CemtA Stem. Surgery Manual. cemented femoral Stem. veterinary implants

Transcription

1 CemtA Stem cemented femoral Stem Surgery Manual veterinary implants

2 CemtA Stem use only with bonecement Size 1 Size 2 #4 #5 #6 #7 #8 Size Range 2

3 1: 1: veterinary implants Surgery Manual Guidelines for the Implantation This manual aims to provide a guideline and suggestions for the successful implantation of the cementable CemtA Stem in order to achieve stable implant anchorage and best patient recovery. Preoperative Planning Implant Size Evaluation: The intended femoral stem plus cementmantle implant size is chosen according to the size and shape of the proximal femoral diaphysis. The stem implant plus the cementmantle should fill the entire width of the femoral diaphysis (Fig 1). Note: It is essential to calibrate the size of your radiograph in order to avoid errors of magnification. This applies to both digital and analog radiographs. It is best to always use a reference marker at the exact level of the acetabulum / proximal femur (Fig 2). Ratio and templating: When using a digital imaging system you should display your images in true size (1:1 ratio) and use the 1:1 scaled templates. Figure 2 When using an analog film system you will need to determine the magnification factor, based on the object-film distance of your radiography system. Templates magnified at 8% (ratio 1.08:1) and 15% (ratio 1.15:1) are readily available. Please contact us, if you require templates of a different magnification scale. Stem Si ze # 6 Stem Size #7 CemA-Se t t m cemented Stem Size #6 Stem Size #7 veterinary implants CemtA - Stem cemented X- Ray Te mplate mm Stem Si ze # 6 Stem Si ze # 7 Rasp Siz e # 7 veterinary implants Cemt A - Stem cemented X-Ray Template X-Ray Template mm M11, 5 : , 15:1 mm 0 Rasp Size # M 1,08: Rasp Size #7 Rasp Size #8 M M IN-M O 1,08: IN-M O Ra sp Siz e #7 Rasp Size #8 0 IN-M O 1:1 Figure 1 3

4 Osteotomie of the femoral Head and Neck An osteotomy of the femoral head and neck should be performed using an oscillating saw according to the osteotomy guide for the appropriate side and perpendicular to the femoral long axis. Note: The cut should not damage the greater trochanter. Resection Plane Stem Axis = Drill Axis Preparation of the femoral Canal, Drilling The entry point and the axis of the intramedullary femoral drill are very important. In most dogs the ideal entry point is located in the trochanteric fossa, just medial to the greater trochanter and slightly caudal to the cranial ridge. Once the medullary canal has been opened, sequentially larger drill bits are used to widen the medullary canal up to the size of the drill bit corresponding to the size of the femoral stem implant plus cement-mantle (for example: ø7mm drill bit for #7 rasp and #6 CemtA Stem; see Table 1). final Drill ø 4mm 5mm 6mm 7mm 8mm 9mm mm final Rasp Size #4 #5 #6 #7 #8 #9 # CemtA Stem Size plus av. 1,0mm cement-mantle - #4 #5 #6 #7 #8 - CemtA Stem Size plus av. 2,0mm cement-mantle Table #4 #5 #6 #7 #8 Cranial Aspect Medial Aspect Caudal Aspect 4

5 Preparation of the femoral Canal, Rasping Procedure Assemble the modular rasp-device by connecting the handle with the rasp. Start with the smallest size. The size of the rasp is marked on the taper. Press to conne ct / disconnect The rasping procedure can be carried out by hand or using a small mallet. However, from stem size #6 upwards, a mallet is definitely required. Progressively and sequentially increase the size of your rasp until the predetermined implant size. Note: Rasp ali sizes without using the mallet if you are concerned about the resistance of the bone. Note: Pay particular attention to the femoral craniocaudal long axis for fissures. 5

6 Trial Assembly and Validation The final rasp is used as the trial implant permitting complete joint assembly and assessment of the final implant position with regard to seating of the femoral stem implant and the femoral head length. Implantation of the Cement Restrictor Cement Restrictor, connecting and depth measurement: Estimate the restrictor size and choose between the two sizes Small and Large. The restrictor and the needed drill size for a seating are shown below : Small = Drill size 5mm - 7mm Large = Drill size 8mm - mm Connect the seating instrument with the cement restrictor by screwing on. 6

7 Adjust the rubber mark for the needed minimum depth of the restrictor by comparing with the length of the chosen implant size and add apprx mm mm Insert the cement restrictor into the femoral canal until the depth of the restrictor reaches the pre adjusted mark. Disconnect the seating handle by unscrewing from the restrictor. The restrictor will be anchored automatically. 7

8 Fill in the Cement Clean again the diaphysis wall with sterile pads before inserting the bone cement. Stem sizes between #4 and #7 require cement portion containing approx. 20 g of cement. For the size #8 it is recommended to mix 30 g. A low viscosity cement is recomended for the femoral stem. Use an adequate device to insert the cement into the restrictor sealed part of the femoral diaphysis. The cement insertion device could be a sterile injector, special gun or syringe. A clean pair of gloves should be worn during cementing to avoid contamination of the cement during handling. Insertion of the Stem The CemtA Stem must be dry and free of fat before get bedded. Don t touch the surface with wet gloves. Pickup the stem by the cone and insert it into the cement mass. Have an attention to the instructions of the cement manufacturer about the possible handling time. After insertion, the overflooded portion of the cement must be removed with a scalpula or thin paddle before starting to get hard. Wait until hardening process is finished without moving the implant. Mixing and Preparing Modeling Hardening Time 8

9 Final femoral Head Selection before final Joint Assembly Using a trial acetabular cup (trial inlay) and the trial femoral heads, the joint can now again be completely assembled and the final femoral head size / neck length can be determined. The trial heads and trial cups are designed to simulate the worst-case scenario with regards to the luxation tendency. The final implants will provide more security against luxation than the trial implants. Note: It is important to check not only the required femoral neck length, but also the complete range of hip movements and for presence of possible impingement. Femoral Head Fixation Connect the head with the stem and fix both together by using the head impactor and a very small mallet. Ensure the needed fixation with small and gentle hits on the device. 9

10 3Con + CemtA Stem Instrument Set Position Description REF No Intramedullary drill 4,0 mm Intramedullary drill 5,0 mm Intramedullary drill 6,0 mm Intramedullary drill 7,0 mm Intramedullary drill 8,0 mm Intramedullary drill 9,0 mm Intramedullary drill,0 mm ø4,0 mm ø5,0 mm ø6,0 mm ø7,0 mm ø8,0 mm ø9,0 mm ø,0 mm 300-CD-4,0 300-CD-5,0 300-CD-6,0 300-CD-7,0 300-CD-8,0 300-CD-9,0 300-CD-, # 4 # 5 # 6 # 7 # 8 # 9 # 500-3CC CC CC CC CC CC CC- 15 Broach impact handle 500-IH Head resection saw guide Head resection saw guide Right Left 300-RG-R1 300-RG-L1 18 Cement restrictor insertion handle 500-CR-0 19 Stem impactor 500-SP-0 Notice: The instrument set containes the 3Con and CemtA Stem instrument equipment.

11 veterinary implants INNOPLANT veterinary Dornier Str Hannover Germany Phone: Fax: Mail: info@innoplant-vet.de IN-M O