Review of Pathologies on MOR 693: An Allosaurus from the Late Jurassic of Wyoming and Implications for Understanding Allosaur Immune Systems

Palaeopathology is important as it provides remarkable insights into the lifestyles of dinosaurs and other prehistoric animals. The Late Jurassic Allosaurus known as Big Al (MOR 693) from Big Horn County, Wyoming preserves at least 19 injuries. About 2% of all bones showed abnormalities, including osteomyelitis on the right foot, on the first phalanx of the third toe, which may have contributed to the animal's death. There would likely have been many more pathologies that did not make it into the paleontological record due do the lack of soft-tissue preservation. Analysis of MOR 693’s immune response to bone infections and comparing it to other theropods, we can confidently say that dinosaurs possessed an immune system that isolated and localized infections like extant Aves.

The Effect of the PCL on Kinematics as it Relates to Soft-Tissue Preservation from Robotic-Arm Assisted Surgery

The use of haptic-based robotic-arm assisted total knee arthroplasty (hRATKA) has demonstrated a decrease in soft tissue damage. Hampp et al. [4] compared the soft tissue damage in a cadaveric study between manual total knee arthroplasty (MTKA) and hRATKA and found that the hRATKA specimens had significantly less damage to the PCL than the MTKA specimens [4]. The purpose of this study is to look at the effect of the posterior cruciate ligament (PCL) on kinematics, as defined by anterior-posterior (AP) tibial translation, during stair climb. Using a 6 degree-of-freedom (6-DOF) joint motion simulator, the stair climb profile was run on four cadaveric knee specimens with the PCL intact and the PCL cut. In the PCL deficient condition, there was more posterior tibial motion than when the PCL was intact, and this was more noticeable during the high flexion portion of the profile. These findings speak to the importance of soft tissue preservation, and the development of haptic-based robotic-arm assisted TKA can help prevent soft tissue damage to the PCL.