Injury
-
The combination of high-resolution three-dimensional medical imaging, increased computing power, and modern computational methods provide unprecedented capabilities for assessing the repair and healing of fractured bone. Fracture healing is a natural process that restores the mechanical integrity of bone and is greatly influenced by the prevailing mechanical environment. Mechanobiological theories have been proposed to provide greater insight into the relationships between mechanics (stress and strain) and biology. ⋯ Medical imaging systems have significantly advanced the capability for less invasive visualization of injured musculoskeletal tissues, but all too often the consideration of these rich datasets has stopped at the level of subjective observation. Computational image analysis methods have not yet been applied to study fracture healing, but two comparable challenges which have been addressed in this general area are the evaluation of fracture severity and of fracture-associated soft tissue injury. CT-based methodologies developed to assess and quantify these factors are described and results presented to show the potential of these analysis methods.
-
Fracture healing is a complex biological process that requires interaction among a series of different cell types. Maintaining the appropriate temporal progression and spatial pattern is essential to achieve robust healing. We can temporally assess the biological phases via gene expression, protein analysis, histologically, or non-invasively using biomarkers as well as imaging techniques. ⋯ Currently few non-invasive measures of biological factors of healing exist; however, recent studies that have correlated non-invasive measures with fracture healing outcome in humans have shown that serum TGFbeta1 levels appear to be an indicator of healing versus non-healing. In the future, developing additional measures to assess biological healing will improve the reliability and permit us to assess stages of fracture healing. Additionally, new functional imaging technologies could prove useful for better understanding both normal fracture healing and predicting dysfunctional healing in human patients.
-
Current evidence indicates that fracture healing assessment is limited to the use of one or two domains (such as pain, range of motion or mobility) in any single study. Functional outcome measures, which include physician-rated or observer-based impairment ratings and patient self-reported or observer-based activity limitation measures, better position the effectiveness of a given intervention towards patient-important outcomes. ⋯ We recommend outcome measures with established and verified reliability and validity. Policy-makers and other stakeholders need to have an accurate assessment of treatment outcome that includes changes in function over time-adequate measures, should be re-applied at periodic intervals.
-
Assessment of gait and function might be as sensitive tool to monitor the progress of fracture healing. Currently available assessment tools for function use instrumented three dimensional gait analysis or pedobarography. The analysis is focused on gait or movement parameters and seeks to identify abnormalities or asymmetries between legs or arms. ⋯ Alternative approaches abstain from directly assessing function in the laboratory but rather determine the amount of activities of daily living or the mere ability to perform defined tasks such as walking, stair climbing or running. Some of these methods have been applied to determine recovery after orthopaedic interventions including fracture repair. The combination of lab-based functional measurements and assessment of physical activities in daily live may offer a valuable level of information about the gait quality and quantity of individual patients which sheds light on functional limitations or rehabilitation of gait and mobility after a disease or injury and the respective conservative, medical or surgical treatment.
-
The progress of fracture healing is directly related to an increasing stiffness and strength of the healing fracture. Similarly the weight bearing capacity of a bone directly relates to the mechanical stability of the fracture. Therefore, assessing the progress of fracture repair can be based on the measurement of the mechanical stability of the healing fracture. ⋯ At lower frequencies the perturbations are induced in the form of vibration and at higher frequencies in the form of ultrasonic waves. Both methods provide surrogates for the mechanical properties at the fracture site. Although biomechanical properties of a healing fracture provide a direct and clinically relevant measure for fracture healing, their application will in the near future be limited to clinical studies or research settings.