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Biomedical subjects

A M Weinberg

Publications and source records attributed to A M Weinberg.

At least 19 recordsLinked to original sources
PubMed2000

A new kinematic model of pro- and supination of the human forearm.

We introduce a new kinematic model describing the motion of the human forearm bones, ulna and radius, during forearm rotation. During this motion between the two forearm extrem-positions, referred to as supination (palm up) and pronation (palm down), effects occur, that cannot be explained by the the established kinematic model of R. Fick from 1904. Especially, the motion of the ulna is not properly reproduced by Fick's model. During forearm rotation an evasive motion of the ulna is observed by various authors, using magnetic resonance imaging MRI) technology. Our new kinematic model also simulates this evasive motion. Furthermore, the model is enlarged to include angulations of the forearm bones. Using these results the influence of forearm fractures on the range of forearm motion can be predicted. This knowledge can be used by surgeons to choose the optimal therapy in re-establishing free forearm mobility.

Biomechanical Phenomena↗
PubMed1999

[Extracorporeal shock wave therapy for delayed union of long bone fractures - preliminary results of a prospective cohort study].

Extracorporal shock wave therapy (ESWT) has been postulated as an additional therapeutic option in nonunion after fracture treatment. We have reexamined patients with nonunions treated at our institution to evaluate the efficacy of the method. In a prospective nonrandomized study patients were investigated with a minimum duration of nonunion of 6 months. Following 2 cycles of ESWT with 2000 impulses/18 kV, the reevaluation was performed at 1, 3 and 6 months after treatment. A total of 27 pseudarthroses was reevaluated, in 11 one or more reosteosyntheses had been performed prior to ESWT. Following ESWT we found a success rate of 41 % (n = 11). The clinical evidence of subjective, clinical improvement was found in 5 of these patients within 1 month, in all of these patients within a period of 3 months. Radiologic evidence of improvement occurred in none of these patients within 1 month, in all of these patients within 6 months. ESWT appears to represent an additional treatment option in patients with longstanding nonunion. If no improvement occurs, the maximum delay of reosteosynthesis is three months.

Adolescent↗
PubMed1997

[Complex trauma of the elbow].

The complex injury is characterized by a fracture and/or dislocation of the elbow in association with a serial injury of the upper extremity, or a severe soft tissue trauma, or a prolonged ischemia caused by vascular injury or compartment syndrome. They are defined as complex injuries because their treatment differs from that of a simple fracture implying that standardized concepts usually cannot be employed. The results of primary treatment show a high rate of complications. They are accompanied by functional deficits including pseudarthrosis and ankylosis. As a consequence, ulnar neuropathy may occur. Inadequate treatment leads to delayed rehabilitation and several secondary operations. The main goal points at the reconstruction of the elbow joint to restore function. Therefore, the logistical pathway of individual therapy is the key for success. The operation has to include fracture stabilisation of all injuries of the upper extremity. Only stable osteosynthesis makes early mobilisation possible. Transfixation of the elbow joint should be reserved for exceptional cases. The principals of AO have proven to be practical both for the distal humerus and the proximal forearm. Successful reconstruction of the elbow joint often demands extended approaches. ORIF of the proximal ulna can be achieved by indirect reposition techniques. Dynamic stabilisation should be established by conservation of the radial head and coronoid process. For treatment of soft tissue injury it is necessary to undertake local reconstructive measures. Operative treatment is widely indicated for forearm compartment syndrome. Diagnosis and therapy of possible accompanying vascular injury should be made early to avoid prolonged ischemia. Operative treatment of nerve injury is only indicated in case of sharp dissection of the nerve. Otherwise the reconstruction should be performed, but not earlier than three months. Rehabilitation outcome depends on primary therapy. Sufficient functional results are only achieved after early mobilisation and intensive physiotherapy. If necessary, arthrolysis is planned early and combined with removal of implants at 6 months post injury.

Compartment Syndromes↗
PubMed1997

[Guidelines in surgery--pediatric traumatology].

Guidelines for the treatment of fractures in children include social and therapeutic parameters, such as adequate hospitalization for children, a definitive therapy with a low degree of invasiveness, and a high degree of freedom of mobility. The selection of a method is linked to the patient's requests. Minimally invasive techniques should be applied in preference. Therapeutic strategies should be compared not only with regard to results, but also with regard to effectivity and efficiency. There are no strict guidelines in therapeutic procedures whatsoever.

Child↗
PubMed1996

[Conservative functional therapy of closed rupture of the Achilles tendon. Treatment approach and analysis of results].

In a prospective study in the period from May 1989 to April 1994, 161 patients at the Unfallchirurgische Klinik in Braunschweig were treated for rupture of the Achilles tendon using a conservative functional method. A follow-up examination was carried out on 132 patients (81%) after an average of 12.6 months. Conservative therapy was indicated if dynamic ultrasonography showed sufficient adaptation of the rupture. Continuous retention of the adapted tendon fragments was guaranteed by means of special footwear that raises the back of the foot (Variostabil). The average age of the patients was 39.5 years. In 97 cases (73.5%) the injury was caused by sports. In 68 ruptures the dehiscence was compensated in plantar flexion. In 48 cases the dehiscence was 1-5 mm, and in 16 cases it was between 6 and 10 mm. The average period of hospitalization was 4.8 days (1/19). The period of inability to work was an average of 4 weeks (27.4 days (0/98)). The rupture healed on an average of 9.5 weeks (5.9/23). Complications included seven cases of re-rupture (5.3%), and, in the course of treatment, four patients (3%) suffered profound leg vein thrombosis that in one case developed into postthrombotic syndrome. In two cases there was tendovaginitis of the Achilles tendon. Early functional conservative therapy using the VARIO-STABIL shoe is a suitable method for treating a newly ruptured Achilles tendon. When there is a precise indication, the method is equally as good as operative therapy and because of the low complication rate, it is even preferable.

Achilles Tendon↗
PubMed1995

[Covered osteosynthesis through cannulated screws in medial Garden type I and II femoral neck fractures].

Fracture of the femoral neck is a common problem in elderly patients. In these patients with concomitant illness and medical complications the hip fracture is then often the reason for a long-term institutionalization with serious implications for the outcome. While the treatment of displaced femoral neck fractures Garden's stage III and IV is quite clear, the procedure for impacted or undisplaced fractures Garden's stage I or II is still the subject of controversy. In a retrospective study was shown that conservative treatment of impacted or undisplaced femoral neck fractures is associated with a high complication rate of 30-40%. When these femoral neck fractures were broken down according to Garden's classification the complication rate in cases of Garden's stage II was found to be 1.5 times that in femoral neck fractures in Garden's stage I. With a P-value less than 0.05 this difference was statistically significant (Wilcoxon test). Because of these major problems associated with conservative treatment we changed our current algorithm. Covered internal fixation with cancellous screws is now considered to be indicated for all impacted or undisplaced femoral neck fractures. Between 1990 und 1992, 53 patients (42 female, 11 male) with femoral neck fracture in Garden's stage I (24 patients) or II (29 patients) were treated in our Department of Traumatology with 6.5 mm cancellous screws. In all case early mobilization and weight-bearing were allowed. In this prospective study the average follow-up was 14.3 +/- 2.1 months (range 8-20 months).(ABSTRACT TRUNCATED AT 250 WORDS)

Activities of Daily Living↗
PubMed1994

[Experience with external fixation in treatment of shaft fractures in childhood].

In a retrospective study 89 shaft fractures sustained during childhood and treated by external fixation were analysed [80 fractures of the lower extremity (59 of the femur) and 9 of the upper extremity]. The operative investment (operating time, period of hospitalization, time for fluoroscopy, general anaesthesia, start of mobilization, number of X-rays) correlated with the success of the treatment. The overall complication rate was 19.1%. Technical errors occurred in 5.6% of all cases; the infection rate was 4.5%; refractures were seen in 4.5% of all patients and reinfarction also in 4.5%. The last 10 femur fractures were analysed separately and the overall complication rate was demonstrably reduced to 3.2%. All technical errors are avoidable and the infection rate could be minimized by better care of the pin, exit points, and by ensuring more stable anchorage of the screws. The consolidation time is longer than with plate osteosynthesis and medullary nailing. But in contrast to adults, in children the treatment was completed with external fixation, and no pseudarthrosis was seen. The consolidation time was shorter with dynamic external fixation. With dynamic systems healing took an average of 7 weeks, while rigid systems needed an average of 9 weeks. Refractures and reinfarction were caused by the rigidity of the external fixation system. In isolated dislocated shaft fractures in childhood the advantages of the fixateur externe are its easy application, low level of invasiveness and early mobilization. It was used in all kinds of fractures in children aged 4-13 years.

Child↗
PubMed1993

[Para-basal metatarsal V fracture: conservative functional treatment].

Fractures of the fifth metatarsal bone, mostly avulsion fractures that result from forced inversion of the plantar foot, are relatively common. There are two distinct types of fracture that involve the proximal portion of the fifth metatarsal bone. The first type is the proximal diaphyseal fracture, the so-called Jones fracture, and the second type involves the area of the metatarsal tuberosity. They are usually not displaced or only slightly displaced. The standard treatment is a below-the-knee walking cast Osteosynthesis for fractures of the fifth metatarsal bone is indicated only in cases where significant displacement cannot be corrected by closed reduction. At the Department of Traumatology in the Städtische Klinikum Braunschweig. 51 patients (32 male, 19 female) with an avulsion fracture of the proximal diaphyseal portion or a Jones fracture of the fifth metatarsal bone were treated functionally with a brace (Caligamed II). The average displacement was 1.4 mm (range 0.8-4.0 mm). In each case the fracture was treated for 2-3 days in a short leg cast and additional antiphlogistic medication was applied. After edema had been reduced, every patient was fitted with a carefully adapted Caligamed II brace, and this was followed by intense mobilization and walking therapy. The average follow-up in this study was 14.2 +/- 1.8 month. In this protocol the patients were examined at our clinic during the first week after trauma in order to check the brace again, again after 5-6 weeks for X-rays and to remove the brace, and for a final check-up after 12 weeks.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

[Prevention of thrombosis in ambulatory patients].

In surgical outpatients who required immobilization with a plaster cast because of injury to the lower limb a deep vein thrombosis occurred in 14%. General thromboprophylaxis seems advisable for surgical outpatients and depends on the severity of trauma and thrombosis risk factors. In a study of 97 patients who received a daily subcutaneous injection of heparin fragment calcium throughout their cast period, only one patient with a deep vein thrombosis was seen.

Adult↗
PubMed1992

[The Pelvic Professional Section of the German Society of Accident Surgery and the German Section of AO-International].

On the occasion of the 1990 Conference of the German Society for Accident Surgery (DGU) in Berlin, a working group "Pelvis" of the DGU and the AO International was established on the initiative of H. Tscherne. It is the objective of this working group to formulate guidelines for the diagnosis and treatment of pelvic girdle fractures, within the framework of a prospective multicentre study based on comparable results. In the annual report for 1991, a total of 460 pelvic fractures were documented. Classification shows that 9.5% belong to group A, 46.3% to group B, and 44.2% to group C. One hundred and eighty-two patients (39.6%) had an isolated pelvic injury, while 278 (60.4%) sustained multiple injuries. The average polytrauma score for all 460 subjects was 23.2 points. The surgical management was shown to depend on the severity of the fracture.

Adolescent↗
PubMed1989

Science, government, and information: 1988 perspective.

Twenty-five years have passed since the appearance of Science, Government, and Information (SGI), the 1963 report by the President's Science Advisory Committee (PSAC). The Information Analysis Center, which was prominently recommended in SGI, has not become a central element of the information system. Instead automation, which was only beginning in 1963, has become dominant. Though extreme automation may be appropriate for those activities that are time constrained, it may lead to clogged information channels for those scientific activities for which time is less important than depth of understanding.

Government↗