Biomedical subjects

E H Kuner

Publications and source records attributed to E H Kuner.

At least 19 recordsLinked to original sources

PubMed2002

[Treatment of complicated fracture of the distal radius with external fixator. Follow-up--complications--outcomes].

The performance of the external fixation regarding severe fractures of the distal radius was evaluated by means of a very detailed retrospective study. Between 1989 and 1994 74 Patients with 76 fractures of the distal radius with a mean age of 69 years for female and 39 years for male patients were treated with the external fixator. 37% were open fractures. Using the ASIF classification, 21% were type A-fractures, 8% were type B-fractures and 71% were type C-fractures. In 44 cases the external fixator was used primarily, in 32 cases secondarily after failed conservative treatment. Additional procedures were partially necessary (K-wires, screws, bone grafts etc.). 32 complications had to be noted, the lesion of the superficial branch of the radial nerve being the most common (16%). After a mean follow up of 36 months 60 patients with 61 fractures could be evaluated clinically and radiologically. With the Sarmiento score as well as the Castaing score, 84% could be classified as very good or good, 16% as fair, no poor results were recorded. From this study we conclude that the primary treatment of complex fractures of the distal radius can be performed with external fixation along with the additional procedures necessary (K-wires etc.). Because of the reliable elimination of pain caused by the fracture, it forms a preventive measure against reflex sympathic dystrophy.

Adult↗

PubMed1998

[Using autoclaved spongiosa].

Since transmission of HIV through allogenic bone grafts has been established, the concept of cryopreservation of allogenic bone had to be reconsidered. The strict guidelines of the scientific board of the Bundesärztekammer of 1990 are very labour-, time- and money-intensive. We have therefore moved to autoclaving allogenic cancellous bone. This is harvested from femoral heads during THR in slices of 2 to 3 mm, then cleaned under non-sterile conditions with a hard water jet followed by an ultrasonic bath for approx. 20 minutes. The slices are then double sealed individually and autoclaved at a temperature of 134 degrees C and a pressure of 2.5 atmospheres. Storage is in sealable containers at room temperature, so the material available at any time. Since the bone tissue has been freed of most organic matter and therefore lost its bone-specific antigenic structure, all that is left is the anorganic component with its inimitable architecture. This treatment results in a cancellous bone graft which is sterile, biocompatible and osteoconductive. Biologically it is inferior to autogenic and cryopreserved bone. Experimental and clinical studies show, however, that autoclaved cancellous bone can be a suitable substitute in well-selected indications. To elucidate the ultrastructural changes of the spongiosa and proteins induced by autoclaving further investigations are necessary. For example, the specific proteins involved need to be determined.

Bone Transplantation↗

PubMed1998

Hemarthrosis and hip joint pressure in femoral neck fractures.

In a prospective clinical study the intraarticular pressure of 55 patients with intracapsular femoral neck fractures was measured intraoperatively with the hip in different positions. Intraarticular hemarthrosis was quantified by a preoperative sonography examination. In 75% of the patients, increased intraarticular pressure caused by the hemarthrosis was found. The spontaneous median pressure increased significantly from 22 mm Hg with extension (28 mm Hg) and internal rotation of the hip joint (56 mm Hg). The lowest pressure was found in 70 degrees flexion (15 mm Hg). The median pressures increased within the first 24 hours after injury from 26 mm Hg in the first 6 hours to 46 mm Hg from 7 to 24 hours. Even in the first and second weeks after trauma, increased median pressures were detected (8.5 mm Hg and 13 mm Hg, respectively). No significant difference was found between undisplaced and displaced fracture types. Because increased joint pressure in other studies correlates with reduced perfusion of the femoral head, it can be deduced that reduction maneuvers without capsulotomy can compromise the circulation of the femoral head. Capsulotomy and osteosynthesis of the femoral neck at the earliest time possible is the best prophylaxis of tamponade. If the osteosynthesis is delayed, a preoperative sonography after admission and a control sonogram after 6 hours is recommended. In the event of relevant hemarthrosis, immediate therapeutic drainage is suggested for patients who will receive joint conserving osteosynthesis.

Adult↗

PubMed1998

[Method for measuring the comparative stability of osteosynthesis in the dorsal pelvic ring].

In the past, biomechanical investigations on the dorsal pelvic ring have generally been performed on a small number of cadaveric pelves in various non-standardized procedures. Significant differences in stability between different internal fixation methods of unstable pelvic ring fractures were not found. The experimental design presented here was based as closely as possible on the physiological loading of the pelvis in one-leg stance. This method made it possible to carry out standardized, reproducible tests on different osteosytheses of the sacroiliac joint. Furthermore, the suitability of artificial bones for such investigations can be assessed on the basis of a larger number of similar experiments on artificial and human pelves and the number of human pelves required for such studies could be reduced.

Biomechanical Phenomena↗

PubMed1997

Restoration of the spinal canal by the internal fixator and remodeling.

It has been observed that after reduction of an unstable vertebral fracture, treated either conservatively or operatively, the encroachment of the spinal canal remaining after reduction can decrease considerably with time. A series of 31 cases, each with a set of CT scans taken preoperatively, immediately after surgery and after implant removal respectively, was assessed using computer-aided planimetry. The mean initial narrowing of the spinal canal was 44.6%. Through surgery this was decreased by 20.4%, leaving a remaining deficit of 24.2%. After implant removal, 15 months after trauma and surgery, the area of the spinal canal increased a further 17.4%, leaving a remaining deficit of only 6.8%. Comparing the values of the spinal canal for T12-L5 directly after surgery and after implant removal, an almost identical degree of restoration for each level can be seen. This additional and gradual restoration of the spinal canal is termed remodeling. This study demonstrates that a residual postoperative narrowing of the spinal canal of up to 25% can be ignored, provided there is no initial neurologic damage.

Adolescent↗

PubMed1997

[Indications for nuclear medicine diagnosis in trauma surgery].

Skeletal scintigraphy is the most frequently utilized nuclear medicine imaging procedure in traumatology. Concerning any skeletal abnormality associated with changes in local perfusion, exudation and metabolism, it is a sensitive functional imaging procedure to detect bony disease. However, because of the varying causes of bony disease, it is characterized by a low specificity. Further, specificity may be enhanced, when patient history, clinical and lab results as well as results obtained from other diagnostic imaging procedures are combined with the result of skeletal scintigraphy. On the other hand, it is known that metabolic abnormalities of the skeleton depicted by radionuclide imaging occur much earlier than structural changes visible on X-ray imaging. Beside skeletal scintigraphy, antigranulocyte antibody or labelled leucocyte imaging may greatly assist in the detection of inflammation or infection following joint replacement surgery, respectively. Ultimatively, a combination of clinical, lab and imaging results including radionuclide imaging may represent the best approach to answer some questions asked by surgical traumatologists.

Bone and Bones↗

PubMed1997

[Indication, technique and complications in the surgical treatment of acetabular fractures].

Almost 50% of acetabular fractures occur in polytraumatized patients; in over 80% additional injuries are found. The surgical goal is anatomical restoration of the acetabulum and stable fixation, in order to avoid postoperative external fixation. Careful clinical and radiological evaluation is essential to successful surgery. Standard radiological investigations include an anteroposterior view of the pelvis, a "spot" radiograph of the affected hip as well as obturator and iliac oblique views. The latter arc is especially helpful in assessing the central segment of the acetabulum ("dome fragment"). The documentation of any primarily traumatic sciatic nerve lesion is very important, and the quality of reduction depends greatly on the timing of surgery. The operation should be performed as early as possible after the surgical procedure has been carefully planned. A 3-D CT scan provides good information in choosing the surgical approach for complex fractures. In most cases, adequate reduction cannot be accomplished without appropriate aids. For internal fixation, both curved ASIF plates and straight plates are used. The operation demands a high degree of experience. Postoperative complications include iatrogenic nerve palsy, insufficient reduction, incorrectly placed implants, unstable fixation, redislocation, etc. With scrupulous aseptic conditions, the postoperative wound infection rate is low. Ectopic bone formation can occur after extensive surgical approaches and may, depending on size (Brooker III and IV), impair the range of motion of the hip. Indomethacin given perioperatively is always indicated. Postoperative radiation treatment should as a rule be viewed critically.

Acetabulum↗

PubMed1997

[Long-term results and late complications following acetabular fractures].

The long-term functional results of acetabular fractures are assessed in terms of the corresponding criteria of Merle-D'Aubigné and Postel (pain, mobility, walking). Other essential criteria include the quality of reduction and the radiological appearance. The age of the patient, the type of fracture and above all, the interval between the accident and the surgical treatment or reduction of the fracture must be counted among the decisive factors which influence the late effects of this injury. Whether or not reduction can correctly center the femoral head in the socket is of paramount importance, but postoperative infection or the development of a hematoma may also critically affect outcome. In addition to a report on the long-term results achieved at the Trauma Department of the University Hospital of Freiburg, Germany, the literature on the late complications of acetabular fracture is also reviewed.

Acetabulum↗

PubMed1996

[Treatment principles in aseptic pseudarthrosis].

Aseptic pseudarthrosis may occur after all kinds of traumatology treatment. Following conservative treatment, incomplete immobilisation or an unattached bone fragment can be causal. After plate osteosynthesis the biomechanical principles are not efficient or the circulatory damage delays healing. There are two broad types of pseudarthrosis: vascular and nonvascular. The extent of vascularisation can be demonstrated by bone scintigraphy as well as X-ray. The treatment of vascular nonunions is very common. Mechanical stability is required, therefore a new osteosynthesis is desirable. Osteoporosis caused by inactivity and dislocation increases the rate of complications. Much more difficult problems are encountered in treatment of unreactive and avital pseudarthrosis, particularly in cases with a defect of bone substance. These defects can be treated with a segment transfer and a fibula-to-tibia operation. Extracorporal lithotripsy has been established as a new method in treatment of active and vascular nonunions. Former osteosynthesis is not a contraindication. Stability and immobilisation are necessary. Treatment in the low-frequency magnetic field shows no effect. Correct biomechanical and biological osteosynthesis with proper attention paid to location, quality of bone and asepsis can avoid the development of a pseudarthrosis.

Adolescent↗

PubMed1996

Injury reduction by the airbag in accidents.

Today an increasing number of automobiles are being equipped with additional passive safety devices: driver and passenger airbags. To examine the efficiency of the airbag in real road traffic accidents, a collective study was conducted from 181 traumatology centres throughout Germany. The inquiry was answered by 81 per cent of the medical centres contacted. From the evaluation of 122 accident victims in 1993 who were protected with an airbag the following was concluded. The patients treated in surgical and in traumatological departments suffered predominantly superficial injuries of the head, cervical vertebra and thorax. Some of these chiefly superficial wounds, such as abrasions and bruises, were initiated by contact with the airbag. It is remarkable that 72.1 per cent of the airbag-protected patients suffered a maximum of MAIS 2. What is also notable is the continuing high number of patients suffering from severe injuries (AIS 3+) of the lower extremities.

Abbreviated Injury Scale↗

PubMed1996

[Recurrent hemarthrosis after cruciate ligament refixation by wire suture. A case report].

Recurrent haemarthros is described as consequence of cruciate ligament repair. The main cause of haemarthros is described after unisometric fixation of the ligaments which leads to the rupture of the synovia membrane. This is a case report of a young man, who suffered from recurrent haemarthros for several years although he has intensively examined by radiological and arthroscopical means. It was falsely presumed to be a muscular arthrophy. The cause, however, was found in a wire suture, which was used to fix the anterior cruciate ligament in the femoral bone. This suture was laying under the synovia within the ligament and there fore could be seen and taken away arthroscopically only after total synovialectomy.

Adult↗

PubMed1996

[Reconstruction of open width of the spinal canal by internal fixator instrumentation and remodeling].

In 106 cases of unstable vertebral fractures treated with the ASIF internal fixator, the degree of restoration of the spinal canal could be studied in detail. Computer-aided planimetry was used to measure the area of the spinal canal. Three series could be studied, where the postoperative CT scans had been performed at different times. The first series of 58 cases had the CT scans taken immediately after surgery; the initial mean traumatic narrowing of the spinal canal had been 42.8%, but after surgery it was only 25.2%. The second series consisted of 74 CT scans performed after implant removal. At this time, a residual defect of only 3.7% was observed. In a third series 31 cases could be analysed where CT scans obtained both directly after surgery and after implant removal were available. This confirmed the first two series insofar as it demonstrated the existence of a further mechanism, i.e. remodeling, that served to increase the degree of restoration of the spinal canal. This biological-functional process operates to approximately the same degree at each fracture level, demonstrated by the almost parallel course of the graph showing reduction plus internal fixation and remodeling. In summary, the remaining deficit of 25% after surgery is restored almost to normal through remodeling and can be neglected, provided there is no neurologic damage.

Adolescent↗

PubMed1995

[Management of tibial shaft fracture with an unreamed intramedullary nail. A principally changed implant].

Unreamed intramedullary tibial nailing is a "biological" method of osteosynthesis. The unreamed AO tibial nail (UTN) is an implant based on a different principle, which no longer requires tight intramedullary fitting, but, as a loose-fitting nail, does need both proximal and distal interlocking. Our experience shows that the use of the solid UTN results in a shift in indications towards fractures with traumatic soft tissue lesions. For the "classical" nailing indications, the AO universal nail continues to be used.

Adolescent↗

PubMed1995

[Can the results of cruciate ligament operations be arthrometrically evaluated? A comparison of subjective assessment, Lysholm score, clinical stability classification and measuring stability with the KT 1000 after complex knee injuries].

In a long-term follow-up of 88 patients with complex ligament knee injuries we examined 70 of these who were operated upon between 1.4. 1988 and 31.3. 1990. We specifically looked at local complications, clinical results and knee stability, using subjective and arthrometrical (KT-1000) results 1 or 2 years after operation. The only parameters with a good correlation with stability were the clinical examination (Lachman-test) and the results with the arthrometer in the anterior-posterior translation. Stability after ACL-reconstruction with augmentation with a polydiaxonaon (PDS) augmentation band was physiological (2 mm under 89 N anterior-posterior traction) in 77% of all knees but only in 57% under maximal anterior-posterior manual stress. Neither the subjective outcome of Lysholm-Score correlated with arthrometry and clinical examination.

Adolescent↗

PubMed1995

[Protective air bags in traffic accidents. Change in the injury pattern and reduction in the severity of injuries].

The effectiveness of air bags, drivers-side and passenger-side, as an additional passive safety system in motor vehicles was tested in a collective study in which 47 trauma centers in Germany participated. The inquiry was answered by 80% of 181 hospitals. The evaluation of a total of 119 air bag-protected patients involved in accidents, who were treated in German trauma centers in the year 1993 shows predominant minor injuries on the head-, cervical- and thorax-region. Some patients had superficial injuries caused by air bag in their face and chest area, such as abrasions and contusions. It is notable, that a large number of patients continue to suffer severe injuries (AIS 3+) in their lower extremities. The trend of the industry to equip more and more vehicles with air bags must be sustained. According to manufacturer statements, in 1994 already more than 60% of all mass produced vehicles in Germany will be provided with this modern passive safety system.

Abdominal Injuries↗

PubMed1995

[Femoral neck fractures in adults: joint sparing operations. I. Results of an AO collective study with 328 patients].

In a multi-center study in 14 trauma hospitals 328 patients with fractures and osteosyntheses of the femoral neck were investigated with reference to time between accident and operation implants used, early and late complications, and results in the years from 1974 to 1987. A follow-up examination was possible in 266 patients a mean of 46.7 months after their accidents. General postoperative complications were recorded in 12.2% and local complications in 11.6%. In 9.8% pseudarthrosis was observed, in 26% an aseptic femoral head necrosis and in 2.4% deep infections. Functional results were excellent to fair in 75%. The best results (significantly better than in other groups) were obtained in patients who were operated on early (< 24 h after trauma) (P < 0.05) and those in whom dynamic hip screws (DHS) were used (P < 0.01). Of all cases of aseptic necrosis 70% were seen within 3 years and 86% within 6 years after trauma. The rate was dependent on the degree of dislocation of the fracture (Garden III and IV), the time from trauma to operation, and the implant used (130 degrees blade plate 30.5%, DHS 9.2%).

Adolescent↗

PubMed1995

[Femoral neck fractures in adults: joint sparing operations. II. The significance of surgical timing and implant for development of aseptic femur head necrosis].

Statistical analysis of the results of the AO multi-center study (Part I) shows significant advantages of early (within 24 h) operative stabilization of the medial neck fracture (P < 0.05) and of use of the dynamic hip screw (DHS) as implant (P < 0.01). Secondary surgery necessitated by implant complications led to higher rates of aseptic femoral head necrosis (FHN) and non-unions (NU) (P < 0.05). According to the so-called logistic regression, the rate of NU is influenced most by the number of implant complications and the choice of implant, the rate of FHN by the interval time-lapse between fracture and follow up, the implant selected (the best being the DHS), primary dislocation (poorest results obtained in Garden types III and IV) and the time-lapse between fracture and operative stabilization. This puts the assumed paramount importance of dislocation in perspective and calls in question the dogma that a dislocated intracapsular neck fracture will necessarily be followed by FHN.

Adolescent↗

PubMed1995

[Classification and osteosynthesis technique of calcaneus fractures. External fixator as temporary distractor].

In the treatment of fractures of the calcaneus, the particularly intricate local anatomy, complicated fracture forms and associated soft tissue damage often prejudice operative, anatomical reconstruction. We propose a simplified classification that is based on the Regazzoni classification of 1993 and has six grades of severity. It can be helpful in the selection of operative treatment and, above all, make it possible to recognize whether operative reconstruction is possible and appropriate. When operative reconstruction is indicated we find the secondary operation important; it is also important to diagnose and treat compartment syndrome if present and otherwise to take steps to prevent it. In the first phase, in special cases we use an external fixator without reconstruction of the full length. The operative technique is largely standardized as as the fixator is placed only temporarily. Correct positioning allows easy correction of shortening or varus deformation, and joint surface reconstruction is also feasible. Autologous bone grafting is possible. The definitive fixation is achieved with internal plate stabilization by a lateral approach and removal of the fixator. Contraindications for this procedure are burst fractures with total destruction of the joint surfaces and cartilage. Out of 54 fractures we used the fixator to aid reduction in 45. In 71% of these we had very good and good results according to the Merle d'Aubigné scoring system.

Adult↗