DARCO LPS Plate SURGICAL TECHNIQUE
Contents Preface 3 Chapter 1 4 Chapter 2 5 5 6 7 9 Appendix 10 10 11 Design Rationale Preoperative Planning Surgical Technique Surgical Approach Joint Preparation Surgical Fixation Closure and Post-op Protocol Ordering Information DARCO Implants DARCO Instruments Proper surgical procedures and techniques are the responsibility of the medical professional. The following guidelines are furnished for information purposes only as techniques used by the describing physicians. 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 Technology, Inc.
Design Rationale Peface The DARCO LPS Locked Plate offers an innovative, stable method of fixation for fusion of the 1st tarsometatarsal (TMT) joint. Advantages of Lapidus Procedure with DARCO LPS Locked Plate»» Extremely stable locked-screw fixation.»» Incremented step-off design permits accurate plantarization of the metatarsal to counter 1st ray shortening.»» Low profile, anatomically contoured plate minimizes soft tissue irritation due to hardware prominence.»» Pre-determined locked screw positions eliminate screw collision, potentially shortening operative time. DARCO LPS Plate 3
Preoperative Planning Surgical Technique as described by Christopher F. Hyer, DPM; Greg Berlet, MD; Thomas Lee, MD; and Ernst Orthner, MD chapter 1 In addition to standard small-joint instrumentation, the following items should be planned for in the operating room:»» intra-operative flouroscopy»» powered handpiece with k-wire driver, jacobs chuck and sagittal saw»» straight and curved osteotomes of varying widths»» straight and curved bone curettes»» bone graft substitute, as indicated by procedure, such as Wright Medical ALLOMATRIX DR Bone Graft Substitute. If the surgeon desires a porous block graft, Wright Medical CANCELLO-PURE Wedges are appropriate. 4 Chapter 1 Preoperative Planning
Surgical Technique chapter 2 Surgical Approach Plan a dorso-medial approach to the proximal 1st TMT, just medial to the EHL tendon. The approach should extend 2-3 cm on either side of the TMT. Figure 1 Create the skin incision taking care to identify and protect any overlying neurovascular structures. Deepen the incision through the fascial layers to the dorsal capsule of the TMT; use blunt dissection to release the EHL off the TMT and retract the tendon laterally. Figure 2 Confirm the location of the 1st TMT joint either directly or using flouroscopy; a 22g needle or k-wire may be used to mark the joint. Figure 3 Perform a capsulotomy at the superior aspect of the 1st TMT to expose the entire joint. Care should be taken to ensure complete exposure of the plantar and lateral aspects of this joint, which is quite deep. Figure 4 A pin-based distractor can be used for easier joint debridement. Figure 1 Figure 2 Figure 3 Figure 4 Chapter 2 Surgical Technique 5
Joint Preparation Take down the cartilage of the 1st TMT joint using a ¼ inch curved osteotome and bone curettes. Remove the cartilage thoroughly until dense subchondral bone is completely exposed on both sides of the joint. Figure 5 Thoroughly perforate the subchondral plates with a small diameter drill or k-wire until rich cancellous bone is exposed. Figure 6 The ¼ inch osteotome is then used to perform a fish scaling technique to further prepare the joint surfaces. At the surgeon s discretion, the intermetatarsal joint between the 1st and 2nd bases may be similarly prepared. This is done to allow some lateralization of the 1st metatarsal (MT) base and create an additional fusion surface for added stability. ALLOMATRIX DR Bone Graft is used to thoroughly grout the fusion sites, filling any voids or incongruities. Figure 7 Figure 5 Figure 6 Figure 7 6 Chapter 2 Surgical Technique
Surgical Fixation Three separate fixation elements are used to facilitate proper correction and fixation of the TMT joint:»» A 3.5 or 4.0mm cannulated compression screw, directed from the base of the 1st MT into the cuneiform. The screw applies compression across the TMT joint prior to fixation of the locked LPS plate.»» The LPS plate itself, which determines plantarization of the MT base and provides definitive fixation.»» A provisional k-wire, placed distally between the 1st and 2nd MT. This wire may be used to close and adjust the intermetatarsal angle. Compression Screw Wire Drive the wire for the cannulated screw through the center of the TMT joint, out the medial plantar aspect of the MT, and out through the skin. Figure 8 Advance the wire until countersunk in the joint; it will be retrograded back into the cuneiform in a later step. Provisional Plate Placement If the 1st ray has any shortening, translate the base of the MT plantarly to compensate. Select the LPS plate that has the corresponding amount of stepoff. Place the plate dorsally over the TMT joint and provisionally fix with 2 k-wires; make sure that the distal k-wire is placed at the most distal extent of the compression slot. Figure 9 (In the case of Metatarsus Primus Varus, the plate may also be placed dorso-medially, which would translate the MT base both plantarly and laterally). Intermetatarsal Angle Adjustment Correct widening of the 1st intermetatarsal angle by using a k-wire distally between the 1st and 2nd metatarsals. Figure 10 Verify correction flouroscopically. Figure 8 Figure 9 Figure 10 Chapter 2 Surgical Technique 7
Cannulated Screw Placement Holding the great toe in dorsiflexion, retrograde the screw k-wire proximally from the MT into the cuneiform under flouroscopic guidance until in contact with the lateral/proximal cortex. Figure 11 Percutaneously place cannulated compression screw per normal protocol. Figure 12 Plate Fixation Recheck the positioning of the Darco LPS plate using fluoroscopy and adjust if needed. Thread the Locking Drill Guide (P/N DC4169) into one of the proximal screw holes; it is imperative to use the Locking Guide for locking screw application. Use the 2.5mm Drill (P/N DC5620) to drill through the guide. Figure 13 Bicortical fixation may be considered in the case of osteoporotic bone, but is generally not required with locked plating systems. Measure using the Depth Gauge (P/N DC4263-2) Figure 14 and advance the appropriate screw until flush with the plate. Figure 15 Figure 11 In the event that a locking screw interferes with the cannulated compression screw, the drill may be redirected freehand within the screwhole and a nonlocking screw used in that location. Use caution going far off the normal drilling axis, as this may result in unwanted screw head prominence. Each of the 4 screws are inserted in the same fashion. If subtle contouring of the plate is required, both Locking Drill Guides can be used as in-situ benders. This method allows the plate to perfectly fit the anatomy while protecting the locking threads within the plate. Figure 12 Figure 13 Figure 14 Figure 15 8 Chapter 2 Surgical Technique
Closure and Post-op Protocol The incision is closed in layers per the surgeon s technique. A well-padded post-operative splint is recommended for the first 10-14 days as the incision heals. Post-operative care and time to weightbearing is the responsibility of the surgeon. Chapter 2 Surgical Technique 9
Ordering Information Appendix Kit List Part No. Description Quantity DMRSKITA DMRSKIT1 Implant Kit Instrument Kit Locked Screws DC 2820-014 14mm x 3.5mm 5 DC 2820-016 16mm x 3.5mm 5 DC 2820-018 18mm x 3.5mm 5 DC 2820-020 20mm x 3.5mm 5 DC 2820-022 22mm x 3.5mm 5 DC 2820-024 24mm x 3.5mm 5 DC 2820-026 26mm x 3.5mm 5 DC 2820-028 28mm x 3.5mm 5 DC 2820-030 30mm x 3.5mm 5 DC 2820-035 35mm x 3.5mm 5 DC 2820-040 40mm x 3.5mm 5 Non-Locked Screws DC 2820-114 14mm x 3.5mm 2 DC 2820-116 16mm x 3.5mm 2 DC 2820-118 18mm x 3.5mm 2 DC 2820-120 20mm x 3.5mm 2 DC 2820-122 22mm x 3.5mm 2 DC 2820-124 24mm x 3.5mm 2 DC 2820-126 26mm x 3.5mm 2 DC 2820-128 28mm x 3.5mm 2 DC 2820-130 30mm x 3.5mm 2 DC 2820-135 35mm x 3.5mm 2 DC 2820-140 40mm x 3.5mm 2 Instruments and accessories DC 35 Box System tray assembly 1 DC 70-481 Bending forceps 1 DC 4157 Bending iron 1 DC 4169 Drill guide 2 DC 4263-2 Depth gauge 1 DC 4197 Forceps 1 DC 4261 Screwdriver, hexagonal, cannulated 1 DC 5136 Drill bit, 2.5mm 2 DC 5620 Cannulated drill bit 2.5mm 1 NO 2228-012 K-wire 140 1.1mm 6 DC 4584 Screw holding and bending iron 1 10 DARCO LPS Plate
Part No. Description Placement in Trays LPS (Lapidus Plating System) DC 2801-000 0mm step DC 2801-001 1mm step DC 2801-002 2mm step DC 2801-003 3mm step DC 2801-004 4mm step DC 2801-005 5mm step DC 2801-006 6mm step PIA (Poly Interpositioning Arthrodesis) DC 2802-000 0mm spacer DC 2802-002 2mm spacer DC 2802-004 4mm spacer DC 2802-006 6mm spacer DC 2802-008 8mm spacer UPS 3.5 (Universal Plating System) DC 2801-012 12mm DC 2801-016 16mm DC 2801-020 20mm DC 2801-024 24mm DC 2801-030 30mm RPS (Rearfoot Plating System) DC 2803-006 37mm, 6 holes DC 2803-008 50mm, 8 holes DC 2803-014 66mm, 14 holes AFP (Arthrodesis Flat Plate) DC 2804-004 12mm DC 2804-005 14mm DC 2804-006 16mm DPS (Displacement Plating System) DC 2806-106 6mm step DC 2806-108 8mm step DC 2806-110 10mm step 0 1 2 3 4 5 6 0 2 4 6 8 12 16 20 24 30 66 37 50 12 14 16 6 8 10 CPS (Calcaneus Plating System) DC 2805-001 S: 54mm DC 2805-002 M: 64mm DC 2805-003 L: 74mm L M S DARCO LPS Plate 11
Additional Products For Bone Voids, Use Allomatrix DR Peri-articular graft 86DR-0300 3cc For Bone Grafting, Use CANCELLO-PURE Wedge 9600-1072 For Ligament Reinforcement, Use Graftjacket Matrix Maximum Force Regenerative Tissue Matrix 8600-4X07 4x7cm Non-meshed Wright Medical Technology, Inc. 5677 Airline Road Arlington, TN 38002 901.867.9971 phone 800.238.7188 toll-free www.wmt.com Wright Medical EMEA Krijgsman 11 1186 DM Amstelveen The Netherlands 011.31.20.545.0100 phone www.wmt-emea.com Trademarks and Registered marks of Wright Medical Technology, Inc. DARCO is a licensed trademark of Wright Medical Technology, Inc. Patents pending. 2007 Wright Medical Technology, Inc. All Rights Reserved. SO 278-807