Ascension PyroCarbon Lunate suture anchor surgical technique Transforming Extremities
table of contents Product Information..........................................................1 Introduction to PyroCarbon Product Description Indications/Contraindications Surgical Guidelines...2 Postoperative Care...5 System Catalog Numbers...Back Cover instrumentation Lunate Sizing Templates Radiopaque Lunate Trials ESSENTIAL PRODUCT USE INFORMATION: For Device Description, Warnings, Precautions and other important information pertaining to the use of this product, please turn to page 5. This information was current at the time of surgical technique printing, but may have been revised after that date. The most current information is available in the product package insert or online at www.ascensionortho.com.
product information Bone-Friendly PyroCarbon PyroCarbon is a specific form of carbon that has been tailored for durability and compatibility. PyroCarbon has portions of 2-D and 3-D crystalline structures, resulting in excellent strength and wear properties between those of graphite and diamond. PyroCarbon should not be confused with carbon fibers, which are minute particles used to strengthen other materials. Pyrolytic Carbon Manufacturing Process Raw Graphite Material Precision Machining Radiopaque Graphite Substrate The elastic modulus of PyroCarbon is very similar to cortical bone resulting in biomechanical compatibility with bone. Unlike surgical grade metals, PyroCarbon transfers load from implant to bone more effectively, thus reducing stress shielding and potential bone resorption. 1 CVD Reaction Chamber Substrate Coating PyroCarbon exhibits exceptional wear performance against bone compared to ceramic and metals. After cyclical testing to 5,000,000 cycles, PyroCarbon demonstrated minimal wear into cortical bone. It was not possible to test the other materials past 375,000 cycles with Cobalt Chrome, 50,000 cycles with Titanium and 25,000 cycles with Zirconia because the bone specimens had worn away. 2 Product Description The Ascension PyroCarbon Lunate is an anatomically designed lunate replacement with essentially the same shape as the native lunate bone. The Lunate implant acts as an articulating spacer to maintain the relationship of adjacent carpal bones after excision and to maintain mobility of the wrist. The articular concavity that captures the capitate is more exaggerated to enhance stability. The Ascension Pyrocarbon Lunate is constructed of a high strength On-X PyroCarbon layer deposited on a graphite substrate. The graphite is impregnated with tungsten making the Lunate implant radiopaque. The Ascension Pyrocarbon Lunate is available in 5 sizes for use in left or right applications. Indications For Use The Ascension PyroCarbon Lunate is intended for replacement of the lunate bone in the proximal carpal row of the wrist in the presence of: Avascular necrosis (Kienboch s disease) Localized osteoarthritic changes Long-Standing dislocations Contraindications Acute or Chronic infection Radial scaphoid arthritis Gross carpal instability Radiolucent Carbon Coating Cortical Bone 23 PyroCarbon Titanium Zirconia CoCr Alloy 29.4 105 210 230 Elastic modulus of metal and ceramic are much greater than that of bone or PyroCarbon. Wear Penetration Rate into Bone (nanometer/cycle) Cyclic Wear Test Against Bone 0 10 20 30 40 5,000,000 cycles 0.2 Polishing 375,000 cycles 4.3 50,000 cycles 30.4 Finished Implant 25,000 cycles 34.7 PyroCarbon CoCr Titanium Zirconia 1. Cook SD, Klawitter JJ, Weinstein AM. The influence of implant elastic modulus on the stress distribution around LTI carbon and aluminum oxide dental implants. J Biomed Mater Res 1981;15:879-887. 2. Strzepa P, Klawitter JJ, Ascension PyroCarbon Hemisphere Wear Testing Against Bone, Poster No. 0897, 51st Annual Meeting of the Orthopedic Research Society. 1
surgical guidelines Step 1: Skin Incision Make a 7-10 cm midline dorsal longitudinal incision across the radiocarpal area. FIGURE 1. The third extensor compartment is incised and then elevated to create and ulnarly based flap of the fourth compartment roof and a radially based flap of the second compartment roof. FIGURE 2. Care is taken to identify and protect the dorsal radial and ulnar sensory nerves. The extensor pollicis longus is retracted radially while the extensor digitorum communis tendons are retracted ulnarward. Surgical Pearl: It is recommended to support the wrist on a modest bump to induce a small degree of flexion. Step 2: Capsulotomy Specific landmarks are identified and palpated on the wrist. These mark the placement of the capsular incision. Caution is taken to protect the terminal branch of the posterior interosseous nerve. Figure 1 Landmarks: 1. The midpoint of the dorsal radiocarpal ligament attachment to the radius. 2. The dorsal tubercle of the triquetrum. 3. The sulcus between the scaphoid and the trapezoid. The landmarks listed above are marked, and the surgeon connects the dots with a full thickness incision. FIGURE 3A. This capsular incision reveals the longitudinally split fibers of the DIC and DRC ligaments. Once the ligament-splitting incisions are made, the capsulotomy can be completed by following the dorsal rim of the radius to the level of the styloid process. When the radio-carpal capsulotomy is complete, the radially based flap of capsule is tangentially elevated off the dorsal surfaces of the capitate and lunate. Surgical Pearl: After the capsulotomy has been created, the surgeon should closely examine the scaphoid fossa within the radius. If there is evidence of significant arthritis, the procedure should be abandoned for an alternative wrist salvage procedure, as ongoing pain will continue at the radioscaphoid fossa despite replacement of the lunate. Figure 2 Figure 3A 2
ALTERNATIVE CAPSULOTOMY: The wrist is palpated and marked prior to elevation of the dorsal capsular flap, which will then provide access to the radiocarpal and midcarpal joints. The distal margin of Lister s tubercle is identified, and a J shape line is drawn toward the dorsal tubercle of the triquetrum. An incision is then made to follow this line, extending from the distal margin of Lister s tubercle obliquely toward the dorsal tubercle of the triquetrum. FIGURE 3B. Alternative Capsulotomy This incision is designed to split the fibers of the radiocarpal ligament and preserve the branches of the posterior interosseous nerve within the flap. The capsular flap is then raised tangentially off the dorsal surface of the scaphoid, lunate, triquetrum, and the proximal portion of the capitate. If additional exposure is required, an additional cut may be made in line with the fibers of the dorsal intercarpal ligament extending from the triquetrum towards the trapezium. This will further expose the neck of the capitate and the waist of the scaphoid bone, if necessary for completion of the surgical procedure. Figure 3B Step 3: Resection of the Lunate The lunate is resected with great care to remove the lunate in-total if possible, to allow for easy assessment of implant size. FIGURE 4. If the lunate has experienced significant collapse or fragmentation, templating against the normal wrist is recommended. Step 4: Sizing The PyroCarbon Lunate comes in 5 sizes for the right and left hand. The deep concavity of the lunate straddles the head of the capitate distally. The shorter flat surface articulates with the scaphoid and the longer surface with the triquetrum. FIGURE 5. The Sizing Template provided can be used to help estimate the implant fit on the surfaces of the triquetrum, scaphoid, and capitate. FIGURE 6. Radiopaque Lunate Trials are also used to help with determining the correct size implant. Implant sizing should always start with the smallest trial incrementing up in size until a comfortable fit in the lunatectomy space is obtained. Surgical Pearl: Reference Gilula s lines and take care to avoid overstuffing the joint, as this can potentially distract the first carpal row and could result in excessive implant force loading and displacement. Figure 4 Larger Triquetral Smaller Scaphoid Figure 5 Figure 6 SIZING TEMPLATE Scaphoid Triquetrum 3
Step 5: Suture Anchor Placement SIZING TEMPLATE SURGICAL PEARL: It is recommended to position the suture anchors in the outer most corner of the sizing template to increase stabilization of the implant FIGURE 7. Triquetrum Utilizing the Sizing Template and a felt tip pen, mark drill points on the scaphoid which will allow insertion of two Mitek mini anchors with several strands of Number 2 Orthocord or similar permanent suture. (DePuy-Mitek, Johnson & Johnson). Two pilot holes are then drilled into the scaphoid, but the anchors are not placed until the triquetrum has been prepared. Figure 7 Scaphoid Attention is turned to the triquetrum surface. Using the Sizing Template, two marks are made using a felt tip pen. It is recommended the marks be placed on the outer most corner of the template to improve implant stability. FIGURE 8. A 2 mm drill is then utilized to prepare holes through the triquetrum to allow passage of two channels through the body of the triquetrum. Step 6: Implant Placement & Capsular Repair SURGICAL PEARL: Utilizing a 18 gauge spinal needle and tendon passer (Chia Passer, DePuy), or simple wire loop, may help facilitate the passage of the suture through the triquetrum. Figure 8 Before inserting the implant, the wound is thoroughly irrigated with saline solution to remove all debris. The PyroCarbon implant should not be handled with metal instruments. Two Mitek anchors are placed in the scaphoid; the suture material is passed through the PyroCarbon Lunate prosthesis and then passed through the previously created channels in the triquetrum. Note that the short flat surface articulates with the scaphoid and the long surface articulates with the triquetrum. FIGURE 9. The sutures that are passing through the implant and triquetrum are brought ulnarly and held snugly around the triquetrum. FIGURE 10. Confirmation X-rays are taken to ensure that the position of the lunate implant is satisfactory. Following conclusion of a satisfactory position confirmation, the two arms of the suture are tied snugly to each other to produce a stabilization of the lunate prosthesis. Scaphoid Figure 9 Figure 10 Triquetral 4
STEP 7: Closure The capsular flap is repaired with 2-0 Vicryl suture and the extensor retinaculum is repaired with 3-0 Vicryl suture. The skin incisions are now closed with 4-0 nylon suture. The wrist may be placed through a range of motion, and the Lunate position can be verified with X-ray imaging. Postoperative Care The extremity is elevated for 1-2 days, and the patient is instructed to move the shoulder and fingers. A sugar tong splint is applied for the first 3-5 days. This is then changed to a short arm cast. Wrist immobilization is maintained for 6-8 weeks. Skin suture can be removed at 2 weeks. Postoperative therapy should include isometric gripping and movements of the shoulder. Full usage of the wrist is resumed at 12 weeks, unless an intercarpal fusion was performed, which requires a longer casting period. essential product information IMPORTANT: The information presented below is also provided in the product package insert. This information was current at the time of surgical technique printing, but may have been revised after that date. The most current information is available in the product package insert or online at www.ascensionortho.com. DEVICE DESCRIPTION The Ascension PyroCarbon Lunate is an anatomically designed lunate replacement with essentially the same shape as the native lunate bone. The Lunate implant acts as an articulating spacer to maintain the relationship of adjacent carpal bones after excision and to maintain mobility of the wrist. The articular concavity that captures the capitate is more exaggerated to enhance stability. The Lunate implant has two suture holes which allow fixation of the implant to the adjacent scaphoid and triquetrium bones to provide temporary postoperative stability while a capsuloligamentous system forms around the implant. The Ascension Pyrocarbon Lunate is constructed of a high strength On-X PyroCarbon layer deposited on a graphite substrate. The graphite is impregnated with tungsten making the Lunate implant radiopaque. The Ascension Pyrocarbon Lunate is available in 5 sizes for use in left or right applications. INDICATIONS FOR USE The Ascension PyroCarbon Lunate is intended for replacement of the lunate bone in the proximal carpal row of the wrist in the presence of: Avascular necrosis (Kienboch s disease) Localized osteoarthritic changes Long-Standing dislocations CONTRAINDICATIONS Acute or Chronic infection Radial scaphoid arthritis Gross carpal inastability WARNINGS AND PRECAUTIONS WARNINGS Strenuous loading, excessive mobility, and articular instability all may lead to eventual failure by loosening, fracture, or dislocation of the device. Patients should be made aware of the increased potential for device failure if excessive demands are made upon it. Do not modify the Ascension PyroCarbon Lunate implant in any manner. Reshaping the implant using cutters, grinders, burrs, or other means will damage the structural integrity of the device. PRECAUTIONS Do not use the Ascension PyroCarbon Lunate in a joint where soft tissue reconstruction cannot provide adequate stabilization. Similar to the native lunate, the Ascension PyroCarbon Lunate attains stabilization from the surrounding capsuloligamentous structures. If soft tissue reconstruction cannot provide adequate stabilization, the device may dislocate or loss of motion may occur. Do not resterilize this device. Resterilization could lead to mishandling and surface damage that could result in implant fracture and/or particulate debris. Do not reuse this device. Reuse of this product may result in infection or other systemic complication that may affect the patient s overall health. Additionally, the reuse of this product could adversely affect function of the device. Any implant that has been damaged, mishandled, or removed from the sterile field may have surface damage that could result in implant fracture and/or particulate and should be discarded. Do not grasp the Ascension PyroCarbon Lunate implant with metal instruments, or instruments with teeth, serrations, or sharp edges. The Ascension PyroCarbon Lunate is made of pyrocarbon, which is a ceramic-like material. Mishandling implants could cause surface damage that reduces their strength which could result in implant fracture and/or particulate debris. Do not use metal suture/wire for implant fixation as damage to the implant may occur that reduces strength which could result in implant fracture and/or debris generation. The Ascension PyroCarbon Lunate has not been evaluated for safety and compatibility in the MR environment. The Ascension PyroCarbon Lunate has not been tested for heating or migration in the MR environment. STERILITY This implant has been sterilized by steam sterilization and is sterile in the unopened, undamaged package. If either the implant or the package appears damaged, or if sterility is questioned for any reason, the implant should not be used. Resterilization of this product is not recommended. ADVERSE EVENTS Potential adverse events reported with implants include pain, loosening, fracture, dislocation tendonitis, or infection. Injury to the surrounding nerves, blood vessels, tendons, or soft tissues can occur as a consequence of implanting this device. Surgical intervention may be required to treat adverse effects. MDR Reporting Reminder: Medical device manufacturers and users are required by law and regulation to report serious injuries and death. SURGICAL PROCEDURE A surgical technique brochure is available which outlines the basic procedure for device implantation and the use of specialized surgical instrumentation. It is the responsibility of the surgeon to be familiar with the procedure before use of these products. Each surgeon must evaluate the appropriateness of the surgical technique used based on personal medical training and experience. Instrumentation is provided to facilitate device implant. Prior to use, instrumentation must be cleaned and sterilized according to existing hospital procedures. TRAINING Surgeons should obtain training from a qualified instructor prior to implanting the Ascension PyroCarbon Lunate to ensure thorough understanding of the implantation and removal techniques and the instrumentation. Please contact Ascension Orthopedics Customer Service toll-free at 877-370-5001 (+1-512-836-5001) to arrange training with a qualified instructor. February 2011 5
Ascension PyroCarbon Lunate Additional upper extremity solutions: First Choice DRUJ System Ascension PyroCarbon CMC Arthroplasty Lunate Implants item / description PyroCarbon Lunate Implant, Size 01 PyroCarbon Lunate Implant, Size 02 PyroCarbon Lunate Implant, Size 03 PyroCarbon Lunate Implant, Size 04 PyroCarbon Lunate Implant, Size 05 catalog no. lun-710-01 lun-710-02 lun-710-03 lun-710-04 lun-710-05 Ascension PyroCarbon & Silicone MCP Joints Ascension PyroCarbon & Silicone PIP Joints Lunate Instrumentation item / description Lunate Trial, Size 01 Lunate Trial, Size 02 Lunate Trial, Size 03 Lunate Trial, Size 04 Lunate Trial, Size 05 Lunate Sizing Template, Size 01 Lunate Sizing Template, Size 02 Lunate Sizing Template, Size 03 Lunate Sizing Template, Size 04 Lunate Sizing Template, Size 05 catalog no. trl-715-01t trl-715-02t trl-715-03t trl-715-04t trl-715-05t szt-715-01s szt-715-02s szt-715-03s SZT-715-04S SZT-715-05S 8700 Cameron Road Austin, Texas 78754 512.836.5001 PH 877.370.5001 TF 512.836.6933 FX customerservice@ascensionortho.com www.ascensionortho.com Caution: U.S. federal law restricts this device to sale by or on the order of a physician. LC-04-717-001 rev B 2011