Proximal femoral focal deficiency/congenital femoral deficiency: a proposal for a new classification.

Congenital femoral deficiency (CFD) or proximal femoral focal deficiency (PFFD) has been a controversial topic to present, describe, classify, and treat. Since 1939, many classifications have been proposed to describe the disease and plan possible treatment - however, no single widely accepted classification. The currently available classification could not fill the gap between description and surgical planning. Some provided a graphical description of the disease with possible treatment plans, yet there is minimal evidence of its reliability and reproducibility. We propose to develop a new classification with specific criteria. The suggested classification has four types of PFFD/CFD: Type 1 morphological abnormality of the whole femur; Type 2 congenital absence of the femur is subdivided into A - total absence and B - partial absence; Type 3 abnormal proximal femur is subdivided into A - apparent neck pseudoarthrosis and B - coxa vara; and Type 4 short femur (congenital short femur).