Conformity Stem Extension Line, #0

The Conformity Stem Extension Line, #0 is a hip prosthesis stem for cementless use in hip arthroplasty. It is indicated for skeletally mature patients with conditions including osteoarthritis, avascular necrosis, traumatic fracture, failed previous hip surgery, and certain cases of ankylosis. The device comes in four variations with different neck angles and lengths.

The subject device has identical material, coating thickness, principle of operation, regulation number, product code, risk class, intended users, fixation method, surface coating, locking mechanism, and sterilization method as the predicate devices. The only differences are in offset specifications and stem length sizes, which were assessed using the same analysis methods as the predicate submission.

Range of Motion (ISO 21535), Neck Fatigue Assessment (ISO 7206-6), Stem Fatigue Test (ISO 7206-4), Characterization of HA Plasma Spray Coating (FDA guidance for Hydroxyapatite Coated Orthopedic Implants), and Usability Evaluation (BS EN 62366-1 and FDA guidance on Human Factors).

The device shares identical intended use, patient population, site of application, conditions of use, and operating principles as the predicate devices (K183312, K242249). The variations introduce new sizes with unchanged design parameters (neck angle, neck length, material, and coating). Non-clinical performance testing using the same methods as the predicate demonstrates the device is substantially equivalent despite the new size offerings.