(30 days)
The Foundation 9 mm Forged Cemented Stem is intended for treatment of patients who are candidates for total or hemi-hip arthroplasty. The indications for use of the total hip replacement prosthesis include: noninflammatory degenerative joint disease including osteoarthritis and avascular necrosis; rheumatoid arthritis; correction of functional deformity; revision procedures where other treatments where devices have failed; and treatment of nonunion, femoral neck and trochanteric fractures of the proximal femur with head involvement, which is unmanageable using other techniques. It is intended to be used with cement with acetabular components or with unipolar heads.
The proximal body of the Foundation™ Non-Porous Stem is trapezoidal in cross-sectional geometry and tapers proximal to distal and lateral to medial. The proximal body has two ribs on the anterior and posterior surfaces that run the length of the proximal body. Polymethylmethacrylate "buttons" are placed on the anterior, posterior, lateral and medial surfaces of the proximal body to assure that the implant is centered in the metaphseal region of the femur with a 1.5 mm cement mantle. The proximal body of the femoral stem is grit blasted to a surface of 4-6 u. This device is fabricated from forged CoCrMo alloy.
The distal portion of the stem is conical in shape. It necks down at the distal end to receive a flanged PMMA canal centralizer . This centralizer assures that the distal stem is centered in the femoral canal and helps to maintain a even cement mantle around the distal stem. The Foundation 9 mm Forged Cemented Stem has a calcar collar and has a Morse type taper to receive modular heads. The neck/stem angle is 132°.
The provided text describes a medical device, the Foundation™ Non-Porous Stem, and its intended use, but it does not contain any information regarding acceptance criteria or a study proving the device meets those criteria.
The "Test Results" section only states two very brief findings:
- "This stem survived a fatigue load of 3300 N."
- "Laboratory testing of the Morse type taper was conducted."
This level of detail is insufficient to answer any of the questions posed. A comprehensive study description, including acceptance criteria, sample sizes, ground truth establishment, expert qualifications, and specific performance metrics, is entirely absent from the provided document.
§ 888.3350 Hip joint metal/polymer semi-constrained cemented prosthesis.
(a)
Identification. A hip joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace a hip joint. The device limits translation and rotation in one or more planes via the geometry of its articulating surfaces. It has no linkage across-the-joint. This generic type of device includes prostheses that have a femoral component made of alloys, such as cobalt-chromium-molybdenum, and an acetabular resurfacing component made of ultra-high molecular weight polyethylene and is limited to those prostheses intended for use with bone cement (§ 888.3027).(b)
Classification. Class II.