US Patent 7311734 Intervertebral spacers

One embodiment of a hollow spinal spacer (10) includes a curved anterior wall (11) having opposite ends (12, 13), a posterior wall (15) having opposite ends (16, 17), two lateral walls (20, 21), each integrally connected between the opposite ends (12, 13, 16, 17) of the anterior (11) and posterior (15) walls to define a chamber (30). The walls (11, 15, 20, 21) include a superior face (35) and an inferior face (40). The superior face (35) defines a first opening (36) in communication with the chamber (30) and includes a first vertebral engaging surface (37). The inferior face (40) defines a second opening (41) in communication with the chamber (30) and includes a second vertebral engaging surface (42).