SpF® Implantable Spinal Fusion Stimulators

See the Difference

Indicated as a spinal fusion adjunct to increase the possibility of fusion success

The SpF-XL IIb Implantable Spinal Fusion Stimulator (2/DM & 2/DW) and SpF PLUS-Mini Spinal Fusion Stimulator (60μA/M & 60μA/W) offer the following features and benefits:

Effective

  • Increases the probability of fusion success rates particularly in patients with specific risk factors1,2,3
  • In one study, SpF stimulators used in conjunction with internal fixation demonstrated a 96% fusion success rate vs. 85% with fixation alone (P=0.02)2,**
  • Provides a constant dose of electrical stimulation for approximately 6 months5

 Scientifically Proven

  • In one pre-clinical study, direct current (DC) stimulation was shown to enhance the expression of several different osteoinductive growth factors, including BMP-2, BMP-6, and BMP-76,*

An Established Product

  • More than 30 years of proven clinical use7
  • No concern regarding patient non-compliance

The SpF stimulator can be used in following surgical applications4

  1. Posterior lumbar fusion with autograft augmentation, with or without internal fixation
  2. Lumbosacral fusion adjunct to internal fixation
  3. Combined facet and intertransverse fusion
  4. Pseudoarthrosis repair

MRI Safety Information

  • MRI scans may be performed safely following specific recommendations and precautions:
    • Using 1.5 Tesla
    • Within a maximum spatial gradient:
      • For the PLUS-Mini, maximum spatial gradient of 250 gauss/centimeter
      • For the XL IIb, maximum spatial gradient of 450 gauss/centimeter
    • Gradient fields of 20 Tesla/second or less
    • Maximum whole body averaged Specific Absorption Rate (SAR) of 1.1 W/kg for 25 minutes of imaging 
  • The effects of MRI procedures using MR systems and conditions above these levels have not been determined
  • Complete MRI Safety Information for SpF Implantable Spinal Fusion Stimulators can be found in the Physician’s Manual and Full Prescribing Information which is available in downloadable form on this website under the Resources section5

Product Description

The SpF PLUS-Mini is a solid state constant current generator producing a constant current of 60 microamperes and is powered by one lithium manganese dioxide battery. The electronics and power source are hermetically sealed within a titanium generator case; an area of approximately 600mm2 on one side of the case is platinum coated and functions as the anode.

The SpF PLUS-Mini lead wires consist of two 15cm leads of drawn brazed strand (DBS) wire covered with silicone and connected to the generator by a titanium connector. The cathodes are available in preformed wave or mesh configurations. In the preformed wave configuration, each lead is terminated in a 12cm (4cm preformed wave) uninsulated triple strand titanium wire which acts as a cathode and is connected to the insulated DBS lead by a titanium connector which disconnects at both the generator and cathode. The mesh cathode consists of two strands of titanium wire woven into a flexible grid with nominal dimensions of 1cm x 4cm.

The SpF-XL IIb is a solid-state constant current generator producing a constant current of 40 microamperes and is powered by one lithium manganese dioxide battery. The electronics and power source are hermetically sealed within a titanium generator case; an area of approximately 400mm2 on one side of the case is platinum coated and functions as the anode.

The SpF-XL IIb lead wires consist of two 15cm leads of drawn brazed strand (DBS) wire covered with silicone and connected to the generator by a titanium connector. The cathodes are available in preformed wave or mesh configurations. In the preformed wave configuration, each lead is terminated in a 24cm (8cm preformed wave) uninsulated triple strand titanium wire which acts as a cathode and is connected to the insulated DBS lead by a titanium connector which disconnects at both the generator and cathode, or is permanently connected with a titanium crimp (fused lead configuration only). The mesh cathode consists of two strands of titanium wire woven into a flexible grid with nominal dimensions of 1cm x 8cm.

Indications

The SpF PLUS-Mini Implantable Fusion Stimulators (Models: 60μA/M & 60μA/W) are indicated as a spinal fusion adjunct to increase the probability of fusion success in one or two levels.

The SpF-XL IIb Implantable Spinal Fusion Stimulators (Models: 2/DM & 2/DW) are indicated as a spinal fusion adjunct to increase the probability of fusion success in three or more levels.

Usage

SpF stimulators have only been studied as an adjunct for lumbar spinal surgery, Posterolateral Fusion (All models). Federal Law (U.S.A.) restricts this device to sale by or on the order of a physician. Rx Only - Prescription Only - Single Use Only - Do Not Reuse.

Contraindications

Any case where SpF Spinal Fusion Stimulators could come into contact with metallic implant components (i.e., those that contain Titanium, Cobalt Chrome and Stainless Steel).

Any surgical implantation procedure such as minimally invasive surgical –MIS procedures requiring the SpF Spinal Fusion cathodes to be disconnected from their corresponding leads prior to or during implantation since this may seriously compromise the electrical performance of the implantable stimulator’s cathodes to deliver a constant current to the fusion site as intended.

Warnings

Do not use with defibrillators.

Precautions

Electrosurgery

Electrosurgical instruments are capable of producing radio frequency voltages of such magnitude that direct coupling can occur between the cautery tip and lead system of the generator. To preclude the possibility of burning of tissues adjacent to the electrode or damage to the generator electronics, electrosurgical equipment should not be used on the patient in the vicinity of the generator after the stimulator has been implanted.

Diathermy

Therapeutic diathermy should not be used in the treatment of a patient who has an implanted stimulator, since this equipment can produce voltages, which may cause damage to the electronics. Diathermy must never be applied over the site of any bone stimulator implant since high currents induced in the electrode lead will cause burning of the tissues in contact with the electrode tip.

Handling

The energy source and electronics of the generator are well protected within the generator case and will be unaffected by normal handling. However, the possibility of damage by mechanical shock, such as a drop onto a hard floor, cannot be precluded. Any stimulator subjected to this type of accident should not be implanted. Do not disconnect the leads from the cathodes during surgical implantation.

Use with Internal Fixation

If the stimulator is used in conjunction with metal internal fixation devices, no metallic part of the stimulator should be allowed to come into contact with the fixation device.

Placement of Generator

To avoid patient discomfort, care should be taken to place the generator in a comfortable tissue pocket so that rising of the skin contour is avoided or minimized.

Placement of Cathodes

The cathodes of the implantable spinal fusion stimulator must be positioned a minimum of 1cm from nerve roots to reduce the possibility of nerve excitation during a MRI procedure.

For complete prescribing information including contraindications, warnings and precautions, please refer to the SpF Implantable Spinal Fusion Stimulators Physician’s Manual and Full Prescribing Information PN1067632L or visit www.zimmerbiomet.com/bonehealing or call 1-877-324-8101.

Financial Disclaimer

In support of their research or for preparation of this work, one or more of the authors may have received remuneration from Zimmer Biomet.

  1. Kane WJ. Direct current electrical bone growth stimulation for spinal fusion. Spine. 1988;13 (3):363-365.
  2. Rogozinski A, Rogozinski C. Efficacy of implanted bone growth stimulation in instrumented lumbosacral spinal fusion. Spine. 1996;21 (21):2479-2483.
  3. Kucharzyk D. A controlled prospective outcome study of implantable electrical stimulation with spinal instrumentation in a high-risk spinal fusion population. Spine. 1999;24 (5):465-468.
  4. SpF Implantable Spinal Fusion Stimulator Surgical Technique Guide, P/N196067L                       
  5. SpF Implantable Spinal Fusion Stimulators Physician’s Manual & Full Prescribing Information Approved FDA Trade Names: SpF PLUS-Mini (60μA/W), SpF PLUS-Mini (60μA/M) and SpF XL llb Implantable Spinal Fusion Stimulator. Certain models of the SpF Implantable Spinal Fusion Stimulator have approved trade names preceded with “EBI” designating the former sponsor and/or applicant. P/N 1067632L–P850035/S020/S022/S031/S033
  6. Fredericks DC,Smuker J, Petersen EB, Bobst JA, Gan JC, Simon BJ, Glazer P. Effects of direct current electrical stimulation on gene expression of osteopromotive factors in a posterolateral spinal fusion model. Spine. 2007;32 (2):174-181.
  7. Data on file at Zimmer Biomet – P850035

 

*Although not indicative of human clinical results, outcomes from pre-clinical research have been implicated in various models of bone repair

**The spinal fusion success rate for treated patients in the original clinical study which led to PMA approval was 81% versus 54% for the control group. This result was statistically significant at P=0.026 (Fisher’s Exact test, one-tail). The criterion used for determining success was based on radiographic fusion.

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EBI, LLC d/b/a Zimmer Biomet
Bone Healing Technologies
399 Jefferson Road
Parsippany, NJ 07054


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