Orthopedic

NKG · Posterior Cervical Screw System

Orthopedic · 21 CFR 888.3075 · Class 2

Overview

Identification

Posterior cervical screw systems are comprised of multiple, interconnecting components, made from a variety of materials that allow an implant system to be built from the occiput to the upper thoracic spine to fit the patient's anatomical and physiological requirements, as determined by preoperative cross-sectional imaging. Such a spinal assembly consists of a combination of bone anchors via screws (i.e., occipital screws, cervical lateral mass screws, cervical pedicle screws, C2 pars screws, C2 translaminar screws, C2 transarticular screws), longitudinal members (e.g., plates, rods, including dual diameter rods, plate/rod combinations), transverse or cross connectors, interconnection mechanisms (e.g., rod-to-rod connectors, offset connectors), and closure mechanisms (e.g., set screws, nuts). Posterior cervical screw systems are rigidly fixed devices that do not contain dynamic features, including but not limited to: non-uniform longitudinal elements or features that allow more motion or flexibility compared to rigid systems.Posterior cervical screw systems are intended to provide immobilization and stabilization of spinal segments in patients as an adjunct to fusion for acute and chronic instabilities of the cervical spine and/or craniocervical junction and/or cervicothoracic junction such as: (1) Traumatic spinal fractures and/or traumatic dislocations; (2) deformities; (3) instabilities; (4) failed previous fusions (e.g., pseudarthrosis); (5) tumors; (6) inflammatory disorders; (7) spinal degeneration, including neck and/or arm pain of discogenic origin as confirmed by imaging studies (radiographs, CT, MRI); (8) degeneration of the facets with instability; and (9) reconstruction following decompression to treat radiculopathy and/or myelopathy. These systems are also intended to restore the integrity of the spinal column even in the absence of fusion for a limited time period in patients with advanced stage tumors involving the cervical spine in whom life expectancy is of insufficient duration to permit achievement of fusion.

Classification Rationale

Class II (special controls). The special controls for posterior cervical screw systems are:

Special Controls

*Classification.* Class II (special controls). The special controls for posterior cervical screw systems are:(1) The design characteristics of the device, including engineering schematics, must ensure that the geometry and material composition are consistent with the intended use. (2) Nonclinical performance testing must demonstrate the mechanical function and durability of the implant. (3) Device components must be demonstrated to be biocompatible. (4) Validation testing must demonstrate the cleanliness and sterility of, or the ability to clean and sterilize, the device components and device-specific instruments. (5) Labeling must include the following: (i) A clear description of the technological features of the device including identification of device materials and the principles of device operation; (ii) Intended use and indications for use including levels of fixation; (iii) Device specific warnings, precautions, and contraindications that include the following statements: (A) “Precaution: Preoperative planning prior to implantation of posterior cervical screw systems should include review of cross-sectional imaging studies ( *e.g.,* CT and/or MRI) to evaluate the patient's cervical anatomy including the transverse foramen, neurologic structures, and the course of the vertebral arteries. If any findings would compromise the placement of these screws, other surgical methods should be considered. In addition, use of intraoperative imaging should be considered to guide and/or verify device placement, as necessary.”(B) “Precaution: Use of posterior cervical pedicle screw fixation at the C3 through C6 spinal levels requires careful consideration and planning beyond that required for lateral mass screws placed at these spinal levels, given the proximity of the vertebral arteries and neurologic structures in relation to the cervical pedicles at these levels.” (iv) Identification of magnetic resonance (MR) compatibility status; (v) Cleaning and sterilization instructions for devices and instruments that are provided non-sterile to the end user, and; (vi) Detailed instructions of each surgical step, including device removal.

Cleared Devices (117)

Top Applicants

• Orthofix, Inc. — 7 clearances
• Medtronic Sofamor Danek USA, Inc. — 7 clearances
• Nu Vasive, Incorporated — 6 clearances
• Medos International SARL — 6 clearances
• Medacta International S.A. — 6 clearances