Compared with the control, a cement volume between 2.0 and 3.0 ml increased the pull-out strength significantly and is relevant for clinical purposes, whereas a volume of 0.5 ml did not. A cement volume beyond 3.0 ml should further increase the pull-out strength because the correlation was linear at least up to 4.0 ml, but the possibility of in vivo cement leakage with increasing volume has to be considered. Pressure-controlled cement application might be a tool to avoid this complication. The cement almost completely penetrated the most proximal perforation.

No abstract

Gentamicin palmitate appears to be a viable coating for the prevention of implant-associated infections. These findings will have to be confirmed in larger animal models as well as in clinical trials.

Revision surgery of joint replacements is increasing and raises the demand for allograft bone since restoration of bone stock is crucial for longevity of implants. Proceedings of bone grafts influence the biological and mechanic properties differently. This study examines the effect of thermodisinfection on mechanic properties of cancellous bone. Bone cylinders from both femoral heads with length 45 mm were taken from twenty-three 6-8 months-old piglets, thermodisinfected at 82.5 °C according to bone bank guidelines and control remained native. The specimens were stored at -20 °C immediately and were put into 21 °C Ringer's solution for 3 h before testing. Shear and pressure modulus were tested since three point bending force was examined until destruction. Statistical analysis was done with non-parametric Wilcoxon, t test and SPSS since p < 0.05 was significant. Shear modulus was significantly reduced by thermodisinfection to 1.02 ± 0.31 GPa from 1.28 ± 0.68 GPa for unprocessed cancellous bone (p = 0.029) since thermodisinfection reduced pressure modulus not significantly from 6.30 ± 4.72 GPa for native specimens to 4.97 ± 2.23 GPa and maximum bending force was 270.03 ± 116.68 N for native and 228.80 ± 70.49 N for thermodisinfected cancellous bone. Shear and pressure modulus were reduced by thermodisinfection around 20 % and maximum bending force was impaired by about 15 % compared with native cancellous bone since only the reduction of shear modulus reached significance. The results suggest that thermodisinfection similarly affects different mechanic properties of cancellous bone and the reduction of mechanic properties should not relevantly impair clinical use of thermodisinfected cancellous bone.

Background: The recommendations for storage temperature of allogeneic bone are varying between –20 °C and –70 °C and down to –80 °C. The necessary temperature of storage is not exactly defined by scientific data, and the effect of different storage temperatures onto the biomechanical and the biological behavior is discussed controversially. Methods: The historical development of storage temperature of bone banks is described. A survey on literature concerning the biomechanical and biological properties of allograft bone depending on the procurement and storage temperature is given as well as on national and international regulations on storage conditions of bone banks (European Council, American Association of Tissue Banks (AATB), European Association of Tissue Banks (EATB)). Results: Short-term storage up to 6 months is recommended with –20 °C and –40 °C for a longer period (AATB), and EATB recommends storage at –40 °C and even –80 °C while the regulations of the German German Medical Association (Bundesärztekammer) from 2001 recommend storage at –70 °C. Duration of storage at –20 °C can be maintained at least for 2 years. The potential risk of proteolysis with higher storage temperatures remains, but a definite impairment of bone ingrowth due to a storage at –20 °C was not shown in clinical use, and no adverse biomechanical effects of storage at –20 °C could be proven. Conclusion: Biomechanical studies showed no clinically relevant impairment of biomechanical properties of cancellous bone due to different storage temperatures. Sterilization procedures bear the advantage of inactivating enzymatic activity though reducing the risk of proteolysis. In those cases a storage temperature of –20 °C can be recommended for at least a period of 2 years, and the risk of undesired effects seems to be low for native unprocessed bone.