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Biomedical subjects

G U Exner

Publications and source records attributed to G U Exner.

At least 19 recordsLinked to original sources
PubMed2006

[Osteoid osteoma. CT guided drilling and radiofrequency ablation].

BACKGROUND: The CT-guided therapy of osteoid osteoma instead of older methods such as open resection has the advantage of exact localization of the nidus intraoperatively and exact documentation of its ablation. Another advantage is the less invasive approach. PATIENTS AND METHODS: A total of 52 patients with osteoid osteoma were treated in our institution between 1996 and 2005 either by radiofrequency ablation (n=11) or by percutaneous resection under CT guidance (n=41). Their age was between 7 and 48 years, mean age was 22.3 years, and follow-up was 31.3 months. RESULTS: In all patients (n=52) the osteoid osteoma was successfully treated. In 50 patients the first treatment resulted in long-term success. In two patients the nidus was first missed; they were successfully treated with another operation using the same technique. CONCLUSION: The CT-guided operation of osteoid osteoma made the therapy much easier because of the exact localization and the less invasive approach. This technique can be used analogously to tumor biopsy. The advantage is the exact documentation of the biopsy path and the possibility to take specimens.

Adolescent↗
PubMed2006

In vitro inhibition of coagulase-negative staphylococci by vancomycin/aminoglycoside-loaded cement spacers.

BACKGROUND: Successful treatment of allograft infections by the temporary implantation of an antibiotic-loaded polymethylmethacrylate cement spacer depends on the diffusion of antibiotics out of the cement and inhibition of bacterial growth in the surrounding tissue. We investigated with an in vitro model how long antibiotics are released by the cement and if gentamicin-resistant coagulase-negative staphylococci (CNS) are inhibited by vancomycin mixed with the gentamicin-loaded cement. MATERIALS AND METHODS: Four formulations of antibiotic-loaded cement disks, i.e. gentamicin, tobramycin, vancomycin and tobramycin combined with vancomycin, respectively, were used to test the inhibition of eight isolates of Staphylococcus epidermidis and two reference strains of Staphylococcus aureus by an agar diffusion test on Mueller-Hinton (MH) agar similar to the routine laboratory disk diffusion method. Moreover, cement spacer cylinders loaded with gentamicin alone or combined with vancomycin were submerged in MH agar for weeks and the capacity to inhibit five different isolates of S. epidermidis was measured. RESULTS: The size of the inhibition zones around the antibiotic-loaded cement disks correlated with the minimal inhibitory concentration (MIC) of the antibiotics against the tested strains. All five strains of S. epidermidis were inhibited by vancomycin-loaded cement spacers for at least 30 days. However, two gentamicin-resistant S. epidermidis strains with MICs of 4 mg/l and 16 mg/l could not be inhibited longer than 3 days by the gentamicin-loaded cement spacer. CONCLUSION: The in vitro data suggest that antibiotic-loaded cement spacers inhibit susceptible bacteria for 4-6 weeks. The addition of vancomycin to commercial aminoglycoside-loaded cements might be helpful in allograft infections in tumor patients to inhibit a broad range of bacteria including gentamicin-resistant CNS very commonly found in such infections.

Aminoglycosides↗
PubMed2006

Additional muscle in idiopathic club foot.

During the dissection of seven club feet of foetuses, aborted between the 25th and 37th week of gestation, an additional muscle bundle was found in a right foot. This muscle arose from both heads of the gastrocnemius muscle, continued downwards onto the posterior surface of the soleus, crossed the calcaneal tendon and assumed a position on the lateral side of the calcaneal tendon. The muscle's tendon was fixed just laterally to the calcaneal tendon in the calcaneal tuberosity with some tiny fibres branching off into the superior fibular retinaculum.

Clubfoot↗
PubMed2006

Free vascularised osteocutaneous filet flap for covering, that permitted sensitive terminal weight-bearing by a thigh stump after transfemoral amputation.

We covered a transfemoral amputation stump with a modified free filet flap including the calcaneus. The flap survived, resulting in lengthening of the femur, improved distal weight-bearing, preserved sensitivity of the stump, and the design of a prosthesis with terminal loading of the femur rather than an ischial contained prosthesis.

Adult↗
PubMed2006

Allograft reconstruction for bone sarcoma of the tibia in the growing child.

The outcome of tibial allograft reconstruction after resection of a tumour is inconsistent and has a high rate of failure. There are few reports on the use of tibial allografts in children with open growth plates. We performed 21 allograft reconstructions (16 osteoarticular, five intercalary) in 19 consecutive patients between seven and 17 years of age. Two had Ewing's sarcoma, one an adamantinoma and 16 osteosarcoma, one with multifocal disease. Five patients have died; the other 14 were free from disease at the time of follow-up. Six surviving patients (eight allograft reconstructions) continue to have good or excellent function at a mean of 59 months (14 to 132). One patient has poor function at 31 months. The other seven patients have a good or excellent function after additional procedures including exchange of the allograft and resurfacing or revision to an endoprosthesis at a mean of 101 months (43 to 198). The additional operations were performed at a mean of 47 months (20 to 84) after the first reconstruction. With the use of allograft reconstruction in growing children, joints and growth plates may be preserved, at least partially. Although our results remain inconsistent, tibial allograft reconstruction in selected patients may restore complete and durable function of the limb.

Adamantinoma↗
PubMed2005

Uncemented short-length diaphyseal segmental replacement prosthesis fixation--finite element analysis and long-term results.

INTRODUCTION: Extensively porous coated segmental replacement prostheses with intramedullary cementless fixation to bone over the whole length of stem often exhibit resorption of the surrounding bone due to stress-shielding. This makes them particularly susceptible to aseptic loosening. STUDY: A finite element analysis of the state of loading of a short-length fixation in a new prosthetic stem design has shown a definite advantage over long-length fixation. The stress pattern within the bone surrounding the prosthesis confirmed that shortening of the ongrowth area in length increases the stress values at the resection level significantly. This stem (Endlock) has been used for diaphyseal anchorage in the treatment of tumors in combination with an artificial joint of proven design in order to reduce stress shielding. RESULTS: No Endlock stem fractures or aseptic loosenings were observed at recent follow-up. The early clinical results comply with the theoretical assumptions. CONCLUSIONS: A short-length fixation system based on intramedullary anchorage of segmental replacement endoprostheses would possibly support physiologic adaptive processes more than fixation over the full length of the stem.

Adult↗
PubMed2004

Foot function after ray resection for malignant tumors of the phalanges and metatarsals.

Four patients with malignant tumors of the proximal toe phalanx who had closed contact or direct involvement of the metatarsophalangeal joints or direct infiltration of the metatarsal bone were treated. Treatment included ray resection and reconstruction either by free microvascular fibula transfer, intermetatarsal bony fusion, or soft-tissue stabilization. Foot function was analyzed by Novel pedobarography. The four patients with a follow-up between 21 months and 8 years show almost normal gait. All patients have remained relapse free. If adequate margins can be achieved, ray resection and appropriate reconstruction may be an alternative to amputation.

Adolescent↗
PubMed2002

Gorham-Stout disease of the shoulder girdle and cervico-thoracic spine: fatal course in a 65-year-old woman.

A case of Gorham-Stout disease of the shoulder girdle and cervico-thoracic spine in a 65-year-old woman is described. The patient presented with progressive neurologic symptoms, pain, and deformities of the cervico-thoracic spine as well as of her left shoulder following a traumatic shoulder luxation. Since the patient had a history of uterine carcinoma, the current disease was clinically difficult to differentiate from osteolytic metastases. The results of the clinical, radiological and histopathologic examination leading to the diagnosis of Gorham-Stout disease are described. Neither attempted surgery nor radiotherapy produced clinical improvement and the patient died 1 year after the first clinical evaluation.

Aged↗
PubMed2002

[Treatment of acute slips and clinical results in slipped capital femoral epiphysis].

In looking at the pathoanatomy of slipped capital epiphysis, it is important to appreciate that the articular cartilage ruptures at the level of the physis as the articular cartilage also covers part of the femoral neck metaphysis. As a consequence, smoothness is lost and already with mild slips the irregularities may injure the acetabular cartilage structures and may cause tears of the labrum. Principally therefore an open revision and restoration of the anatomy as perfectly as possible is needed. The technique for open reduction was developed by Dunn in 1964 and then refined by Ganz in 1997 applying new anatomical vascular studies. However, the long-term data on the "conservative" approach of only using transfixation to avoid further slipping show relatively good results and long-term studies of a more aggressive open approach will be needed to show evidence of further improvement. For the more severe cases, restoration of the correct anatomy by open reduction or improved axial relationships by more distant osteotomies have already been proven to give better results. Besides the extent of the slip, it is important to consider whether the slip is acute or chronic or acute and chronic. So far there are no data showing that the surgical treatment of slipped capital femoral epiphysis must be made on an emergency basis. However, prevention of further slips, e.g., by supine transport, is to be considered an emergency.

Adolescent↗
PubMed2002

[Indication for and results of intertrochanteric osteotomy in slipped capital femoral epiphysis].

The progression of degenerative changes of the hip after slipped capital femoral epiphysis (SCFE) largely correlates with the patient's age at the time the deformity occurs and with the degree of the epiphyseal gliding. From the pathogenetic point of view, the altered biomechanical conditions of the hip joint with deformation of the proximal femur may result in an impingement of the femoral neck metaphysis against the anterior acetabular rim. Observations of the "natural course" or after "in situ fixation" of the epiphysis show the development of secondary hip arthritis at an average of 20 years after SCFE, specifically in slips with more than 30 degrees of epiphyseal gliding. The intertrochanteric osteotomy as introduced by G. Imhäuser aims at restoring joint congruity to reduce the prearthrotic deformity and thus to decrease the incidence of later hip arthritis. The reorientation of the predominantly posteriorly slipped femoral epiphysis is achieved by an intertrochanteric flexion osteotomy, which reduces the potential for femoroacetabular impingement. On the basis of a long-term evaluation, the indication for and results of an intertrochanteric osteotomy for chronic unilateral SCFE were presented. Of the 51 patients operated on between 1962 and 1972 and examined clinically and radiographically at an average follow-up time of 24 years (20-29 years) after osteotomy, 55% showed a hip free of degenerative changes, 28% had developed moderate degenerative changes, and 17% had advanced arthritis. Aside from a few technical errors, the correction at the intertrochanteric level for moderate slips proved to be a safe procedure regarding risk for femoral head necrosis. The long-term development after SCFE is most important for patients with SCFE. More than half of the patients have hip joints free of degenerative changes more than 20 years after intertrochanteric osteotomy according to G. Imhäuser, which compares favorably to the "natural course" or to "in situ fixation" and which supports the indication for this corrective procedure in SCFE.

Adolescent↗
PubMed2001

Localized Ewing tumor of bone: final results of the cooperative Ewing's Sarcoma Study CESS 86.

PURPOSE: Cooperative Ewing's Sarcoma Study (CESS) 86 aimed at improving event-free survival (EFS) in patients with high-risk localized Ewing tumor of bone. PATIENTS AND METHODS: We analyzed 301 patients recruited from January 1986 to July 1991 (60% male; median age 15 years). Tumors of volume >100 mL and/or at central-axis sites qualified patients for "high risk" (HR, n = 241), and small extremity lesions for "standard risk" (SR, n = 52). Standard-risk patients received 12 courses of vincristine, cyclophosphamide, and doxorubicin alternating with actinomycin D (VACA); HR patients received ifosfamide instead of cyclophosphamide (VAIA). Tumor sites were pelvis (27%), other central axis (28%), femur (19%), or other extremity (26%). The initial tumor volume was <100 mL in 33% of cases and > or =100 mL in 67%. Local therapy was surgery (23%), surgery plus radiotherapy (49%), or radiotherapy alone (28%). Event-free survival rates were estimated by Kaplan-Meier analyses, comparisons were done by log-rank test, and risk factors were analyzed by Cox models. RESULTS: On May 1, 1999 (median time under study, 133 months), the 10-year EFS was 0.52. Event-free survival did not differ between SR-VACA (0.52) and HR-VAIA (0.51, P =.92). Tumor volume of >200 mL (EFS, 0.36 v 0.63 for smaller tumors; P =.0001) and poor histologic response (EFS, 0.38 v 0.64 for good responders; P =.0007) had negative impacts on EFS. In multivariate analyses, small tumor volumes of <200 mL, good histologic response, and VAIA chemotherapy augured for fair outcome. Six of 301 patients (2%) died under treatment, and four patients (1.3%) developed second malignancies. CONCLUSION: Fifty-two percent of CESS 86 patients survived after risk-adapted therapy. High-risk patients seem to have benefited from intensified treatment that incorporated ifosfamide.

Adolescent↗
PubMed2001

[Clubfoot orthosis with integrated dynamic cuff for retention and redressing].

Conservative treatment of clubfoot deformities with braces and bandages is traditionally several hundred years old. The clubfoot braces of Venel, Scarpa, and Schulthess, as well as the redressing bandage of Cheselden, are reviewed as typical examples. The treatment of clubfoot deformities was initiated in the Balgrist Hospital for Orthopedic Surgery by W. Schulthess. Recently, in Balgrist, we developed a brace that retains and redresses the foot. This brace is described, and early clinical results are reported.

Bandages↗
PubMed2001

Osteoid osteoma: technique of computed tomography-controlled percutaneous resection using standard equipment available in most orthopaedic operating rooms.

Symptoms of osteoid osteoma are cured by removing the nidus. 'En-bloc' resection is often not successful because the nidus is hard to find and remove totally. Recently, minimally invasive procedures have been advocated for the resection of osteoid osteoma. Preceding investigators have used a set of special instruments. The nidus is best localized with computed tomography (CT). Surgery under CT control is only possible with minimal invasive procedures. A technique using standard equipment usually available in the operating room can be used successfully for CT-guided removal of the nidus. We report our preliminary results with 17 patients (12 men, 5 women) with an average age of 22 years (range 6-57 years). All patients were pain-free immediately after the operation. The average follow-up was 8.4 months (range 1-22 months) and the average operating time 75 min (range 50-130 min). Ten patients could be treated as outpatients. The average time in hospital after surgery was 1.5 days (range 1-3 days). There were two complications, one superficial wound infection and one change of operative technique to an open procedure due to a technical problem. The diagnosis could be confirmed histologically.

Adolescent↗
PubMed2001

Missed chronic anterior Monteggia lesion. Closed reduction by gradual lengthening and angulation of the ulna.

Two consecutive cases of chronic dislocation of the head of the radius after missed Bado type-I Monteggia lesions are presented. Reduction was successfully achieved in both patients after ulnar corticotomy, gradual lengthening and angulation of the ulna using an external fixator. Open reduction or reconstruction of the radio-ulnar capitellar joint was not undertaken. The age at injury was seven years in the older and two years in the younger patient. The time from injury to treatment was five years in the older and three months in the younger child. At follow-up, nine years after completion of treatment in the older and eight months in the younger patient, both show satisfactory movement, function of the forearm and reduction of the head of the radius. This technique may be considered in missed Monteggia lesions before open procedures on the radio-ulnar capitellar joint are undertaken.

Bone Lengthening↗
PubMed2000

Osseous lesions of the distal ulna: atypical location--unusual diagnosis. Report of three cases with similar imaging and different pathologic diagnoses.

Three cases with destructive bone lesions of the distal end of the ulna caused by different pathologic entities (Ewing's sarcoma, osteosarcoma, rheumatoid pseudotumoral synovitis) are presented, all with similar clinical and comparable x-ray and magnetic resonance imaging features. Although the distal end of the ulna may be resected without significant functional impairment, careful evaluation of treatment strategies compatible with oncologic standards is warranted.

Adult↗
PubMed1999

[Osteofibrous dysplasia and its differential diagnosis].

We present a case of a 13 year old girl with swelling and pain of the right lower leg persisting for four months. The radiological and histological diagnosis is osteofibrous dysplasia. Osteofibrous dysplasia is a rare bone lesion predominantly affecting the cortex of the tibia. Almost all patients are younger than ten years at presentation. Swelling is a typical clinical manifestation. Radiologically and even histologically the distinction between the osteofibrous dysplasia and the more aggressive adamantinoma can be difficult. Other bone lesions potentially mimicking osteofibrous dysplasia include: fibrous dysplasia, osteoid osteoma, osteosarcoma, osteoblastoma and intracortical Brodie's abcess. The natural course of the disease is unpredictable. Lesions with typical radiological appearance are considered to be "no touch lesions". In equivocal cases block resection (with both a diagnostic and therapeutic purpose) should be performed.

Adolescent↗