Antibiotic delivery systems based on biodegradable polymers have found considerable interest for the local therapy of bone infections. In this study polylactide based polymer and composite delivery systems for the release of gentamicin have been fabricated from poly‐L‐lactides and a poly(L‐lactide‐co‐D,L‐lactide) as well as biodegradable inorganic fillers (calcium hydrogen phosphate, calcium sulfate dihydrate). The in vitro release profiles of the polymer delivery systems were characterized by an initial burst release followed by a sustained release of small gentamicin amounts up to 3 weeks. In the composite delivery systems a loss of retardation was observed with an increasing content of inorganic filler material. It was found that the in situ complex formation of gentamicin by adding defined amounts of sodium dodecyl sulfate represents a valuable tool to overcome this problem and to modulate the release profile of the delivery systems in a wide range. Under in vitro conditions, calcium sulfate dihydrate containing delivery systems are rapidly degraded in aqueous medium within several months. Based on these results, the developed composite delivery systems are promising candidates for the efficient treatment of bone infections.

Poly(methyl methacrylate) (PMMA) bone cements fill the space between the prosthesis and the bone; this connection is only a mechanical bond. The irregularities of the surface of the bone and the penetration of the cement into these irregularities are of great importance for the bond. The PMMA-layer has the effect of an elastic buffer between the prosthesis and the bone. Thus, the main function of the bone cement is to transfer load from the prosthesis to the bone or increase the load-carrying capacity of the surgical construct. Due to its low rigidity it can reduce the stress concentrations at the interface of the bone. The PMMA-cement must endure considerable stresses when used for in vivo applications. Thus, strength characteristics are important for its clinical success. If the imposed stresses are higher than the load-carrying capacity of the cement, then a cement fracture may occur leading to the failure of the construct. Therefore, it is evident that accurate and extensive data on the mechanical properties of a particular cement being used are indispensable for its optimum use in surgery. The effectiveness of surgical bone cement must be viewed in the light of its mechanical properties. Generally, there are two possibilities for the determination of the mechanical strength of bone cements: static tests and dynamic tests.

bis 30 °C. Der Effekt kann bei Zementen mit einem relativ hohen Gehalt an weichmachenden Comonomeren dazu führen,

Since the beginning of the 1960s, bone cement as we know it today has been widely used for a variety of indications, of which the most important is the fixation of endoprostheses in the hip, knee, and other joints. During that time, much experience with this material was gathered. Very importantly, it has been found that not only the properties of the cement itself are responsible for clinical success, but also the technique used for mixing and application. These findings led to modern cementation techniques, in which the use of systems for vacuum mixing and application is recommended [1].

Many years of intensive research by Otto Röhm led to the development of poly(methylmethacrylate) (PMMA), the basis of bone cements, in 1934. In 1936, Kulzer was founded by the German firms Heraeus and Degussa to produce artificial dentures made from PMMA. In 1936, the cold curing of methylmethacrylate was developed in Kulzer’s laboratory.

In the field of bone surgery, bone cement has gained a considerable importance for the fixation of osteosynthesis material. This paper deals with the investigation of a new bone cement which is mixed with bioactive glass ceramic. In comparison to the conventional bone cement, all data pertaining to the material are improved, and histological examinations reveal an osseous connection to the superficially located glass ceramic particles.

Compound bone cement on a PMMA base with an additive of bioactive glass ceramic particles in different portions and different particle sizes are tested in animal experiments. The tissue reactions to extracorporal polymerized specimens and to in situ polymerized specimens are observed. The experiments with an implantation period up to six months demonstrate a tight bonding between the newly formed osseous tissue and the glass ceramic particles at the interface. The inflammatory reactions in the vicinity of the implant are small. It is the objective of the investigations to improve the adherance of the bone cement at the interface to achieve a more durable anchorage of bone cement in the tissue.