Development and validation of a computational model for investigation of wrist biomechanics.

In this study, a computational model of the wrist joint complex was developed and validated for investigating the biomechanical function of the joint in clinically representative scenarios. Joint behavior and kinematics were dictated only by osteoarticular contact, ligamentous constraints, and muscle loading. Three-dimensional articular surfaces of each bone were generated from CT images, while ligaments and muscles were modeled as linear springs and constant-magnitude force vectors, respectively. Commercially available rigid body dynamics software was to both build the model and simulate joint function. Range of motion model predictions were compared to a cadaveric study analyzing the effects of scaphoid distal pole excision and triquetral excision after radioscapholunate (RSL) fusion for validation. The computational model was able to accurately predict flexion, extension, radial deviation, and ulnar deviation motions in four states: normal (intact), RSL fusion, RSL fusion with the scaphoid distal pole excised, and RSL fusion with both the scaphoid distal pole and triquetrum excised. The model was also able to calculate other parameters of interest that are not easily obtainable experimentally, such as midcarpal forces. This model and modeling approach are anticipated to have value as a predictive clinical tool including effect of injuries or anatomical variations and initial outcome of surgical procedures for patient specific planning and custom implant design.