CarpoFit the trapeziometacarpal joint system

Transcription

1 CarpoFit the trapeziometacarpal joint system Surgical Technique

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3 CarpoFit the trapeziometacarpal joint system The CarpoFit trapeziometacarpal joint system was developed in cooperation with Prof. Dr. med U. Joosten, orthopaedic surgeon Clinic for Traumatology Marienhospital Osnabrück Germany. Table of Contents DESIGN CHARACTERISTICS 2 SURGICAL TECHNIQUE 3 IMPLANTS 13 INSTRUMENTS 14 Note : The surgical technique here described refl ects the authors suggested surgical treatment in uncomplicated primary and secondary trapeziometacarpal arthritis. The treating physician should determine for each specifi c patient the preferred and most effective treatment. Copyright Information: DiaLoc, CarpoFit ACS, CCI, DiaLoc, EcoFit, BethaLoc, LOAD SHIFT, implavit, implavit und implatan are registrered trademarks of implantcast GmbH. The use of these trademarks and / or the reproduction of information from this brochure, either in whole or in part is only allowed after written permission from implantcast GmbH 1

4 design characteristics Articulating components PressFit Cup Metacarpal Stems Cementless Trapeziometacarpal Joint Replacement with Metal-on-Metal Articulation. Metacarpal Components The CarpoFit Trapeziometacarpal Joint Replacement System consists of three modular components. The metacarpal stems are available in four sizes 5,6,7, and 8 mm. The shafts are made of forged implatan Titanium alloy. A TriCalciumPhosphate coating provides an additional bone ingrowth facility. Articulating components The articulating components of casted implavit, CoCrMo-alloy are available in 4 neck lengths and each will fi t any of the 4 metacarpal stems. PressFit-Cup The conical press-fi t cup enables an optimal primary fi xation in the bone. For the secondary, bone in-growth, stability a TCP coating is applied on these components, manufactured from implavit CoCrMo-alloy. Instruments All trial components are color coded to simplify the selection of the components to be implanted after trial reduction. 2

5 surgical technique INDICATIONS Painfull, isolated primary and secondary trapeziometacarpal arthritis with functional impairment and rheumatoid arthritis. The goal is the complete absence of pain and restoration of range of motion with full retention of the thumb length The procedure is performed under plexusanesthaesia using a tourniquet. The surgical approach is dorsolateral, but also a dorsal or volar approach can be utilized A slightly S-shaped skin incision is made at the volar-dorsal junction. The capsule is opened in line with periost of the metacarpal bone. The proximal insertions of the interosseus muscles are released. Also the insertion of the M. abductor pollicis longus is freed. 3

6 The metacarpal bone is exposed using two Hohman retractors. A 3 mm thick bone cut is performed perpendicular to the metacarpal accis The insertion of the M. abductor pollicis longus should be protected. At this time any osteophytes, especially at the volar site should be removed. The resected bone is removed. 4

7 Locate any osteophytes at the os trapezium and remove them. Care should be taken not to harm the horns of the os trapezium. Preparation for the stem of the metacarpal components. Two Homans retractors are placed to expose the joint. The shaft reamer of the size determined at the preoperatvie X-ray should be used. 5

8 The modular reamer handle is used to accomodate the selected shaft reamer. The reamers should be fully inserted to ensure that the component is fully seated on the resected metacarpal bone. Upon preparation of the hexagonal canal the metacarpal stem can be inserted. Alternatively the trial for the metacarpal stem can now be used. The metacarpal stem is mounted on the stem inserter. The metacarpal stem should be inserted in a gentle manner using very little force on the hammer. The top of the stem should lie fl ush with the resected bone. 6

9 The metacarpal stem closes the prepared canal (picture left). The Press Fit seating of the stem component. The trapezium is exposed. A centering guide is use to determine the correct, centered position for the guide wire. 7

10 The guide wire is fi rst inserted with the pin inserter, followed by further insertion with a power drill. The correct position of the guide wire can be checked with an image intensifi er. Special care should be taken to acquire the correct position in case of a dysplastic trapezium. Once the correct positioning is obtained, the canulated reamer can be advanced over the guide wire and the bone can be reamed manually. The reamer is inserted in such a manner that the proximal part lies fl ush with the cut surface of the trapezium. The reamer can then be removed. 8

11 The guide wire is removed. The press fi t cup can now be inserted. The press fi t cup is inserted with the cup introducer. The press fi t cup should be fully covered by bone. 9

12 Correct placement of the press fi t cup. The soft tissue tension is checked and the neck length of the component to be used, is determined. The corresponding articulating trial component is selected and inserted. Trial reduction is performed and the stability of the joint is tested. Suffi cient tissue tension should prevent any luxation. The trial component is removed and the fi nal implant, with the determined length (S, M, L and XL) is selected and inserted. 10

13 A fi nal check for mobility and stability is made with the defi nitive implants. The wound is lavaged, the capsule is closed and a small wound drain is inserted. The wound is closed in a standard manner with Steristrips and a sterile bandage. The joint is immobilized for two weeks in a cast. Postoperative Treatment After two weeks the cast can be removed and physiotherapy should be started. Active exercise is allowed at this stage. Power training can be allowed 4 weeks postoperatively. 11

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15 implants CarpoFit metacarpal stem material: implatan, forged TiAl6V4- alloy. acc. to DIN ISO 5832/3 with TCP-coating mm mm mm mm CarpoFit articulating component material: implavit, casted CoCrMo-alloy. acc. to DIN ISO 5832/ short medium long extra long CarpoFit PressFit cup material: implavit, casted CoCrMo alloy acc. to DIN ISO 5832/12 with TCP-coating

16 instruments CarpoFit instrument tray CarpoFit trial stem mm mm mm mm CarpoFit stem inserter CarpoFit joint component short medium long extra long CarpoFit Pin inserter CarpoFit guide wire ic hammer

17 instruments CarpoFit forceps for articulating components CarpoFit retractor CarpoFit centering instr. for guide wire CarpoFit trapezium reamer CarpoFit cup introducer CarpoFit inserter f. articulating components ic awl CarpoFit broaches mm mm mm mm 15

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20 your local distributor: implantcast GmbH Lüneburger Schanze 26 D Buxtehude Germany phone: fax: internet: CARPOOPE *+E1ICCARPOOPE++* *+$$E1IC *