Publications (18)17.77 Total impact
- [Show abstract] [Hide abstract] ABSTRACT: Background In most cases, loosening of a prosthesis stem is accompanied by periprosthetic osteolysis. This article presents the short-term clinical and radiological results after revision of total hip arthroplasty (THA) with bone substance deficiencies using a modular noncemented femoral stem system (LINK MP). Patients and methods Between March 2003 and November 2005, 91 LINK MP modular revision stems were implanted in 90 patients. Eighty-one patients (51 stem revisions, 24 revisions of stem and shell, and six reimplantations after a Girdlestone situation) were available for prospective clinical and radiological evaluation at an average follow-up time of 16.7±6.5 (6–36) months. The average patient age at revision was 67.2±10.5 (31–87) years. Results Bone defects in the proximal femur were evaluated according to the Paprosky classification and showed type 2 in five cases, type 3A in 73 cases, and type 3B in three cases. The Merle d’Aubigné score increased significantly from 10.4±2.3 (4–15) preoperatively to 14.7±2.2 (9–18) at the latest follow-up (p<0.001). Migration analysis in conventional radiographs revealed an average stem subsidence of 3.4 mm. Thirty-one intraoperative and postoperative complications were noted in 28 (34.5%) patients. Conclusion After a short-term follow-up, the modular noncemented femoral stem system LINK MP was shown to be a reliable tool for revision of THA with bony defects of the proximal femur. Our results are comparable to those for other modular noncemented revision stems. As expected, complication rates were higher than with primary THA.
- [Show abstract] [Hide abstract] ABSTRACT: In most cases, loosening of a prosthesis stem is accompanied by periprosthetic osteolysis. This article presents the short-term clinical and radiological results after revision of total hip arthroplasty (THA) with bone substance deficiencies using a modular noncemented femoral stem system (LINK MP). Between March 2003 and November 2005, 91 LINK MP modular revision stems were implanted in 90 patients. Eighty-one patients (51 stem revisions, 24 revisions of stem and shell, and six reimplantations after a Girdlestone situation) were available for prospective clinical and radiological evaluation at an average follow-up time of 16.7+/-6.5 (6-36) months. The average patient age at revision was 67.2+/-10.5 (31-87) years. Bone defects in the proximal femur were evaluated according to the Paprosky classification and showed type 2 in five cases, type 3A in 73 cases, and type 3B in three cases. The Merle d'Aubigné score increased significantly from 10.4+/-2.3 (4-15) preoperatively to 14.7+/-2.2 (9-18) at the latest follow-up (p<0.001). Migration analysis in conventional radiographs revealed an average stem subsidence of 3.4 mm. Thirty-one intraoperative and postoperative complications were noted in 28 (34.5%) patients. After a short-term follow-up, the modular noncemented femoral stem system LINK MP was shown to be a reliable tool for revision of THA with bony defects of the proximal femur. Our results are comparable to those for other modular noncemented revision stems. As expected, complication rates were higher than with primary THA.
- [Show abstract] [Hide abstract] ABSTRACT: A prospective, controlled, randomised trial was performed to compare the effect of high-energy extracorporeal shock wave therapy (ESWT) versus low-energy ESWT in treatment of rotator cuff tendinopathy. Forty adult patients were included in the study. Patients in the intervention group received 6000 impulses of high-energy (ED+ 0.78 mJ/mm2) in 3 sessions under local anaesthesia. Patients in the control group received 6000 impulses of a low-energy ESWT (ED+ 0.33 mJ/mm2) under local anaesthesia. Follow-up examinations were performed 12 weeks and one year after treatment by an independent observer. An increase in function and a reduction of pain were found in both groups (p < 0.001). Although the improvement in Constant score was greater in the high-energy group compared to the low-energy group, statistical analyses showed no significant difference between the groups with respect to all parameters studied (Constant score/pain/subjective improvement) after 12 weeks and one year follow-up. No statistically significant differences were found between the results of high-energy and low-energy ESWT of rotator cuff tendinopathy.
- [Show abstract] [Hide abstract] ABSTRACT: We introduce a new method to determine the anatomic rotation center of the hip. In total, 214 healthy hip joints were examined and statistically analyzed. As a reference point we used the intersection between Koehler's line and a line between the upper rims of the two foramina obturatoria. In relation to the reference point the anatomic hip center is localized 7.7% in vertical direction and 17.4% in horizontal direction for male individuals and 7.75 and 15.4% for female individuals, respectively. Those data were referred to the pelvic height. Our data can be used to determine the anatomic hip center in an easy and reliable way, not only for preoperative planning but also for retrospective investigations.
- [Show abstract] [Hide abstract] ABSTRACT: The purpose of this study was to survey and to evaluate the first clinical and radiological results with the cementless ZMR taper hip prosthesis. The modular distal-tapered stem was designed with a roughened titanium surface and sharp splines to achieve secure distal fixation and rotational stability. 90 ZMR taper hip prostheses were implanted between October 1999 and July 2002. Out of these, 4 interventions were primary and 86 were revision procedures. In 43 cases a complete hip prosthesis revision and in 43 cases a stem revision was necessary. The mean age of the 90 patients (42 males, 48 females) was 67.1 years. The mean follow-up period was 7.6 months (3 to 25 months). The stem displayed an excellent distal fixation. The mean subsidence could be measured with 4.3 mm. Furthermore, most cases showed a particularly favourable remodelling of the proximal femoral bone stock. Complications associated with revision included intraoperatively 4 femur fractures, 3 femur fissures, 5 femur perforations, 2 trochanter fractures and postoperatively 19 dislocations, 5 superficial wound infections, 2 transient palsies, 1 pulmonary embolism, 1 stem rotation and 4 wound healing failures. Considering these complications 15 re-revisions were necessary and the ZMR taper hip prosthesis had to be exchanged in 3 cases. On the one hand the ZMR taper hip prosthesis proved its value, particularly with regard to the stem modularity, the excellent distal fixation in conjunction with the possibility of partial body weight bearing and the rapid bone remodelling of the femur. On the other hand an increased number of postoperative complications and re-revisions occurred. Further long-term studies seem to be essential.
- [Show abstract] [Hide abstract] ABSTRACT: To analyze and to optimize interdisciplinary clinical processes, to introduce an IT-supported model for demand-driven system evolution in healthcare, and to demonstrate the feasibility of the approach for a clinical example and to present an evaluation. System evolution and change management are viewed as two sides of the same coin, thus formal methods for process analysis and IT system evolution were embedded into a goal-oriented change management model. Based on a process model, a Failure Mode and Effects Analysis (FMEA) and a computer simulation were performed. A tool for rapid application development (RAD) was used to incrementally improve the healthcare information system according to newly arising needs. Each of the formal methods used contributed to the successful reorganization of the interdisciplinary clinical process. An evaluation demonstrated significant improvements. An integrated IT application was implemented to support the optimized process. Process improvement is feasible and effective when formal methods for process analysis and requirements specification are used in a reasonable and goal-oriented way. It might be necessary to trade off costs and benefits or simplify a given method in the context of a particular project. As the same information is utilized in different tools, it is supposed that the efforts for process analysis, documentation and implementation of adapted applications could be reduced if different tools were integrated and based on a single coherent reference model for description of clinical processes.
- [Show abstract] [Hide abstract] ABSTRACT: summary. Storing autologous blood as whole blood (WB) has been proposed for increasing the cost-effectiveness of preoperative autologous blood donation programmes. However, experimental data suggest that autologous leucocytes might lead to immunomodulation similar to the effect attributed to allogeneic leucocytes. In a retrospective analysis, the postoperative outcome of 120 patients undergoing elective orthopaedic surgery and having donated up to two units of autologous WB (AWB) was compared with that of a control group of 52 patients, whose autologous donation had been processed into buffy coat-depleted red cell concentrates (RCC). At least one autologous unit, but no allogeneic units, had been transfused in all analysed patients. Donation schemes were equally efficacious in both groups. There was no significant difference in postoperative infection rates between the two groups. Overall rates were 7·7% in the RCC group and 8·3% in the WB group. Surgical, thromboembolic and other recorded complications, length of postoperative hospital stay and days of the use of antibiotics were also not significantly different between the two groups. The results of this study suggest that transfusion of up to two units of unmodified AWB is as efficacious as the transfusion of autologous RCC and does not negatively influence the postoperative outcome in elective orthopaedic surgery.
- [Show abstract] [Hide abstract] ABSTRACT: Between 1985 and 1998, 12,331 patients were included in the general neonatal ultrasound hip screening programme for developmental dysplasia of the hip (DDH). Patients who needed treatment (604) were compared with a second group of 73 unscreened children treated conservatively and surgically for DDH. The incidence of Graf sonographic hip types IIc to IV varied throughout the observation period. Femoral and pelvic osteotomies were almost entirely restricted to the unscreened group of patients. The six to ten per year recorded in the period 1985 to 1990 declined subsequently to three or less per year. The yearly admissions to hospital fell noticeably after six years of screening. Late presentations of DDH were reduced to three or less per year from 1990 to 1994, none between 1995 and 1998 and one or two per year from 2000. We conclude that general neonatal sonographic hip screening can reduce significantly surgical procedures, hospitalisation and late presentation of DDH.
- [Show abstract] [Hide abstract] ABSTRACT: We retrospectively compared the influence of surface finish with respect to the long-term durability of a cemented titanium alloy stem of the same design but different surface finish. From 1984 to 1994, the stem was made of a titanium-aluminum-vanadium alloy. A total of 201 patients with 220 smooth stems (mean follow-up 11 years and 4 months) out of 612 implanted between 1984 and 1987 and 319 patients with 343 rough stems (mean follow-up 5 years and 10 months) out of 812 implanted between 1991 and 1993 could be reviewed clinically and radiologically for comparison. The average age of the patients with the smooth stem was 58.1 years and of the patients with the rough stem, 62.2 years. In both groups, 35% of patients were male and 65% female. The mean Merle d'Aubigné hip score increased from 10.5 to 16.0 points in the smooth stem group and from 11.0 to 16.9 points in the rough stem group. The distribution of radiolucent lines, according to the zones of Gruen, was similar in both groups. The smooth stem required revision in 18 cases after a mean follow-up of 11 years and 4 months and the rough stem in 30 cases after a mean follow-up of 5 years and 10 months. The survival analysis (Kaplan-Meier) revealed 95.4% survival after 13 years for the smooth femoral component and 76.7% survival after 8 years for the rough femoral component. The implantation of titanium alloy stems with a rough surface finish cannot be recommended because of its high aseptic loosening rate.
- [Show abstract] [Hide abstract] ABSTRACT: In September 2002 the Federal Ministry of Health (BMG) has passed a decree in respect to the diagnosis related group system (G-DRG) for German hospitals (KFPV). From 2003 on the basis of this decree German hospitals were offered for the first time to use the G-DRG system optionally according to the " Section 17b Abs.4 of the Hospital Financing Law (Krankenhausfinanzierungsgesetz-KHG)". In addition the preliminary calculation data for the German DRG-System were published. The goal of this study was to compare the development of the cost weights and the average lengths of hospital stay in Australian teaching hospitals between 1998 and 2001 with the cost weights and average lengths of hospital stay in German hospitals according to the data published in the first German calculation (G-DRG V1.0). An analysis was performed using the publically accessible reports on the national hospital cost data collections from 1998 until 2001 as they were published by the Commonwealth Department of Health and Aged Care in Australia. These data were compared with the cost weight calculation and average lengths of hospital stay calculation of the Institute for the Assessment of Cost Weights (InEK GmbH) published in the G-DRG V1.0 version. From 1998 until 2001 the cost weights of medical procedures such as spine fusion operations and joint arthroplasty revision operations on the hip and on the knee with severe complications and co-morbidities increased continuously. This development was not seen in DRG's without complications and co-morbidities, in food and ankle procedures and in shoulder procedures. The average length of hospital stay decreased continuously with very few exceptions. The average length of stay for so called C-DRG's (I09, I12, I13, I68, I69, I71, I75, I76) and in particular so called Z-DRG's (I16-I27) are in general longer by a factor of at least 2 in German hospitals when compared to Australian hospitals. A high quality of right-coding of ICD and ICPM Codes is a prerequisite to reach the correct revenue-relevant DRG. In Germany the average length of hospital stay is significantly longer than in Australia. In general the MDC-8-DRG's have demonstrated a smaller range when compared with the first calculated German DRG's in respect to the complexity of the procedures. Future management of the expected reductions in hospital stay will be based on a continuous co-operative efforts to improve the structural-, process- and (clinical guidelines and clinical pathways) and outcome quality of our medical procedures. The central objective of this effort is the well-being of our patients.
- [Show abstract] [Hide abstract] ABSTRACT: Die sogenannte angeborene Hüftdysplasie, die im englischen Sprachgebrauch ihren pathophysiologischen Entstehungsmechanismen entsprechend präziser „developmental dysplasia of the hip (DDH)“ genannt wird, ist auch im Zeitalter des Ultraschallscreenings die häufigste und wichtigste kongenitale Gelenkerkrankung geblieben.
- [Show abstract] [Hide abstract] ABSTRACT: Introduction: In our hospital, preoperative autologous blood donation (PABD) is performed in an interdisciplinary co-operation between the clinic for orthopaedic surgery and the institute for transfusion medicine. On the occasion of the introduction of a hospital information system (HIS), a computer assisted investigation was performed to analyse and optimise the organisation of PABD. Methods: First, the actual situation was evaluated. Time recording was performed for all procedures and persons involved (patients and staff). Flow of information and materials was analysed. The actual work flow was depicted in a graphic model using Visio -4 as computer software. Then new organisation structures were designed and tested in a dynamic model (Bonapart ®). Results: The analysis of the graphic model of the PABD process identified weak spots like redundant processes and insufficient flow of information. Suggestions for improvement could be developed, e.g.: a checklist for patient suitability for PABD was integrated in the HIS menu of the orthopaedic clinic. Suitability was checked at the first ambulant preoperative consultation at the orthopaedic clinic. Thus a second preoperative consultation could be cancelled. Now, information about refusal of patients, termination of PABD, provided blood units and their storage time are passed to the person responsible for scheduling surgery. The implementation of new organisation structures, which were tested and optimised in a dynamic computer simulation before implementation, resulted in optimised time scheduling in the two departments and reduced waiting periods for patients. Conclusions: It could be proved, that computer software is suitable to describe interdisciplinary co-operation. Thus suggestions for improvement of the organisation of PABD could be developed. In addition, dynamic computer simulations could be successfully applied to test new process organisation before implementation. Computer-assisted remodelling of PABD resulted in better process quality, improved utilisation of resources (staff and facilities) and reduced waiting periods for patients.
- [Show abstract] [Hide abstract] ABSTRACT: Can a cementless hemispheric acetabular component which is made of ultra-high-density polyethylene (UHMW-PE) and a heat-bounded porous titanium mesh coating be recommended 10 years after implantation? Between 1986 and 1988, 279 total hip arthroplasties in which the cementless socket had been used were performed in 261 patients. The results of 145 patients with 159 hip sockets (55.5%) were reviewed clinically and radiologically for comparison after a minimum of 10 years. The clinical and radiological re-examination was documented in a standardized questionnaire in which several scores were integrated. All X-rays were stored and analysed by a special hardware and software computer system. The mean age of the female patients (n = 85) was 63.1 years and of the male patients (n = 60) 60.9 years. The mean follow-up period was 10 years and 3 months. The Merle d'Aubigné hip score increased from 10.9 to 16.5 points at the follow-up evaluation. Radiolucent lines and cysts according to the zones of DeLee/Charnley were seen only in 2% of all cases. The mean polyethylene wear (head disarrangement) was measured with 1.79 mm after 10 years and 1.92 mm after 11 years. In total, 16 revisions (5.7%), 13 (4.6%) aseptic and 3 (1.1%) septic, out of 279 implanted sokets had to be performed. In particular, the acetabular cup with a diameter of 48 mm demonstrated a high loosening rate (4 of 9). The 10-year survival analysis (Kaplan-Meler) was measured with 92.8%. Our results with a cementless socket with titanium mesh coating show insignificant radiolucent lines and an exceptional high 10-year survivorship in which the particular implant philosophy is of great importance for the long-term success. In conclusion, the acetabular component can be recommended for further implantation.
- [Show abstract] [Hide abstract] ABSTRACT: Are the results of cemented titanium hip arthroplasty as bad as described in literature? We present the 10-year results of a cemented mild grid blasted Titanium-Aluminium-Vanadium Stem in Total-Hip-Arthroplasty. The clinical and radiological reexamination was documented in standardized questionnaire in which several scores were integrated. All X-rays were stored and analysed by a special hardware and software computer system. 35% of all patients could be reexamined both clinically and roentgenologically. 71 patients were male (mean age 56.1 years) and 130 female (mean age 59.3 years). The average follow-up period was 11 years and 4 months. The mean Merle d'Aubigné hip score increased from 10.5 to 16.0 points at the follow-up evaluation. Radiolucent lines were according to the zones of Gruen seen in 1% to 22% depending on the zone and the size of the femoral component. 18 reoperations of the femoral component (2.9%) had to be performed. The survivorship analysis (Kaplan-Meier) showed a 95.4% survival of the femoral component after 10 years. Our findings with a cemented mild grid blasted Titanium-Aluminum-Vanadium stem demonstrate excellent results unlike it was reported for cemented femoral components of similar alloy but different design and cementation philosophy.
Universitätsklinikum Gießen und Marburg
Marburg, Hesse, Germany
- Klinik für Orthopädie und Rheumatologie
Philipps University of Marburg
Marburg, Hesse, Germany
- Klinik für Orthopädie und Rheumatologie (Marburg)