ROGOZINSKI THORACOLUMBAR SPINAL ROD

K954696 · Smith & Nephew Richards, Inc. · KWP · Mar 11, 1996 · Orthopedic

Device Facts

• Record ID: K954696
• Device Name: ROGOZINSKI THORACOLUMBAR SPINAL ROD
• Applicant: Smith & Nephew Richards, Inc.
• Product Code: KWP · Orthopedic
• Decision Date: Mar 11, 1996
• Decision: SN
• Submission Type: Traditional
• Regulation: 21 CFR 888.3050
• Device Class: Class 2
• Attributes: Therapeutic

Intended Use

Posterior pedicle screw fixation: The Rogoziński Thoracolumbar Spinal Rod System Direct ("U"-shaped head) and Offset ("T"-shaped head) screws when placed in the pedicles of vertebral levels L3 to S1 are intended only for patients: (a) having severe spondylolisthesis (Grades 3 and 4) of the fifth lumbar - first sacral (L5-S1) vertebral joint; (b) who are receiving fusions using autogenous bone graft only; and (c) who are having the device fixed or attached to the lumbar and sacral spine. Otherwise, the Direct and Offset Screws are intended only for sacral/iliac attachment as specified below. Posterior hook and/or sacral/iliac screw fixation: The Rogoziński Thoracolumbar Spinal Rod System is intended for the treatment of degenerative disc disease (defined as spinal instability and one or more of the following: decreased disc height, ridging of vertebral end plates, osteophyte formation, scarring or thickening of ligamentous tissues and/or changes in facet joint morphology); pseudarthrosis; stenosis; scoliosis; spondylolisthesis; fracture; unsuccessful previous attempts at spinal fusion; or tumor resection. The Rogoziński Thoracolumbar Spinal Rod system is limited to non-cervical use.

Device Story

System consists of stainless steel rods, interlaminal hooks, and pedicle screws; universal cross-bars connect rods for rigid construct. Screws feature "T"-shaped (offset) or "U"-shaped (direct) heads for rod attachment. Surgeon implants device during spinal fusion procedures to stabilize vertebral segments. Provides three-column spinal control; restores/maintains physiologic alignment; facilitates fusion in degenerative conditions. Benefits include improved fusion rates and clinical outcomes compared to non-instrumented fusion. Used in clinical/surgical settings by orthopedic or neurosurgeons.

Clinical Evidence

Evidence includes a meta-analysis (889 patients) and a historical cohort study (2,684 patients) comparing pedicle screw fixation to non-instrumented fusion. Pedicle screw group showed significantly higher fusion rates (89.1% vs 70.4%) and improved clinical outcomes. A randomized study (124 patients) further supported superior fusion rates for pedicle screw systems (up to 95%) versus non-instrumented controls (65%). Complication rates were comparable to other marketed Class II devices.

Technological Characteristics

Construct consists of stainless steel rods, hooks, and screws. Screws available in various lengths/diameters with "T" or "U" shaped heads. Modular components include couplers, crossbars, and set screws. Non-cervical application. Mechanical fixation system; no energy source or software.

Indications for Use

Indicated for patients requiring spinal stabilization for degenerative disc disease, pseudarthrosis, stenosis, scoliosis, spondylolisthesis, fracture, failed fusion, or tumor resection. Pedicle screw fixation (L3-S1) specifically for severe spondylolisthesis (Grades 3-4) at L5-S1 using autogenous bone graft. Non-cervical use only.

Regulatory Classification

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.

Predicate Devices

• Harrington "Lag" Screw (Zimmer, Inc)
• ISOLA® Spinal System (Acromed, Inc.)
• CD Spinal System (Sofamor/Danek)
• GDLH™ Posterior Spinal System (Sofamor/Danek)
• TSRH™ Spinal System (Sofamor/Danek)
• Paragon™ Posterior Spinal System (Sofamor/Danek)
• Unit Rod System (Sofamor/Danek)
• MOSS™ Modular Segmental Spinal Instrumentation System (Depuy/Motech™)
• Modulock™ Posterior Spinal Fixation System (Zimmer, Inc.)
• Wiltse System of Internal Fixation (Advanced Spine Fixation Systems, Inc.)

Submission Summary (Full Text)

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510(k) Summary

K954696

Rogoziński Thoracolumbar Spinal Rod System
Smith & Nephew Spine
a division of Smith & Nephew Richards Inc.
1450 Brooks Road
Memphis, TN 38116

MAR 11 1996

# 1. Description

The Rogoziński Thoracolumbar Spinal Rod System consists of two stainless steel rods attached to the spinal column through the use of interlaminal hooks and/or screws. Universal cross-bars may be used to connect rods to rods to provide a more rigid construct, as well as screws to rods and hooks to rods. Screws are provided in a variety of lengths and diameters and up-angle, neutral, down-angle and pedicle hooks are provided in several sizes to accommodate varying patient morphology. Screws used with this system feature either a "T"-shaped head for offset attachment to the rod using a coupler, crossbar, and set screw or a "U"-shaped head for direct attachment to the rod using a hookbar and set screw. Up-angle, down-angle, neutral and pedicle hooks may be attached either directly to the rod or offset from the rod attached with to the rod with crossbar mechanism.

# 2. Identification of the Predicate Device(s)

The Rogoziński Thoracolumbar Spinal Rod System Screws are substantially equivalent to the Harrington "Lag" Screw manufactured by Zimmer, Inc, the ISOLA® Spinal System by Acromed, Inc., the CD Spinal System by Sofamor/Danek, the GDLH™ Posterior Spinal System by Sofamor/Danek, the TSRH™ Spinal System by Sofamor/Danek, the Paragon™ Posterior Spinal System by Sofamor/Danek, the Unit Rod System by Sofamor/Danek, the MOSS™ Modular Segmental Spinal Instrumentation System by Depuy/Motech™, the Modulock™ Posterior Spinal Fixation System by Zimmer, Inc., and the Wiltse System of Internal Fixation by Advanced Spine Fixation Systems, Inc.

# 3. Intended Use(s)

Posterior pedicle screw fixation: The Rogoziński Thoracolumbar Spinal Rod System Direct ("U"-shaped head) and Offset ("T"-shaped head) screws when placed in the pedicles of vertebral levels L3 to S1 are intended only for patients: (a) having severe spondylolisthesis (Grades 3 and 4) of the fifth lumbar - first sacral (L5-S1) vertebral joint; (b) who are receiving fusions using autogenous bone graft only; and (c) who are having the device fixed or attached to the lumbar and sacral spine. Otherwise, the Direct and Offset Screws are intended only for sacral/iliac attachment as specified below.

Posterior hook and/or sacral/iliac screw fixation: The Rogoziński Thoracolumbar Spinal Rod System is intended for the treatment of degenerative disc disease (defined as spinal instability and one or more of the following: decreased disc height, ridging of vertebral end plates, osteophyte formation, scarring or thickening of ligamentous tissues and/or changes in facet joint morphology); pseudarthrosis; stenosis; scoliosis; spondylolisthesis; fracture; unsuccessful previous attempts at spinal fusion; or tumor resection. The Rogoziński Thoracolumbar Spinal Rod system is limited to non-cervical use.

# 4. Information Bearing on Safety and Effectiveness

Mardjetko et al. presented the results of a meta-analysis of the literature relating to degenerative spondylolisthesis. Accepted for inclusion in this meta-analysis were 25 papers published between 1970 and 1973 representing 889 patients presenting with degenerative spondylolisthesis with radicular leg pain or neurogenic claudication involving the lumbar spine from L1-S1. Degenerative spondylolisthesis is characterized by degenerative arthritis of the facet joints is association with disc degeneration. Remodeling of the facet joint allows anterolisthesis of the cephalad on the cauda lumbar vertebra. This meta-analysis stratified papers into the following groups: (i) Nonoperative/natural history - 3 papers with 278 patients total, (ii) Posterior decompression procedures without fusion - 11 papers with 216 patients total, (iii) Posterior decompression with fusion procedure without instrumentation - 6 papers with 84 patients total, (iv) Posterior decompression with fusion with "control" device, i.e., legally marketed Class II devices - 4 papers with 138 patients total, (v) Posterior decompression with fusion with pedicular instrumentation - 5 papers with 101 patients total, (vi) Anterior spinal fusion - 3 papers with 72 patients total. Mardjetko stated that the recognized advantages of pedicular instrumentation over control devices as an adjunct to posterolateral spinal fusion include (i) the ability to achieve three-column spinal control from a posterior approach, (ii) the restoration and maintenance of physiologic spinal alignments in all planes, (iii) no space-occupying metallic devices within the degenerative lumbar spinal canal, and (iv) the ability to achieve fixation across segments with deficient or absent posterior spinal elements, potentially minimizing the spinal segments requiring instrumentation and fusion. Mardjetko concluded that the results of this meta-analysis support the clinical impression that in the surgical management of degenerative lumbar spondylolisthesis, spinal fusion significantly improves patient satisfaction, and adjunctive spinal instrumentation enhances spinal fusion rates. FDA Class II devices and pedicular instrumentation are comparable with regards to rates of fusion, patient satisfaction, and complications. The results of an open, nonblinded, historical cohort study presented by Yuan et.al. support Mardjetko findings. This historical cohort study collected data on patients who had undergone spinal fusions using pedicle screw devices as well as those who had received legally marketed spinal fusion devices or no instrumentation at all. A total of 2,684 patients with degenerative spondylolisthesis were included in this cohort study with 2,177 (81.1%) in the pedicle screw group, 456 (17.0%) in the non-instrumented group, and 51 (1.9%) in the non-pedicle screw instrumentation group. The safety of pedicle screw devices for the treatment of degenerative spondylolisthesis was assessed by analyzing the nature and frequency of intraoperative and postoperative events. Intraoperative events related to pedicle screw devices occurred infrequently. The rate of implant breakage was extremely low (0.2%). The remaining intraoperative events were felt to be related to surgical technique rather than the implant. Pedicle screw device related postoperative events were comprised mainly of screw fracture and screw loosening. Since the dominant control group for degenerative spondylolisthesis was non-instrumented fixations, no such rate comparisons for these events could be made. However, many of these events were without clinical consequence. For postoperative events that could have occurred in both treatment groups, the nature and frequency of these events were comparable. Additionally, the time adjusted rates of events were not statistically different between the two treatment groups. The rate of reoperation was higher in the pedicle screw group than in the non-instrumented group (17.6% versus 15.0%) primarily due to device removals. The rates of refusion and other reoperations, which can occur in both treatment groups were similar. In terms of effectiveness, the pedicle screw treatment group had a statistically higher rate of fusion than the non-instrumented control group (simple: 89.1% versus 70.4%). Additionally, the time to fusion tended to be faster for the pedicle screw group patients. Maintenance of spinal alignment and degeneration at other levels, although not statistically different, favored the pedicle screw fixation group. Yuan concluded that the benefits of pedicle screw fixation for the treatment of degenerative spondylolisthesis were demonstrated in significantly higher fusion rates compared to conventional non-instrumented control surgical treatments with pedicle screw patients achieving better overall clinical outcomes. Garfin in a summation of the works of Mardjetko et.al. and Yuan et.al. states that data derived from a scientifically valid study show that pedicle screws-based devices can offer help to a significant number of people. The literature review as well as the cohort study show that the fusion rate markedly improves when internal fixation is added and that pedicle screw systems are at least as effective as the currently marketed, commercially available Class II instrumentation in terms of increasing the fusion rate. Garfin further states that although the complication rates are higher in those that have instrumented fusions versus in situ fusion, pedicle screw devices have no higher complication rates and no more significant complications than the currently marketed, commercially available Class II instrumentation. Therefore, in properly chosen patients, matched to the appropriate device and procedure, the results in obtaining a fusion and successful outcome may be better using pedicle screw devices, than with other system that are

J950929C DOC

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currently available and approved for use in the United States. Zdeblick³⁴ reported the results of a randomized study of 124 patients undergoing lumbar or lumbosacral fusion for degenerative conditions of the spine. Patients were randomly assigned to one of the following three treatment groups: (I) posterolateral fusion using autogenous bone graft, (II) autogenous posterolateral fusions supplemented with the Luque II screw/plate fixation system (Sofamor/Danek), and (III) autogenous posterolateral fusions supplemented with the TSRH screw/rod fixation system (Sofamor/Danek). Of the 124 patients entered into the study, 56 presented with degenerative or isthmic spondylolisthesis: 21 in Group I, 18 in Group II, and 17 in Group III. The fusion rate for degenerative spondylolisthesis for Groups I, II, and III were 65%, 50%, and 86%, respectively. The fusion rate for isthmic spondylolisthesis for Groups I, II, and III were 80%, 89%, and 100%, respectively. Overall fusion rates for Groups I, II and III were 65%, 77%, and 95%, respectively. Zdeblick also assessed each patient clinically and assigned each a rating of either "excellent", "good", "fair", or "poor". The overall good or excellent clinical results were 71% in Group I, 89% in Group II, and 95% in Group III. Zdeblick concluded that pedicle screw fixation led to a significantly higher rate of fusion in degenerative lumbar disease than did fusion without instrumentation and that the clinical results mimic the radiographic results in all three Groups.

1950920C.DOC

¹ Mardjetko SM, Connolly PJ, Shott S: Degenerative Lumbar Spondylolisthesis: A Meta-Analysis of Literature 1970-1993. Spine 19(20S):2256S-2265S, 1994.
² Yuan HA, Garfin SR, Dickman CA, Mardjetko SM: A Historical Cohort Study of Pedicle Screw Fixation in Thoracic, Lumbar, and Sacral Spinal Fusions. Spine 19(20S):2279S-2296S, 1994.
³ Garfin SR: Summation. Spine 19(20S):2300S-2305S, 1994.
⁴ Zdeblick TA: A Prospective, Randomized Study of Lumbar Fusion. Spine 18(8):983-991, 1993.