Illuminated Endoscopic Pedicle Probe With Dynamic Real Time Monitoring For Proximity To Nerves

Abstract

An endoscopic pedicle probe has an elongate body with a proximal end and a distal end. A tip on the distal end is pushed into the pedicle to form the hole, and an enlarged head on the proximal end enables a surgeon to manipulate the probe. The body has an inner shaft with a cylindrical sleeve telescopically engaged over it. An endoscope extends through a longitudinal bore in the shaft, with a camera at the tip end connected with a monitor to enable a surgeon to visually observe the area being treated. A light extends through another bore to illuminate the area, and a further bore conducts irrigation fluid to and from the area. The sleeve is made of electrically non-conductive material and the shaft and tip are made of electrically conductive material to enable stimulation of nerves at the treatment area.

Claims

1. An endoscopic pedicle probe for use during spinal surgery to form a hole in a pedicle for reception of a pedicle screw, said probe comprising: an elongate body having a proximal end and a distal end, a tip on the distal end that may be pushed through the pedicle to form the hole, and an enlarged head on the proximal end for cooperation with the hand of a surgeon to manipulate the probe; said body comprising an inner shaft extending from the head to the tip; an endoscope extending through an endoscope bore extending longitudinally through said shaft, said endoscope including a camera at said tip end, said camera being connected with a monitor to enable a surgeon to visually observe the area being treated; light means extending through an illumination bore to illuminate the area being treated; irrigation and aspiration means connected with an irrigation and aspiration bore to conduct an irrigating fluid to the area being treated and to aspirate the irrigating fluid and any debris away from the area being treated; a cylindrical sleeve telescopically engaged over said shaft from the distal end to the proximal end; and said sleeve being made of electrically non-conductive material and said shaft and tip being made of electrically conductive material.

2. The endoscopic pedicle probe as claimed in claim 1, wherein: a plurality of lateral ports is in said head; said endoscope extends through one of said ports to connect said camera to said monitor; another of said ports connects with said illumination bore to connect a source of light with said light means; and a further of said ports connects said irrigation and aspiration bore to a source of irrigating fluid and to a suction source for aspiration of fluid and tissue away from the area being treated.

3. The endoscopic pedicle probe as claimed in claim 2, wherein: a longitudinal bore extends through the shaft and the head for receiving a k-wire.

4. The endoscopic pedicle probe as claimed in claim 3, wherein: cut-outs in the area immediately above the lateral ports expose the proximal end of the shaft so that a variety of EMG/MMG clips can be attached to the shaft.

5. The endoscopic pedicle probe as claimed in claim 4, wherein: the sleeve is connected to the head by a threaded connection in the bottom of the head, and the shaft is held to the head by the sleeve.

6. The endoscopic pedicle probe as claimed in claim 5, wherein: said tip is attached to the distal end of the shaft by engagement of a shaped end on the tip with a complementally shaped opening and retainer in the distal end of the shaft.

7. The endoscopic pedicle probe as claimed in claim 6, wherein: the tip has corresponding bores aligned with the bores in the shaft.

8. The endoscopic pedicle probe as claimed in claim 7, wherein: the distal end of the tip is recessed to provide clearance for the camera and light means; and a transparent shield is positioned on the tip at the proximal end of the recessed area in overlying relationship to the camera and light source.

9. The endoscope and pedicle probe as claimed in claim 8, wherein: irrigation ports in the tip double as cutting flutes.

10. The endoscope and pedicle probe as claimed in claim 9, wherein: the sheath is slid over the shaft from the distal end of the shaft and the proximal end of the sheath is threaded for attachment to the head; and an inturned lip at the distal end of the sleeve engages against the distal end of the shaft to hold the shaft rearwardly against the head.

11. An endoscopic pedicle probe for use during spinal surgery to form a hole in a pedicle for reception of a pedicle screw, comprising: an elongate body having a proximal end and a distal end; a tip at the distal end that may be pushed into the pedicle to form the hole; and an enlarged head on the proximal end for cooperation with the hand of a surgeon to manipulate the probe; an endoscope and light extending through the body, said endoscope being connected with a monitor to enable a surgeon to visually observe the area being treated; and a mechanomyographic monitoring system connected with the probe to perform real time dynamic pedicle integrity assessments during a procedure to detect a breach or potential breach of the pedicle and alert the surgeon.

12. The endoscopic pedicle probe as claimed in claim 11, wherein: said body comprises an inner shaft extending from the head to the tip, and a cylindrical sleeve telescopically engaged over said shaft from the distal end to the proximal end.

13. The endoscopic pedicle probe as claimed in claim 12, wherein: said shaft and tip are made of an electrically conductive material and said sleeve is made of an electrically non-conductive material.

14. The endoscopic pedicle probe as claimed in claim 13, wherein: said shaft has a plurality of longitudinal bores extending therethrough from the proximal end to the distal end; and means is connected with one of said bores to conduct an irrigating fluid to the area being treated and to aspirate the irrigating fluid and any debris from the area.

15. The endoscopic pedicle probe as claimed in claim 14, wherein: said endoscope and light extend through another of said bores.

16. The endoscopic pedicle probe as claimed in claim 15, wherein: a laterally extending port in said head connects with said another of said bores; and said endoscope and light extend through said laterally extending port to said monitor.

17. The endoscopic pedicle probe as claimed in claim 16, wherein: another laterally extending port in said head connects a source of irrigating fluid with said one bore to conduct an irrigating fluid to said one bore.

18. The endoscopic pedicle probe as claimed in claim 17, wherein: a source of suction is also connected with said another laterally extending port to aspirate irrigating fluid and debris through said one bore and away from the area being treated.

19. The endoscopic pedicle probe as claimed in claim 18, wherein: cut-outs are in said head in position to expose the proximal end of said shaft and enable electrical conductors to be connected to said shaft.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The foregoing as well as other objects and advantages of the invention will become apparent from the following detailed description when considered in conjunction with the accompanying drawings, wherein like reference characters designate like parts throughout the several views, and wherein:

[0044] FIG. 1 is an isometric view of a typical prior art device.

[0045] FIG. 2 depicts a system incorporating a probe with MMG or EMG capability according to the invention.

[0046] FIG. 3 is an enlarged fragmentary view of the pedicle probe of the invention, looking at an angle from slightly above and positioned to form a hole in a pedicle.

[0047] FIG. 4 is an enlarged fragmentary view of the proximal end of the probe of the invention, looking at a slight angle from above.

[0048] FIG. 5A is an enlarged fragmentary isometric view showing one side of the distal end of the probe of the invention.

[0049] FIG. 5B is a further enlarged fragmentary isometric view of the area within the square in FIG. 5A.

[0050] FIGS. 6A and 6B are views similar to FIGS. 5A and 5B, but showing the opposite side of the distal end of the probe.

[0051] FIG. 7 is a further enlargement of the distal end of the probe as shown in FIG. 5A, but with the tip omitted.

[0052] FIG. 8 is a further enlargement of the distal end of the probe as shown in FIG. 5B, but with the tip omitted.

[0053] FIG. 9 is an enlarged side view in elevation of the head of the probe and through which all connections are made.

[0054] FIG. 10 is an enlarged side view in elevation of the head of the probe, taken at 90° to FIG. 11.

[0055] FIG. 11 is a longitudinal sectional view taken along line 11-11 in FIG. 10.

[0056] FIG. 12 is a side view in elevation of the tip of the invention, shown removed from the probe shaft.

[0057] FIG. 13 is a longitudinal sectional view of the tip of FIG. 12.

[0058] FIG. 14 is an enlarged end view looking toward the proximal end of the probe shaft.

[0059] FIG. 15 is an enlarged end view looking toward the distal end of the probe shaft.

[0060] FIG. 16 is a side view in elevation of the sheath that is applied to the probe shaft in assembling the probe of the invention.

[0061] FIG. 17 is a longitudinal sectional view of the sheath of FIG. 16.

[0062] FIG. 18 is a side view in elevation of the probe shaft of the invention, shown with the sheath removed.

[0063] FIG. 19 is a longitudinal sectional view of the shaft of FIG. 18.

[0064] FIG. 20 is an enlarged fragmentary view looking at a slight angle toward the distal end of the probe shaft.

[0065] FIG. 21 is an enlarged fragmentary view similar to FIG. 20, but looking toward the opposite side of the shaft.

[0066] FIG. 22 shows a jamshidi needle being used for form a hole in a pedicle for receipt of a k-wire.

[0067] FIG. 23 shows a k-wire inserted and the jamshidi removed.

[0068] FIG. 24 shows the probe of the invention being placed, after which the k-wire is removed.

[0069] FIG. 25 shows the probe of the invention being manipulated to form a hole in the pedicle for receipt of a pedicle screw.

[0070] FIG. 26 shows the k-wire replaced and the probe being removed.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0071] An awl as commonly used in the prior art to form a hole in a pedicle is indicated generally at 10 in FIG. 1. The awl has an enlarged head 11 at the proximal end for engagement with the hand of the surgeon, and an elongate shaft 12 terminating in a tip end 13 for forming the hole.

[0072] In accordance with the invention, either electromyography (EMG) or mechanomyography (MMG) may be used with the probe of the invention to alert the surgeon when a nerve is approached or a breach is about to occur. An MMG system generally is regarded as having a faster response and a higher sensitivity for detection of nerves at a lower threshold than does EMG. A suitable MMG system usable with the probe of the invention can be the Sentio MMG system available from Sentio LLC of Wixom, Mich.

[0073] A system as it might be constituted according to the invention when using either a mechanomyographic (MMG) monitoring system or an electromyographic monitoring (EMG) monitoring system is represented schematically at 20 in FIG. 2. The system would include a control unit 21 connected via a data cable 22 with a patient module 23. An EMG or MMG harness 24 and return electrode 25 are connected with the patient module, and a pedicle probe 26 according to the preferred form of the invention is also connected to the patient module via an electrical lead 27. The invention capitalizes on the insulating characteristics of bone, specifically that of the medial wall of the pedicle, and the conductivity of the adjacent nerve roots. That is, if the medial wall of the pedicle is breached or in danger of being breached, i.e., the layer of bone is too thin to provide enough insulation to prevent stimulation of adjacent nerves, a stimulation signal applied to the target site will cause the various muscle groups coupled to the nerve roots to react. The employment of electromyographic or mechanomyographic monitoring in the present invention to assess whether the muscle groups in the leg are innervating in response to the application of a stimulation signal does not require visual observation of twitching of the nerves.

[0074] In the case of an EMG system, the harness 24 relies on needles to detect subtle changes in electrical signals in muscle. In contrast, a mechanomyographic system such as the Sentio MMG® system employs proprietary accelerometer technology in the harness 24. These non-invasive accelerometer-based sensors measure MMG (mechanomyography) activity, or the mechanical “twitch” associated with muscle contraction.

[0075] With either MMG or EMG the control unit 21 includes a touch screen display 28 and a base 29, which collectively contain the essential processing capabilities for controlling the system 20. The data cable 22 establishes digital and/or analog electrical connections and communications between the control unit 21 and patient module 23. The main functions of the control unit 21 include receiving user commands via the touch screen display 28, activating stimulation, processing signal data according to defined algorithms as known in U.S. Pat. No. 8,255,044, for example, displaying received parameters and processed data, and monitoring system status and reporting fault conditions. The touch screen display 28 is preferably equipped with a graphical user interface (GUI) capable of communicating information to the user and receiving instructions from the user. The display 28 and/or base 29 may contain patient module interface circuitry that commands the stimulation sources, receives digitized signals and other information from the patient module 23, processes the EMG or MMG responses to extract characteristic information for each muscle group, and displays the processed data to the operator via the display 28.

[0076] As seen in FIGS. 3-21, the probe 20 comprises a head 30 adapted to be held in the hand of the surgeon for manipulation of the probe, an elongate body 31 secured at its proximal end to the head, and a tip 32 secured to the distal end of the body for forming a hole in a pedicle P.

[0077] The body 31 is made up of a central shaft 33 enclosed in a sleeve or sheath 34. In a preferred embodiment the shaft and tip are made of an electrically conductive material (e.g. a suitable metal), and the sheath is made of an electrically non-conductive material (e.g. plastic). As shown in FIGS. 7 and 16-19, the sheath is slid over the shaft from the distal end of the shaft and the proximal end of the sheath is threaded at 34′ or otherwise configured for attachment to the head. An inturned lip or shoulder 35 at the distal end of the sleeve engages against the distal end of the shaft to hold the shaft rearwardly against the head.

[0078] The tip 32 is attached to the distal end of the shaft by engagement of a shaped end 36 on the tip with a complementally shaped opening and retainer 37 in the distal end of the shaft 33 (see FIGS. 12, 13 and 20, 21).

[0079] As seen best in FIGS. 14 and 19, a center bore 40 extends through the length of the shaft 33 for receiving a k-wire 41 (see FIGS. 23 and 24) during minimally invasive surgery (MIS). This bore also serves for supply of an irrigating fluid to the surgical site when the k-wire is removed, and for aspirating the irrigating fluid and debris from the site. A second bore 42 extends through the shaft at one side of the center bore for receiving an endoscopic camera 43 and third and fourth bores 44 and 45 are on opposite sides of the center bore for receiving fiber optic light bundles 46 to illuminate the surgical site (see FIGS. 5B, 6B, 8 and 14).

[0080] The tip 32 has corresponding bores aligned with the bores in the shaft. See, for example, the irrigation/aspiration bore 47 in FIG. 8 and bore 48 in FIG. 13 for receiving the camera. The distal end of the tip is recessed or cut away at 49 to provide clearance for the camera and lights, and a transparent shield 50 is positioned on the tip at the proximal end of the cut away area in overlying relationship to the camera and light source.

[0081] The head 30 has a plurality of lateral ports in its side, including a port 51 for connection with a source 51′ of irrigating fluid, a port 52 for connection to a suction source 52′ for aspiration of fluid and tissue away from the surgical site, and a port 53 for insertion of the endoscope 43 into the bore extending through the shaft. A longitudinal bore 54 extends through the center of the head for receiving a k-wire (see FIG. 11). Cut-outs 55 are provided in the area immediately above the lateral ports to expose the proximal end of the shaft 33 so that a variety of EMG/MMG clips can be attached to the shaft. In the particular example shown, the sleeve 31 is connected to the head by a threaded connection 56 in the bottom of the head (see FIG. 11). Irrigation ports 61 in the tip 32 (see FIG. 6B) double as cutting flutes.

[0082] During a minimally invasive surgical procedure, depicted in FIGS. 22-26, a jamshidi 60 is used to form a pilot hole in a pedicle P (see FIG. 22), and a k-wire 41 is then inserted and the jamshidi removed (see FIG. 23). The probe of the invention is then put in place and the k-wire removed, as shown in FIG. 24. The surgeon then initiates irrigation and aspiration and applies axial pressure to the probe 26 while rotating it, visually observing until a safe and sufficient cannulation is present, as depicted in FIG. 25. The k-wire is then replaced and the probe removed as depicted in FIG. 26, after which the hole is tapped and a screw placed.

[0083] The endoscopic pedicle probe of the invention provides the surgeon with an illuminated, direct visual indication of the exact location of the probe and alerts the surgeon if a breach has occurred or is about to occur. It provides for flushing body fluids and debris away from the area being treated, whereby the hole can be formed with accuracy and precision.

[0084] The pedicle probe disclosed herein may be reusable, or the entire probe, inclusive or not inclusive of the endoscope, may be made disposable following a single use. Materials suitable for this purpose, such as hard plastics or carbon fiber, for example, may be used in the construction of the probe. In a preferred embodiment, as described herein, the probe shaft and tip are made of an electrically conductive material such as metal, and the sheath is made of a non-conductive material such as plastic.

[0085] While particular embodiments of the invention have been illustrated and described in detail herein, it should be understood that various changes and modifications may be made to the invention without departing from the spirit and intent of the invention as defined by the scope of the appended claims.