DFS STANDARD FIXATOR DFS ANKLE CLAMP DFS T-CLAMP

Transcription

1 DFS STANDAD FIXATO DFS ANKLE CLAMP DFS T-CLAMP SUGICAL TECHNIQUE Dr. James V. Nepola Professor of Orthopaedics University of Iowa Hospitals and Clinics Iowa City, Iowa Patent No. 5,662,650

2 C ontents DynaFix DFS Standard Fixator Application Assembly/Disassembly...Page 2 Additional Components...Page 5 T-Clamp...Page 5 Supplemental Bone Screw Clamp...Page 5 Ankle Clamp...Page 5 Operative Technique...Page 6 Supplemental Bone Screw Clamp...Page 14 T-Clamp...Page 15 Ankle Clamp...Page 16 Equipment equired and Sterilization ecommendation...page 19 Device Descriptions/Indications...Page20 1

3 L ASSEMBLY/ DISASSEMBLY 2 L Locking Connector Bolt Locking Set Screw Locking Connector Bolt CENTAL BODY COMPONENT L Dual Locking Connector L Inner Body (Female) Inner Body (Male) Inner Body otation Component 1A. Central Body Component The inner body rotation component is comprised of two portions: inner body male and inner body female. When male and female portions are joined care should be taken to insure that serrated discs and locking set screw are in line. Assembly is then correct and set screw is tightened. This component allows 360 of rotation about the axis of the fixator. B. Dual locking connectors provide serrated discs at 90 angles relative to one another. The serrated discs interface with the serrated discs of the inner body rotation component and the telescoping fixator arm. These components are assembled and secured by means of the locking connector bolts. The outer-most serrated discs of the dual locking connectors are identified by L or. When correctly assembled, the telescoping fixator arms marked L and should correspond to the L and of the dual locking connectors. Dual Locking Connector

4 TELESCOPING AM COMPONENTS Locking Connector Bolt Clamp Cover Clamp Cover Locking Bolts L or Male Stem Female Clamp Locking Set Screws 2A. Telescoping Fixator Arms The male stem is secured to the remaining serrated disc of the dual locking connector component. Note: The L of the dual locking connector should match the L of the male stem. The of the dual locking connector should match the of the male stem. This assures alignment of fittings to be tightened. Male stem components are available in two lengths. The male stem accommodates 0-5 cm excursion capability. The longer male stem allows 0-8 cm excursion. B. The female clamp provides for excursion (compression/distraction) over the male stem when positioned parallel to the long axis of the bone. The female clamp opening must be correctly oriented in order to slide into position. The locking set screws of the female clamp should seat into the channel of the male stem. There are four locking points on the female clamp, two clamp cover locking bolts and two set screws. The two clamp cover locking bolts secure the bone screws within the clamps. One clamp locking set screw (most adjacent to central body component) maintains the position of the female clamp in relation to the male stem. The remaining locking set screw secures the compression/distraction module within the female clamp. ASSEMBLY/DISASSEMBLY 3 3

5 4 COMPESSION/ DISTACTION MODULE Locking Connector Bolt C. Modular compression/distraction mechanism provides incremental excursion (compression/ distraction) capability to the telescoping fixator arm component. The modular C/D mechanism is turned clockwise into the threaded hole in the end of the male stem. It is then positioned such that the flat side of the mechanism faces the locking set screw. The locking set screw is then secured. Clamp Cover L or Male Stem Female Clamp Note: Clamp locking set screw must be loosened prior to operation of the compression/distraction mechanism. The compression/distraction mechanism is available in lengths corresponding to the lengths of the telescoping fixator arms. Clamp Cover Locking Bolts Locking Set Screws Compression/ Distraction Mechanism In diaphyseal applications where two 0-5 cm telescoping fixator arms are employed there is a total distraction capability of 10 cm. In metaphyseal applications, where one telescoping fixator arm is employed, there is a total distraction capability of 5 cm. In those cases where extreme shortening exists, it is recommended that the longer 0-8 cm telescoping fixator arm be employed. Clockwise insertion into Male Stem, secure with locking set screw

6 1 T-CLAMP ADDITIONAL COMPONENTS 2 SUPPLEMENTAL BONE SCEW CLAMP ASSEMBLY/DISASSEMBLY 3 ANKLE CLAMP ADDITIONAL COMPONENTS T-Clamp T-Clamp may be substituted for a telescoping fixator arm component where horizontal bone screw placement is desired. The T-Clamp is attached at the dual locking connector by means of a locking connector bolt. Note: In those cases where extreme shortening exists, it is recommended that the 0-8 cm telescoping fixator arm be employed. Supplemental Bone Screw Clamp The supplemental bone screw clamp is utilized for individual, independent screw placement. Ankle Clamp Assembly for the left ankle requires removal of the telescoping fixator arm and the dual locking connector. The ankle clamp is then secured to the inner body rotation component by means of a locking connector bolt. The modular compression/distraction mechanism is utilized in the remaining telescoping fixator arm to obtain length. Locking of the hinge of the ankle clamp is in the direction of the arrow etched on the clamp. Assembly for a right ankle requires removal of the L telescoping fixator arm and the L dual locking connector. The ankle clamp is then secured to the inner body rotation component by means of a locking connector bolt. The modular compression/distraction mechanism is utilized in the remaining telescoping fixator arm to obtain length. Locking of the hinge of the ankle clamp is in the direction of the arrow etched on the clamp. Note: The proximal telescoping fixator arm and central body component should be parallel to the long axis of the tibia medially. Positioning the fixator in this fashion will insure free excursion of the telescoping fixator arm and provide for predictable intra-op adjustments. 5

7 6 SUGICAL TECHNIQUE 1 2 Pre-operative planning is recommended prior to the application of this device. Assess potential screw site location based on available bone stock and soft tissue considerations. Additional modules may be utilized for horizontal screw placement or fracture specific applications. Selected screw sites must accommodate the length of the central body component. All constructs should include at least one telescoping fixator arm. The telescoping fixator arm should be positioned such that it is parallel to the long axis of the bone to which it is to be secured. Axial alignment of the telescoping fixator arm helps assure free excursion (compression/distraction). Fixator components are used as templates. Hand-held templates are optional in the insertion of bone screws. Prep and drape in routine fashion. Obtaining a preliminary reduction is recommended. The first bone screw is generally inserted in the shortest or most difficult fragment. Assess available bone stock for desired screw position. When possible, allow 4 cm of distance between fracture site and first bone screw.

8 3 A 1 cm incision is made and blunt dissection continued to bone. 4 The trocar and appropriate length soft tissue guide are then utilized to identify the center of the bone and to establish the orientation of the screw tract to be pre-drilled. The orientation of the insertion of the bone screws should be perpendicular to the long axis of the bone. SUGICAL TECHNIQUE 7

9 8 5 Once the screw site is selected use gentle pressure to maintain contact between the soft tissue guide and the cortex of the bone. Extract the trocar. 6 The soft tissue guide is tapped with a mallet to engage the soft tissue guide with bone. 7 Insert appropriate drill guide into the soft tissue guide. Note: Drill Guide Drill Bit Screw 4.8 mm 4.8 mm 6/5 mm Cortical 3.2 mm 3.2 mm 6/5 mm Cancellous 3.2 mm 3.2 mm 4.5/3.5 mm Cortical 2.9 mm 2.9 mm 3.5/3.2 mm Cortical (Bone screw diameter should not exceed 1/3 diameter of bone.)

10 8 A. Insert matching drill bit with drill stop into the drill guide. Drill the near cortex. Drilling is halted upon contact with the far cortex. Be sure pre-drilled screw tract is perpendicular to the long axis of the bone. 5mm B. Upon contact with the far cortex the drill stop is re-positioned and secured approximately 5 mm from the base of the drill guide. The drill stop will prevent over penetration of the drill bit into underlying soft tissue structures. The far cortex is then drilled. SUGICAL TECHNIQUE 9

11 10 9 After bi-cortical penetration of the drill, the drill bit and drill guide are withdrawn. Maintain contact and position of the soft tissue guide. 10 The appropriate length screw is then inserted through the soft tissue guide. The bone screw T-wrench is used to advance the screw into bone. To obtain optimal purchase, all bone screws must be bi-cortical with no less than 2 mm protruding from the far cortex and about 5 mm remaining outside the near cortex. Image intensification is utilized to confirm depth of penetration. Note: Care must be taken to avoid over-penetration. Due to the tapered design bone screws must not be backed out or they will lose purchase.

12 11 Loosen A. the clamp cover locking bolts of the telescoping fixator arm such that the soft tissue guide and existing bone screw are accommodated. At this point a second bone screw may be introduced into the same female clamp to insure a parallel relationship of the telescoping fixator arm to bone. epeat steps 3-10 making sure to snug down the female clamp cover locking bolts to prevent toggle of the soft tissue guides within the clamp. This helps maintain proper bone screw alignment. O B.It is also possible at this point to address the opposing bone screw cluster. The locking connector bolts of the central body component are tentatively tightened. Leave approximately 1 cm of distance in the telescoping fixator arms for subsequent excursion. Proceed to opposite telescoping fixator arm. Identify and secure screw placement following steps Align telescoping fixator arms such that they are parallel to the long axis of the bone. Insert soft tissue guide and trocar, snug down clamp cover locking bolts, and proceed with subsequent bone screw insertion steps SUGICAL TECHNIQUE 11

13 12 12 emove soft tissue guides and tighten clamp cover locking bolts providing at least 3 cm clearance between fixator body and skin surface. 13 Final A. reduction may be addressed systematically. Length is accomplished by the distraction (manually or incrementally) of the telescoping fixator arms. Note: For angular or translational adjustments as described in 13 B and C there should be a corresponding adjustment in length. This is achieved through the telescoping fixator arm most adjacent to the location of desired correction.

14 L L L B. otation about the axis of the fixator may be achieved by releasing the set screw of the inner body rotation component. C. Each dual locking connector will provide angular adjustments in two planes relative to fixator position as applied to the bone. Utilize the dual locking connector most adjacent to fracture for angular corrections. SUGICAL TECHNIQUE 13

15 L L 13 Continued 14 L L D. Translational adjustments are performed by releasing two opposing dual locking connectors in the same plane as desired correction. E. Supplemental fixation may be employed when off plane or additional single screw placement is required utilizing the supplemental bone screw clamp. A bone screw shank is secured to another bone screw shank within the proximal or distal bone screw cluster by means of a 6 mm connecting rod. Note: Manipulation forceps are available to enhance the operators mechanical advantage. The locking screws of these forceps are positioned and tightened within the clamp cover locking bolts.

16 14 T-Clamp When horizontal screw placement is desired a T-clamp is added to the fixator construct. The position of the T-clamp and the corresponding axial alignment and length of the fixator must be considered when selecting screw site location. The T-Clamp should be applied first repeating steps Attach fixator T-clamp to fixator at the dual locking connector. Assess selected diaphyseal screw sites to assure a parallel relationship between telescoping fixator arm and the bone. Insert diaphyseal bone screws following steps Obtain reduction and definitively tighten all fixator locking bolts. Note: Since the T-clamp attaches directly to the central body component the effective excursion of the fixator has been diminished to 0-5 cm. This is a result of the removal of one telescoping fixator arm. The 0-8 cm telescoping fixator arm may be employed to provide added working length. SUGICAL TECHNIQUE 15

17 16 15 Ankle Clamp A. After achieving a preliminary preop reduction, the first screw to be introduced should be positioned medially in the talar neck such that it is parallel to the dome of the talus following steps 3-9 of standard operative technique. B. After bi-cortical penetration, release the 3.2 mm drill bit and evaluate its position fluoroscopically to confirm a parallel relationship to the talar dome. e-attach drill to drill bit and extract the drill bit. epeat step 10 of standard operative technique. C. D. Attach the ankle clamp onto the talar bone screw and screw guide with the window of the device positioned medially and anterior to facilitate lateral radiographic evaluation. Clamp cover locking bolts of the ankle clamp must be facing distally for access. Using the ankle clamp as a template select second screw position in the calcaneus allowing for desired plantar/dorsi flexion. epeating steps 3-10 of standard operative technique, insert second bone screw. Confirm bone screw position and depth of penetration utilizing image intensification.

18 E. Attach fixator body to ankle clamp at the inner body rotation component by means of a locking connector bolt. Note: Assembly for left ankle application requires removal of the telescoping fixator arm and dual locking connector. For right ankle application, remove L telescoping fixator arm and L dual locking connector. F. G. Spacially relocate the talus under the tibia and position remaining bone screws through the telescoping fixator arm in the tibial diaphysis perpendicular to the long axis of the tibia. Secure clamp locking bolts. eduction is maintained by locking all fixator fittings. The hinge of the ankle clamp is tightened in the direction of the arrow etched on the clamp. SUGICAL TECHNIQUE 17

19 18 16 Suggested Screw Site Care At the conclusion of fixator application and fracture reduction, wounds are dressed in routine sterile fashion. Care should be taken to insure all fixator fittings are securely tightened. Dry sterile gauze is wrapped around the shanks of the bone screws to prevent pistoning of the soft tissues on the bone screws. Once wounds have healed and sutures are removed, routine postoperative screw site care is recommended. Screw sites should be monitored during subsequent clinic visits. All fixator fittings should be evaluated for tightness during subsequent clinic visits.

20 EQUIPMENT EQUIED DFS Standard Fixator Complete / (P/N ) DFS T-Clamp Complete / (P/N ) Trocar / (P/N ) Soft Tissue Guides 40 mm / (P/N ) 60 mm / (P/N ) 100 mm / (P/N ) 160 mm / (P/N ) Drill Guides 4.8 mm / (P/N ) 3.2 mm / (P/N ) 2.9 mm / (P/N ) 5 mm Allen Wrench / (PN ) 3 mm Allen Wrench / (PN ) T-Wrench For Bone Screws / (PN ) Drill Bits 4.8 mm / (P/N ) 3.2 mm / (P/N ) 2.9 mm / (P/N ) Bone Screws (bone screw diameter should not exceed 1/3 diamter of bone) 6/5 mm cortical 6/5 mm cancellous 4.5/3.5 cortical 3.5/3.2 cortical STEILIZATION ECOMMENDATIONS The fixator should be completely dismantled for cleaning, but it may be sterilized in the assembled state, provided all screws and couplers are left loosened. The DFS components and instrumentation are provided non-sterile, and must be sterilized prior to use. All packaging materials must be removed prior to sterilization. All fixator components should be sterilized in a loosened state such that connected components move freely. The following steam sterilization parameters are recommended: Cycle: Vacuum Temperature: 270 F / 132 C Time: 4 minutes Note: Allow for cooling Individuals or hospitals not using the recommended method, temperature and time are advised to validate any alternative methods or cycles using an approved method or standard. Manipulation Forceps / (P/N ) Hand Held Templates Additional soft tissue instrumentation Air Drill Image Intensifier EQUIPMENT EQUIED AND STEILIZATION ECOMMENDATIONS 19

21 20 DEVICE DESCIPTIONS/ INDICATIONS Indications: The EBI XFIX DYNAFIX System is a unilateral external fixation device intended for use in the treatment of bone conditions including leg lengthening, osteotomies, arthrodesis, fracture fixation, and other bone conditions amenable to treatment by use of the external fixation modality. Caution: Federal Law (U.S.A.) restricts this device to sale by or on the order of a physician. Warning: This device is not approved for screw attachment or fixation to the posterior elements (pedicles) of the cervical, thoracic, or lumbar spine. See package insert for full prescribing information. To reorder call: (800) or FAX (800) EBI, as the manufacturer of this device, and their surgical consultants do not recommend this or any other surgical technique for use on a specific patient. The surgeon who performs any implant procedure is responsible for determining and utilizing the appropriate techniques for implanting the device in each individual patient. EBI and their surgical consultants are not responsible for selection of the appropriate surgical technique to be utilized for an individual patient.

22 PN L EBI, L.P. 100 Interpace Parkway, Parsippany, NJ /00