Philipp Bergschmidt

Metal hypersensitivity in total knee arthroplasty: revision surgery using a ceramic femoral component - a case report.

We present a case involving the revision of a total knee arthroplasty with a metal femoral component using a ceramic implant due to metal hypersensitivity. A 58-year-old female patient underwent total knee arthroplasty (TKA) with a standard metal bicondylar knee system. She suffered from persistent pain and strong limitations in her range of motion (ROM) associated with flexion during the early postoperative period. Arthroscopic arthrolysis of the knee joint and intensive active and passive physical treatment, in combination with a cortisone regime, temporarily increased the ROM and reduced pain. No signs of low grade infection or other causes of implant failure were evident. Histology of synovial tissue revealed lymphoplasmacellular fibrinous tissue, consistent with a type IV allergic reaction. Allergometry (skin reaction) revealed type IV hypersensitivity against nickel-II-sulfate and palladium chloride. Revision surgery of the metal components was performed with a cemented ceramic femoral component (same bicondylar design) and a cemented titanium alloy tibial component. Postoperative evaluations were performed 10days, and 3 and 12months after the revision surgery. There was an increased ROM in flexion to 90° at the 12month follow-up. No swelling or effusion was observed at all clinical examinations after the revision surgery. No pain at rest and moderate walking pain were evident. The presented case demonstrates that ceramic implants are a promising solution for patients suffering from hypersensitivity to metal ions in total knee arthroplasty.

Alternative Werkstoffe und Lösungen in der Knieendoprothetik für Patienten mit Metallallergie

The annual number of total knee replacement implantations is rising continuously. A progressive cutaneous hypersensitivity rate against metallic materials in the population has been registered which can lead to an increase of allergy-induced reactions associated with implant loosening in the future although the correlation with an allergic cutaneous sensitisation has not been proven in all cases. On apparent allergy against metallic implant components different alternative solutions to standard endoprostheses should be taken into account for primary implantation or revision of total knee replacement, for example the application of implant components without metallic elements (e.g. ceramics), the use of non-allergic metallic implants, such as titanium or ZrNb alloys, or potential allergy-inducing metallic materials after masking the implant surface using a suitable coating. In the case of primary or revision surgery most patients with metal allergy are treated with a Ti(Nb)N-coated knee implant made of cobalt-chrome or titanium alloys in our hospital. Within an international multi-centre study we are currently implanting a newly developed knee endoprosthesis system with a ceramic femoral component as an alternative.

Alternative materials and solutions in total knee arthroplasty for patients with metal allergy

The annual number of total knee replacement implantations is rising continuously. A progressive cutaneous hypersensitivity rate against metallic materials in the population has been registered which can lead to an increase of allergy-induced reactions associated with implant loosening in the future although the correlation with an allergic cutaneous sensitisation has not been proven in all cases. On apparent allergy against metallic implant components different alternative solutions to standard endoprostheses should be taken into account for primary implantation or revision of total knee replacement, for example the application of implant components without metallic elements (e.g. ceramics), the use of non-allergic metallic implants, such as titanium or ZrNb alloys, or potential allergy-inducing metallic materials after masking the implant surface using a suitable coating. In the case of primary or revision surgery most patients with metal allergy are treated with a Ti(Nb)N-coated knee implant made of cobalt-chrome or titanium alloys in our hospital. Within an international multi-centre study we are currently implanting a newly developed knee endoprosthesis system with a ceramic femoral component as an alternative.

Third-body abrasive wear of tibial polyethylene inserts combined with metallic and ceramic femoral components in a knee simulator study

Aim Total knee arthroplasties have reached a high grade of quality and safety, but most often fail because of aseptic implant loosening caused by polyethylene wear debris. Wear is generated at the articulating surfaces, e.g. caused by third-body particles. The objective of this experimental study was to determine the wear of tibial polyethylene inserts combined with metallic and ceramic femoral components under third-body wear conditions initiated by bone cement particles. Methods and Materials Wear testing using a cemented unconstrained bicondylar knee endoprosthesis (Multigen Plus CR knee system) was performed in a knee wear simulator. Tibial polyethylene inserts were combined with the identical femoral component design, but made of two different materials (cobalt-chromium and ceramic). Bone cement debris including zirconium oxide particles was added every 500,000 cycles between the articulating surfaces. After 5 million load cycles, the amount of wear was determined gravimetrically and compared with results from standard wear test conditions. The surfaces of tibial inserts were also analyzed. Results The average gravimetrical wear of the tibial polyethylene inserts in combination with cobalt-chromium and ceramic femoral components under third-body wear conditions amounted to 31.88 ± 4.53 mg and 13.06 ± 1.88 mg after 5 million cycles, respectively, and was higher than under standard wear test conditions in both cases. Conclusions The wear simulator test demonstrates that wear of polyethylene inserts under third-body wear conditions, in combination with ceramic femoral components, was significantly lower than with metallic femoral components.

The importance of wear couples for younger endoprosthesis patients

ZusammenfassungDer Erfolg und die Langzeitergebnisse der modernen endoprothetischen Versorgung der großen Gelenke führt zu einer hohen Patientenzufriedenheit und hat mit der fortschreitenden technischen Entwicklung zur Ausdehnung des Einsatzes auch für immer jüngere Patienten geführt. Limitationen für die etablierten Systeme sind die Langzeitüberlebensraten, die maßgeblich durch den Verschleiß der artikulierenden Gelenkpartner und daraus resultierender Folgeprobleme bestimmt werden. In der Hüftendoprothetik werden neben „klassischen“ langstieligen zementierten Endoprothesen mit einer Gleitpaarung aus Metall gegen Polyethylen vermehrt Kurzschaft- oder Kappenprothesen mit einer Hart-Hart-Paarung eingesetzt. Diese Arbeit reflektiert den gegenwärtigen Entwicklungsstand in der endoprothetischen Versorgung jüngerer Patienten. Im Zentrum des Interesses stehen die Wahl der Gleitpaarung und ein Ausblick auf zukünftige Entwicklungen. Ein besonderer Schwerpunkt sind die Vor- und Nachteile der keramischen Gleitpaarung, die Implantatallergie, Probleme bei Abrieb und Schmierung und das Design von Endoprothesen in Hinblick auf Vermeidung von Impingement.AbstractThe success and long-term survival rates of modern joint arthroplasty leads to a high patient satisfaction and, together with its technical improvements, has broadened the indications to an increasingly younger population. Limitations to the established systems are the long-term survival rates, which are mainly influenced by wear of the articulating parts and the resulting problems. Beside „classic“ long-stemmed cemented shafts articulating with metal against polyethylene, short-stemmed or cup designs with a hard-hard self pairing are increasingly used in total hip arthroplasty. This paper reflects the current state of the art in joint arthroplasty for younger patients with the focus on wear couples and discusses future perspectives. Special interest is focused on the advantages and disadvantages of ceramic bearings, problems with allergies to implant components and the design of endoprostheses with regard to avoidance of impingement.

Ceramic Femoral Components in Total Knee Arthroplasty - Two Year Follow-Up Results of an International Prospective Multi-Centre Study

Background: Total knee arthroplasty can be considered as a reliable surgical procedure with a good long-term clinical result. However, implant failure due to particle induced aseptic loosening as well as the aspect of hypersensitivity to metal ions still remains an emerging issue. Methods: The purpose of this prospective international multi-centre study was to evaluate the clinical and radiological outcomes and the reliability of the unconstrained Multigen Plus Total Knee System with a new BIOLOX® delta ceramic femoral component. Cemented total knee arthroplasty was performed on 108 patients (110 knees) at seven hospitals in three countries. Clinical and radiological evaluations were performed preoperatively, and after 3, 12 and 24 months postoperatively using the HSS-, WOMAC-, SF-36-score and standardised X-rays. Results: The mean preoperative HSS-Score amounted to 55.5 ± 11.5 points and improved significantly in all postoperative evaluations (85.7 ± 11.7 points at 24 months). Furthermore, improvements in WOMAC- and SF-36-score were evaluated as significant at all points of evaluation. Radiolucent lines around the femoral ceramic component at 24 months were found in four cases. Progression of radiolucent lines was not seen and no implant loosening was observed. During the 24 month follow-up eight patients underwent subsequent surgery due to reasons unrelated to the implant material. Conclusions: The observed clinical and radiological results are encouraging for a long-term survival of the ceramic femoral component. Therefore, ceramic implants could be a promising solution not only for patients with allergies against metallic implant materials, but also for the osteoarthritic knee joint. Long-term follow-up is necessary to draw conclusions regarding the superiority of the ceramic knee implants concerning in vivo wear and long-term survivorship.

Impact of Preoperative Function on Early Postoperative Outcome after Total Hip Arthroplasty

Purpose. To investigate the impact of preoperative functional status on early postoperative outcomes after total hip arthroplasty (THA). Methods. 39 men and 36 women aged 50 to 76 years who underwent cementless THA for osteoarthritis were followed up for at least 2 years. Patients were evaluated pre- and post-operatively (at 6, 12, and 24 months) using the Harris Hip Score (HHS), 36-item Short Form Health Survey (SF-36), and Western Ontario and McMaster University Osteoarthritis Index (WOMAC). Patients were classified into 3 groups based on their preoperative HHS (poor, <45; intermediate, 45–55; good, >55). Differences between and within groups were compared. Results. Patients with a poor preoperative HHS had worse early postoperative outcomes in terms of HHS, SF-36, and WOMAC. Postoperative pain and function correlated with preoperative HHS, but postoperative range of motion and deformity did not. Conclusion. Poor preoperative function may affect recovery unfavourably and lead to prolonged pain. Earlier THA in the course of functional decline may associate with better outcomes.

Die Bedeutung der Gleitpaarung beim jüngeren Endoprothesenpatienten

ZusammenfassungDer Erfolg und die Langzeitergebnisse der modernen endoprothetischen Versorgung der großen Gelenke führt zu einer hohen Patientenzufriedenheit und hat mit der fortschreitenden technischen Entwicklung zur Ausdehnung des Einsatzes auch für immer jüngere Patienten geführt. Limitationen für die etablierten Systeme sind die Langzeitüberlebensraten, die maßgeblich durch den Verschleiß der artikulierenden Gelenkpartner und daraus resultierender Folgeprobleme bestimmt werden. In der Hüftendoprothetik werden neben „klassischen“ langstieligen zementierten Endoprothesen mit einer Gleitpaarung aus Metall gegen Polyethylen vermehrt Kurzschaft- oder Kappenprothesen mit einer Hart-Hart-Paarung eingesetzt. Diese Arbeit reflektiert den gegenwärtigen Entwicklungsstand in der endoprothetischen Versorgung jüngerer Patienten. Im Zentrum des Interesses stehen die Wahl der Gleitpaarung und ein Ausblick auf zukünftige Entwicklungen. Ein besonderer Schwerpunkt sind die Vor- und Nachteile der keramischen Gleitpaarung, die Implantatallergie, Probleme bei Abrieb und Schmierung und das Design von Endoprothesen in Hinblick auf Vermeidung von Impingement.AbstractThe success and long-term survival rates of modern joint arthroplasty leads to a high patient satisfaction and, together with its technical improvements, has broadened the indications to an increasingly younger population. Limitations to the established systems are the long-term survival rates, which are mainly influenced by wear of the articulating parts and the resulting problems. Beside „classic“ long-stemmed cemented shafts articulating with metal against polyethylene, short-stemmed or cup designs with a hard-hard self pairing are increasingly used in total hip arthroplasty. This paper reflects the current state of the art in joint arthroplasty for younger patients with the focus on wear couples and discusses future perspectives. Special interest is focused on the advantages and disadvantages of ceramic bearings, problems with allergies to implant components and the design of endoprostheses with regard to avoidance of impingement.

Comparative Study of Clinical and Radiological Outcomes of Unconstrained Bicondylar Total Knee Endoprostheses with Anti-allergic Coating.

Background: Hypersensitivity reactions to implant materials have become more important in total knee replacement (TKR). The purpose of this retrospective comparative study was to evaluate the clinical and radiological outcomes of unconstrained bicondylar total knee prostheses with and without anti-allergic titanium(niobium)nitrite (Ti(Nb)N) coating. Methods: Twenty-four patients (25 TKRs) underwent a preoperative clinical evaluation and then a postoperative evaluation after 26.2 months in the allergy group treated with coated implants (n=13 implants) and after 24.5 months in the control group treated with uncoated implants but identical geometry (n=12) using HSS, WOMAC and SF-36 scores. Radiological evaluations were performed using standard anterior-posterior (a.p.) and lateral X-rays. Results: During follow-up two patients of the allergy group had to undergo revision surgery due to non-implant-related reasons. A comparative analysis of both study groups showed a significant difference in the HSS scores at both evaluation time points (MW test p≤0.050); these findings are remarkable since the control group had a significantly lower score preoperatively (54.0 vs 65.0 points) and a significantly higher score (82.5 vs 75.0 points) postoperatively. The preoperative and postoperative WOMAC and SF-36 scores were comparable in both groups (MW test p≥0.052), although the postoperative increase in the score for the allergy group was lower. The radiological results were comparable in both groups and were unlikely to influence the results. Conclusions: This clinical study demonstrates the restricted outcome in postoperative function and quality of life in the allergy group compared to the control group.

Influence of the distal femoral resection angle on the principal stresses in ceramic total knee components

PURPOSE A certain failure mode using a newly developed cemented ceramic femoral component in total knee replacement was observed in clinical application, i.e. fracture of the femoral component during intraoperative impaction. This may be caused by unintentional deflection of the saw blades during cutting with consecutive higher resection angle of the distal femur than desired, leading to bending of the femoral component during implantation. A finite-element-analysis was carried out to simulate implantation of the femoral component and to evaluate the influence of distal femur preparation on implant stress. SCOPE We developed and validated a numerical model of the ceramic femoral component including a contact formulation which allowed calculating the principal stresses of the implant during implantation onto the resected femur. The analysis considered different anterior and posterior resection angles with a total of 17 variations. By increasing the femoral resection angle in the finite-element-model it could be shown that a deviation of three degrees from the intended resection angle can cause critical stress amounts during implantation. CONCLUSIONS When implanting the ceramic component in total knee arthroplasty, the femoral resection angles should be prepared very precisely, in particular anterior saw blade deflection has to be avoided. The implant manufacturer increased implant safety through an additional resection template. Moreover, the impaction of the ceramic femoral component during cementing was not further recommended by using a hammer.