Process and instrumentation for arthroscopic reduction of central and peripheral depression fractures

[0002] 1. Field of Invention

[0003] This invention relates to surgical processes and instrumentation for the repair of a specific type of fracture found in human and animal joints.

[0004] 2. Discussion of Prior Art

[0005] In the field of Orthopaedic surgery, patients frequently present with serious depression fractures of the articulating surfaces in joints. Such trauma is relatively common in the articulating surfaces of the femoral condyles and the tibial plateau. These fractures result from overloading the joint surfaces during falls, automobile accidents, sports play and other high impact situations. The extreme pressures of the impact actually overload the strength of the joint articulating surfaces, causing one joint surface to be driven into the other joint surface; commonly the rounded condyles into the more planar surfaces of the tibial plateau. Here-to-fore, surgeons needed to incise the joint wide open to repair such depression fractures. Even though it has been widely known and accepted to do joint repairs with a minimum of invasion, there was no technique available which was reduced to the combination of a process and a set of specially designed instruments.

[0006] Mention of the desirability of an Arthroscopic procedure for reducing depression fractures is found in the medical book “Orthopaedic Trauma Protocols” Eds. Sigvard T. Hansen, Jr. and Marc F. Swiontkowski both of Harborview Medical Center; Publisher, Raven Press, Ltd., New York, N.Y. An additional publication, Technique for Arthroscopic Fracture Management System, a commercial advertising flyer put out in 1995 by Acufex Microsurgical Inc., suggests that using a device called an “intra-articular guide” (which is sold by Acufex Microsurgical, and was designed for other procedures) will aid surgeons to reduce intra-articular fragments. This literature does not suggest instruments for remotely manipulating bone fragments, nor does it speak to a process for adjusting the level of the articular surface to make it anatomically correct.

[0007] Nowhere in the literature is there mention of a cohesive procedure and/or set of instruments for actually performing an Arthroscopic reduction of an articular depression fracture. Further, nowhere is there the suggestion that a depression fracture may be reduced arthroscopically by a lateral approach.

[0008] Accordingly, several objects and advantages of our invention are:

[0009] The object of this invention is to provide a process and the required instruments to enable a surgeon to repair depression fractures through an incision only 1 to 2 cm long. This is an Arthroscopic procedure with a minimum of invasion. In addition to the 1 to 2 cm incision in the above sentence, there are typically two more incisions (standard Arthroscopic portals) ½ cm long; the second one for the arthroscope and the third for irrigation.

[0010] The combined procedure and hardware of this invention allows a skilled surgeon to accomplish an Arthroscopic reduction of an articular surface depression fracture in a joint, with only limited incisions, using a lateral approach. This procedure and instrument system allow a surgeon to affect a reduction of depression fractures, especially those of the central and peripheral tibial plateaus, without opening wide the knee. Further, this technique does not require soft tissue stripping.

[0011] The same above mentioned incisions are used again when bone grafting any bone deficit. All necessary bone grafting is performed using the procedure and two of the instruments of this invention.

[0012] This procedure and instrument system further allows a surgeon to fixate a loose body fracture fragment. Only one 1 to 2 cm incision and the usual Arthroscopic portals are required, that is, the procedure is performed arthroscopically. Previous surgical techniques required a very extensive incision; opening the entire knee.

[0013] This invention saves time. It requires much less time to open and close a 1 to 2 cm incision than a 25 cm incision.

[0014] This invention saves trauma. Much less damage is done to soft tissue; muscles and tendons and ligaments need not be resected. This surgery has very minimal invasion. Previous surgical techniques required much greater invasion. Increased scarring and devascularization are associated with extensive invasion.

[0015] This invention reduces rehabilitation time. The standard incision, such as cutting a knee wide open, requires that all of the affected tissues be dissected or split. Rehabilitation then requires that all of the affected tissue heal and revascularize. This healing, growing back, is time consuming. The patient is uncomfortable and out of the work force.

[0016] This invention may reduce future joint problems. It is widely known that articular surface irregularities lead to early arthritis. In the medical community it is well known and accepted that Arthroscopic surgery is less traumatic to the patient than major invasive open surgery. Less trauma means that there is less rehabilitation.

[0017] Further objects and advantages of our invention will become apparent from a consideration of the drawings and ensuing description.

[0018] FIG. 1 is a perspective drawing of the seven instrument set of this invention.

[0019] FIG. 2 shows instrument #2, the regular metaphyseal reduction instrument, pushing up a depressed central tibial plateau articular surface.

[0020] FIG. 3 shows instrument #7, the bone graft reservoir with impacter, inserted into the lateral supra-fibular incision in the knee, described in this process.

[0021] FIG. 4 shows details of the ends of the probes in instruments #'s 2, 3 and 4.

[0022] 1. Disimpacter

[0023] 2. Regular Metaphyseal reduction Instrument

[0024] 3. Great Curvature Metaphyseal Reduction Instrument

[0025] 4. Curved Dome Metaphyseal Reduction Instrument

[0026] 5. Intra-articular Counter Reduction Instrument

[0027] 6. Bone Graft Impacter

[0028] 7. Bone Graft Reservoir

[0029] 7a. Bone Graft Reservoir with Impacter inserted

[0030] 8. Probe

[0031] 9. Handle

[0032] 10. Planar surface of instruments #2 and 3, diamond grooved

[0033] 11. Hemispherical surface of instrument #4, diamond grooved

[0034] The invention of this specification is the combination of a process and the required instruments to arthroscopically reduce a depression fracture of an articulating surface in a human or animal joint. Specifically, this invention allows a surgeon to reduce depression fractures of the central and peripheral tibial plateau, with a minimum of invasion and trauma. The surgery is Arthroscopic, performed through a 1 to 2 cm incision and several standard ½ cm Arthroscopic portals.

[0035] FIG. 1 shows a perspective view of the instrument set used to affect the process of this invention. The instruments, numbers 1 through 5 have rod-like probes, #8, attached to handles, #9. The probes are sufficiently long to reach from outside the skin of the patient, to the depths of the damaged joint. Each probe is shaped to enable access to the joint inner anatomy. The terminal tip of each probe is shaped to perform a particular task.

[0036] To do an Arthroscopic reduction of a central or peripheral depression fracture of the tibial plateau, utilizing a lateral approach, make a 1 to 2 cm incision anterior and lateral to the fibular head. Using the C Arm for fluoroscopic observation, drill a 4.5 mm diameter hole through the lateral cortex of the tibia, at the approximate level of the epiphysis. This hole should be inferior to or at the level of the bone fragments which are resulting from the depression fracture. The purpose of this 4.5 mm hole is to afford access to the base of the fracture. Push instrument #1, the disimpacter, into the 4.5 mm hole, along the axis of the hole. (See FIG. 2.) The disimpacter has a rod shaped probe which has a flat end to push the bone. This flat end is angled relative to the axis of said probe. Work with the angular face of the instrument directed toward the desired final position of the bone fragments. As you manipulate, observing with the aid of the C Arm fluoroscope and arthroscope, gently force the compressed, depressed bone fragments up to the proper level (the anatomically correct level). This maneuver will create a void in the bone, when the instrument is removed. Observe the articular surface which was depressed by the extreme forces of the accident. It is now necessary to level any area and make it anatomically correct, as before the fracture. Refer to FIG. 1. Instruments numbers 2, 3, and 4 have curved probes. The probes terminate in faces shaped specifically to enable the user to access and manipulate the bone stock upward from beneath the articulating surface. Refer to FIG. 4, #'s 10 and 11. The faces of the probes of instruments 2 and 3 are planar and are angled relative to the axis of curvature. These faces are further grooved in a “diamond” pattern to enhance manipulation of bone fragments. See FIG. 4. Select from these instruments the one or more which provide access to the region beneath the tibial plateau where it must be manipulated. For a more proximal region, select instrument #2. For a rather more distal region, select instrument #4. Instrument #3 may be used for intermediate regions. Note again that each of the instruments has an end which is textured and treated to facilitate the remote manipulation of bone fragments. Instrument #4 has a probe of a substantially long radius. Said probe is terminated in a hemisphere. FIG. 4, #11. The surface of this rounded end is grooved in a “diamond” pattern. Instrument #5, the intra-articular counter reduction instrument, is used to smooth out the articular surface. The probe of instrument #5 is rod shaped, with the distal portion of the rod shaped to a flattened curve. Said shape facilitates smoothing of the damaged articular surface to an anatomically correct shape. To use this instrument, enter it into a hole above the articular surface, in the joint space. One of the two holes in the joint space which are used for irrigation and arthroscoping may be used for this process. Observing with the aid of the arthroscope and the fluoroscope of the C Arm, smooth down the freshly pushed up articular surface so that it is anatomically correct. It may be necessary to simultaneously push up from beneath the fracture with either instrument #2 and or 3 and or 4 as you smooth down the articular surface with instrument #5. It may also be necessary to re-attach (fixate) a bone fragment with a fastener (bone screw). When the surface is anatomically correct, withdraw the instruments. At this time, there will be a void in the bone (a bone deficit). This void will be filled by performing a bone graft.

[0037] Prepare a quantity of morselized bone material to use in a bone graft. Place this bone grafting material into the bowl of the bone graft reservoir cup, instrument #7, FIG. 1. Insert the small tube of the bone graft reservoir cup into the 4.5 mm hole in the tibia. Refer to FIG. 3. Push the bone graft impacter, instrument #6, into the small hole in the bone graft reservoir cup, see FIG. 1, # 7a. A hole in the bottom of the cup communicates with a lateral hole in the cup into which the bone graft impacter has been entered. Bone graft material settles down said communicating hole into this lateral hole, and the bone graft impacter then pushes the bone material through the tube into the hole and ultimately into the bone deficit in the subject tibia. Having pumped the appropriate quantity of morselized bone material into the bone deficit, remove the bone reservoir. The fresh bone graft may require fixation by a bone screw and small plate or washer. If there is a loose bone fragment which requires fixation, it is possible to use the same fastener for both the loose body and for covering the hole into which the bone graft was pumped.

[0038] Thus, the reader will see that this invention, the process and instrumentation for Arthroscopically reducing central and peripheral depression fractures of the joints, provides the surgeon both the tools and method for cutting surgical time, reducing trauma, and enhancing recovery. Arthroscopy is widely accepted today as a valuable new technique in surgery. The process and hardware of this invention is a breakthrough in joint surgery.

[0039] While our above description contains many specificities, these should not be construed as limitations on the scope of the invention, but rather as an exemplification of one preferred embodiment thereof. Many other variations are possible. For example, the curves of the instruments may vary in radius, as may the angles. The diameter of the individual probes may be smaller or larger. The number of instruments may vary so as to include compound angles, compound curves for ease of access. There may be fewer instruments. The materials may vary, to include other metals, and even plastics. A probe may be articulated so as to afford bone manipulation telemanually. The bone graft reservoir may include a grinder, to particulate the bone. The instruments may be of use in approaches other than lateral. The process and instruments may be used in joints other than tibial/femoral.

[0040] Accordingly, the scope of the invention should be determined not by the embodiment(s) illustrated, but by the appended claims and their legal equivalents.