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Biomedical subjects

G Muhr

Publications and source records attributed to G Muhr.

At least 73 records · Page 4Linked to original sources

Burst fracture of the fifth lumbar vertebra: results of posterior internal fixation and transpedicular bone grafting.

Burst fractures of the fifth lumbar vertebra are rare, and there are only a few reports on this subject, which is characterised by its unique anatomical and biomechanical features. This retrospective analysis reports on ten patients whose fractures of L5 were stabilised with a short internal fixator in combination with a posterior fusion as well as transpedicular bone grafting. The average follow-up period was 22 months. Radiometric data were surveyed and compared to the functional results. The height of the fractured vertebra remained nearly unchanged throughout the course. Loss of lordosis of 4 degrees in the upper disc space and 4 degrees in the lower disc space were observed postoperatively. At the time of follow-up, the values of segmental lumbar lordosis were significantly below the preoperative level. The narrowing of the neural canal was reduced from 57% to 28% with the surgical intervention. However, there was no correlation between the functional and the radiological outcome. Neurological deficits were documented in two patients, which declined during the course. There were no severe postoperative complications. The results of the present study demonstrate that the described surgical procedure in fractures of the fifth lumbar vertebra does not promote an anatomic restoration of the fractured vertebra, nor of the segmental lordosis. However, the clinical results do not correlate with the radiological outcome. Nonoperative treatment with early mobilisation without external support seems to be the treatment of choice.

Adolescent↗

Noncontiguous unstable spine fractures.

STUDY DESIGN: Evaluation of 1054 patient charts and 100 random roentgenogram charts as well as clinical investigation of 39 patients. OBJECTIVES: Noncontiguous unstable spine fractures are rare, easy overlooked, and difficult to treat. The purpose of the study was to evaluate the delay in diagnosis and clinical and radiologic outcome of these fractures. SUMMARY OF BACKGROUND DATA: Noncontiguous spine fractures are reported in about 1.6-16.7% in the literature. In most of the studies stable fractures, which did not need any special treatment, were also included. Therefore, in this study only unstable fractures requiring treatment were reinvestigated. METHODS: A total of 1054 patients with fractures of the spine were treated over a period of 14 years in the spinal cord injury unit and retrospectively reviewed; 141 (13.4%) of the patients had multiple fractures, but only 39 (3.7%) had a noncontiguous spine fracture, most frequently from a fall or jump from a greater height, or traffic accidents. RESULTS: Thirty patients (76.9%) had all fractures diagnosed at the first examination. Nine patients (23.1%) had a delayed diagnosis of the secondary lesion, but this delay resulted in no neurologic deterioration. A total of 32 extraspinal injuries were diagnosed and treated 14 times surgically. Loss of correction was seen after surgical treatment (n = 21), and increasing deformity occurred after conservative treatment (n = 18). The neurologic deficit improved in 10 conservatively (4) and operatively (6) treated patients and deteriorated in one patient after surgery. CONCLUSION: A delayed diagnosis of the second fracture was frequently seen without clinical consequences, and neurologic improvement occurred after conservative and operative treatment. Surgical treatment resulted in significantly earlier mobilization and less kyphotic deformity.

Adolescent↗

[Outcome quality in trauma surgery].

Trauma surgery and orthopedic trauma surgery have been accompanied not only by internal quality assessment, but also by external quality assessment procedures right from the beginning. The reasons for these mechanisms were based on legal regulations of treatment of work-related accidents. In 1958, the Arbeitsgemeinschaft für Osteosynthese (Working Group on Osteosynthesis, AO group) was founded. The results of the AO's scientific activities built the basis of osteosyntheses. In 1988, legal regulations changed again in Germany. Since this reform of some important facets of public health care, each hospital or institution is committed to perform external and internal quality assessment. In addition, the introduction of a payment system based on diagnosis-related groups makes it necessary to install basic quality management systems within the next few years. This paper presents some well-established procedures, especially the diagnosis-related study in the whole district of Westphalia-Lippe. The aim of the study was a quality assessment of the treatment of intracapsular fractures of the collum of the femur. Problems in data analysis and interpretation are shown. Because of some grave problems, certain changes in the study design seem to be warranted. Despite these facts, however, we are convinced that we not only need this kind of quality assessment, but that we should try to expand these studies based on the experiences we gained.

Accidents, Occupational↗

[Differential therapy of radial head fracture: a critical analysis based on outcome of 53 patients].

We investigated 53 patients with 57 radial head fractures (4 patients with bilateral fractures) treated between 1993 and 1998. We focused on patients with radial head fractures asking about (1) the relation between fracture type and therapy and (2) the correlation between chosen treatment and result. We saw the following fractures: Mason I: 3 cases, Mason II: 26 cases, Mason III: 11 cases, and Mason IV: 15 cases. Good results were achieved by 30 patients with 31 fractures, fair results by 8 patients with 9 fractures, and poor results by 13 patients with 14 fractures. Patients with a Mason I fracture achieved good results with functional therapy. Of the 26 Mason II fractures, 14 were treated with screws, 14% of whom had poor results subjectively. Six patients were treated with a K wire, titanium nail, or prevot nail, none of whom had poor results. Of 11 patients with a Mason III fracture, 10 were treated by resection of the radial head, and in 1 patient we implanted a prosthesis due to an intraoperatively detected elbow instability after resection and achieved good postoperative results. Only one patient (9%) had poor long-term results subjectively. Of 15 patients with a Mason IV fracture, 11 were treated by resection of the radial head: 5 patients (33%) had poor long-term results, only 3 of whom (20%) subjectively considered the results poor.

Adolescent↗

[Coracoid pseudarthrosis caused by anterior shoulder dislocation with concomitant coracoid fracture].

Fractures of the coracoid process are rare and represent only 2-5% of all fractures of the scapula. The most frequent cause of a coracoid fracture is direct trauma, but indirect trauma may also lead to a fracture of this kind. Avulsion injuries as part of an acromioclavicular dislocation are the most frequent forms of trauma. For the rare cases of an anterior shoulder dislocation with concomitant coracoid fracture, two different mechanism are discussed. One cause of the coracoid fracture could be direct impact of the dislocated head of the humerus on the coracoid process, another may be the occurrence of a sudden strong pull of the muscles inserting at the coracoid process during shoulder dislocation.In the majority of cases, conservative treatment with six weeks of immobilization is appropriate. If a pseudarthrosis occurs and there is persistent pain, we recommend the operative fixation of the distal coracoid fragment by insertion of cancellous bone graft taken from the iliac crest and stabilization with a cannulated AO titanium small fragment screw and PDS cord.

Adult↗

[Septic arthritis of the shoulder following intra-articular injection therapy. Lethal course due to delayed initiation of therapy].

Detection of a bacterial arthritis of the shoulder represents an absolute indication for intervention. Irrespective of the cause of the infection, the most decisive prognostic factors are early diagnosis and therapy. We report on two patients who suffered from generalized sepsis and resulting death after delayed treatment of iatrogenic joint infections of the shoulder caused by intra-articular injection therapy. Both patients suffering from septic shock syndrome had been transferred to our hospital for surgical and intensive care treatment. They died in spite of maximal intensive care and aggressive surgical treatment. On the basis of the cases presented, it can be concluded that an acute infection of the shoulder joint must be excluded early when painfully limited range of motion in combination with clinical and laboratory signs of inflammation become apparent. Successful therapy of joint infection also requires early surgical treatment, including resection of infected tissue. If surgical joint revision is not performed or is performed too late, there is the risk of irreversible damage to the afflicted joint, even septic spread endangering the patient's life.

Aged↗

[Retrogastral located gastrointestinal stromal tumor (GIST) as a sonographically detected rare incidental finding].

Gastrointestinal stromal tumors (GIST) represent compared to carcinomas a rare group of neoplasias of the gastro-intestinal tract of unclear dignity. We report the example of a patient suffering from a big retrogastral located gastrointestinal stromal tumor which had been detected as an incidental finding without previous complaints. Because origin and dignity of the process could not definitely be diagnosed, total resection (R0-resection) without systemic lymphadenectomy of the process measuring 11.5 cm x 11 cm x 7 cm was performed. Mitotic activity and tumor-size are regarded as predictive factors of potenzial malignancy of GISTs. In general tumors with low mitotic activity of up to 5 mitoses per 50 high power fields (HPFs) and a diameter smaller than 5 cm are regarded as benign. In the presented case, up to 4 mitoses per 50 HPFs could be detected and thus, in connection with tumor-size, an uncertain biological behaviour of the process has to be expected. Since no generally accepted consensus on the treatment of the GISTs exists, also patients originally suffering from tumors regarded as borderline-malignant should undergo a close-meshed follow-up in regular intervals.

Adenocarcinoma↗

[The reality of preclinical treatment in thoracic trauma - a prospective study].

AIM OF THE STUDY: Because of the well proven fact of outcome improvement by early, preclinical intubation and ventilation of multiple injured and polytraumatized patients, the guidelines of different medical associations recommend this procedure especially in combination with blunt chest trauma. By the means of a prospective study protocol we analyzed whether these treatment standards were respected and whether the kind of preclinical treatment was influencing treatment outcome. PATIENTS AND METHODS: Using a prospective study protocol data were sampled and analyzed. From 1.12.2000 to 25.9.2001 48 consecutive patients were included into the protocol. 12 patients (25 %) had preclinical intubation (group A). 8 patients of group A were intubated by the helicopter emergency team. 36 patients had no tracheal tube (group B). In 34 cases mechanical ventilation has to be started during the emergency room procedures. Two patients were intubated after they were admitted to the intensive care unit (ICU). Insertion of a chest tube was done in 5 patients at the scene by the emergency team, in 15 cases after admission to the hospital and 21 at the ICU. Although the average age of years of patients was higher in group B (37,2 +/- 15,0 y vs. 46,9 +/- 21,1 y), p values calculated by ANOVA test revealed no significant difference. The two groups did not differ regarding to injury severity assessed by the "Injury severity score" (group A: 30,9 +/- 13,3; group B: 29,5 +/- 9,2). The mean duration of mechanical ventilation was 9,4 +/- 9,0d vs. 19,2 +/- 20,4 d in group A vs group B. Patients of group A required intensive care treatment for 12,6 +/- 8,7d vs 21,9 +/- 20,4 d of group B. One patient of group A died because of severe cranio cerebral trauma. 13 Patients of group B died (1 x pulmonal embolism, 12 x multiple organ failure). CONCLUSIONS: Assessment of injury severity by the emergency medical teams failed in a very high percentage. Especially the blunt trauma to the chest was not diagnosed and therefore not respected.

Adult↗

Laser doppler flow imaging of open lower leg fractures in an animal experimental model.

PURPOSE: Open lower leg fractures are frequently associated with severe soft tissue damage, followed by osteomyelitis. Using an animal experimental model, we investigated the effect of timing of coverage of a tibial fracture with a local muscle flap. METHODS: 80 rabbits had a tibial fracture induced in a standardised fashion, which was stabilised by screw osteosynthesis. After 3 (group A; n=40) and 7 days (group B; n=40), respectively, the tissue defect was covered by a local gastrocnemius flap. In increasing intervals from 1 to 2, 4, 8, and 16 weeks, the rabbits from each group were killed and the bone fracture was analysed histomorphologically. Cortical microcirculation was measured by 2-channel laser doppler flowmetry. RESULTS: Muscle flaps after 3 days improved perfusion significantly as compared with 7 days (24 Flux [standard error, 5 Flux] versus 10 Flux [3 Flux]; baseline, 1.4 Flux). Group A animals also displayed a lower rate of necrosis (0 versus 38). The incidence of osteomyelitis was higher in group B than in group A (24% versus 0%). CONCLUSION: Laser doppler flowmetry was proven to be a reliable, minimally invasive means for identifying avital tissue, leading to reduction in the loss of vital bone tissue in experimental settings.

Animals↗

[Patient monitoring after discharge by teleconsultation].

The Televisite application is a post-stationary consulting method, whose main aim is to reduce the treatment time of inpatients. It provides a high quality home consultation after the patient has been discharged from the hospital. The technical handling and the validity of the new method of caring will be analysed--particularly the human-machine interface. In a prospective study case injured patients were attend using the Televisite. For communications with the consulting doctor they were supplied with a high resolution digital camera and a mobile PC with an integrated HCSCD cell phone. The doctor examined the data transmitted by the patient and remotely consulted the patient using the Televisite. Through a simple self-explaining user interface, a smooth information transfer was guaranteed.

Computer Systems↗

[Rapid analysis of biocompatibility with graded test samples exemplified by Ni-NiTi-Ti].

The biocompatibility of nickel-titanium alloys was investigated by single-culture experiments on functionally graded samples with a stepwise change in composition from nickel to titanium, including NiTi shape memory alloy of a 50:50 mixture. This approach permitted a considerable decrease of experimental resources by simultaneously studying a full variation of composition. The results indicate a good biocompatibility for a nickel content up to about 50%. The cells used in the biocompatibility studies comprised human osteoblast-like osteosarcoma cells (SAOS-2, MG-63), primary human osteoblasts (HOB), and murine fibroblasts (3T3).

Animals↗

[Can costs be lowered by post-hospital patient management with telecare].

The idea of Televisite is to equip the patients with a camera and a communication panel at the time of their discharge from the hospital. In that way patients and physicians are able to continue the treatment and the rehabilitation program. An easy to handle interface helps the patient to answer simple questions or to send voice recordings, pictures or videos via a service centre to the doctor in attendance. This concept has the great advantage that the patients has to visit the physician in the office or in the hospital only when absolute required. Routine checks can be done by telecommunication. Thus the efficiency of the system may significantly contribute to lower costs in the health care system.

Computer Communication Networks↗

[Pyogenic infection after joint replacement operations: incidence and economic effects].

Infection following arthroplasty is a rare but significant and threatening complication. The incidence is about 2%. Treatment of an infected joint replacement may be demanding, time consuming and expensive. For the treating institution there is a risk of substantial financial losses due to inadequate reimbursement. Calculated on the basis of approximately 150,000 implanted joint protheses/a, an infection rate of 2% and treatment costs of approximately 50,000 [symbol: see text]/infected case the economic burden is an estimated 150 million [symbol: see text]/a in Germany. This amount should justify a sound evaluation of costs related to infection in arthroplasty, which should be the effort of the health insurance organisations. Additionally specific research in the field of infection prevention must be sponsored. The system of reimbursement should be adequately adopted and corrected.

Arthritis, Infectious↗

[The diagnostic concept of acute infection of the shoulder joint].

INTRODUCTION: It is generally accepted that septic conditions of the shoulder often lead to an earnest situation with joint damage. Because of the low incidence of shoulder infections there are only a few cases reported in the literature. Therefore, unlike joint infections of the knee no diagnostic and therapeutic standard procedure is documented for the shoulder. MATERIALS AND METHODS: In a retrospective study the results of 15 patients with a surgical revision at the BG-Clinic-Bergmannsheil-Bochum between 1 January 1989 and 31 August 1999 after an infection of the shoulder joint were analyzed. We registered the following parameters: etiology, intervall until the first clinical symptoms, clinical signs, diagnostic procedure, intraoperative site (Gächter classification), and operative treatment. The diagnostic procedure followed an algorithm, including CRP-determination, ultrasound of the shoulder, ultrasound-guided aspiration and a Gram stain. If the result was positive, surgical joint revision followed. The infection stage was classified intraoperatively according to the criteria of the Gächter classification. Eight patients were reexamined after an average follow-up of 4.8 years. RESULTS: Fourteen infections followed injection. All patients demonstrated increasing CRP levels and a painful limited range of motion. In all Gram stains we detected bacterial organisms. The diagnosis of an acute infection according to the criteria of this diagnostic algorithm was verified intraoperatively in all 15 joints. Two patients with delayed admission died postoperatively due to septic multiorgan failure despite maximal treatment under intensive care conditions. CONCLUSION: If there are suspicious clinical symptoms after a typical anamnesis, we recommend an immediate diagnostic algorithm, including CRP determination, ultrasound of the shoulder, ultrasound-guided joint puncture and a Gram stain. If there is acute joint infection, time-consuming diagnostic procedures must be avoided because of the risk of secondary reduced joint mobility or life-threatening complications.

Acute Disease↗

[Internal fixation of subcapsular fractures of the femoral neck].

Beside of modern surgical and implant techniques and basic pathophysiological knowledge, internal fixation of subcapsular fractures of the neck of the femur is still known to be connected with a high rate of complications. Implant failure, the typical early complication arising within the first 3 months, non-union, avascular necrosis of the femoral head and late segmental collapse are the typical complications. The type of fracture, timing of operation (emergency operation), quality of reduction and implant positioning have all been shown to predict outcome significantly. However, it is also suggested that further therapeutical interventions like intra-articular pressure decrease by evacuation of hematoma, the kind and technique of reduction, special surgical techniques and postoperative treatment can influence outcome, as well as patient-associated factors like age, degree of osteoporosis, neurological disease, and alcoholism. The superiority of one of the 100 different existing implants have not been proved either by clinical or by biomechanical trials. However, besides screw osteosynthesis, the sliding screw plate and less often sliding nail plate implants are commonly used. Because of the very different biomechanical principles it is of great importance to adhere to the special operative techniques to avoid intraoperative complications that might cause treatment failure. To reduce the frequency of these almost always fatal and in special circumstances lethal complications, we need some more detailed information from good clinical trials and sufficient external quality assurance.

Femoral Neck Fractures↗

[Supracondylar femoral fractures in knee endoprostheses. Stabilizing with retrograde interlocking nail].

The treatment of supracondylar fractures of the femur in total knee arthroplasty is still challenging, and a variety of methods has been recommended. In a retrospective analysis, we reviewed six patients (average age: 70.5 years) with this type of fracture that had been stabilized with a retrograde intramedullary locking nail [Green-Seligson-Henry (GSH) nail]. The fracture had occurred 34.5 months after implantation of total knee arthroplasty. The average time of the operation was 97.16 min. There were no intra- or postoperative complications. All patients could be followed up at 17.3 months on average. Fracture healing was uneventful in all six cases. The postoperative range of motion was similar to the prefracture level in five patients. One patient demonstrated a loss of extension (10 degrees) associated with a valgus malalignment of 10 degrees. According to our experience, retrograde intramedullary nailing of supracondylar fractures in total knee arthroplasty is a promising alternative, which allows closed reduction and preservation of the soft tissue envelope. Immediate mobilization with partial weight bearing is possible, and the rate of complications is low.

Aged↗

Midshaft fractures of the clavicle with a shortening of more than 2 cm predispose to nonunion.

Up to 15% of all fractures involve the clavicle. Nonunion of the clavicle is a rare complication after conservative treatment. It mainly presents as pain at the fracture site and a limited range of motion of the shoulder. The purpose of this study is to define a certain type of fracture of the clavicle that is predisposed to malunion and therefore should be treated surgically after failure of conservative treatment. Thirty-nine patients with delayed or malunion of the clavicle were analyzed. There were 13 women and 26 men. The average age of the male patients was 36.4 years (range 20-59 years) and of the female patients, 43.6 years (range 18-55 years). The mean follow-up period was 2.3 years (range 6 months to 4.2 years). All of them were treated surgically. There were 33 Allman I fractures and 6 Allman II fractures. Of the Allman I fractures, 30 (91%) were shortened by at least 2 cm. Allman I fractures were treated using a reconstruction plate or a dynamic compression plate in combination with bone grafting. The time of operation after fracture ranged from 6 weeks to 8.5 years (average 9.8 months). Pain at the fracture site was the leading symptom in all patients. At 6 months after the operation, 38 patients were free of pain with an unlimited range of motion of the shoulder. One patient (2.6%) complained of a slight weakness on the operated site. One fracture failed to unite (2.6%) and had to be replated. There were no refractures, infections, vessel or nerve lesions. To conclude, in Allman I fractures with a shortening of more than 2 cm, we recommend operative treatment in symptomatic patients if there are no signs of callus formation after 6 weeks.

Adolescent↗