agree that operation is the treatment of choice. In early stages, complete healing is possible. Fixation in situ is sufficient. If there is more severe dislocation of the head of the femur, the results become worse. More sophisticated and more difficult interventions aim at correction of the deformity, which may be a preliminary stage ['prearthrosis'] of osteoarthritis later in life. According to the extent of the slip, the surgeon may choose among different operations. The decision in a particular case is not easy. Complications are relatively frequent and sometimes severe. Long-term control show the late results and can thereby give guidelines for the surgeon's choice. Early diagnosis, however, is still decisive for a good prognosis in later life. As the disease is rather rare, the doctor who sees the patient first must be aware of it. Even at an early stage diagnosis can always be made on the basis of history, clinical findings and two X-rays.

Bone Nails↗

[Orthoses in patients with poliomyelitis].

Poliomyelitis, in spite of vaccination, is still a problem: in the third world as well as for the victims of the epidemics of the first half of this century, who now, becoming older, have growing difficulties to overcome their paralyses. They needed and still need orthoses for walking. How do they manage? And what can orthopedic technique offer them today?

Adolescent↗

[Fibrous dysplasia and osteofibrous dysplasia].

Fibrous and osteofibrous dysplasia are benign lesions of the bone involving single bones as monostotic or multiple bones as polyostotic forms. When the patient is in the growth phase, the lesions, which are usually asymptomatic initially, may lead to deformities with typical bowing of the proximal femur ("shepherd's crook") and fractures. It is important to recognize osteofibrous dysplasia of the tibia and fibula, where any surgical measures, even a small biopsy, may activate the process and cause the lesion to grow, although it may spontaneously rest around puberty. Polyostotic fibrous dysplasia may rarely be associated with areas of cutaneous pigmentation and endocrine disturbances, especially precocious puberty (McCune-Albright syndrome).

Adolescent↗

[Reconstruction of segmental bone defects using massive osseous and osteocartilaginous allograft].

The reconstruction of large segmental defects after the resection of malignant bone tumors is usually done with modular or custom-made endoprostheses, so far, they appear to work well. From the experience with other indications for endoprostheses it must be admitted that failures will be a matter of time only. With the improved prognosis for patients with primary malignant bone tumors with regard to relapse-free survival and increased chances for permanent cure, the trend for reconstruction procedures should be directed to more 'biological' techniques. The reconstruction of osseous and osteocartilaginous defects with massive allografts is somewhere between the use of autologous bone and artificial replacement. From the experience with 14 allograft reconstructions in primary malignant bone tumors (osteosarcoma, malignant fibrous histiocytoma, leiomyosarcoma, chondrosarcoma, lymphoma) or other aggressive lesions (aneurysmal bone cyst, recurring giant-cell tumor, solitary metastasis) of the humerus (one osteoligamentous graft in combination with an endoprosthesis, one intercalary graft), the femur (three intercalary grafts, two osteoarticular distal femurs, one combination with an endoprosthesis), and the proximal tibia (four osteocartilaginous, two intercalary grafts) in patients aged 10 to 64 years, we feel that this type of reconstruction allows for a reconstruction without sacrificing more bone and soft tissue than needed for the surgical margins. Fusion between the patient's bone and the allograft has been seen after 6 to 18 months. From this small series it is concluded that using allografts might allow for the preservation of joint structures that need to be resected for the implantation of an endoprosthesis, increasing the possibilities for salvage procedures.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

[Lengthening, axial correction and segmental reconstruction of the extremities using the distraction method].

Between 1988 and 1992 lengthenings axial, corrections and reconstructions have been performed by distraction on lower arms, upper and lower legs in 25 patients because of deviations in length due to either congenital or acquired (multiple cartilaginous exostoses, posttraumatic conditions, congenital pseudarthrosis deformations or defects (fibula-defect, amnion-band-complex, amputation). On the average elongation amounted to 4 cm for an average installation time of the fixator system of 22 weeks and a mean duration of 25 weeks for the adaptation to full strength. Problems arose in the form of soft tissue infections at the rod perforation sites, the necessity for secondary interventions because of early fractures and for corrections of the fixator respectively. Complications compromising the expected goal of treatment did not occur. Consideration of the biological principle of distraction is essential whereas the type of fixator-system is of only minor importance.

Adolescent↗