Biomedical subjects

W Hein

Publications and source records attributed to W Hein.

80 records · Page 5Linked to original sources

PubMedDate not supplied

[Does the NexGen LPS flex mobile knee prosthesis offer advantages compared to the NexGen LPS?--a comparison of clinical and radiological results].

UNLABELLED: Under experimental conditions, mobile bearing knee prostheses have several advantages. The optimized congruence of the tibio-femoral joint surface allows a knee flexion of more than 120 degrees without creating instability or increase of wear. AIM: The aim of this study is to compare the results of a prospective randomized study after implantation of the mobile bearing knee prosthesis NexGen LPS Flex with the results of the fixed bearing knee prosthesis NexGen LPS. METHODS: Sixty patients underwent a total knee replacement (30 patients with NexGen LPS Flex mobile, 30 patients with NexGen LPS) via a mid vastus approach. All implants were cemented (Palacos) including the patella resurfacing. We evaluated the Hospital for Special Surgery Score (HSS) and different radiological parameters (maximal flexion, positioning of the implants, leg axis) preoperatively as well as 3 months and 3 years (34.6 +/- 7.3 months) postoperatively. RESULTS: After 3 months the NexGen LPS Flex group showed better results in the scores for pain, range of motion (122.5 degrees vs. 107.33 degrees ) as well as the overall HSS (87.21 vs. 82.68 points) compared to the NexGen LPS group. Three years postoperatively there were no differences in all scores between the two groups. CONCLUSION: The theoretical advantages of the mobile bearing knee prostheses were reflected in the clinical results only partly and temporarily. Probably the results of long-term follow-ups will show characteristic advantages or disadvantages of mobile bearing knee prostheses.

Aged↗

PubMedDate not supplied

[Osteoporosis--a neglected issue in orthopaedics? Results of a survey amongst German orthopaedic surgeons].

AIM: Patients with fragility fractures have a significantly increased risk of sustaining additional fractures. Therefore one should consider avoidance of further fractures as the primary treatment principle. Since orthopaedic surgeons manage most of fragility fractures, but might not be well attuned to osteoporosis itself, it was the aim of the Bone and Joint Decade (BJD) and the International Osteoporosis Foundation (IOF) to survey orthopaedic surgeons in order to assess their knowledge of prevention, diagnosis, and treatment of osteoporosis. MATERIAL AND METHODS: The multinational survey questionnaire was developed by a working group of national project co-ordinators in France, Germany, Italy, Spain, the United Kingdom, and New Zealand and based to some extent on an American survey. Following translation into the national language it was distributed in 2002 to the members of the orthopaedic societies to assess the management of prevention, diagnosis, and therapy of osteoporosis and fragility fractures, comparing both different health-care systems and different working environments. 5 700 questionnaires were distributed in Germany with a 20 percent response rate. RESULTS: As the main result of the German survey -- independent of the working environment -- a substantial deficit concerning training and knowledge about the management of prevention, diagnosis, and treatment of osteoporosis and fragility fractures was seen. In addition, the majority of participants requested educational opportunities to become qualified for a better disease control. CONCLUSION: In order to satisfy the increasing need for adequate management of prevention, diagnosis, and therapy of osteoporosis and fragility fractures, structured educational opportunities have to be offered to the German orthopaedic community. In the mean time first steps have been initiated: training courses to qualify as "Osteologe DVO" and the "White Book Osteoporosis", which was initiated by BJD and IOF and developed by several German medical societies and patient organisations it is based on the German DVO guidelines providing an evidence-based and structured overview concerning all relevant aspects of osteoporosis and fragility fractures.

Attitude of Health Personnel↗

PubMedDate not supplied

[Axial load in case of press-fit fixation of the ACL graft--a fundamental study].

AIM: The aim of this study was the determination of the axial fixation load resting on smooth press-fit dowels needed for fixation of the patellar tendon graft (BTB) in order to reach the same fixation properties compared to the interference screw on anterior cruciate ligament (ACL) plasty. METHOD: Bovine test specimens with 27 BTB grafts fixed in tibial drill holes were used and divided in 3 groups: interference screw, and press-fit cylinder (Ø 7 mm) with 150 N and 100 N axial loads. Prior to fixation, impactation of the transplant into bone was carried out. Failure testing was done in a tensiometer at a cross-head speed of 50 mm/min. Determinations of peak load and stiffness were also made. RESULTS: Similar peak loads and stiffness were reached on introducing a press-fit dowel (slashed circle 7 mm) with 100 N and 150 N axial load compared to interference screw fixation of the BTB graft. Peak load: 988.1 N +/- 365.1 (screw) versus 1 210.4 N +/- 292.4 (dowel 150 N) and 1 109.8 N +/- 505.4 (dowel 100 N). Stiffness: 86.4 N/mm +/- 20.5 (screw) versus 102.4 N/mm +/- 15.2 (dowel 150 N) and 77.1 N/mm +/- 11.0 (dowel 100 N). There was no significant difference. CONCLUSION: When introducing a press-fit dowel (slashed circle 7 mm) with 100 N axial load into a preformed bone bed, the same fixation properties are reached as in the case of an interference screw on BTB-ACL plasty.

Animals↗

PubMedDate not supplied

[Cage failure following replacement of the third lumbar vertebral body in Hodgkin's disease].

AIM: We present a case report and the histological analysis of cage failure following vertebral body replacement in Hodgkin's disease. METHOD: In a 35-year-old patient with a single metastasis of Hodgkin's disease replacement of the third lumbar vertebral body (Harms-titanium-mesh-cage, DePuy Acromed, completely filled with autogenous spongiosa from the iliac crest) was performed. 51 months postoperatively, the patient presented with acute back pain without trauma. The X-ray showed a collapse of the Harms-titanium-mesh-cage. The cage fragments had caused ventral dislocation of the main blood vessels and dura compression without neurological deficits. After the replacement of the failed Harms-cage (Synex, Synthes) histological analysis (light microscope, non-decalcified horizontal cuts, thickness of 150-200 microm, Giemsa und van Gieson staining) was done. RESULT: The histology showed a remodelling of new bone in the area of the endplates without contact to the cage wall. In the region of the cage corpus, bony necrosis and connective tissue rich in cells was found. CONCLUSION: Bridging fusion in vertebral body replacement cages is not proven. As a result cage failure may occur. Therefore, in tumour patients with high live expectancy, Palacos filling of the cages should be discussed.

Adult↗

PubMedDate not supplied

[Comparison of roentgenological, macroscopic and histological degree of degeneration in varus gonarthrosis].

In 20 cases of varus gonarthrosis the degree of severity of osteoarthrosis was assessed preoperatively, intraoperatively and postoperatively for the medial and lateral compartments, respectively. The preoperative assessment was carried out on the basis of x-ray taken in an anterior-posterior and lateral view, whereas the intraoperative assessment was based on the recognizable macroscopic alteration of the femur and tibia. Following implantation of a total knee prosthesis, the resected osteocartilogical samples were assessed from a histological point of view. In the case of varus gonarthrosis there is a distinct difference in the degree of degeneration in the medial and lateral compartments. This difference becomes less noticeable if the assessment is carried out intraoperatively. The histological analysis shows that there are certainly differences between the compartments from a quantitative point of view but a late stage of osteoarthrosis was discernible both medially and laterally. From a histological point of view the radiological concept of the so-called "unicompartmental varus gonarthrosis" cannot be supported. In both compartments the osteoarthrotic process is more uniform than is to be expected.

Aged↗

PubMedDate not supplied

[Cerebellar hemorrhage as an early complication of spinal operations. 2. Case reports and review of the literature].

GOAL: The present paper investigates the etiology and pathogenesis of cerebellar hemorrhage after spine surgery. METHOD: This paper reports two patients in those this complication was seen. In respect to the current literature we discuss the etiology and pathogenesis of cerebellar hemorrhage due to spine surgery. RESULTS: Cerebellar hemorrhages represent a life-threatening situation. There are no reports in the literature about cerebellar hemorrhage as an early complication of intraoperative dura injuries in spine surgery. It seems that a bigger cerebrospinal fluid loss is responsible for the developing of cerebellar hemorrhages. The loss creates a pressure gradient from infratentoriell to site of lesion and also leads to mechanical stress on cerebellar blood vessels such as traction, tearing and kinking. CONCLUSIONS: Every condition after spine surgery with dura injuries and neurological deficits should be carefully evaluated and intracranial hypotension as well as hemorrhage should be ruled out.

Adult↗

PubMedDate not supplied

[Long-term outcome of Dega acetabulum-plasty].

The authors reviewed the results of Dega acetabuloplasty in developmental dysplasia of the hip performed simultaneously with intertrochanteric osteotomy (predominant derotation-varusosteotomy DVO). 74 hips in 55 patients were assessed at a follow-up of 7-17 years (mean 10 years). Measurements of the acetabulum and the head-acetabulum-relation were found to be normal or slightly pathologic in 80-93% of the hips. Values of the femoral head and neck were in the low normal percentage. Poor clinical and radiological outcome was caused by avascular necrosis of the femoral head or revalgisation after DVO. The rate of avascular necrosis after conservative treatment was 23.4%, the rate as a consequence of the operation was 5.4%. Therefore, we prefer at present the subtrochanteric osteotomy of the femur.

Acetabulum↗

PubMedDate not supplied

[Previous experience with subcapital femoral neck osteotomy in severe cases of epiphysiolysis capitis femoris].

In severe cases of epiphyseolysis capitis femoris the high-grade dislocation of the epiphysis near the deformation is corrected by subcapital femoral neck osteotomy. In the period from 1976-1986 the subcapital femoral neck osteotomy was carried out ten times at the Department for Orthopaedic Surgery of Martin-Luther-University Halle. Our own operative procedures as well as the results achieved are represented.

Acute Disease↗