Demystifying the complex patellar form via ratios and indices

Indices and ratios are effective tools for defining balanced dimensions as they compensate for extremes in sizes and do not rely on absolute measurements for establishing normal values. The present study was designed to characterize patellar morphology in the form of useful 'patellar ratios' and 'patellar indices'. The study was conducted on 200 adult North Indian male patellae (100 each of right and left sides respectively). The patellar dimensions were found to be smaller for the North Indians as compared with other populations. The predominant phenotype for North Indians emerged to be a Wiberg type II (60%) patella. The North Indian patellae were classified as medium height (50-55)/medium width (51-56) patellae. The present study is the pioneer study where these indices have been determined and quantified for a population. The paucity of literature on morphology of patella gives credibility and relevance to the present pioneer work on patellar shape, ratios and indices.