DDS SPINAL SYSTEM

K960107 · Encore Orthopedics, Inc. · MNH · May 3, 1996 · Orthopedic

Device Facts

• Record ID: K960107
• Device Name: DDS SPINAL SYSTEM
• Applicant: Encore Orthopedics, Inc.
• Product Code: MNH · Orthopedic
• Decision Date: May 3, 1996
• Decision: SN
• Submission Type: Traditional
• Regulation: 21 CFR 888.3070
• Device Class: Class 2
• Attributes: Therapeutic

Intended Use

It is intended for patients with severe spondylolisthesis (Grades 3 and 4) having fusions at the L5-S1 joint using autogenous bone graft, to be fixed/attached to the lumbar and sacral spine. The components are intended to be removed after development of a solid fusion mass. The screws are limited to L3-S1 or iliac screw fixation.

Device Story

DDS Spinal System is a multi-component spinal fixation device consisting of titanium alloy (Ti-6Al-4V) pedicle screws, rods, and spacers. Used by surgeons in clinical settings to stabilize the spine during fusion procedures for severe spondylolisthesis. Components are implanted to provide structural support while autogenous bone graft achieves fusion; intended for removal after solid fusion mass development. System facilitates implantation via spacers sliding over screw threads. Clinical benefit derived from stabilization of L3-S1/iliac segments.

Clinical Evidence

Bench testing only. Mechanical performance evaluated via axial compression (1403.2±90.6 N), bending (24.38±.63 Nm), torsion (42.30±2.44 Nm), and screw pullout testing (unembedded: 818.5±341.8 N; embedded: 785.0±289.7 N). No clinical data provided.

Technological Characteristics

Materials: Ti-6Al-4V titanium alloy conforming to ASTM F136. Components: Pedicle screws (6.5 mm thread diameter, 35-55 mm lengths), rods (5 mm diameter, 40-600 mm lengths), and spacers (2, 4, 6 mm heights). Mechanical fixation principle. Non-powered, mechanical device.

Indications for Use

Indicated for patients with severe spondylolisthesis (Grades 3 and 4) requiring fusion at the L5-S1 joint, utilizing autogenous bone graft, with fixation to the lumbar and sacral spine (L3-S1 or iliac).

Regulatory Classification

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.

Special Controls

*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.

Predicate Devices

• Moss Spinal System (K894184)

Submission Summary (Full Text)

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K96-007
MAY - 3 1996

# Summary of Safety and Effectiveness

April 3, 1996
Encore Orthopedics™, Inc.
8900 Shoal Creek
Building 300
Austin, TX 78757
512-795-8696
Ashley M. Bock

**Trade Name:** DDS Spinal System
**Common Name:** Spondylolisthesis Spinal Fixation Device
**Classification Name:** Unclassified, preamendments device

**Description:** The DDS Spinal System is a multi-component system consisting of pedicle screws, rods and spacers. The screws are available in five lengths and one diameter; the rods in twelve lengths and the spacers in three thicknesses. The screws are fabricated from titanium alloy (Ti-6Al-4V) that conforms to ASTM F136. The screws have a 6.5 mm thread diameters and are available in five lengths, 35, 40, 45, 50 and 55 mm. The rods are also manufactured from Ti-6Al-4V and are 5 mm in diameter. The rods are available in 12 lengths ranging from 40 mm to 600 mm. Round, smooth spacers of three different heights (2, 4, and 6 mm) slide over the threaded portion of the screw to facilitate implantation of neighboring screws at the same level. The spacers are also made of Ti-6Al-4V.

**Intended Use:** It is intended for patients with severe spondylolisthesis (Grades 3 and 4) having fusions at the L5-S1 joint using autogenous bone graft, to be fixed/attached to the lumbar and sacral spine. The components are intended to be removed after development of a solid fusion mass. The screws are limited to L3-S1 or iliac screw fixation.

**Comparable Features to Predicate Device(s):** Features comparable to predicate devices include Moss Spinal System cleared for commercial distribution in K894184.

**Test Results:** The results of the testing are summarized in the following table and graph.

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Encore Orthopedics, Inc.
510(k) Submission
DDS Spinal System

| Test | # of Specimens | Max. Load | Deformation | Stiffness |
| --- | --- | --- | --- | --- |
| Axial Compression | 5 | 1403.2±90.6 N | 2.69±.61 mm | 929.2±117.6 N/mm |
| Bending | 5 | 24.38±.63 Nm | 20.86±1.67 mm | 3.07±.53 Nm/mm |
| Torsion | 5 | 42.30±2.44 Nm | 38 degrees | 2.58±.09 Nm/deg |
| Screw Pullout* | 16 | 818.5±341.8 N | NA | NA |
| Screw Pullout** | 5 | 785.0±289.7 N | NA | NA |

*Unembedded specimens
**Wrapped, embedded specimens