TaperFit. Cemented Total Hip Replacement Surgical technique

Transcription

1 TaperFit Cemented Total Hip Replacement Surgical technique

2 TaperFit Contents Operative summary 4 Pre-operative templating 5 Surgical exposure 5 Femoral neck resection 5 Acetabular preparation 5 Cenator cup acetabular preparation and implantation 6 Reaming the acetabulum 6 Insertion of the acetabular cup 6 TaperFit femoral preparation 7 Opening the femur 7 Reaming the medullary canal 7 Rasping the medullary canal 7 Trial using rasp 7 Restrictor sizing and insertion 8 Insertion of definitive femoral implant 8 Modular head insertion 8 Sizing guide 9 Ordering information 10 2

3 TaperFit Design I History I Function Cemented total hip replacement 3

4 TaperFit Operative summary a. Femoral canal preparation b. Tapered IM reaming c. Rasping d. Trial reduction 4 e. Restrictor sizing f. Restrictor insertion g. Stem implantation h. Modular head insertion

5 Taperfit System Device part no(s): E Description: Taperfit stem Device size: 45mm offset, Size 1 Trunnion type: EuroCone Pack No. Sheet 2 of 9 MAGNIFICATION: 115% (1.15:1) TaperFit Cemented Total Hip Replacement Surgical technique Trinity Advanced Bearing Acetabular System Surgical technique includes Template No: REV: 01 ECR: DATE: 11 Nov 10 Pre-operative templating Pre-operative templating using the Corin X-ray templates provided allow the surgeon to identify the implant offset and sizes appropriate for the patient, and also to plan the position in which the components will be placed. Whilst templating, allowance must be made for a complete cement mantle for the chosen component. Surgical exposure Full exposure of both the acetabulum and proximal femur are required to permit effective preparation and implantation. Femoral neck resection The osteotomy line for neck resection usually runs from the superior surface of the base of the neck to a point midway between the upper margin of the lesser trochanter and the inferior aspect of the head. However, since the TaperFit stem is a collarless device, the level and orientation of neck resection is not critical to this procedure. Acetabular preparation The acetabulum is prepared as instructed for the chosen acetabular cup system. The TaperFit stem can be used in combination with the Trinity acetabular cup system or the Cenator cemented polyethylene cup please refer to the respective surgical technique (see overleaf for Cenator). 5

6 TaperFit Cenator cup acetabular preparation and implantation 6 Step 1. Reaming the acetabulum The acetabular rim is identified and any osteophytes and capsular remnants are removed. The acetabulum is reamed up to the appropriate size, using sequentially larger reamers, until bleeding sub-chondral bone is exposed and the acetabulum is hemi-spherical. In order to ensure an adequate cement mantle, the final size of reamer used should be 4mm larger than the cup to be implanted, e.g. to accept a 44mm cup the acetabulum must be reamed to 48mm. Step 2. Insertion of the acetabular cup Trial cups may be used to confirm the size selection made at pre-operative templating.the acetabulum is then prepared to accept bone cement which is applied according to usual practice. If a flanged Cenator cup is to be used (which has a 0.75mm thick flange and is marked with concentric rings 2mm apart), then the flange should be trimmed to the contours of the acetabular rim prior to cementing in place. The chosen acetabular component is then mounted on the acetabular cup holder by inserting the two prongs on the holder into the two holes in the implant. Note: If a cup with an EPW (extended posterior wall) is chosen then the implant must be placed on the introducer in the correct orientation: For a right hip, the letter R on the face of the implant should be visible in the R-window of the introducer. For a left hip, the letter L on the face of the implant should be visible in the L-window of the introducer The cup can then be inserted into the bone cement. The cup holder permits orientation of the cup as follows: with the handle parallel to the long axis of the body, and the metal shaft at 90 to the long axis, the cup will be placed at 45 of abduction, in neutral so anteversion may then be applied by appropriate rotation of the handle. Pressure is applied to the back of the cup holder with the pusher and excess bone cement removed. The cup introducer is removed by squeezing the trigger. The plastic-headed cup pusher is inserted into the cup and firm pressure is maintained until the bone cement has fully polymerised.

7 TaperFit femoral preparation Step 1. Opening the femur The proximal femur is opened using the box osteotome ensuring that this is positioned laterally into the greater trochanter and with the appropriate anteversion. Step 2. Reaming the medullary canal The medullary canal is identified and opened using the tapered reamer. Step 3. Rasping the medullary canal The medullary canal is then rasped sequentially starting with the smallest rasp of appropriate offset until the rasp equivalent to the prosthesis chosen at templating is seated within the femur. The rasp handle may be impacted directly using a mallet, or the slap hammer may be used to both impact and loosen the rasp. Step 4. Trial using rasp Stability and fit are assessed and, if satisfactory, the rasp handle is removed. A trial neck is placed on the spigot, a standard trial modular head of appropriate diameter placed on the trial neck and a trial reduction carried out. Long or short trial heads may be used if adjustment is necessary. The neck trials are suitable for use with all rasp offsets. A pin may be placed through the holes in the rasp to increase leg length and to maintain the rasp position within the femur whilst performing a trial reduction. 7

8 TaperFit Step 5. Restrictor sizing and insertion The rasp is removed using the rasp handle and slap hammer. The correct size of cement restrictor is determined by using the four double-ended Corin restrictor sizer instruments. Aim for a firm fit so that third generation cementing techniques can be used effectively if required. Place the chosen size of restrictor onto the end of the introducer and push down into the femoral canal to a depth of 20mm distal to planned final stem tip position. Note: Ideally the canal should be thoroughly cleaned and dried using pulse lavage and tamponade prior to retrograde cement injection with a cement gun and proximal cement pressurisation. Step 6. Insertion of definitive femoral implant The definitive implant is mounted onto the stem introducer and the stem centraliser placed on the distal tip. The stem is then pushed firmly into the bone cement until it reaches the level at which the rasp sat during the trial reduction (this may be checked by reference to the three marks on the implant). Pressure is applied, excess bone cement is removed, and the stem introducer detached from the stem when the cement has fully polymerised. Step 7. Modular head insertion A further trial reduction may be carried out, using a trial head or a definitive modular head (matching the trial head used) is then securely placed onto the trunnion. The wound is then closed according to the surgeon s usual practice. 8

9 Sizing guide offset CDH stem stem size CDH offset (mm) 36.0 neck length (mm) 35.9 stem length (mm) stem size neck length stem length 38mm offset stems 45mm offset stems offset (mm) neck length (mm) stem length (mm) offset (mm) neck length (mm) stem length (mm) mm offset stems offset (mm) neck length (mm) stem length (mm) major diameter cement restrictors restrictor size minor diameter (mm) major diameter (mm) core diameter (mm) IM size recommendations (mm) 8 Ø < Ø < Ø < Ø < 24 core diameter minor diameter 9

10 TaperFit Ordering information TaperFit femoral stems Eurocone (12/14) options mm Offset CDH mm Offset size mm Offset size mm Offset size mm Offset size mm Offset size mm Offset size mm Offset size mm Offset size mm Offset size mm Offset size mm Offset size mm Offset size mm Offset size mm Offset size mm Offset size 4 Centralisers and impaction grafting TaperFit PMMA centraliser (pack of 5) Impaction grafting canal occluder size Impaction grafting canal occluder size Impaction grafting canal occluder size 3 Complementary products Hardinge femoral canal occluder, box Canal occluder introducer TaperFit X-ray templates % % % % Cenator cemented polyethylene acetabular cups Standard cups with EPW mm OD 22mm ID mm OD 22mm ID mm OD 22mm ID mm OD 22mm ID mm OD 28mm ID mm OD 28mm ID Flanged cups with EPW mm OD 22mm ID mm OD 22mm ID mm OD 22mm ID mm OD 22mm ID mm OD 26mm ID mm OD 26mm ID mm OD 26mm ID mm OD 26mm ID mm OD 28mm ID mm OD 28mm ID mm OD 28mm ID Standard cups without EPW mm OD 22mm ID mm OD 22mm ID mm OD 22mm ID mm OD 22mm ID mm OD 28mm ID mm OD 28mm ID mm OD 28 mm ID Flanged cups without EPW Cement restrictors mm OD 22mm ID mm OD 22mm ID mm OD 22mm ID mm OD 22mm ID mm OD 26mm ID mm OD 26mm ID mm OD 26mm ID mm OD 26mm ID mm OD 28mm ID mm OD 28mm ID mm OD 28mm ID Cement restrictor size Cement restrictor size Cement restrictor size Cement restrictor size Canal occluder introducer 10

11 Modular heads for use with Cenator cup CoCr modular heads Eurocone (12/14) options E mm short E mm medium E mm long E mm short E mm medium E mm long E mm short E mm medium E mm long Modular heads for use with the Trinity acetabular cup CoCr modular heads Eurocone (12/14) E Small -3.5mm 28mm E Small -4.0mm 32mm E Small -4.0mm 36mm E Small -4.0mm 40mm E Medium -0.0mm 28mm E Medium -0.0mm 32mm E Medium -0.0mm 36mm E Medium -0.0mm 40mm E Long +3.5mm 28mm E Long +4.0mm 32mm E Long +4.0mm 36mm E Long +4.0mm 40mm E Extra long +7.0mm 32mm E Extra long +8.0mm 36mm E Extra long +8.0mm 40mm BIOLOX delta ceramic modular heads Eurocone (12/14) Small -3.5mm 28mm Small -4.0mm 32mm Small -4.0mm 36mm Small -4.0mm 40mm Medium -0.0mm 28mm Medium -0.0mm 32mm Medium -0.0mm 36mm Medium -0.0mm 40mm Long +3.5mm 28mm Long +4.0mm 32mm Long +4.0mm 36mm Long +4.0mm 40mm Extra long +7.0mm 32mm Extra long +8.0mm 36mm Extra long +8.0mm 40mm Instrumentation TaperFit instrument set TaperFit impaction grafting instrument set Standard impaction grafting instrument set Cenator instrument set 11

12 References: 1. Fowler JL, Gie GA, Lee AJC, Ling RSM. Experiences with the Exeter total hip replacement since Orthop Clin North Am 1988:19; Ramos JL, Pandit HG, Edwards S, Grover ML. Lateral approach to the hip joint; does it predispose to malalignment of the femoral component in total hip arthroplasty? British Orthopaedic Association, Annual Congress 1999, Glasgow, Free Paper Session Malchau H, Herberts P. Prognosis of total hip replacement: Revision and rerevision rate in THR: A revision-risk study of 148,359 primary operations. Scientific exhibition presented at the 65th Annual Meeting of the American Academy of Orthopaedic Surgeons, March 1998, New Orleans. The Corinium Centre Cirencester, GL7 1YJ t: +44 (0) f: +44 (0) e: info@coringroup.com Printed on 9lives 80 which contains 80% total recycled fibre and is produced at a mill which holds the ISO for Environmental Management Systems. The pulp is bleached using Elemental Chlorine Free processes. BIOLOX delta is a registered trademark of CeramTec GmbH 2012 Corin P No I1078 Rev2 09/2012 ECR 12143