Biomedical subjects

P Regazzoni

Publications and source records attributed to P Regazzoni.

At least 55 records · Page 3Linked to original sources

PubMed1996

[Proximal humeral multiple fragment fractures--failures after T-plate osteosynthesis].

Dislocated compound fractures of the proximal humerus are often difficult to treat. The choice of treatment influences the final functional result. From 1984-1991 108 patients with dislocated compound fractures of the proximal humerus were operated with a T-plate osteosynthesis, retrospectively examined and classified according to the Neer-Classification. At an average follow up time of 5 years 72 patients had a clinical and radiological examination. 68% of these patients with 3-fragment fractures and 80% with 4-fragment fractures showed a modest to unsatisfactory result caused by fracture biology, imprecise fracture reduction or poor surgical procedure. Incorrect position of T-plates and inadequate material were distinguishable. The T-plate which was widely used in the late eighties for internal fixation has to be considered a failure for these particular types of fractures and should be limited for Collum chirurgicum fractures.

Adult↗

PubMed1996

Fractures of the distal end of the radius treated by internal fixation and early function. A preliminary report of 20 cases.

Fractures of the distal end of the radius should be treated on the same principles as other fractures involving joints. Displaced articular fractures require open reduction to allow anatomical reconstruction of both the radiocarpal and the radio-ulnar joints. For extra-articular fractures with severe comminution and shortening this enables the radial length to be re-established achieving radio-ulnar congruency. Stable internal fixation can be achieved with two 2.0 AO titanium plates placed on each of the 'lateral' and the 'intermediate' columns of the wrist at an angle of 50 degrees to 70 degrees. This gives good stability despite the tiny dimensions of the plates, and allows early function. We report a series of 20 fractures treated by this method of internal fixation with satisfactory results in all.

Adult↗

PubMed1995

The unstable shoulder girdle: early functional treatment utilizing open reduction and internal fixation.

The unstable shoulder girdle--a combination of a scapular neck fracture with a clavicular fracture, acromioclavicular dislocation, or sternoclavicular dislocation--represents a rare and often underestimated injury. Sufficient treatment to permit early function is necessary to avoid a frozen shoulder as well as to treat concomitant thoracic injuries. This is possible only by open reduction and internal fixation. In most cases this can be achieved by a sole osteosynthesis of the clavicular injury. We retrospectively analyzed 12 cases and classified the results according to the Constant Score. This analysis showed excellent functional results in nearly all cases.

Acromioclavicular Joint↗

PubMed1995

Intramedullary nailing and pulmonary embolism: does unreamed nailing prevent embolization? An in vivo study in rabbits.

Pulmonary embolism in reamed femoral nailing has been reported and discussed over recent years. Does an unreamed nailing technique with a solid nail prevent this rare but serious complication of intramedullary fixation? In an animal model in rabbits, we studied the pathophysiologic impact on pulmonary function and the impact on hemostasis of reamed and unreamed nailing of intact femora and tibiae, and of femoral fracture in relation to intramedullary pressure. No statistical difference of PaO2, PaCO2, and PCO2et was found in the femur whether a reamed or unreamed procedure was performed. Two of six animals with unreamed femoral nailing, one of six animal with reamed femoral nailing, and one of five animals with a femoral fracture fulfilled four of four or three of four criteria for embolization (increase of the difference of PaCO2 and PCO2et, decrease of PaO2, increase of blast cells in central-venous blood and bone marrow/fat in histologic section of the lungs and bone). Tibial nailing did not alter pulmonary function in either group. Intramedullary pressure was increased in all animals with perioperative impairment of pulmonary function (375 to 676 mbar). Analysis of the hemostatic results showed a significant difference of platelet activation in reamed versus unreamed nailing of the femur 1 hour after nailing (p < 0.01) and a significant decrease of fibrinogen and antithrombin III (p < 0.001/p < 0.01) in reamed femoral nailing. We conclude that unreamed nailing of the femur with a solid rod may also cause bone marrow embolization with alteration of pulmonary function as long as an important increase of the intramedullary pressure is generated during the nailing procedure.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1995

[Functional and morphological results of transplantation of vascularized knee joints in a dog model--a preliminary report].

Functional and morphological results of transplantation (n = 3) and replantation (n = 4) of vascularised total knee joints were compared in a canine model. Follow up time was 6 months. All vascular anastomoses remained patent and all osteotomies healed. Replanted animals displayed normal static weight bearing in contrast to the transplant recipients, which showed reduced weight bearing after 6 months compared to preoperative values. Mild to moderate signs of chronic allograft rejection were detected in all transplanted animals. Functional results were correlated with morphological outcome demonstrating the relevance of adequate control of rejection.

Animals↗

PubMed1994

How does a pure muscle cross-leg flap survive? An unusual salvage procedure reviewed.

An exceptional indication for a cross-leg gastrocnemius flap used as a pure muscle flap in the distal third of the lower leg is presented. The vascular status of the patient after the accident and extensive colonized wounds in the injured lower leg did not favor any microvascular reconstruction. Because no cross-leg muscle flap has been mentioned in the literature so far, technical details of the procedure are explained. This case report leads to a discussion of the principles of wound healing in cross-leg muscle flaps as an example for early loss of axial blood supply. Furthermore, it adds new variety to the numerous procedures that use the gastrocnemius flap.

Adult↗

PubMed1994

[Surgical technique in vascularized auto- and allotransplantation of the knee joint in a dog model].

Experimental transplantation of vascularized canine knee joints has so far been associated with high complication rates in both auto- and allografts. We have now compared 4 autografts and 4 allografts that were successfully performed at our institution. This report details our surgical technique. Stable internal fixation enabling immediate postoperative weight bearing, microsurgical end-to-end anastomoses of popliteal artery and vein and postoperative control of immunosuppression in transplanted animals are crucial. Thus, an interdisciplinary approach of experts in microsurgery, orthopedic and trauma surgery and immunologists appears to be a prerequisite for successful joint transplantation.

Animals↗

PubMed1994

[Treatment of displaced and comminuted multifragment fractures of the head of the radius: is resection a therapeutic option?].

The treatment of displaced comminuted fractures of the radial head type III of the Mason classification is still controversial. The restoration of anatomy including additional lesions with a stable fixation is a prerequisite of early mobilisation. Removal of the radial head, in case of severe comminution, and complete separation of the fragments from the radial neck remain the exception. Insertion of a prosthesis as a spacer is only recommended if there is a remaining instability of the elbow after resection of the radial head. With this treatment modality we have 22/29 good to very good results evaluated by the Morrey score after a follow-up period of 8 years (4-11 years).

Adult↗

PubMed1994

[Stable joint-bridging extension of malleolar dislocations and pilon fractures with the AO pinless external fixator].

The pinless external fixator, introduced into clinical practice for open tibial fractures, suggested itself for use as a traction substitute because of its pinless frame. The aim of this feasibility study was to replace the conventional calcaneal pin traction by a joint-bridging pinless fixator, inserted under local anesthesia. 10 patients with 6 malleolar dislocation fractures, 3 pilon tibial and 1 open distal tibial fracture were immobilised by a joint-bridging pinless fixator during 10.4 days (5-16 days) till swelling had subsided and definitive fracture treatment, consisting of plate fixation, took place. The implantation of the joint-bridging pinless fixator in local anaesthesia was well tolerated by all patients. This traction substitute offered good patient comfort and easy care. Although the provided stability was less than a conventional fixator, all patients were able to lift up their fractured extremity without pain.

Aged↗

PubMed1994

[Surgical treatment of lateral clavicular fracture with the "clavicular hooked plate"].

We know different surgical techniques for the treatment of lateral clavicle fractures (type 2 of the Neer-classification). Often an exercise stable osteosynthesis and early functional aftercare can be realized only with a jointconnecting transfixation (acromioclavicular joint). With a new osteosynthesis implant it is possible to solve the problems of this fracture with a save and relatively simple operation. The suggested implant guarantees an exercise-stable osteosynthesis that allows immediate functional aftercare. With this technique we can reduce the complication rate and reach full working capacity earlier. Within an observation period of about five years we used this implant on 21 patients and the clinical and radiological follow-up shows good to very good results in the medium and long-terms.

Acromioclavicular Joint↗

PubMed1994

[Classification of patellar fractures].

The AO-Classification of patellar fractures, introduced 1979 is based on difficult radiomorphologic criteria. It has never been widely accepted. The suggested classification should allow a clear therapeutic concept. The prognostic value will be analysed in a further study.

Fracture Fixation, Internal↗

PubMed1994

Operative treatment of distal humeral fractures in the elderly.

We treated 49 patients at an average age of 80 years (75 to 90) with distal mostly intraarticular humeral fractures by open reduction. There were 8 class A, 13 class B and 28 class C fractures on Müller's classification. The patients were reviewed at a postoperative average of 18 months. The patients' assessment of the result was very good in 31%, good in 49%, fair in 15% and poor in 5%. The flexion-extension range was very good in 41%, good in 44% and fair in 15%. The incidence of implant failure, pseudarthrosis of the olecranon osteotomy and ulnar nerve lesion was no higher in these elderly patients than in younger patients. Old age is not a contraindication to open reduction and internal fixation; it is important to restore full function.

Age Factors↗

PubMed1993

[The DHS (dynamic hip screw) buttress plate in the management of unstable proximal femoral fractures].

The DHS-implant system is a technically simple and widely used operative treatment modality for pertrochanteric fractures of the femur. In unstable 4-part fractures rotation of the head and neck fragment around the lag screw and significant impaction might lead to lateralisation of the greater trochanter and therefore to marked shortening. To prevent these effects we treated 17 patients with 4-part fractures with a prototype of a modular trochanteric DHS buttress plate. With this additional implant lateralisation of the greater trochanter could be prevented in all cases. This also leads to a limitation of telescoping, with less shortening even with immediate full weight bearing.

Adult↗

PubMed1993

[Malleolar fractures with ankle joint instability--experience with the positioning screw].

UNLABELLED: Malleolar fractures with an unstable ankle joint require additional stabilization. Different implants exist: We present the results of 135/155 patients treated with the so-called positioning screw. In 123 patients the positioning screw showed a spontaneous loosening with functional treatment and was therefore removed with the rest of the implants after eight to twelve months. In twelve cases the screw was broken. In 3/21 patients with the old 3.5 mm cortical screw with a core diameter of 1.9 mm in a correct position and in 9/113 patients with the new 3.5 mm cortical screw with inner core of 2.4 mm in an incorrect position. CONCLUSION: Positioning screws require early removal only if they fail to loosen or if a persistent limitation of dorsiflexion is still present after three months.

Adult↗

PubMed1993

[Quality of emergency admission (resuscitation, REA) and first aid in multiple trauma].

Undue delay between hospital admission and the beginning or urgent operative procedures is considered as a major mortality risk for polytraumatized patients in any trauma center. As part of a quality control study at our institution (Kantonsspital, University of Basel), the time spent for early resuscitation and diagnostic procedures was therefore prospectively recorded in 20 patients (mean age 38 years) with a mean ISS of 26.9 (range: 13 to 43). Time spent in the resuscitation room averaged 31.4 min (range: 10 to 50 min). Conventional radiographic diagnostic procedures took 34.7 more min (range: 20 to 60 min). An additional CT scan was performed in 15 patients requiring 19.5 min per region (head/thorax/abdomen/spine). Four patients underwent angiography necessitating 28 more min (mean). Time elapsed between admission and arrival of the patient in the OR or the ICU respectively accounted for an average of 89 min (range 22 to 200 min). For comparable injury severities this interval was shorter during the day than during the night (77 and 103 min respectively). Diagnoses established during this period were both accurate and comprehensive, as detectable from the low rate of missed diagnosis (three minor fractures). Although our results match favorably with figures reported in the literature we feel that further improvements could be achieved by performing the conventional radiographic procedures simultaneously with the early resuscitation in the resuscitation room. At present time, for reasons of X-ray protection, this is not possible in our institution.

Adolescent↗

PubMed1993

[Distal humerus fractures in patients over 75 years of age. Long-term results of osteosynthesis].

The aim of this retrospective analysis was to evaluate the adequacy of internal fixation of distal humerus fractures in patients over 75 years of age. 49 patients were evaluated. The mean age was 80 (75-93) years. The fractures were classified as 28 C-, 13 B- and 8 A-types according to the AO-system. Primary stable fixation was followed by early assisted mobilisation. The mean average follow-up time was 18 months. Excellent and good functional results were observed in 85%. 66% of all patients have no pain. There were 6 sensible ulnar nerve lesions, one deep wound infection, one pseudarthrosis of the distal humerus and one non union of the olecranon osteotomy. We conclude from our results that open reduction and internal fixation is indicated also for patients over 75 years with distal intraarticular humeral fractures.

Aged↗

PubMed1993

[Experience with the AO universal femoral intramedullary nail for management of femur shaft fractures].

57 fractures of the femoral shaft, treated with an AO femoral interlocking nail, have been analysed in a retrospective study. 40 nails have been implanted primarily, 17 as secondary procedures following different operations. In the group of primary nailing 35/40 reached a good or very good result, 8 of them however, following secondary operations. In the group of the secondary nailing, 9/17 patients had a good or a very good result. 3 pseudarthroses persisted. The AO femoral interlocking nail therefore appears to be an adequate implant for the treatment of femoral shaft fractures, but a precise implantation technique is a prerequisite for the successful outcome.

Bone Nails↗

PubMed1993

[Fractures of the proximal femur: rehabilitation and socioeconomic repercussions].

Only insufficient statistical data for epidemiologic analysis and calculations of socioeconomic costs are available in Switzerland. The total number of fractures of the proximal femur per year has nearly doubled in the 10 years from 1980 to 1990, climbing from 5500 to 9800 cases. A number of 15,000 cases is foreseen for the year 2020. In 85% of the cases the patients are older than 65 years. The global annual incidence is estimated to be 145/100,000, the partial incidence for the population of more than 65 years being 825/100,000. The mean hospitalization is 30 days. The total number of hospital days per year climbed from 200,000 to 300,000 in ten years, thus increasing the number of required beds by 50%. The mean costs for primary hospitalization is estimated to 15,000.-Swiss francs per case in 1990 and 146 Million francs globally per annum, i.e. the double of the amount in 1980. In the statistics of the National Accident Insurance Company the mean global economic costs for a fracture of the proximal femur in the active population is 57,000.-Swiss francs approximately and 72,000.-francs for patients of more than 45 years of age. Only roughly 20% of the costs are caused by medical treatment, whereas pensions, per diems and other compensations produce 80% of the costs. The mortality for patients over 65 varies from 2-7% during the primary hospitalization and rises up to 30% after 1 to 2 years after the accident. The relationship between the duration of acute hospitalization and rehabilitation is essential for planning. The evaluation of the chances for a successful rehabilitation is very important, the general medical conditions of the patients before the accident being the main determinant factor. A mean hospitalization of 3 weeks in a surgical unit and 6 to 7 weeks in a rehabilitation hospital seems to be realistic. Appropriate criteria for the selection of patients amenable to successful rehabilitation are essential. The question of the social outcome of these patients should be analyzed on a large scale nationwide study.

Adolescent↗