(97 days)
The M.U.S.T. pedicle screw system is intended for posterior non-cervical pedicle fixation (T1-S2/ilium) or anterolateral fixation (T8-L5). These devices are indicated as an adjunct to fusion for all of the following indications: degenerative disc disease (defined as back pain of discogenic origin with degeneration of the disc confirmed by history and radiographic studies); spondylolisthesis; trauma (i.e., fracture or dislocation); spinal stenosis; curvatures (i.e., scoliosis, kyphosis, and/or lordosis); tumor; pseudoarthrosis; and failed previous fusion in skeletally mature patients.
The M.U.S.T. pedicle screw system is intended to be used for the stabilization and the fusion of the lumbar and thoracic spine. The M.U.S.T. pedicle screw system is characterized by different sizes of screws and rods. The screws are fixed in the pedicle and the vertebrae. The rods act as a connector between the different screws to create a stable construct. The M.U.S.T. pedicle screw implants can be applied with the common surgical technique for posterior instrumentation. The M.U.S.T. pedicle screw implants are made of Titanium alloy (Ti6Al4V ELI - ISO 5832-3, ASTM F136) and CoCrMo (ISO 5832-12, ASTM F 1537). The M.U.S.T. pedicle screw implants consist of either cannulated or non cannulated poly-axial pedicle screws. The screws are offered with a diameter between 4.5 and 7mm and a length between 20 and 90mm. The screw shaft is color anodized to simplify the identification of the screw diameter. The pedicle screw has a dual lead thread to simplify the screw insertion and reduce the number of turns. The threads are designed with a cylindrical diameter. The pedicle screw is connected by 5.5mm Titanium alloy (Ti6Al4V ELI - ISO 5832-3, ASTM F136) or CoCrMo (ISO 5832-12, ASTM F 1537) rods to create a stable construct. The rods are offered straight and pre bent. The pre bent rods have a curvature of 200mm. The construct is secured using a set screw made of CoCrMo (ISO 5832-12, ASTM F 1537). The pedicle screws, set screws and rods are available both in sterile and unsterile packaging.
The Medacta M.U.S.T. pedicle screw system's acceptance criteria and the study proving it meets these criteria are described below:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria (Measured Metric) | Predicate Device Performance (Reference Standard) | M.U.S.T. Pedicle Screw System Performance |
|---|---|---|
| Static Torsion Yield Torque | Met for predicate devices | Substantially equivalent |
| Static Torsion Stiffness | Met for predicate devices | Substantially equivalent |
| Static Axial Compression | Met for predicate devices | Substantially equivalent |
| Dynamic Axial Compression Performance | Met for predicate devices | Substantially equivalent |
2. Sample Size Used for the Test Set and Data Provenance
The document does not explicitly state the "sample size" in terms of number of screws or rods tested for the M.U.S.T. pedicle screw system. It states that "mechanical testing of the M.U.S.T. pedicle screw system included static and dynamic compression bending and static torsion according to ASTM F1717." ASTM F1717 is a standard for spinal implant testing that typically specifies the number of samples required for each test. However, the exact number used in this specific submission is not detailed.
The data provenance is from mechanical testing in a laboratory setting, not from clinical human or animal data. Therefore, there is no country of origin or retrospective/prospective designation in the human data sense.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Their Qualifications
Not applicable. The ground truth for this device is based on engineering standards and mechanical testing results, not expert medical consensus or clinical outcomes. The "ground truth" is defined by the performance benchmarks established by the ASTM F1717 standard and the performance of legally marketed predicate devices.
4. Adjudication Method for the Test Set
Not applicable, as the "test set" involves objective mechanical measurements against a standard, not subjective interpretation requiring adjudication.
5. If a Multi Reader Multi Case (MRMC) Comparative Effectiveness Study Was Done
No, an MRMC comparative effectiveness study was not done. This device is a mechanical implant, and its primary evaluation for substantial equivalence is based on biomechanical performance against established standards and predicate devices, not on human reader performance.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
Yes, in a conceptual sense, the performance testing described is "standalone" as it focuses solely on the mechanical properties of the device itself (algorithm only, if one considers the device's design and material properties as its "algorithm") without human intervention during the actual tests of the device's mechanical strength and durability.
7. The Type of Ground Truth Used
The ground truth used is based on mechanical performance standards (ASTM F1717) and the demonstrated performance of legally marketed predicate devices. The M.U.S.T. pedicle screw system was deemed "substantially equivalent" to these predicates in terms of mechanical performance.
8. The Sample Size for the Training Set
Not applicable. This report describes the evaluation of a physical medical device (pedicle screw system) through mechanical testing, not a machine learning algorithm that requires a "training set" of data.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as there is no "training set" in the context of this device's evaluation.
§ 888.3050 Spinal interlaminal fixation orthosis.
(a)
Identification. A spinal interlaminal fixation orthosis is a device intended to be implanted made of an alloy, such as stainless steel, that consists of various hooks and a posteriorly placed compression or distraction rod. The device is implanted, usually across three adjacent vertebrae, to straighten and immobilize the spine to allow bone grafts to unite and fuse the vertebrae together. The device is used primarily in the treatment of scoliosis (a lateral curvature of the spine), but it also may be used in the treatment of fracture or dislocation of the spine, grades 3 and 4 of spondylolisthesis (a dislocation of the spinal column), and lower back syndrome.(b)
Classification. Class II.