This paper details the differential diagnosis of an adult female skeleton displaying features consistent with a cartilaginous dysplasia and Osgood-Schlatter's disease. This burial was excavated in 1940 from a Mississippian platform mound at the DeArmond site (40RE12) in Roane County, Tennessee as part of the Works Progress Administration (WPA) and Tennessee Valley Authority (TVA) archaeological investigations. The right humerus and left femur of this individual display traits consistent with achondroplasia, such as shortened length and normal width. However, the rest of the long bones display typical morphology. The affected humerus and femur are 82 mm and 58 mm shorter than their counterparts, respectively. This makes for obvious asymmetry. A review of the various cartilaginous dysplasias was undertaken to identify those conditions concordant with the differential manifestation of the long bone asymmetry. Morphological and radiographic analyses were used to rule out possible diagnoses. The most likely candidate is enchondromatosis out of the presented conditions, as it most commonly affects the long bones, does not affect every bone in the skeleton, and is asymmetrical in its manifestation. In addition to the cartilaginous dysplasia, both anterior proximal tibial metaphyses of this individual display defects that are roughly triangular with pitted, irregular floors. Osgood-Schlatter's disease is caused by repeated trauma to the tibial tuberosity during childhood. This individual would have walked with an obvious limp, and perhaps the added biomechanical stress on both quadriceps muscles as a result caused the injuries and resultant defects to its attachment points. Evidence of these conditions in an adult indicates that the Mississippian people in this community offered some sort of social support to differently-abled individuals.