An orthopedic device includes a posterior shell (2120) having first and second wing portions (2122) which form an opening for a dorsal shell (2102). The dorsal shell can be positioned between the first and second wing portions (2122) and it includes a proximal shell portion (2104) connected to a distal shell portion (2108). The dorsal shell (2102) defines a raised reinforcing ridge (2110) extending along the dorsal shell (2102). Further, the ridge (2110) contains a pump assembly receiving opening (2106) and a plurality of clearances holes (2112) on opposing sides of the raised reinforcing ridge (2110).