CLICK-OFF Screws TWIN Compression Screws

Transcription

1 CLICK-OFF Screws TWIN Compression Screws

2 > TWIN compression screw with double thread 1. Characteristics of the TWIN compression screw The TWIN compression screw has one thread at the screw head (1) and one thread at the screw tip (2) The thread at the screw head has a larger diameter and a smaller pitch than on the screw tip. When the head thread enters into the bone, this pulls the distant fragment in, that is, it produces compression. The result is therefore stable internal fixation of the fragment by means of compression. 2 Dimensions of the TWIN compression screw 2. Indication Scarf and chevron osteotomy, arthrodesis of the large toe base joint, scaphoid fractures. Screw diameter: Core diameter: Pitch: Inner hexagon: Cannulation Screw lengths: Material: 3.00/4.00 mm 1.90/2.80 mm 1.25/1.00 mm 2.00 mm 1.15 mm mm Ti6Al7Nb (ISO ) > > CLICK-OFFSCREW 1. Characteristics of the CLICK-OFF screw 02 The CLICK-OFF screw is utilised in frontal foot surgery, particularly in Weil osteotomy. The screw is applied directly into the bone with the drill and breaks off at the intended break point when the correct torque is reached. CLICK-OFF screw is self drilling and self cutting. Dimensions of the CLICK-OFF screw 2. Indication Weil osteotomy, chevron osteotomy or Scarf osteotomy on the metatarsal V. Screw diameter: Core diameter: Shaft diameter: Pitch: Connection diameter: Screw lengths: Material: 2.00 mm 1.20 mm 1.30 mm 1.00 mm 4.00 mm mm Ti6Al7Nb (ISO ) Page 1

3 > SCARF osteotomy with guide wire CLICK-OFF and TWIN compression screw 1. SCARF osteotomy 01 The first step is to remove the pseudoexostosis. This is followed by Z-shaped osteotomy of the metatarsal I. Subsequent lateral shift of the distal bone block. 2. Introduction of the guide wires 02 Fixation of the osteotomy with the reduction forceps (REF: ) and introduction of the guide wires Ø 1.0 mm (REF: ). 3. Length measurement of the screws 03 Length measurement of the guide wire lying within the bone, using the length measuring stick (REF: ). Page 2

4 > SCARF osteotomy with guide wire 4. Drilling 04 Drilling with the cannulated drill Ø 2.0 mm (REF: ). If a reliable length measurement was not possible using the length measuring stick, the screw length can be determined after drilling open, using the length measurement device (REF: ). 5. Insertion of the TWIN compression screw with double thread 05 Turning in the TWIN compression screw via the Ø 1.0 mm guide wires by using of the screw driver (REF: ) and handle (REF: ). > SCARF osteotomy without guide wire 1. SCARF osteotomy 01 The first step is to remove the pseudoexostosis. This is followed by Z-shaped osteotomy of the metatarsal I. Subsequent lateral shift of the distal bone block. Page 3

5 > SCARF osteotomy without guide wire 2. Drilling 02 Fixation of the osteotomy with the reduction forceps (REF: ). Then the two core holes are drilled with the step drill Ø2.0/2.9 mm (REF: ). 3. Length measurement of the screws 03 Determination of the two screw lengths using the depth gauge (REF: ). 4. Insertion of the TWIN compression screws 04 Insertion of the TWIN compression screws using the screw driver (REF: ) and handle (REF: ). Page 4

6 > CHEVRON osteotomy 1. CHEVRON osteotomy / Reverdin Green osteotomy 01 The first step is to remove the pseudoexostosis. This is followed by V or L shaped osteotomy of the head from MFK 1. It must be noted whether the chevron osteotomy might be done with a longer plantar cut, since this technique improves the blood circulatory situation of the head. 2. Insertion of the guide wire 02 Insertion of the Ø 1.0 mm guide wire to the joint surface. (REF: ) 3. Length measurement of the screws 03 Length measurement of the guide wire within the bone using the length measuring stick (REF: ). The screw is generally chosen to be 3 mm shorter than the measurement result so that the proximal thread part is fully within the corticalis and never protrudes into the joint. Page 5

7 > CHEVRON osteotomy 4. Drilling with the twist drill 04 Drilling with the cannulated twist drill Ø 2.0 mm ). (REF: 5. Drilling with the head room drill 05 Drilling with the head room drill Ø 2.9 mm, with stop (REF: ). 6. Insertion of the TWIN compression screw 06 Turning in the TWIN compression screw via the Ø 1.0 mm guide wire by using of the screw driver (REF: ) and handle (REF: ). Page 6

8 > Weil osteotomy 1. Weil osteotomy Shortening the metatarsal II - V. The slanted osteotomy should be extracapsular to reduce the risk of arthrofibrosis. If applicable, a 1-2 mm thick bone slice can be removed to obtain increased dorsalisation of the metatarsal protuberance. 01 Bone slice 2. Insertion of the CLICK-OFF screw The self drilling, self cutting CLICK-OFF screw is turned directly into the bone with the drill. When the corticalis is reached, the osteotomy is fixed by means of compression. The torque, which increases due to the compression, and the slight axial shift of the drill from the screw axis breaks off the head of the CLICK-OFF screw at the intended break point. If applicable, the CLICK-OFF screw can be turned further in with the screw driver (REF: ). Then the protruding bone area is removed Removal of the CLICK-OFF screw Removal or reimplantation of the CLICK-OFF screw is done using the screw driver (REF: ) and handle (REF: ). 03 Page 7

9 > Arthrodesis of the large toe base joint (MP joint) in the CUP-Cone technique 1. Access 01 Dorsomedial access to the large base toe joint, approx. 4-5 cm. Sharp dissection to the joint capsule with careful avoidance of nerves and blood vessels Dissecting skin flaps should be avoided. The joint capsule is incised lengthwise. Improved exposure of the joint by pushing the joint capsule off sub-periostally using the rasparatorium. Both side ligaments should be cut so that the joint is more exposed. Then maximum flexion of the large toe. 2. Milling the protuberance MFK I 02 With the protuberance now well exposed, the osteophytes are removed. The centre of the protuberance should then be found. This is most easily accomplished by laying 2 3 lines across the entire circumference of the protuberance with the electrical knife. The intersection of the 2 3 lines represents the centre. After it has been determined which of the two concave head milling tools (S (REF: ) or M (REF: )) most closely corresponds to the size, this is now placed into the previously determined centre of the protuberance with its central tip. Then the drill is used to mill the joint surface to the subchondral spongiosa. (Fig. 2) 3. Milling open the base joint phalanx 03 The centre of the base phalanx must be determined with the aid of the electrical needle, using a similar technique as for the protuberance. Then the convex milling tool (S (REF: ) or M (REF: )) is also placed on the centre with its central point. Here as well, the base is milled to the spongiosa. (Fig. 3) With marked sclerosis, the bone can be spongiosed additionally with the 2 mm drill. Page 8

10 > Arthrodesis of the large toe base joint (MP joint) in the CUP-Cone technique 04 4.Positioning the two components The base phalanx must now be positioned with reference to the protuberance at an angle of approx. 15 extension (Fig. 4 top) as well as 10 valgus (Fig. 4 below) as compared to the metatarsal I. The base joint has a conical form, so that the dorsal bone presents a nearly level surface. Furthermore, the plantar part must possess sufficient dorsal extension. Under the image magnifier, the position can be verified using two flat chisels. After the correct position is reached, temporary fixation takes place by means of a K wire. Then the arthrodesis is securely fixed using two cannulated TWIN compression screws (crossed insertion). (Fig. 5) Side view: Extension Top view: 10 valgus Page 9

11 > Varisation of the large toe base phalanx (AKIN procedure) 1. Osteotomy of the large toe base phalanx 01 In the case of hallux valgus interphalangeus, the cut is extended to the large toe base phalanx. The large toe base phalanx is then shown. Exposure with 2 Hohmann levers to protect the flexion and extension tendons. Subsequent introduction of the K-wire parallel to the base joint surface of the large toe phalanx. Herein, the lateral corticalis is maintained. 4-5 mm Note: The diameter of the K-wire must correspond to the diameter of the staples. That is, an Ø1.0 mm K- wire must be used for the small clamp, and an Ø1.6 mm K-wire for the large staple. Parallel to the introduced K-wire, the oscillating saw is used to perform a distal osteotomy in which the lateral corticalis also remains intact. In accordance with the previously determined wedge which is to be removed, a slanted osteotomy is then performed distally to this, also with the oscillating saw. Here as well, the lateral corticalis remains intact. Now the bone segment is removed, and the osteotomy is closed. (Fig. 1) Drilling Now a drill hole is applied 4-5 mm distal to the osteotomy gap, using the corresponding K-wire. Then the K- wire is removed. (Fig. 2) Alternatively, the staple can be easily inserted into the proximal hole When the osteotomy is folded shut, the correct distance can be marked by scratching the bone. 4-5 mm 4-5 mm 3. Insertion of the staple 03 Now the staple is introduced into both drill holes by using a forceps. This results in a stable osteosynthesis of the varisation osteotomy. (Fig. 3) Page 10

12 TWIN compression screws Article number Screw length 12 mm 14 mm 16 mm 18 mm 20 mm 22 mm mm mm mm mm 32 mm 34 mm 36 mm Thread lenght 5 mm 7 mm 7 mm 7 mm 7 mm 7 mm CLICK-OFF Screws Article number Srew length mm mm mm mm Staples, small, straight Staples, large, straight Staples, small, angled ( Staples, large, angled (REF: ) (REF: ) REF: ) (REF: ) Article number Diameter Length Width mm 1.60 mm 1.00 mm 10.5/12 mm 14.5/16 mm 12 mm 13/15.5 mm mm 15/17.5 mm 12 mm Page 11

13 CLICK-OFF and TWIN compression screw INSTRUMENTS IN THE SET Description Article number: Foot reduction forceps Screw holding forceps Screw driver for the CLICK-OFF screw Step drill Ø 2.0/2.9 mm, drilled through, for angle drilling Step drill Ø 2.0/2.9 mm with stop Drill Ø 2.0 mm x 65 mm, drilled through, 3-fluted Countersink Ø 2.9 mm, with stop, cannulated Screw driver for TWIN screw Description Head milling tool, convex, small Head milling tool, convex, medium Head milling tool, concave, small Head milling tool, concave, medium Handle with quick coupling Length measuring stick for TWIN screw Depth Gauge for TWIN screw Article number Page 12

14 Guide wire Ø1.0 x 70 mm (REF: ) Guide wire Ø1.6 x 150 mm (REF: ) Description Article number Graphics cassette with implant rack Implant rack Lid for implantat rack Page 13

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16 Dieter Marquardt Medizintechnik GmbH Robert-Bosch-Str Spaichingen Telephone: +49 (0) 7424 / Fax: +49 (0) 7424 / info@marquardt-medizintechnik.de Issue date: 03/09/08