Biomedical subjects

C Josten

Publications and source records attributed to C Josten.

At least 19 recordsLinked to original sources

PubMed2003

Proximal humeral fractures: how stiff should an implant be? A comparative mechanical study with new implants in human specimens.

BACKGROUND: The objective of this study was to determine the in vitro characteristics of the clinically used and newly developed implants for the stabilization of proximal humeral fractures under static and cyclic loading. The goal was to optimize implant stiffness for fracture stabilization even in weak bone stock. METHODS: In a laboratory study using 35 fresh human humeri, the specimens were randomized into 5 groups, which included the clinically used humerus T-plate (HTP), the cross-screw osteosynthesis (CSO), the unreamed proximal humerus nail with spiral blade (UHN), the recently developed Synclaw Proximal Humerus Nail (Synclaw PHN) and the angle-stable Locking Compression Plate Proximal Humerus (LCP-PH). The implant stiffness was determined for three clinically relevant load cases: axial compression, torsion and varus bending. In addition, a cyclic varus-bending test was performed to determine the implant properties under cyclic loading. RESULTS: In contrast to a rather elastic and minimally invasive implant(LCP-PH), the conventionally designed ones (Synclaw PHN, CSO, HTP, UHN) showed rather high stiffness values under static loading. In cyclic loading, a strong decrease in stiffness ( p<0.05) was found for the rigid implants HTP and UHN. In comparison with the other implants, only the elastic implant (LCP-PH) showed a significantly lower load reduction in a weak bone stock (17+/-6.2%). CONCLUSION: The high initial stiffness of rigid implants led to an early loosening and failure of the implant-bone interface under cyclic loading. Implants with low stiffness and elastic characteristics, however, appear to minimize the peak stresses at the bone-implant interface, making them particularly suitable for fracture fixation in osteoporotic bone.

Adult↗

PubMed2003

[Thoracolumbar spine fractures after conservative and surgical treatment. Dependence of correction loss on fracture level].

QUESTION: This retrospective study presents results after conservative and operative treatment of thoracolumbar fractures as function of its localization. METHODOLOGY: In 2 years 70 patients with A1/A2 fracture were conservatively treated, 38 patients with A3/B/C injury were treated by internal fixtor. For evaluation 3 vertebral sections(Th5-10,Th11-L2,L3-5)were defined. Follow-up took place 1 year after implant removal or end of conservative treatment. RESULTS: The correction-loss was highest in thoracic, lowest in lumbar region. After conservative therapy,correction-loss was located to 3/4 in vertebra itself, after operative treatment especially in adjacent disc spaces. There was no general correlation to complaints. CONCLUSION: In consequence of these results A1/A2-fractures in the upper thoracic spine ( 15 degrees will be stabilized anteriorly, in other regions functional treated. A3-fractures of thoracic spine and thoracolumbar junction will be operated from anterior, in lower lumbar spine (>L3) from dorsal. B- and C-injuries should be instrumented with a combined dorsoventral procedure.

Adolescent↗

PubMed2003

[Tibial plateau fracture--biodegradable bonecement-augmentation].

Between October 1996 and January 1999,29 patients (f:16,m:13,age: 22-86) with fractures of the lateral tibial plateau were operated on arthroscopic,fluoroscopic control or were treated with open reduction and internal fixation. 15 of them were retrospective and 14 prospective analysed. The metaphyseal defect after elevation of the depressed fragment was augmented in 11 cases with autologous spongeous bone grafting,in 9 cases with biodegradable bone cement (Norian SRS). Augmentation was unnecessary in 9 cases. The results according to the Lysholm score and the radiological results were good or excellent. Concerning the kind of augmentation no difference was noted. In the Norian SRS-group the duration of postoperative treatment was shorter than in the other group. The duration of partial weight bearing was shorter too. The results of the present study suggest that an injectable calcium phosphate cement may be a competent material for augmentation in lateral tibial plateau fractures because of the application form and the initial high mechanical stability.

Adult↗

PubMed2003

[Unicondylar knee arthroplasty--indications and outcome].

Continuous development of new materials, improved operative technique and exact patient selection lead to increasing survival rates of unicondylar sleigh arthroplasties during the last decade as it's demonstrated in this review on the literature. During the 80s the average survival rate after 5 years was 85 %, after 9 years 60 %. In the 90s significantly better results were noted with 5 and 10 years survival in more than 95 % of the cases. Thus, like current studies prove, unicondylar sleigh arthroplasties have reached the standard of complete surface replacement. Additionally minimal loss of bone stock, sparing of the crucial ligaments and of the femoropatellar joint as well as short operation time and low morbidity are advantages of these arthroplasties.

Equipment Failure Analysis↗

PubMed2003

[Triangular vertebropelvine stabilisation of unstable posterior pelvic ring fractures].

UNLABELLED: It is the objective of this investigation to describe the early results (2 years outcome) after triangular vertebropelvine stabilisation (TVPS) of unstable fractures of the posterior pelvic ring. PATIENTS: Between 1.1.1997 and 31.12.2000 35 patients were treated. C1 fractures occurred 9 times (25.7 %), C2 injuries 16 times (45.7 %) and 10 patients suffered fom C3 fractures (28.6 %). The mean age of the injured was 36.6 years (15 to 77 years). 22 patients (62.8 %) were treated with the TVPS. Suffering from a monotrauma, mobilisation with full weight bearing of the injured pelvis was resumed immediately on the first postoperative day. In case of polytrauma mobilisation was continued when the additional injuries allowed so, after 8.8 days on average. RESULTS: After an average of 23.4 months 18 of 22 patients with TVPS were controlled. Radiological criteria as well as quality of life were ascertained. It could be proved, that TVPS offered good reduction and stable retention of the pelvic fractures. 16 patients (89.0 %) suffered from moderate or mild pain, 15 (83.3 %) had slight problems in walking. No restriction in the range of motion of the lumbal vertebral column could be observed. CONCLUSION: The following advantages of the TVPS could be demonstrated: anatomical reduction and stable retention of instable pelvic fractures, full weight bearing from the first day after surgery, and only slight restriction of the quality of life two years after operation

Adolescent↗

PubMed2003

Ventilation by the Open Lung Concept in spite of traumatic lung herniation.

Traumatic herniation of the lung is uncommon. We report a patient suffering from multiple injuries including severe pulmonary contusion and traumatic parasternal lung herniation, who developed acute respiratory distress syndrome. In spite of the lung herniation, we used mechanical ventilation according to the Open Lung Concept. Oxygenation improved rapidly, and early operative stabilization was possible.

Aged↗

PubMed2002

[The open lung concept. Clinical application in severe thoracic trauma].

INTRODUCTION: The pathomorphological substratum of the pulmonary contusion is a parenchymatous hemorrhage followed by interstitial and alveolar edema, finally resulting in a severe damage of the surfactant system. The pathophysiological consequence is an imbalance between ventilation and perfusion, which causes the clinical finding of hypoxia. METHODS: Between December 1997 and December 2000, we treated 32 polytraumatized patients (ISS 43, PTS 32) additionally suffering from severe chest contusion (AIS 5, PTST 14), by ventilation according to the Open Lung Concept (OLC). The initial disturbance of oxygenation was shown by a mean paO2/FIO2-ratio of 134 (96;181) mmHg. The OLC recruits atelectatic lung areas by the application of a defined temporary positive inspiratory pressure (PIP), which is called the "opening pressure". The recruited lung areas were kept open by high total-PEEP. RESULTS: For the recruitment procedure, a mean PIP of 65 (51;65) mbar was required. Recruited alveoli were kept open by a total-PEEP of 22 (20;23) mbar. The paO2/FIO2-ratio increased significantly (P < 0.001) from 134 (96;181) to 522 (433;587) mmHg. After the recruitment procedure, we could reduce PIP and FIO2. In spite of the minimal tidal volumes of 3.5 (3.0;3.9) ml per kg bodyweight by which our patients were ventilated, the levels of oxygenation and normocapnia could be maintained. There were no evidences for side-effects like perfusion impairment. Two patients (6.25%) died of extrapulmonary causes. CONCLUSION: Ventilation according to the OLC seems to be a highly effective treatment of ventilation-perfusion-impairment following pulmonary contusion. Minimal tidal volumes and the low PIP-levels after the recruitment procedure meet the demands of a lung-protective Low-Tidalvolume-Ventilation.

Adolescent↗

PubMed2002

[Endoscopically assisted minimally invasive reconstruction of the anterior thoracolumbar spine in prone position].

Irrespective of an anterior open or endoscopic approach, the combined postero-anterior instrumentation of thoracolumbar fractures requires time consuming intraoperative maneuvers changing the patients position from prone to lateral.A standardised anterior endoscopically assisted approach for the segments Th4 to L4 is described, allowing the patient to remain in prone position, using a 4-5cm incision combined with a retractor system. The approach to the anterior spine in prone position is feasible by using a self holding retractor system for the region from Th4 to L4. Time of anaesthesia for the one stage combined procedure can be reduced by about 40 min, when changing the position of the patient is no longer necessary. The minimal incision in combination with the retractor system allows mainly the use of conventional instruments and implants, which provides reasonable lower costs. The advantages of the open and the endoscopical technique are combined. The main advantage of the prone position is the opportunity to access the anterior and posterior spine simultaneously, which is extremely helpful in reduction maneuvers.

Adult↗

PubMed2002

[Early clinical management after polytrauma with 1 and 4 slice spiral CT].

In the early clinical phase the comprehensive imaging of patients with multiple trauma using helical CT is already established. Aim of this study was to assess whether MSCT may improve the patient management and the diagnostic results. The procedure is designed as follows: after life-thretening treatment x-ray of chest and ultrasound are carried out in the emergency room. Then the patient is moved to CT. From 1998 to december 2000 241 patients were examined using a single slice helical CT (Somatom plus 4), in 2001 79 patients using a 4-slice helical CT (Somatom VZ, Siemens Med.Sol.). After CT selected radiograms of the extremities were taken. 359 of 360 procedures were carried out successfully. Excluding 1 case (death during 1-sl.h CT) all relevant lesions of head, neck, and body were diagnosed. Although the patients had an injury severity score of approximately 30. The change from 1 slice-helical CT to 4 slice-helical CT allowed us to reduce the stay in the CT room from 28 to 16 min. The total lethality decreased by approximately 4%. Advantages for the patient arose from the standardized examination protocol using multislice CT. If integrated in an interdisciplinary management concept, it is a good compromise between examination time, comprehensive diagnostic imaging, life-saving therapeutic procedures, and therapy planning.

Efficiency, Organizational↗

PubMed2002

[Age- and gender-related distribution of bone mineral density and mechanical properties of the proximal humerus].

PURPOSE: To evaluate age- and gender-related mechanical properties and bone mineral density (BMD) of the proximal humerus at different levels and regions. MATERIALS AND METHODS: Mechanical indentation testing, DXA, QCT, pQCT and the radiogrammetry (Cortical Index, CI) were carried out in 70 freshly harvested humeri from 46 human cadavers (23 females, 23-males; median age 70.5 years). RESULTS: In the female group, a high correlation between age and BMD was found (rho = 0.62 to -0.70, p < 0.01) with statistically significant differences between specimens of patients 69 years or younger, and 70 years or older (p < 0.05). In the group of female specimens of age 70 years or older, BMD values were found to be significantly lower compared to their male counterparts (p < 0.05). Regardless of the specimen's age, the highest BMD and bone strength were found in the proximal aspect and in the medial and dorsal regions of the proximal humerus. CONCLUSION: These findings provide an insight into the fracture mechanism of the proximal humerus and should be the basis for designing structure-oriented implants with improved implant-bone stability in osteoporotic patients.

Absorptiometry, Photon↗

PubMed2001

Conservative functional treatment of ankle fractures.

Thirty-eight patients (mean age 49 years; range 19-91 years; nine of them over 60 years; 28 women, 10 men) suffering from an isolated Weber B fracture with a dislocation of less than 1 mm underwent functional therapy using a pneumatic ankle brace and were included in a prospective study. The clinical outcome was measured according to the Olerud-Molander ankle score. Functional therapy was finished in 34 cases successfully. Twenty-one patients were scored after 17 months on average (range 8-27 months) with the Olerud-Molander ankle score. A very good result was seen in 18 patients, including 12 with 100 points, a complete remission. The remaining 3 patients showed good results (1 had 90, 2 had 85). However, functional treatment failed in 4 cases due to secondary dislocation. These patients underwent surgery without further complications. The control group, 31 operated patients, did not show as good results. Functional therapy of stable Weber-B ankle fractures appears to be superior to surgery. We were able to avoid surgery in 90% of our patients and got better results than with patients undergoing open reduction and internal fixation.

Adolescent↗

PubMed2001

[Conservative or operative treatment of humeral head fractures in the elderly?].

The humeral head fracture in the elderly represents an unresolved problem, which is reflected by the variety of existing therapeutic strategies ranging from conservative treatment to humeral head replacement. The main factors influencing the prognostic outcome are the fracture type, age of the patient and biologic criteria such as osteoporosis, blood supply at the fragments, and the degree of soft tissue trauma. For selection of the optimal treatment, the general condition of the patient, additional injuries and chronic diseases have to be respected as much as the patient's compliance and personal demands. According to experimental and clinical findings, for displaced two- and three-part fractures of the elderly patient minimal osteosynthesis and in the future plate osteosynthesis with angular stability should be preferred. For these fracture types, conservative treatment must be included in the therapeutic spectrum. In contrast, displaced four-part fractures and fracture dislocations are indications for primary humeral head replacement. This is explained by the fact that neither conservative treatment nor surgical reconstruction procedures meet the main goal of primary therapy, aiming for early painless mobilization and for timely discharging the elderly patients in their social environment.

Aged↗

PubMed2001

[Perioperative local instillation of ropivacaine for postoperative pain relief after surgery on extremities].

INTRODUCTION: The relief of postoperative pain remains one of the most important goals for adequate surgical patient care. METHODS: Prospective, randomised, double-blinded study, including 118 patients (67 M;/ 51 F; median age 43 years, min. 18, max. 74). Two groups were formed. In the verum group a wound instillation with ropivacaine was performed, in the control group not. Intensity of pain, demand for analgesics and satisfaction of the patient were evaluated postoperatively. In 10 patients ropivacaine plasma levels were measured. RESULTS: Significant postoperative pain relief and a decrease in analgesic consumption were found on instillation of ropivacaine. Compared to the control group, patients receiving ropivacaine were significantly more satisfied with the postoperative pain management. Potential toxic plasma levels were not found. CONCLUSION: By the presented method, the surgeon actively contributes to a significant reduction in postoperative pain and analgesic consumption. Furthermore, the patient's benefit is reflected by higher satisfaction with the pain management. Complications due to toxic plasma levels are not seen.

Adolescent↗

PubMed2001

[Crossed screw osteosynthesis of proximal humerus fractures].

Between March 1997 and October 1999 thirty-one patients with displaced proximal humeral fractures were treated with crossed screw osteosynthesis. Insertion of the screws was realized by using a deltoideo-pectoral approach placing the screws anteriorly and posteriorly in a crossed manner from the distal fragment into the humeral head. Additionally, in all two-part-fractures a tension band was applied. In all three-part-fractures, the greater tuberosity was reattached by additional screws. In 21 patients (14 female, 7 male, median age 62 years, 18-86) a clinical and radiological follow-up (median 18 months, 10-29) was obtained. Fractures were classified as two-part-fractures in 10 patients and as three-part-fractures in 11 patients. According to the Constant-Score, "excellent" and "good" results were achieved in 15 patients, "moderate" results were found in 3 patients. However, in 3 patients results were only "poor" (1 two-part-, 2 three-part-fractures). The complication rate was 29% (premature hardware removal due to head perforation in 3 cases; humeral head necrosis necessitating prosthetic replacement in 2 patients; secondary displacement in 1 case). Crossed screw osteosynthesis represents an justified alternative in the surgical treatment of displaced proximal humeral fractures permitting early functional therapy.

Adolescent↗

PubMed2001

[Fracture of the acromion. Diagnosis--treatment strategy--outcome].

The case of an 22-year-old man is presented, who sustained a dislocated fracture of the left acromion process and a not dislocated fracture of the left scapular body with a large subcutaneous décollement as well as a dammage of nervus axillaris occurring during a traffic accident. After resuming diagnostics by means of CT, a tension banding of the ventral part of the acromion and a plate osteosynthesis of the dorsal part was performed. 7 weeks after injury neurolysis of nervus axillaris has been done. 4 months after accident the patient shows a satisfying functional result in the Constant score. Diagnostic, treatment and functional results after operative treatment of dislocated fractures of the acromion are shown and discussed.

Acromion↗

PubMed2001

Fracture-dislocations of the elbow joint--strategy for treatment and results.

Between January 1993 and December 1996, 41 patients with fracture dislocation of the elbow joint were treated in our department. In 28 patients (median age 46 years, range 15-77 years; 16 male, 12 female), a clinical and radiological follow-up was obtained after median 34 months (range 12-59 months). In addition to the humero-ulnar dislocation, isolated fractures were present in 13 patients and combined fractures in 15 (all with involvement of the radial head). Primary neurological deficits were found in 7 and open fractures in 3 patients. In 7 patients, primary definitive surgical therapy was carried out by open reduction and internal fixation. A two-step surgical management (initial closed reduction and immobilization, 5 patients with external fixator, 7 with plaster; secondary open surgical procedure) was performed in 12 and conservative treatment in 9 patients. According to the Leipzig Elbow Score, taking subjective, clinical and radiological criteria into consideration, 4 patients achieved 'excellent' and 5 patients a 'good' result. Ten patients were scored 'moderate' and 9 'poor'. The rate of secondary complications necessitating revision was 36%. Poor results were primarily caused by extensive initial soft-tissue damage, delayed definitive surgical therapy, and ectopic heterotopic ossification. In contrast, fracture localization and degree of arthrosis were not of significant importance for the final outcome. In fracture dislocations, the goal is a primary definitive surgical treatment aiming for early postoperative physiotherapy.

Adolescent↗

PubMed2001

Arthroscopic-assisted simultaneous reconstruction of the posterior cruciate ligament and the lateral collateral ligament using hamstrings and absorbable screws.

Arthroscopic-assisted simultaneous reconstruction of the posterior cruciate ligament (PCL) and the lateral collateral ligament (LCL) using hamstring tendon grafts is described. The femoral tunnel is drilled through an incision over the medial femoral condyle and the tibial tunnel through the same skin incision used for harvesting the tendon graft. PCL reconstruction is performed using a 4-strand hamstring tendon graft and absorbable screw fixation. The tendon of the semitendinosus muscle of the uninvolved knee is used as a lateral loop for LCL reconstruction. After pulling the transplant through the fibular head, femoral fixation of the loop is made with an absorbable screw.

Absorbable Implants↗

PubMed2001

[Evidence-based nursing--the missing link between research and practice].

UNLABELLED: Evidence-based nursing (EBN) is being introduced promising to professionalize and emancipate nursing. Three questions are discussed as to whether this can be accomplished. The analysis comes to the following conclusions: Evidence-based nursing (EBN) as a problem solving process will become part of the German health care service by means of social legislation. The concept joins clinical experience and best evidence under the principle of patient adapted intervention. This complies with the demand for rationally justified, transparent, and economically comparable performance. One specific trait of research in nursing is the importance of qualitative methods that make the dimension of subjective meaning comprehensible. Only under a normative paradigm can the concept of evidence-based intervention be applied immediately. This leads to problems of adaptation that have to be solved when introducing EBN. Evidence-based nursing practice fits into modern concepts of professional nursing as well as into current visions regarding the reform of German nursing education. However, some peculiarities that characterize German nursing practice in particular must be taken into consideration. This includes the professional ideology of nursing staff as well as applied nursing science, which is still in its beginnings. CONCLUSION: With careful implementation the concept of evidence-based intervention can develop its potential to improve nursing practice. Further, EBN offers Germany an opportunity to catch up with international standards.

Clinical Nursing Research↗