Methods, systems and devices for preventing prosthetic articulating surfaces from separating from each other. A containment system according to one embodiment seeks to prevent an implant stem head from dislocating from a prosthetic component while providing an increased range of motion over conventional constrained components. In one embodiment, an implant structural member includes a cavity and an opening having a lip, including a web along a portion of the lip. An implant stem head has a cooperating surface that corresponds with the web, so that when the cooperating surface of the implant stem head is aligned with the web, the head may be inserted into the implant structural member. The implant stem head is then rotated and the femoral stem component attached, thereby preventing dislocation of the head.