Minimally Invasive Lumbar Fusion

Transcription

1 Minimally Invasive Lumbar Fusion

2 Biomechanical Evaluation (1) coflex-f screw

3 Biomechanical Evaluation (1) coflex-f intact Primary Stability intact Primary Stability Extension Neutral Position Flexion Coflex crimped Coflex rivet Rotation in Test w/o intervertebral support!

4 Biomechanical Evaluation (1) coflex-f Segmental Tilt y- Axis x- Axis Test w/o intervertebral support!

5 Philosophie Minimally Invasive Lumbar Fusion The missing piece The coflex-f implant offers an alternative to pedicle screw fixation. bridging the gap

6 ConceptMinimally Invasive Lumbar Fusion Interspinous stabilization with coflex-f is an ideal adjunct to fusion in cases of degenerative disc disease with or without mild instabilities in the lumbar spine. coflex-f allows for segmental stabilization in combination with interbody fusion cages and is bridging the gap between stand-alone anterior solutions and 360-Fusions using pedicle screw fixation. coflex-f can be applied in a less-invasive tissuesparing procedure significantly reducing iatrogenic damage and promoting shorter rehabilitation for patients.

7 ConceptAdjunct to Interbody Fusion Reduced Iatrogenic Trauma Less muscle trauma Less blood loss Smaller skin incision Reduced Cost Shorter operating time Faster patient rehabilitation Reduced Surgical Risks Excellent safety profile of implant Protection of neurological structures Easy and precise application Ease of use Simple surgical technique Easy instrumentation

8 coflex-fbiomechanical Rationale (2) Extension Flexion intact defect cage stand alone Cage / coflex-f Cage / Ped. Screw System 250% 200% 150% 100% 50% 0% 0% 50% 100% 150% 200% 250% Range of motion and neutral zone normalized with the intact state (100%) ROM NZ Prof. H.-J. Wilke: coflex-f: Biomechanical comparison of two posterior fixation systems. Institute of Orthopaedic Research and Biomechanics, Germany In combination with cages anteriorly both the coflex-f implant and the pedicle screw system reduced the ROM significantly.

9 Product Features

10 Design Features coflex-f Design Features Pin allows pressfit wing attachment on spinous process Secure anchorage through screw and sleeve fixation U-shape provides large surface area, different sizes allow adjustment of sagittal balance Good bone anchorage through teeth on inside of wings

11 Design Features coflex-f Design Features Ball and socket screw/wing interface for optimized load distribution in various wing angulations

12 Design Featurescoflex versus coflex-f Standardhole Ømm Ball and Socket connection with Rivet Ø mm 1,5 mm 2,1 mm Patent Pending!

13 Design Featurescoflex versus coflex-f 1,5 mm 2,1 mm Patent Pending!

14 Design Featurescoflex versus coflex-f Patent Pending! Standard Trials Special Trials

15 Overview Overview Indication vs. Contra-Indications

16 IndicationsAdjunct to Interbody Fusion The coflex-f system is intended for permanent implantation as an adjunct to fusion in the region from L1-L5 in up two levels. + The purpose is to achieve stabilization and to promote fusion in patients with degenerative disc disease

17 IndicationsContra-Indications The coflex-f system is contraindicated in cases of: Degenerative Spondylolisthesis greater than 1 according to Meyerding classification. Any forms of isthmic spondylolisthesis. Prior decompressive laminectomy, hemilaminectomy or significant lamina fenestration which weakens the spinous process. Multilevel applications Cases of L5/S1

18 Surgical Technique

19 Surgical Technique Surgical Technique Patient Positioning The patient is placed in the prone position on a surgical frame avoiding hyperlordosis of the spinal segment(s) to be operated upon.

20 Surgical Technique Surgical Strategy Lumbar Interbody Fusion L1 to L5 Anterior Lumbar Interbody Fusion (ALIF) 1. ALIF 2. coflex-f Insertion Posterior Lumbar Interbody Fusion (PLIF) 1. PLIF 2. coflex-f Insertion Transforaminal Lumbar Interbody Fusion (TLIF) 1. TLIF 2. coflex-f Insertion 1 2

21 Surgical Technique Intervertebral Implants Select lordotic cages to ensure maximum cage endplate contact. Avoid undersizing cages! Bone graft should be placed anterior, lateral and medial to the cages to ensure optimal fusion success. Intervertebral space preparation: Care is taken to remove all nucleus material (which inhibits osteogenesis) prior to cage insertion. ALL

22 Surgical Technique Facet Joints Status Maintain at least 50% of the medial facet and all of the facet capsules Add bone chips (anterior/ lateral and medial to cages) to promote fusion process OK Too much

23 Surgical Technique Surgical Technique Implant Site Preparation After the intervertebral device (cage or machined allograft) has been inserted, trials are utilized to define the appropriate implant size. Trial instrument is placed to evaluate the proper contact with the spinous processes avoiding any facet distraction.* * It is most appropriate to use a coflex-f implant one size smaller than to have distraction of the facets.

24 Surgical Technique Surgical Technique-PLIF Make sure that the oposing facing surfaces of the superior and inferior spinous processes are parallel for enhanced contact onto the legs of the coflex-f implant Flat surfaces can be obtained using either osteotomes, rongeurs or drills. Maintain adequate spinous process anatomy for optimal fixation strength.

25 Surgical Technique Intervertebral Implants If the laminae are steeply pitched (which can block proper seating of device wings), use a burr or rongeur to bilaterally fashion the juncture of laminae and base of interspinous process so that the wings seat at the appropriate depth. The device should seat so that the apex of the U rests at midlevel of the corresponding facet joints of the treated level. Mid Portion of facet joint ideal place for U portion

26 Surgical Technique Surgical Technique Implant Insertion Prior to insertion bending pliers may be necessary to separate the wings. The coflex-f implant is introduced via impaction utilizing a mallet. Proper depth is determined if a beaded tip probe can be passed freely leaving 2-3 mm separation from the dura. By deep insertion at the level of the facet joints the coflex-f continues to counteract the majority of posterior column forces.

27 Surgical Technique Surgical Technique It is recommended to crimp the implant wings prior to screw insertion. This ensures proper contact to the spinous processes and delivery of the fixation screw later. Once proper placement has been achieved punching pliers are utilized to create holes in the spinous processes for later introduction of the coflex-f screws.

28 Surgical Technique Surgical Technique Implant Insertion Prior to insertion of the coflex-f screws it is recommended to clean the holes using the coflex-f probe.

29 Surgical Technique Surgical Technique Implant Insertion The coflex-f screws are applied using the screw inserter. A tight fit is required for controlled fixation. Teeth of both wings should be firmly engaged into the cortices of the spinous processes. Slight additional compression can be obtained manually with wrenches.

30 Surgical Technique Surgical Technique

31 Surgical Technique Surgical Technique Wound Closure A surgical drain may be placed as per surgeon preference. The supraspinous ligament is reattached through bone. Skin is closed in the usual manner.

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33 Coflex-F Marketing Tools coflex-f Marketing Tools - Product Brochure Table of Content: Coflex-F (Introduction + Key Features) Surgical Technique Patient Cases Product Information

34 Coflex-F Marketing Tools Coflex-F Marketing Tools - Advertisement The coflex-f implant provides significant segmental stability with all the advantages of an interspinous implant and is the alternative to pedicle screw fixation as an adjunct to interbody fusion. Reduced iatrogenic trauma Faster patient rehabilitation Protection of neural structures Shorter operating time Secure anchorage through screw and sleeve fixation

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36 Coflex-F Marketing Tools DCI Workshop Friday May 30 th, 2008