(79 days)
Reduction and stabilization of grades III & IV spondylolisthesis of the fifth lumbar to first sacral vertebral interspace only. The Webb-Morley Spine System is for temporary use and must be accompanied by the application of autogenous source bone graft only. Once solid fusion is achieved, surgical removal of the device system is recommended. Planned removal of the device occurs within one year of the original surgery in adults and within two years of reaching skeletal maturity for adolescents.
The Webb-Morley Spine System is made from surgical implant grade Stainless steel meeting ASTM F-138-86 requirements. The Webb-Morley Spine System has the same indications for use as the recently cleared TSRH® and PLSA systems. The use of the Webb-Morley Spine System as a pedicle screw system involves screw attachment at the sacrum, the L5 vertebral pedicles, the L4 vertebral pedicles and in isolated cases, the L3 vertebral pedicles. The inclusion of additional pedicular levels may sometimes be necessary in order to reduce the spondylolisthetic deformity at L5 - S1 and maintain adequate correction. The Screws of this system are limited to L3-S1 or iliac screw fixation.
Acceptance Criteria and Device Performance for Webb-Morley Spine System
This document summarizes the acceptance criteria and study proving the Webb-Morley Spine System meets these criteria, based on the provided text.
1. Table of Acceptance Criteria and Reported Device Performance
The Webb-Morley Spine System's acceptance criteria are implicitly defined by its claim of "Substantial Equivalence" to two predicate devices: the TSRH® Posterior Spine System (K932029) and the Posterior Lumbar Sacral Attachment (PLSA) Spine System (K945064). The acceptance criteria, therefore, are that the Webb-Morley system performs equivalently or superiorly to these predicate devices in terms of mechanical strength, fatigue, and corrosion resistance, and shares the same indications for use, contraindications, and other design features.
| Acceptance Criterion (Implicit, based on Substantial Equivalence claims) | Reported Device Performance (Webb-Morley Spine System) |
|---|---|
| Functional Equivalence/Superiority in Strength and Fatigue | "Static testing showed that the Webb-Morley Spine System has sufficient strength to perform in a functionally equivalent manner to the comparison device systems. The Webb-Morley Spine System demonstrates excellent fatigue and strength characteristics. Based on the testing, the Webb-Morley Spine System is equal or superior in performance to the TSRH® Spine System." |
| Material Composition | Made from surgical implant grade Stainless steel (ASTM F-138-86 requirements), same as or equivalent to predicate devices. (TSRH® uses Titanium Alloy & 316 LVM Stainless Steel, PLSA uses Titanium Alloy. Webb-Morley specifically uses 316 LVM stainless steel as per Feature Comparison Table, demonstrating equivalence to the stainless steel component of TSRH®). |
| Indications for Use | "Reduction and stabilization of grades III & IV spondylolisthesis of the fifth lumbar to first sacral vertebral interspace only." - Stated to have the "same indications for use as the recently cleared TSRH® and PLSA systems." |
| Contraindications | Same general contraindications as the predicate devices (spinal infection, morbid obesity, mental illness, pregnancy, metal sensitivity, inadequate tissue coverage, open wounds local to the operative area). |
| Surgical Approach | Posterior Surgical Approach (same as predicate devices) |
| Design Elements (e.g., rods, pedicle screws, hooks, transverse interconnection) | "Design of the rods and pedicle screws... do not represent a significant departure from long established designs... The Webb-Morley Spine System utilizes identical implant materials... The design features... are equivalent to those offered by the TSRH® and PLSA systems." "Components of the comparable systems are all made from the same or equivalent implant grade materials." Specific details in the Feature Comparison Table corroborate this for hooks, rods, screws, and transverse interconnection. |
| Sterilization Method | Steam autoclave sterilization (recommended as gravity steam sterilization for 45 minutes at 121°C), with a Sterility Assurance Level (SAL) of 10⁻⁶. "Essentially the same as that used for the TSRH® and the PLSA systems." |
| Compliance with Standards | Meets BS-7252, ISO-5832-1 & ASTM F-138-86 (comparable or equivalent to predicate devices ASTM F-138-86, Gr. 2 & F-136-92). |
| Performance in Clinical Context | "Performance of the Webb-Morley Spine System for severe spondylolisthesis of L5/S1 is expected to be comparable to the TSRH® and PLSA devices." |
2. Sample size used for the test set and the data provenance
The study primarily relies on physical testing of the device components and a comparison against predicate devices.
- Test Set Sample Size: Not explicitly stated as a number of devices or components. The testing appears to have been conducted on an unspecified number of Webb-Morley Spine System implants.
- Data Provenance: The data comes from in-house engineering review and commercial laboratories that performed static and fatigue testing. This is likely prospective testing specifically conducted for this submission. The origin of the data is the company (Electro-Biology, Inc.) and the commercial laboratories they contracted. No patient data or clinical trial data is mentioned for this specific device. The clinical experience listed for the Webb-Morley system is "European," suggesting that some observational data or initial use might have occurred there, but this is not part of the described "physical testing."
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
The concept of "ground truth" as typically applied to diagnostic algorithms (e.g., expert consensus on medical images) is not applicable here. The "ground truth" for this device's performance acceptance is based on:
- Engineering Standards: Established ASTM, ISO, and BS standards for implant materials and design.
- Performance of Predicate Devices: The established safe and effective performance of the TSRH® and PLSA systems.
- Qualified Commercial Laboratories: These labs performed the physical testing (static and fatigue) to objective engineering criteria. Their qualifications are mentioned as "qualified commercial laboratories," but specific expert numbers or individual qualifications (e.g., "bioengineers with 10 years of experience") are not provided.
4. Adjudication method for the test set
Not applicable. The evaluation is based on objective physical testing results against established engineering criteria and direct comparison with predicate device performance, not on subjective expert review requiring 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
No, a multi-reader multi-case (MRMC) comparative effectiveness study was not conducted and is not applicable to this type of device (spinal implant system). This device is a physical medical implant, not an AI-powered diagnostic or assistive tool for human readers.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
No, a standalone algorithm performance study was not conducted. This device is a physical medical implant.
7. The type of ground truth used
The ground truth for this submission is based on:
- Objective Engineering Test Results: Data from static and fatigue testing.
- Compliance with Recognized Standards: Adherence to ASTM, ISO, and BS material and performance standards.
- Predicate Device Performance: The established safety and effectiveness of the legally marketed predicate devices (TSRH® and PLSA systems), against which the Webb-Morley system demonstrated equivalence or superiority.
8. The sample size for the training set
Not applicable. This submission concerns a physical medical device, not an AI or machine learning algorithm requiring a training set.
9. How the ground truth for the training set was established
Not applicable. This submission concerns a physical medical device, not an AI or machine learning algorithm.
§ 888.3070 Thoracolumbosacral pedicle screw system.
(a)
Identification. (1) Rigid pedicle screw systems are comprised of multiple components, made from a variety of materials that allow the surgeon to build an implant system to fit the patient's anatomical and physiological requirements. Such a spinal implant assembly consists of a combination of screws, longitudinal members (e.g., plates, rods including dual diameter rods, plate/rod combinations), transverse or cross connectors, and interconnection mechanisms (e.g., rod-to-rod connectors, offset connectors).(2) Semi-rigid systems are defined as systems that contain one or more of the following features (including but not limited to): Non-uniform longitudinal elements, or features that allow more motion or flexibility compared to rigid systems.
(b)
Classification. (1) Class II (special controls), when intended to provide immobilization and stabilization of spinal segments in skeletally mature patients as an adjunct to fusion in the treatment of the following acute and chronic instabilities or deformities of the thoracic, lumbar, and sacral spine: severe spondylolisthesis (grades 3 and 4) of the L5-S1 vertebra; degenerative spondylolisthesis with objective evidence of neurologic impairment; fracture; dislocation; scoliosis; kyphosis; spinal tumor; and failed previous fusion (pseudarthrosis). These pedicle screw spinal systems must comply with the following special controls:(i) Compliance with material standards;
(ii) Compliance with mechanical testing standards;
(iii) Compliance with biocompatibility standards; and
(iv) Labeling that contains these two statements in addition to other appropriate labeling information:
“Warning: The safety and effectiveness of pedicle screw spinal systems have been established only for spinal conditions with significant mechanical instability or deformity requiring fusion with instrumentation. These conditions are significant mechanical instability or deformity of the thoracic, lumbar, and sacral spine secondary to severe spondylolisthesis (grades 3 and 4) of the L5-S1 vertebra, degenerative spondylolisthesis with objective evidence of neurologic impairment, fracture, dislocation, scoliosis, kyphosis, spinal tumor, and failed previous fusion (pseudarthrosis). The safety and effectiveness of these devices for any other conditions are unknown.”
“Precaution: The implantation of pedicle screw spinal systems should be performed only by experienced spinal surgeons with specific training in the use of this pedicle screw spinal system because this is a technically demanding procedure presenting a risk of serious injury to the patient.”
(2) Class II (special controls), when a rigid pedicle screw system is intended to provide immobilization and stabilization of spinal segments in the thoracic, lumbar, and sacral spine as an adjunct to fusion in the treatment of degenerative disc disease and spondylolisthesis other than either severe spondylolisthesis (grades 3 and 4) at L5-S1 or degenerative spondylolisthesis with objective evidence of neurologic impairment. These pedicle screw systems must comply with the following special controls:
(i) The design characteristics of the device, including engineering schematics, must ensure that the geometry and material composition are consistent with the intended use.
(ii) Non-clinical performance testing must demonstrate the mechanical function and durability of the implant.
(iii) Device components must be demonstrated to be biocompatible.
(iv) Validation testing must demonstrate the cleanliness and sterility of, or the ability to clean and sterilize, the device components and device-specific instruments.
(v) Labeling must include the following:
(A) A clear description of the technological features of the device including identification of device materials and the principles of device operation;
(B) Intended use and indications for use, including levels of fixation;
(C) Identification of magnetic resonance (MR) compatibility status;
(D) Cleaning and sterilization instructions for devices and instruments that are provided non-sterile to the end user; and
(E) Detailed instructions of each surgical step, including device removal.
(3) Class II (special controls), when a semi-rigid system is intended to provide immobilization and stabilization of spinal segments in the thoracic, lumbar, and sacral spine as an adjunct to fusion for any indication. In addition to complying with the special controls in paragraphs (b)(2)(i) through (v) of this section, these pedicle screw systems must comply with the following special controls:
(i) Demonstration that clinical performance characteristics of the device support the intended use of the product, including assessment of fusion compared to a clinically acceptable fusion rate.
(ii) Semi-rigid systems marketed prior to the effective date of this reclassification must submit an amendment to their previously cleared premarket notification (510(k)) demonstrating compliance with the special controls in paragraphs (b)(2)(i) through (v) and paragraph (b)(3)(i) of this section.