Fig. 3.

OPL. Three models exist, labeled A, B, and C. The OPL is a forged titanium alloy, stem-shaped implant whose surfaces have a plasma-sprayed coating, up to 0.5 mm thick, to promote bone ingrowth and rapid integration. The external portions of the collars are treated with titanium niobium oxynitride ceramic to promote smooth soft-tissue gliding, limiting the probability of symptomatic soft-tissue adhesion and tethering. Proximal fluted fins provide initial rotational stability, akin to a Wagner-style hip arthroplasty stem. Fig. 3-A OPL types A, B, and C with matching dual cone abutment adapters. Type A has a flat abutment with a relatively long smooth collar and a proximal tail that is tapered to accept an extension nail or an arthroplasty attachment, when indicated. Type B has a conical abutment that embeds into the distal bone with a smaller, smooth extraosseous collar; these also possess the tapered tail adapter, identical to Type A. Type C features the same abutment and collar style as Type B but the body is shorter, and instead of a tapered tail adapter, there is a 135° hole bored near the proximal tail to accept a femoral neck screw, which can prophylactically be used to prevent femoral neck fractures. This type is most suitable for short femoral residua. All models use a similar dual cone connection mechanism to the external prosthetic limb. All models’ dual cone adapter features titanium niobium oxynitride ceramic at the portion exposed to the skin to prevent skin adhesion. Fig. 3-B Exploded view of a Type-A implant, with the components arranged at approximately the proximal-distal levels in which they would be once assembled and implanted in a patient who had undergone a femoral amputation. 1, proximal cap screw; 2, OPL body; 3, safety screw; 4, dual cone abutment adapter; 5, permanent locking propeller screw; 6, proximal connector; and 7, prosthetic connector. Fig. 3-C Radiograph of OPL Type A in a patient who had undergone a femoral amputation.