Determination of the ideal plate for medial femoral condyle fracture fixation: an anatomical fit and biomechanical study.

BACKGROUND: The aim of this study is to determine the best plate to use as a substitute to fix a medial femoral condyle fracture. MATERIALS AND METHODS: The first part is to measure the best fit between several anatomical plates including the Proximal Tibia Anterolateral Plate (PT AL LCP), the Proximal Tibia Medial Plate (PT M LCP), the Distal Tibia Medial Locking Plate (DT M LCP) and the Proximal Humerus (PHILOS) plate against 28 freshly embalmed cadaveric distal femurs. Measurements such as plate offset and number of screws in the condyle and shaft shall be obtained. The subsequent part is to determine the compressive force at which the plate fails. After creating an iatrogenic medial condyle fracture, the cadavers will be fixed with the two plates with the best anatomical fit and subjected to a compression force using a hydraulic press. RESULTS: The PT AL LCP offered the best anatomical fit whereas the PHILOS plate offered the maximal number of screws inserted. The force required to create 2 mm of fracture displacement between the two is not statistically significant (LCP 889 N, PHILOS 947 N, p = 0.39). The PT AL LCP can withstand a larger fracture displacement than the PHILOS (LCP 24.4 mm, PHILOS 17.4 mm, p = 0.004). DISCUSSION AND CONCLUSION: Both the PT AL LCP and the PHILOS remain good options in fixing a medial femoral condyle fracture. Between the two, we would recommend the PT AL LCP as the slightly superior option.

A review of the manufacturing process and infection rate of 3D-printed models and guides sterilized by hydrogen peroxide plasma and utilized intra-operatively.

3D printing in the context of medical application can allow for visualization of patient-specific anatomy to facilitate surgical planning and execution. Intra-operative usage of models and guides allows for real time feedback but ensuring sterility is essential to prevent infection. The additive manufacturing process restricts options for sterilisation owing to temperature sensitivity of thermoplastics utilised for fabrication. Here, we review one of the largest single cohorts of 3D models and guides constructed from Acrylonitrile butadiene styrene (ABS) and utilized intra-operatively, following terminal sterilization with hydrogen peroxide plasma. We describe our work flow from initial software rendering to printing, sterilization, and on-table application with the objective of demonstrating that our process is safe and can be implemented elsewhere. Overall, 7% (8/114 patients) of patients developed a surgical site infection, which was not elevated in comparison to related studies utilizing traditional surgical methods. Prolonged operation time with an associated increase in surgical complexity was identified to be a risk factor for infection. Low temperature plasma-based sterilization depends upon sufficient permeation and contact with surfaces which are a particular challenge when our 3D-printouts contain diffusion-restricted luminal spaces as well as hollows. Application of printouts as guides for power tools may further expose these regions to sterile bodily tissues and result in generation of debris. With each printout being a bespoke medical device, it is important that the multidisciplinary team involved in production and application understand potential pitfalls to ensuring sterility as to minimize infection risk.

The status of triangular fibrocartilage complex after the union of distal radius fractures with internal plate fixation.

PURPOSE: Distal radius fractures are associated with a high incidence of triangular fibrocartilage complex (TFCC) tears. This study aims to evaluate the status of TFCC after the healing of distal radius fractures, and its clinical significance. METHODS: Wrist arthroscopies were performed on 43 distal radius fractures, with an average age of 54 years old. RESULTS: Twenty-six complete tears and 15 partial healed tears were noted. Five out of eight patients with intact TFCC tears had neither signs nor symptoms, while eight patients with TFCC tears had no complaint. While no association was found between ulnar wrist pain and TFCC tears, there was association between DRUJ instability and TFCC tears and fovea tears. The function outcome did not differ with respect to the integrity of TFCC. CONCLUSIONS: A large majority of TFCC tears remained unhealed after the union of distal radius fractures. However, not all patients with tear were symptomatic.