(163 days)
This device is indicated for use in total hip replacement or bipolar hip replacement . undergoing primary and revision surgery for the following conditions: non-inflammatory degenerative joint disease such as osteoarthritis, avascular necrosis, ankylosis, protrusion acetabuli, and painful hip dysplasia; inflammatory degenerative joint disease such as rheumatoid arthritis; correction of functional deformity; treatment of non-union, femoral neck fracture and trochanteric fractures of the proximal femur with head involvement, unmanageable using other techniques; revision procedures where other treatments or devices have failed.
This device is designed for cementless use.
This subject device is a modification and an additional size extension to the previously cleared "UNITED" UTF Stem (K110245). The materials, safety and effectiveness of this subject device are identical to "UNITED" UTF Stem (K110245). Compared with the UTF Stem (K110245), the distal width of UTF Stem-reduced is reduced to provide more selection for clinical demand, and the thread diameter of impact hole of UTF Stem-reduced is enlarged to increase the mechanical strength of stem holder which is locked with impact hole.
As the same as UTF Stem (K110245), UTF Stem-reduced, forged from a Ti-6A1-4V alloy (ASTM F136), is a modular, wedge-shaped stem with 12/14 neck taper and 130° neck angle. The proximal part of each femoral stem is plasma coated with CP Ti powder (ASTM F1580) in thickness 500±127μm. UTF Stem-reduced is available with standard and high offset options, and each,type is available in sizes #111. The specifications of UTF Stem-reduced in size #16 and #9 are identical with UTF Stem (K110245) in size #7.5, 9, 10, 11, 12, 13, 16.5, respectively, while size #7, 8, 10 and 11 are new items which is between size # 13 and #22 in UTF Stem (K110245). These modifications will not affect its safety and effectiveness.
For total hip replacement, UTF Stem-reduced can be used in conjunction with UNITED Femoral Head (K994078, K022520, K111546 and K122504), Ceramic Femoral Head (K103497, K112463), U2 Acetabular Cup Liner (K050262), XPE Cup Liner (K111546), U2 HA/Ti Plasma Spray Cup (K050262, K12177), U2 Ti Plasma Spray Cup (K050262, K121777) and U2 Ti Porous Coated Cup (K111546). As using with U2 Acetabular Cup Liner (K050262), UTF Stem-reduced can be used with 26 mm and 28 mm metal Femoral Head (K994078, K022520, K122504) and 28 mm Ceramic Femoral Head (K103497). As using with XPE Cup Liner (K111546), UTF Stem can be used with 28 mm, 32 mm and 36 mm metal Femoral Head (K022520, K111546, K122504) and 28 i mm, 32 mm and 36 mm Ceramic Femoral Head (K103497, K112463).
For bipolar hip replacement, UTF Stem-reduced also can be used in conjunction with 26 mm, 28 mm, 32mm and 36mm metal Femoral Head (K994078, K022520, K111546, K122504), 28 mm, 32 mm and 36 mm Ceramic Femoral Head (K103497, K112463) and Bipolar implants (K101670). UNITED Femoral Head and Bipolar Cap are made of Co-Cr-Mo alloy, while Ceramic Femoral Head is manufactured from alumina. Acetabular Cup Liner and Bipolar Cap Liner are made of UHMWPE, while U2 Acetabular Cup shells are manufactured from forged Titanium alloy.
Here's a breakdown of the acceptance criteria and the study that proves the device meets them, based on the provided text:
Acceptance Criteria and Device Performance
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Stem fatigue strength conformance (ISO 7206-4) | Not numerically stated, but FEM analysis indicated that modifications did not decrease strength. The predicate device's (UTF Stem K110245) stem fatigue test was completed per ISO 7206-4. |
| Neck fatigue strength conformance (ISO 7206-6) | Not numerically stated, but FEM analysis indicated that modifications did not decrease strength. The predicate device's (UTF Stem K110245) neck fatigue test was completed per ISO 7206-6. |
| Chemical analysis of modified coating | Conforms to FDA Guidance, "Guidance for Industry on the Testing of Metallic Plasma Sprayed Coatings on Orthopedic Implants..." |
| Microstructural characterization of modified coating | Conforms to FDA Guidance, "Guidance for Industry on the Testing of Metallic Plasma Sprayed Coatings on Orthopedic Implants..." |
| Mechanical strength of modified coating | Conforms to FDA Guidance, "Guidance for Industry on the Testing of Metallic Plasma Sprayed Coatings on Orthopedic Implants..." |
Study Information
This submission is for a medical device (UTF Stem, reduced) and does not involve an AI/ML-based diagnostic or prognostic device, therefore many of the typical questions related to such studies (sample size for test/training sets, ground truth establishment, MRMC studies) are not applicable. The provided document is a 510(k) summary for a modified orthopedic implant. The "study" described is primarily non-clinical engineering analysis and refers to previous testing of a predicate device.
- Sample size used for the test set and the data provenance: Not applicable. No specific "test set" in the context of image-based or data-driven AI diagnostics is mentioned. The non-clinical testing involved mechanical testing of the predicate device and engineering analysis of the modifications to the subject device.
- Number of experts used to establish the ground truth for the test set and the qualifications of those experts: Not applicable. No ground truth in the context of expert review for diagnostic accuracy is mentioned.
- Adjudication method for the test set: Not applicable.
- If a multi-reader multi-case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance: No MRMC study was done, as this is not an AI/ML-based device.
- If a standalone (i.e. algorithm only without human-in-the-loop performance) was done: Not applicable. This is not an AI/ML-based device.
- The type of ground truth used: For the non-clinical testing of the predicate device, the "ground truth" was defined by international standards (ISO 7206-4 and ISO 7206-6) for mechanical performance criteria. For the modified coating, it was conformance to FDA Guidance.
- The sample size for the training set: Not applicable. No training set for an AI/ML model is mentioned.
- How the ground truth for the training set was established: Not applicable.
Summary of the "Study" and Basis for Acceptance
The submission is for a modification and size extension to a previously cleared hip stem ("UNITED" UTF Stem, K110245). The core argument for acceptance is substantial equivalence to the predicate device.
- Non-Clinical Testing of Predicate Device: The predicate device (UTF Stem K110245) had its stem fatigue test completed according to ISO 7206-4 and its neck fatigue test according to ISO 7206-6. These tests established the performance benchmarks for the original design.
- Engineering Analysis for the Subject Device (UTF Stem, reduced): For the new "UTF Stem, reduced" device, no additional non-clinical mechanical testing was performed on the stem itself. Instead, the manufacturer relied on Finite Element Method (FEM) analysis. This analysis concluded that the modifications (reduced distal width and enlarged thread diameter of the impact hole) did not decrease the stem fatigue strength or neck fatigue strength compared to the predicate device.
- Materials Testing: For the modified coating, chemical analysis, microstructural characterization, and mechanical strength were evaluated. The results were found to conform to the requirements of the FDA Guidance, "Guidance for Industry on the Testing of Metallic Plasma Sprayed Coatings on Orthopedic Implants to Support Reconsideration of Postmarket Surveillance Requirements."
- Clinical Testing: No clinical testing was required or performed for this submission, further indicating the reliance on substantial equivalence and non-clinical data.
- Conclusion: Based on the engineering analysis of the design modification and the materials testing, the manufacturer determined that the "UTF Stem, reduced" is substantially equivalent to legally marketed predicates, meaning it is considered "as safe, as effective, and performs at least as safely and effectively."
§ 888.3358 Hip joint metal/polymer/metal semi-constrained porous-coated uncemented prosthesis.
(a)
Identification. A hip joint metal/polymer/metal semi-constrained porous-coated uncemented 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 has a femoral component made of a cobalt-chromium-molybdenum (Co-Cr-Mo) alloy or a titanium-aluminum-vanadium (Ti-6Al-4V) alloy and an acetabular component composed of an ultra-high molecular weight polyethylene articulating bearing surface fixed in a metal shell made of Co-Cr-Mo or Ti-6Al-4V. The femoral stem and acetabular shell have a porous coating made of, in the case of Co-Cr-Mo substrates, beads of the same alloy, and in the case of Ti-6Al-4V substrates, fibers of commercially pure titanium or Ti-6Al-4V alloy. The porous coating has a volume porosity between 30 and 70 percent, an average pore size between 100 and 1,000 microns, interconnecting porosity, and a porous coating thickness between 500 and 1,500 microns. The generic type of device has a design to achieve biological fixation to bone without the use of bone cement.(b)
Classification. Class II.