(81 days)
The Zweymueller SL Femoral Hip Stem is intended to replace the anatomy of the femur in cases of total hip replacement. In addition, the Zweymueller SL Femoral Hip Stem is intended to be intraoperatively assembled to the commercially available Sulzer Orthopedics Limited (SOL) or Intermedics Orthopedics, Inc. (IOI) femoral bearing heads.
The general indications associated with the use of Zweymueller SL:
- 2. Fracture or avascular necrosis.
- Conditions consequent to earlier operations such as joint 3. reconstruction (Osteotomy), arthrodesis, hemi-arthroplasty, or total hip replacement (THP), total knee replacement, as well as operations on shoulder and elbow joints, and spinal surgery.
The Zweymueller SL Femoral Hip Stem employs a Sulzer 12/14 configured trunnion for attachment to femoral heads, including Biolox ceramic heads, featuring a Sulzer 12/14 configured bore. The Biolox heads have been determined substantially equivalent by the FDA via 510(k) number K892644. The Biolox ceramic heads are available in two sizes (28mm and 32mm outer diameters (OD)).
The Zweymueller SL Femoral Hip Stem is a line extension of an existing legally marketed SOL's Zweymueller-SL Hip Prosthesis which has previously been determined substantially equivalent by the FDA via 510(k) #K871453. The Zweymueller SL Femoral Hip Stem is identical in design to the predicate Zweymueller-SL Hip Prosthesis except for the following:
- The Zweymueller SL Femoral Hip Stem is provided sterile; and
- The Zweymueller SL Femoral Hip Stem is available in sizes 01 and 0 in addition to sizes 1 through 12.
The Zweymueller SL Femoral Hip Stem is designed as a conical straight stem with a rectangular cross section to ensure rotational stability. The proximal portion of the hip stem employs an extraction hole to facilitate removal of the stem in revision cases. The widened proximal geometry of the Zweymueller SL Femoral Hip Stem reduces stresses due to compressive and torsional forces by allowing forces to be transmitted over a larger area (Stress = Force/Area). The proximal/lateral portion of the hip stem employs four holes for optional use with a cerclage wire to provide enhanced fixation of the hip stem to the greater trochanter.
The entire stem below the neck of the hip stem is grit blasted to provide enhanced fixation in both cemented and cementless total hip arthroplasties. In a cemented application, the grit blasted surface provides greater cement interdigitation with bone cement. In a pressfit or cementless application, the grit blasted surfaces provide an enhanced bone/prosthesis interface.
The distal tip of the Zweymueller SL Femoral Hip Stem is of pyramidal shape and is rounded off at the transition to the shaft. This facilitates transmission of load to the distal cortical bone.
This document is a 510(k) Premarket Notification Summary for a medical device, specifically the Zweymueller SL Femoral Hip Stem. It is not a study demonstrating the device meets acceptance criteria based on performance metrics that would typically be seen in a clinical trial or a study for an AI/ML device.
Instead, this document focuses on demonstrating substantial equivalence to predicate devices already on the market. In the context of 510(k) submissions, substantial equivalence is the primary acceptance criterion.
Therefore, many of the requested fields (like sample size for test sets, number of experts for ground truth, MRMC studies, standalone performance, training set details) are not applicable to this type of regulatory submission because it isn't a performance study in the way typically associated with AI/ML or new drug/device trials.
Here's how to interpret the document in relation to your request, with "Not Applicable" for fields that don't fit this regulatory context:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria (for 510(k) submission) | Reported Device Performance (Summary of Technological Characteristics Comparison) |
|---|---|
| Substantial Equivalence to Predicate Devices | The Zweymueller SL Femoral Hip Stem is presented as substantially equivalent to existing predicate devices (Zweymueller-SL Hip Prosthesis and SL-Plus). |
| Identical in Design (except noted changes) | "The Zweymueller SL Femoral Hip Stem is identical in design to the predicate Zweymueller-SL Hip Prosthesis except for the following: |
- The Zweymueller SL Femoral Hip Stem is provided sterile; and
- The Zweymueller SL Femoral Hip Stem is available in sizes 01 and 0 in addition to sizes 1 through 12." |
| Similar Technological Characteristics | Material: Titanium Alloy (matches predicate)
Rectangular cross-section: Yes (matches predicate)
Holes on the lateral side: Yes (matches predicate)
Pyramidal shaped distal tip: Yes (matches predicate)
Application: Cementless (matches predicate) |
| Intended Use (consistent with predicate) | Intended to replace the anatomy of the femur in cases of total hip replacement, and to be assembled to commercially available femoral bearing heads (consistent with predicate device function). |
| Mechanical Performance (implied to be equivalent) | Not explicitly tested or reported in this summary, but the design characteristics implying similar stress distribution and fixation are described (e.g., "widened proximal geometry...reduces stresses," "grit blasted surface provides enhanced fixation"). This is assumed to be comparable to the legally marketed predicates. |
2. Sample size used for the test set and the data provenance
- Sample Size: Not applicable. This is not a study with a "test set" in the sense of patient data. The "test" is the comparison against predicate devices' specifications and functional descriptions.
- Data Provenance: Not applicable. The "data" here refers to the design specifications and established characteristics of the subject device and the predicate devices.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
- Number of Experts: Not applicable. No "ground truth" was established by experts for a test set in this context. The "ground truth" for a 510(k) is the regulatory standard of substantial equivalence and the established characteristics of the predicate devices.
- Qualifications of Experts: Not applicable.
4. Adjudication method for the test set
- Adjudication method: Not applicable. There was no test set requiring expert adjudication.
5. 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
- MRMC Study: No. This device is a mechanical hip stem, not an AI/ML-assisted diagnostic device that would involve human readers.
- Effect Size: Not applicable.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
- Standalone Performance: No. This is not an algorithm.
7. The type of ground truth used
- Type of Ground Truth: Not applicable in the traditional sense of clinical outcomes or pathology. For a 510(k) submission seeking substantial equivalence, the "ground truth" implicitly refers to (a) the established safety and efficacy of the predicate devices and (b) engineering principles and design specifications that support the new device's comparable performance.
8. The sample size for the training set
- Sample Size: Not applicable. No training set is involved as this is not an AI/ML device.
9. How the ground truth for the training set was established
- Ground Truth Establishment: Not applicable.
§ 888.3353 Hip joint metal/ceramic/polymer semi-constrained cemented or nonporous uncemented prosthesis.
(a)
Identification. A hip joint metal/ceramic/polymer semi-constrained cemented or nonporous uncemented prosthesis is a device intended to be implanted to replace a hip joint. This device limits translation and rotation in one or more planes via the geometry of its articulating surfaces. It has no linkage across-the-joint. The two-part femoral component consists of a femoral stem made of alloys to be fixed in the intramedullary canal of the femur by impaction with or without use of bone cement. The proximal end of the femoral stem is tapered with a surface that ensures positive locking with the spherical ceramic (aluminium oxide, A12 03 ) head of the femoral component. The acetabular component is made of ultra-high molecular weight polyethylene or ultra-high molecular weight polyethylene reinforced with nonporous metal alloys, and used with or without bone cement.(b)
Classification. Class II.