Lateral TTC Plate SURGICAL TECHNIQUE

Transcription

1 MAXLOCK EXTREME Lateral TTC Plate SURGICAL TECHNIQUE

2 Contents Overview 2 Exposure 3 Surgical Technique 4 Implants and Instruments Proper surgical procedures and techniques are the responsibility of the medical professional. The following guidelines are furnished for information purposes only. Each surgeon must evaluate the appropriateness of the procedures based on his or her personal medical training and experience. Prior to use of the system, the surgeon should refer to the product package insert for complete warnings, precautions, indications, contraindications and adverse effects. Package inserts are also available by contacting Wright Medical. Please contact your local Wright representative for product availability. Advantages Inferior Eyelet Anatomic Design Targeting Jig The plate s distal contour wraps plantarly and accommodates a 7.0 mm compression screw that is directed across both joints to provide outstanding compression and multiplanar stability Contours to the lateral aspect of the TTC joints for minimal bone sculpting and a low profile fit Construct specific instrumentation designed for the simple and reproducible placement of two percutaneus 7.0 mm cannulated MaxTorque Screws Overview A tibiotalocalcaneal (TTC) arthrodesis is one which includes the ankle and the subtalar joint. Generally, even substantial coronal and sagittal plane deformities can be corrected with a TTC arthrodesis alone. The indications for a TTC arthrodesis are arthritis with or without associated deformity of the ankle and subtalar joint, avascular necrosis of the talus, rheumatologic arthritis and deformity, and Charcot neuroarthropathy. The TTC arthrodesis should not be used as an alternative to an isolated ankle arthrodesis if arthritis and deformity is limited to the tibiotalar joint. The technique described below applies to both the tibiotalocalcaneal and a tibiocalcaneal (TC) arthrodesis where a partial or total talectomy is necessary. 2

3 Surgical Approach A lateral transfibular approach to the ankle and hindfoot is used for the arthrodesis and correction of deformity. This approach is particularly useful in the setting of severe deformity in either the sagittal or coronal plane or both. Exposure The incision is made vertically, directly over the fibula, extending down distally over the sinus tarsi toward the inferior aspect of the calcaneus. The sural nerve must be identified and then retracted inferiorly and posteriorly with the peroneal tendons. It may be necessary to retract the nerve and tendons anteriorly depending on the soft tissue, scarring and deformity. In some cases it is acceptable to cut the peroneal tendons, particularly where they are already torn, a common finding with a chronic varus hindfoot and ankle deformity. With the peroneal tendons retracted, the calcaneofibular and anterior talofibular ligaments are cut exposing the entire distal fibula. A fibulectomy is now performed. It is ideal to use the fibula for bone graft, and this can be morcellized following an osteotomy with a saw. Alternatively, a small acetabular reamer can be utilized prior to the fibulectomy to harvest the distal fibula. The reamer is applied with pressure to the fibula, and is used to completely denude and decorticate the bone leaving only a shell of the inner cortex behind and yielding copious cancellous graft. For application of the plate, it is necessary to remove 8-10 cm of the distal fibula. If the reamer was utilized prior to creating the fibular osteotomy, the remaining fibula is cut more proximally with a saw and discarded. The lateral aspect of the calcaneus must partially be exposed in order to visualize the plantar lateral margin of the calcaneus for apposition of the plate. The approach for preparation of the joint surfaces depends on the need for preservation of the anatomy and the presence of deformity. If there is minimal deformity present, then it is preferable to use a chisel to thoroughly denude the ankle and subtalar joints. One must be careful not to remove excess bone laterally from either joint since this will tilt the arthrodesis into valgus. If deformity is present, the joint surfaces can be prepared by making flat cuts with a saw. A wide fan shaped saw blade is used while protecting the soft tissue on the posterior and anterior ankle with malleable retractors. The saw is oriented perpendicular to the tibial shaft and the cut, is conducted in order to remove approximately 2 mm in the center of the joint increasing to about 5 mm anteriorly and 7 mm posteriorly (depending on the presence of osteophytes in the anterior and posterior ankle). Then while holding the ankle in neutral dorsiflexion and 5-7 degrees of valgus, a parallel flat cuts are made on the dome of the talus removing approximately 5 mm of bone. Depending on the ability to obtain a plantigrade foot and a neutral position of the ankle, the medial malleolus may be cut obliquely through a separate incision on the medial ankle. This cut is made obliquely so that it exits at the level of the tibial plafond. This osteotomy will permit easy translation of the talus under the tibia in any direction to facilitate deformity correction. Once the foot is in a neutral position under the tibia, the neutral position should be verified under fluoroscopy and provisionally maintained by two crossing guide wires. The lateral flare of the distal tibia will require ostectomy with a chisel or osteotome to allow the plate to sit flush on the bone surface. 3

4 Surgical Technique Special Note: The Lateral TTC Plate Caddy is intended to be used in conjunction with both the MAXLOCK EXTREME System and the MaxTorque System. Ensure all sets are available for use at the time of surgery. Step 1 After the appropriate joint preparation has been achieved, position the plate over the lateral aspect of the TTC joint complex. Insert the plate deep with respect to the peroneal tendons (the tendons can be excised if torn) in order to avoid compromising either skin closure or ultimate peroneal function. Once the desired position is achieved, the plate can be provisionally fixed by a combination of k-wires and olive wires. Generally, placing Olive Wires in slotted holes over the tibia and in one of the calcaneal screw holes will be sufficient to secure the plate and ensure good bony apposition. Place olive wires in the most proximal portion of the slotted holes. This will allow for compression in subsequent steps. Note: In order for the plate to lie flush on the calcaneus, talus and tibia, it may be necessary to shave down prominent ridges and osteophytes particularly along the distal metaphysis of the tibia. Re-apply the plate and re-contour with a saw until the plate lies flush with the lateral bone surfaces. Note: If needed, the TTC Distal Plates are available for smaller anatomy. The TTC Distal Plates have a modified distal geometry and hole positions to accommodate additional patient populations or reduced talar body height. Standard TTC Plate Distal TTC Plate Step 2 4 Attach the Primary Targeting Guide to the plate. The threaded insert in the targeting guide will thread into the central hole over the talus as shown. The distal portion of the guide will sit outside the incision and wrap under the inferior aspect of the calcaneus. This guide will facilitate the insertion of a MAXTORQUE 7.0 mm screw from the calcaneus into the tibia.

5 Step 3 Assemble the Guide Wire Insert into the distal head of the Targeting Guide as shown. The Insert is orientation specific and will not fit into the Targeting Guide if it is not oriented correctly. Step 4 Insert the 2.3 mm Guide Wire from the MAXTORQUE set through one of the holes in the Guide Wire Insert. This guide wire will be utilized for the placement of a 7.0 mm MaxTorque cannulated compression screw that spans both the subtalar and ankle joints. The Guide Wire Insert has three options labeled #1, #2 and #3 with graduations of 5. The appropriate option will depend on the height of the talus. The intended trajectory is such that the wire exits the medial tibia just superior to the medial malleolus. Select the angle that best captures the distal medial tibia and confirm under fluoroscopy. Note the selected hole number as this will determine the available options for subsequent homerun screw placement. 5

6 Step 5 Following fluoroscopic verification of the Guide Wire position, remove the Guide Wire Insert by pulling it over the guide wire. Step 6 Use the provided depth gauge to determine the appropriate length for the cannulated screw. Ensure the depth gauge is fully seated against the bone when taking the reading. Consider the amount of compression to be generated when selecting a screw length. A shorter screw than indicated by the depth gauge may be required. Step 7 Use the 4.7 mm cannulated drill bit to perforate the calcaneus, talus and the cortical edge of the distal tibia. Step 8 Using the MAXTORQUE 7.0 Driver, insert the desired length 7.0 mm short thread screw to compress across both the ankle and the subtalar joints. The olive wires within the slotted holes in the tibia may remain in place to ensure good apposition of the plate is maintained during compression. All other provisional fixation should be removed prior to final tightening to ensure maximum compression is achieved. 6

7 Optional Secondary 7.0 mm Screw Insertion (steps 9 13) The Secondary Targeting Guide can be used if a second 7.0 mm homerun compression screw is desired. This guide will allow placement of a 7.0 mm homerun screw through the center of the calcaneus into the anterior aspect of the distal tibia and will prevent collision with the primary screw. The guide is designed to introduce the guide wire into either the posterior calcaneus or anterior aspect of the distal tibia, depending on surgeon preference. Step 9 Insert the Secondary Targeting Guide through the hole corresponding to the operative side in the Primary Targeting Guide. Adjust the shaft to the desired position and fix in place by tightening the Hexalobe Lock Nut using the MAXTORQUE 7.0 mm Driver. Step 10 The Secondary Targeting Guide provides three hole options labeled #1,#2, and #3 for the position of the secondary 7.0 mm screw. To ensure no collision, use an equal or lesser hole number than was previously used for the primary 7.0 mm screw in Step 4. For example, if the #2 hole was used in Step 4, the holes labeled 1 or 2 may be used for the positioning of the secondary 7.0 mm screw. Insert a 2.3 mm k-wire through the desired guide hole as the desired exit point in just superior to the anterior flare of the distal tibia. Drive the wire across both joints and confirm under fluoroscopy. 7

8 Step 11 Following fluoroscopic verification of the position of the guide wire, remove the entire targeting guide assembly. Step 12 Measure using the provided depth gauge and insert the desired length 7.0 mm short thread screw. Note: The depth gauge reading corresponds to the working length of the screw (from distal tip to underneath the screw head). Step 13 Use the 4.7 mm cannulated drill bit to perforate the calcaneus, talus and the anterior cortical edge of the distal tibia. Step 14 Use the MAXTORQUE 7.0 driver to insert the desired length 7.0 mm short thread screw. The remaining plate screw holes may be filled with either MAXLOCK EXTREME 3.5 mm Fixed-Angle Locking Screws, 3.5 mm Non- Locking Screws or 4.0 mm Non-Locking Screws as desired based on the need for stability and fixation. Note: Screw holes that line the main body of the plate lie on the same plane and have the potential for interference with the primary 7.0 mm screw. In addition, the posterior talar screw holes lies on the same plane as the secondary 7.0 mm screw. For this reason, if adjuvant fixation is needed, these holes should be drilled and filled with caution to avoid damage to installed hardware. Step 15 To drill for locking screws, use either the fixed drill guide or the Keyway Drill Guide. The fixed drill guide threads into the locking hole to provide the proper angle for drilling. To use the Keyway Drill Guide, align the lobes on the tip of 8

9 the guide with the lobes in the threaded hole and press into the plate while drilling to ensure proper alignment. Step 16 Using the 2.4 mm drill bit drill to the desired depth. Take care to not move the plate after drilling for a fixed angle locking screw in order to maintain the proper pilot hole alignment and prevent locking screw cross-threading. Lateral View of Final Construct Posterior View of Final Construct Step 17 Measure using the provided depth gauge and insert the appropriate length screw using the HEXSTAR driver. Step 18 If desired, non-locking screws may be placed in the slots or any threaded hole. Use the 2.7 mm drill bit and 2.7 mm drill guide to prepare a pilot hole for a 4.0 mm non-locking screw. Measure with the provided depth gauge and insert an appropriate length screw using the HEXSTAR driver. 9

10 Ordering Information IMPLANTS Plates Description Part # Right Lateral Plate ANK-002-TTCR Left Lateral Plate ANK-002-TTCL Right Lateral Distal Plate ANK-002-TTCR-D Left Lateral Distal Plate ANK-002-TTCL-D Screws Description Part # ø7.0 mm Screw MSD XXX ø3.5 mm Fixed-Angle Locking Screw MFT XX ø3.5 mm Non-Locking Screw MFT XX ø4.0 mm Non-Locking Screw MFT XX 10

11 INSTRUMENTS Description Part # ø2.3 mm Guide Wire CSS ø2.3 mm Threaded Guide Wire CSS T ø1.1 mm K-Wire MFT SS Threaded Olive Wire XL MFT-040T-XL ø4.7 mm Drill Bit CSS ø4.7 mm Square Drill Bit CSS SQ ø2.4 mm Drill Bit MFT ø2.7 mm Drill Bit MFT Lateral Targeting Guide ANK-167 Lateral K-Wire Guide Insert ANK Lateral Secondary Targeting Guide ANK Lateral Primary Targeting Guide ANK Lateral Primary Targeting Guide Healobe Lock Nut ø2.3 mm Drill Bit Sleeve (available by request) ANK ANK

12 1023 Cherry Road Memphis, TN Nesbitt Avenue South Bloomington, MN Trademarks and Registered marks of Wright Medical Group N.V. or its affiliates Wright Medical Group N.V. or its affiliates. All Rights Reserved. ANK Rev B ECN Apr-2016