In this study, with our technique of filtering out projection-related imaging errors, computer-assisted implantation of total knee replacements improved the frontal and sagittal alignment of the femoral component but not of the tibial component. We found that the rotational alignment of the component was not improved through navigation by solely referencing to the epicondylar axis for the femur and the tuberosity for the tibia.

The results indicate a relation between structural, mechanical and histological changes in all stages of the degeneration. With increasing ICRS Grade the cartilage stiffness, which is primarily influenced by the integrity of the extracellular matrix, decreases. Therefore, methods of stiffness determination such as indentation may be used to characterize cartilage in all stages of OA. However, the data suggest that differentiating between healthy cartilage and ICRS Grade 1 may be difficult using mechanical testing alone.

No abstract

Insufficient post-traumatic skeletal muscle regeneration with consecutive functional deficiency continues to be a serious problem in orthopedic and trauma surgery. Transplantation of autologous muscle precursor cells has shown encouraging results in muscle trauma treatment but is associated with significant donor site morbidity. In contrast to this, bone marrow-derived (BMD) cells can be obtained without any functional deficit by puncture. The goal of this study was to examine whether regular muscle regeneration can be improved by local application of autologous BMD cells in a rat model of blunt skeletal muscle trauma. One week after standardized open blunt crush injury to the left soleus muscle, 10(6) autologous BMD cells were injected into the traumatized muscle of male Sprague Dawley rats. Rats of the control group received saline solution as treatment. Three weeks after application, the fast twitch and tetanic contraction capacity of the soleus muscles was measured bilaterally by stimulating the sciatic nerves. Contraction forces of injured soleus muscles in control animals recovered to 39 +/- 10% (tetanic) and 59 +/- 12% (fast twitch) of the contralateral noninjured soleus muscles (p < 0.001). In contrast, autologous BMD cell injection significantly restored contractile forces to 53 +/- 8% (tetanic) and 72 +/- 13% (fast twitch) compared to those observed in contralateral noninjured soleus muscles. Thus, muscle function was significantly increased by BMD cell treatment (tetanic, p = 0.014; fast twitch, p = 0.05). In conclusion, autologous BMD cell grafting leads to an increase in contraction force, 14% in tetanic and 13% in fast twitch stimulation, demonstrating its potential to improve functional outcome after skeletal muscle crush injury.