Response of primary fibroblasts and osteoblasts to plasma treated polyetheretherketone (PEEK) surfaces.

Polyetheretherketone (PEEK) is a synthetic polymer with suitable biomechanical and stable chemical properties, which make it attractive for use as an endoprothetic material and for ligamentous replacement. However, chemical surface inertness does not account for a good interfacial biocompatibility, and PEEK requires a surface modification prior to its application in vivo. In the course of this experimental study we analyzed the influence of plasma treatment of PEEK surfaces on the cell proliferation and differentiation of primary fibroblasts and osteoblasts. Further we examined the possibility of inducing microstructured cell growth on a surface with plasma-induced chemical micropatterning. We were able to demonstrate that the surface treatment of PEEK with a low-temperature plasma has significant effects on the proliferation of fibroblasts. Depending on the surface treatment, the proliferation rate can either be stimulated or suppressed. The behavior of the osteoblasts was examined by evaluating differentiation parameters. By detection of alkaline phosphatase, collagen I, and mineralized extracellular matrix as parameters for osteoblastic differentiation, the examined materials showed results comparable to commercially available polymer cell culture materials such as tissue culture polystyrene (TCPS). Further microstructured cell growth was produced successfully on micropatterned PEEK foils, which could be a future tool for bioartificial systems applying the methods of tissue engineering. These results show that chemically inert materials such as PEEK may be modified specifically through the methods of plasma technology in order to improve biocompatibility.

Quadriceps tendon ruptures-is there a complete functional restitution?

From January 1986 to November 1999, 35 patients with 36 traumatic ruptures of the quadriceps tendon, all without medical risk factors, were treated (33 men, 2 women; mean age 55 years). Thirty patients were operated within 14 days after trauma. With an average follow up of 55.4 months (7-168) 29 of 30 still living patients (96.7%) were studied retrospectively. Questionnaire (Lysholm score), physical examination, X-ray of both knees and isokinetic testing were performed. The outcome was significantly (P < 0.001) dependent on the time of operative procedure. Twenty-four patients treated within the first 14 days had 20 excellent and 4 good results, the other 5 one good, 1 satisfying and 3 poor results. Twenty-one of 23 patients (91%) could return to work. The type of repair (direct or transosseous suture with or without augmentation), the kind of postoperative physiotherapy, the age and the body mass index had no influence on the final outcome.

[The use of fillet flaps in upper extremity and shoulder reconstruction]. / Die Filetlappenplastik zur Rekonstruktion ausgedehnter Defekte der oberen Extremität einschliesslich Schulterregion.

Extensive soft tissue defects of the upper extremities were reconstructed with major fillet flaps in nine patients over a 5-year period at two institutions. Etiologies included trauma and tumor resection. Defect locations were the shoulder ( n=3), combined defects of the shoulder plus neck, arm or chest wall ( n=4) as well as one upper arm and one forearm defect. Seven of nine flaps required microsurgical free tissue transfer. Fillet flaps harvested from amputated parts represent the "spare part" concept, providing coverage of defects without additional donor site morbidity. Unlike the classic "spare part" fillet flap concept, the partial or complete conversion of an anatomically intact arm was performed for the coverage of large defects, especially for tumor reconstruction, in this series. Fillets flaps facilitate reconstruction in difficult and complex cases. Major fillet flaps represent a valuable option for reconstruction in the upper extremities with either pedicled or free tissue transfers involving extensive tissue defects.