1. A computer-automated method for estimating at least one characteristic of a knee joint based on a model parameterization, the method comprising: a. creating a deformable statistical template comprising a set of parameters that, as a set, represent spatial positions of features of the knee joint and variations of the spatial positions from a population mean; b. a computer system fitting at runtime, in a two-dimensional image of the skeleture of a target knee, a plurality of loci associated with features of the image of the target knee to allow parameterization of the image of the target knee in terms of the deformable statistical template; c. the computer system parameterizing positions of the plurality of loci in the image of the target knee to derive values for parameters of the deformable statistical template; d. the computer system estimating a position of a tibial spine and a position near an edge of the target knee on the image of the target knee based on at least one of a subset of the plurality of loci and the derived parameters of the deformable statistical template; and e. the computer system estimating at least one characteristic of at least one position along a line from the estimated position of the tibial spine to the estimated position near the edge of the target knee on the image of the target knee based on at least one of a subset of the plurality of loci and the derived parameters of the deformable statistical template.