Zeitschrift fur Orthopadie und ihre Grenzgebiete最新文献

Aim: The aim of this study is to compare the course of disease of patients with a degenerative instability of the lumbar spine after PLIF or ALIF.

Materials and methods: Between October 1995 and January 2000 115 patients underwent a ventral or dorsal spondylodesis due to a degenerative instability in the Department of Neurosurgery of the Unfallkrankenhaus Berlin Hospital and in the Department of Neurosurgery of the Friedrichshain Hospital in Berlin. At an average of 25 (13-64) months after surgery these patients were followed up in a clinical examination and a questionnaire concerning their sense of pain and quality of life.

Results: Significant improvement after surgery has been shown in both groups. The recovery rate was 52 % which is a beneficial result. The fusion rate was 91 %. The postoperative sense of pain declined with regard to the visual pain scale. The intake of analgetics decreased in a quantitative as well as in a qualitative way. With 94 % the acceptance of the operation was comparatively high. The number of complications was low in comparison with the literature (4 %). There was no operative lethality.

Conclusions: With regard to the indications and contraindications the PLIF as well as the ALIF is accepted unquestioningly as an up-to-date method.

Aim: The aim of this study was the detection of areas at risk at the proximal femur after implantation of different femur neck prostheses using the photoelastic stress analysis.

Methods: Twelve pairs of human femurs were used as examination material. The analysis of the stress pattern was done with a stepwise increasing load up to the quadruple of body weight before and after implantation of three models of femur neck prostheses which were implanted cementless. The "CUT" and "Cigar" models are coated with a tripod structure. The "Cigar" model has a lateral thrust plate. The lateral end of the "CUT" model is curved and this end is attached to the lateral corticalis. The third model, the "rip prosthesis" has two layers for rotational stability. Subsequently, the micromotions of the implanted prosthesis in the femural neck were examined with alternating weight loads (1000 +/- 700 N).

Results: The Cigar prosthesis showed the most changes of stress distribution because of the lateral thrust plate with concentration of isochromatic lines to the lateral boring. In the region of the oseotomy an increase of strain up 1440 microm/m could be detected for the Cigar and up to 1000 microm/m for the rib prosthesis. The stress pattern after implantation of the CUT prosthesis remained very similar apart from a slight increase of stress values (720 microm/m). Only for the Cigar prostheses were the measured micromotions below the critical value for a possible osteointegration with a mean value of 134 microm/m.

Conclusion: The stress pattern after implantation of the CUT prosthesis remained most similar to the preinterventional stress distribution. Because of this, it is to be expected that the osseous modification would stay at a low level. The question of osteointegration can only be answered in long-term in-vivo studies.

Purpose: Balloon kyphoplasty is a minimally invasive procedure for the stabilization of osteoporotic and osteolytic vertebral fractures. The purpose of this prospective study was to evaluate this operative procedure in the treatment of osteolytic vertebral fractures with regard to the reduction of pain and functional improvement of the patients and further to evaluate the restoration of vertebral height postoperatively.

Materials and methods: In this study 26 patients (21 male, 5 female) with osteolytic vertebral fractures were treated with balloon kyphoplasty. In total, 59 vertebral fractures were treated with balloon kyphoplasty. Preoperatively conventional radiographs in lateral and a. p. views, CT and/or MRI were preformed. Pre- and postoperatively the clinical parameters using VAS (visual analogue scale) and the Oswestry score were evaluated. Radiographic scans were performed pre- and postoperatively and after 3, 6, 12 and 24 months. The vertebral height and endplate angles were measured.

Results: The median pain scores (VAS) decreased from pre- to post-treatment significantly (p < 0.05) as also did the Oswestry score (p < 0.05). Balloon kyphoplasty led to a significant and sustained reduction of pain resulting in a significant functional improvement for the patients. A significant restoration of vertebral height and reduction of the kyphotic angle could be achieved with the balloon technique (p < 0.05). Furthermore, the minimal-invasive procedure was able to stabilize the spine also over a longer period of 24 months. A radiation therapy and/or chemotherapy could be performed without loss of time.

Conclusion: In the treatment of osteolytic vertebral fractures balloon kyphoplasty led to a quick and sustained reduction of pain and as well as a functional improvement for the patients. A restoration of the vertebral height and reduction of the kyphotic angle was especially attributable to the balloon technique. The balloon kyphoplasty was able to stabilize the fractured vertebrae in the long-term and was able to prevent an increase of kyphotic deformity. Balloon kyphoplasty is an outstanding alternative in comparison to the established therapeutic concepts in the treatment of osteolytic vertebral fractures.

During pregnancy changes of the bone metabolism can occur. Femoral neck fractures are known as a very rare consequence of transient osteoporosis in pregnancy. In a case report we present the clinical, radiological and histological features of a bilateral fracture of the femoral neck. A 29-year-old woman presented with pain in the right hip, which occurred in the 34 (th) week of pregnancy. The symptoms were initially interpreted as a sacroiliac joint affection and consequently a conservative treatment was initiated. Five days after a Caesarean section a dislocated fracture of the femoral neck was diagnosed on the left side. On the contralateral side the fracture was not dislocated. For therapy this patient underwent a total hip replacement on the left hand side and an internal fixation on the other side. Especially during pregnancy changes of the bone are diagnosed late due to the side effects of radiation. This case report indicates that MR imaging and other non-ionising techniques should be considered if such symptoms persist in spite of therapy.

Aim: The awareness and prevention of perioperative morbidity are essential in revision total hip arthroplasty [THA]. Therefore, it was the purpose of this study to assess the rate of perioperative complications following revision THA in order to evaluate the impact of patient- and procedure-related variables.

Methods: 169 consecutive patients with a mean age of 71.7 years suffering from aseptic loosening of their THA were included in this retrospective study. Multivariate logistic regression models with estimation of the odds ratio [OR] and 95% confidence interval [CI] served to analyze the influence of operation duration, gender, revision status, ASA classification, and type of fixation of the primary implant on the perioperative morbidity.

Results: 68.6% of the cases were primary revisions, and 31.4% secondary or multiple revisions. 49.7% of the operations involved exchange of the complete implant whereas 39.1% comprised exchange of the cup and 11.2% exchange of the stem only. Mean operation duration was 130 minutes [min] (range: 40-260 min), and mean intraoperative blood loss was 2.6 L (0.5 to 12 L). The rate of intraoperative complications was 10.1 % with a 6.5 % fracture rate. Postoperatively the complication rate was 25.4% with an 8.3% rate of luxations. 11.8% of the patients had revision within the first three weeks after surgery. Regression models showed the significant impact of revision status (primary vs. secondary or multiple: OR 2.90, 95% CI 1.42-5.92) and operation duration (per min starting from the mean operation time: OR 1.01, 95% CI 1.00-1.02) on the resulting complication rate. Analysis of the perioperative complication rate following primary revisions revealed a significant difference (p = 0.03) between patients with cemented (15/36, 41.7%) and non-cemented (8/45, 17.8%) implants.

Conclusions: Revision status with a three-fold increase in patients with multiple revisions as well as operation duration with a 1 % increase per min starting from the mean operation time significantly influence the perioperative morbidity. Patients with a first revision, furthermore, seem to be at greater risk for an adverse event perioperatively if their implant is fully cemented. These findings should be taken into account prior to initiating surgery.

Aim: The aim of this study was to assess the influence of culture conditions on the differentiation of human chondrocytes expanded in monolayer (2 D) or a three-dimensional (3 D) biodegradable collagen type I matrix, with regard to chondrocyte-specific markers.

Method: Human arthrotic chondrocytes were taken from nine adult donors (average age 72.1 years) undergoing knee replacement. The isolated cell suspensions were split and cultivated either in a 3-dimensional collagen gel (3 D) or in a monolayer (2 D). The amounts of mRNA for collagen I and II, aggrecan and melanoma inhibitory activity (MIA) were quantified by means of real-time PCR at different times.

Results: The 2 D-passaged cells showed a significant increase of collagen I between P 00 and P 01 (p = 0.009), whereas the expression of collagen II decreased significantly (p = 0.022). There was no significant change for collagen I in 3 D-cultivation, whereas the collagen II expression decreased significantly after 2 to 4 weeks (p = 0.001).

Conclusion: Human adult chondrocytes obtained from elderly patients showed a decreased expression of collagen II with increased passaging in the monolayer (2 D). The decrease was delayed in 3 D-cultivation. We thus question the assumption that the dedifferentiation of chondrocytes can be prevented or reversed by 3 D-cultivation. Based on our results, we recommend the use of freshly isolated and therefore sparsely dedifferentiated chondrocytes for transplantation.