Surgical technique MkII instrumentation

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Joshua Taylor
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1 MiniHip Surgical technique MkII instrumentation

Contents Operative summary 4 Overview 5 Pre-operative templating 6 Operative technique 7 1. Intra-operative templating 7 2. Neck starter awl 7 3. Curved starter awl 8 4. Femoral canal preparation 8 5.

2 Contents Operative summary 4 Overview 5 Pre-operative templating 6 Operative technique 7 1. Intra-operative templating 7 2. Neck starter awl 7 3. Curved starter awl 8 4. Femoral canal preparation 8 5. Fin templating 9 6. Finishing broach 9 7. Trial reduction Calcar reaming Implantation of the stem Final reduction 11 Appendix: Stem extraction 12 Ordering information 12 Description 14 Indications / Contraindications 14 Sizing guide 15 References 15 2

3 MiniHip Responsible Innovation 3

4 Operative summary a. Intra-operative templating b. Neck starter awl c. Curved starter awl d. Femoral canal preparation e. Fin templating f. Finishing broaching g. Trial reduction h. Implantation 4

Overview Representing a natural progression in hip joint replacement, MiniHip offers all the advantages of traditional total hip replacement, with the added benefits of bone and soft tissue

5 Overview Representing a natural progression in hip joint replacement, MiniHip offers all the advantages of traditional total hip replacement, with the added benefits of bone and soft tissue conservation. MiniHip is less invasive to bone and soft tissue, and in addition offers an ideal solution to patients with excessive femoral bow, diaphyseal deformities and pre-existing orthopaedic interventions [1]. Importantly, MiniHip lends itself to less invasive surgical procedures that may result in quicker recovery times. With an optimised CT based design, MiniHip conservative hip stem is designed to address the challenges presented by today's changing patient demographics, and to offer an ideal solution for those that may require treatment options into their second, third and fourth decades. Note: MiniHip is suitable for Dorr type A and B bone quality. MiniHip is not suitable for type C, osteoporotic stove femurs. Responsible Innovation 5

Pre-operative templating When using the MiniHip system, pre-operative planning is very helpful to determine the optimal size, neck angle and offset of the

The MiniHip X-ray templates are available in four different magnifications (100%, 110%, 115% and 120%). The 115% magnification is provided as standard.

A/P and M/L X-rays taken with the patients feet internally rotated should be used in combination with the templates to determine the correct size and

The resection guideline or demarcation line is defined by using a medium length head (0mm) on the template overlaid onto the centre of rotation.

finally distal lateral cortices contact.

6 Pre-operative templating When using the MiniHip system, pre-operative planning is very helpful to determine the optimal size, neck angle and offset of the implant. Templating will help determine the level of neck resection and optimal cup position. The MiniHip X-ray templates are available in four different magnifications (100%, 110%, 115% and 120%). The 115% magnification is provided as standard. Digital templates are also provided. A/P and M/L X-rays taken with the patients feet internally rotated should be used in combination with the templates to determine the correct size and positioning of the implant. The resection guideline or demarcation line is defined by using a medium length head (0mm) on the template overlaid onto the centre of rotation. The template is then rotated to achieve fit and fill of the neck superior/ laterally whilst in turn maximising possible coverage of the medial calcar and then finally distal lateral cortices contact. When using the M/L X-ray, proximal contact should be achieved posteriorly and anteriorly, and distal contact should be achieved posteriorly. If the hip to be operated on is too affected, template on the contralateral side. The demarcation line is where the cementless coating ends proximally To restore biomechanics the following three key stages need to be implemented: 1. Define centre of rotation 2. Fit and fill in the neck 3. Maximal medial calcar contact The neck resection/demarcation line of the stem should always be parallel to the head-neck junction as shown by the red line in Figure 1. Figure 1. Pre-operative templating 6

Operative technique 1. Intra-operative templating When defining the neck resection in situ take the neck resection guide in combination with the head to define the level of resection.

Use the piriformis fossa as a constant landmark to determine the level of resection. 2.

7 Operative technique 1. Intra-operative templating When defining the neck resection in situ take the neck resection guide in combination with the head to define the level of resection. Set the neck resection guide to the size of stem template. Identify the centre of rotation of the head,identify the head neck junction and make the cut parallel to this. Use the piriformis fossa as a constant landmark to determine the level of resection. 2. Neck starter awl Using the neck starter awl and guide, open up the neck 3-4mm slightly superior and posterior to the centre of the neck to create a pathway for the starter awl into the top of the diaphysis. This will help prevent both undersizing of the stem and misalignment of the starter awl and broaches. Responsible Innovation 7

3. Curved starter awl The curved starter awl is used for further femoral preparation, accommodating the natural curvature of the proximal femur.

The blunt end allows you to feel the lateral cortex. Note: Make sure you are in the femoral canal before proceeding. 4.

8 3. Curved starter awl The curved starter awl is used for further femoral preparation, accommodating the natural curvature of the proximal femur. This allows the compaction impactors to follow a sequential pathway. Do not hammer the awl but gently advance aiming down the femur with a twisting motion. The blunt end allows you to feel the lateral cortex. Note: Make sure you are in the femoral canal before proceeding. 4. Femoral canal preparation The stem is designed to be supported by compacted cancellous bone gaining mechanical stability and fixation in the neck and metaphysis. Always start with the smallest impactor, progressively using larger impactors until the pre-templated size is achieved, or a stable fit is achieved. Note: Version is determined by the neck cut not broach position. To alter version re-cut the neck. A stable fit is achieved when the impactor fits and fills the femoral neck and the face of the final impactor sits flush with the resection line, as detailed in the pre-operative templating. 8

M/L A/P excluding fins A/P including fins 5.

broach for sizes 1-4 and a 2mm for sizes 5-9. Except posterior- lateral where there will be very little, if any, cancellous bone.

You can confirm the size and position of the fins by using the fin templates provided to gain a visual representation of the next stem size and the extent of the

Part number Size A/P excluding fins (mm) A/P including fins (mm) M/L (mm) 580.0001 1 13.6 15.0 22.0 580.0002 2 15.2 16.7 23.9 580.0003 3 16.7 18.4 25.8 580.

9 M/L A/P excluding fins A/P including fins 5. Fin templating (optional step) In order to ensure that the femur will accommodate the planned size of implant, 1mm cancellous bone should be maintained around the broach for sizes 1-4 and a 2mm for sizes 5-9. Except posterior- lateral where there will be very little, if any, cancellous bone. Usually 2-4mm of cancellous bone around the medial calcar is also observed. You can confirm the size and position of the fins by using the fin templates provided to gain a visual representation of the next stem size and the extent of the increase in fin engagement into the cortices without committing to the definitive implant. Part number Size A/P excluding fins (mm) A/P including fins (mm) M/L (mm) Finishing broach The finishing broach corresponds with the last impactor selected. Advancing the finishing broach into the femur cuts a pathway in the cancellous bone for the fins (minus coating) to allow reproducible seating of the stem. The fins will not cut cortical bone, they compact bone. Responsible Innovation 9

7. Trial reduction A trial reduction may then be performed by selecting the correct trial neck and head trial on the final

Calcar reaming (optional step) The finishing broach also allows for the possibility of fine adjustment of leg length by

The calcar reamer is advanced on the top of the broach until a new resection level has been created. 9.

10 7. Trial reduction A trial reduction may then be performed by selecting the correct trial neck and head trial on the final finishing broach. 8. Calcar reaming (optional step) The finishing broach also allows for the possibility of fine adjustment of leg length by seating the broach further beyond the resection line. The calcar reamer is advanced on the top of the broach until a new resection level has been created. 9. Implantation of the stem The final finishing broach indicates the size of the definitive implant, which is inserted by hand. If the definitive stem seats by more than 10mm proud above the resection line when placed in by hand, remove the stem, re-broach with the final impactor 2-4mm below the resection line and re-insert the stem. 10

11 Once the stem is seated by hand the stem impactor can be used to fully seat the implant until the edge of the bicoat (demarcation line) is flush with the resection line. 10. Final reduction Once the acetabular cup is implanted, a full trial reduction can be performed allowing for fine tuning of the head offset. The definitive head is impacted onto the stem ensuring the trunnion is free from debris. The hip can then be reduced and closure performed. Responsible Innovation 11

Appendix Ordering information MiniHip standard tapered stem 580.0001 Size 1 Cementless 580.0002 Size 2 Cementless 580.0003 Size 3 Cementless 580.0004 Size 4 Cementless 580.0005 Size 5 Cementless 580.

5mm 28mm 104.3200 Short -4.0mm 32mm 104.3600 Short -4.0mm 36mm 104.4000 Short -4.0mm 40mm Stem extraction In the unlikely event that the stem needs to be removed the stem extractor set can be used.

Note: Do not overtighten the thread as this will cause damage to the plastic collar on the extractor. It should be tight enough to form an interference fit around the base of the neck to aid removal.

12 Appendix Ordering information MiniHip standard tapered stem Size 1 Cementless Size 2 Cementless Size 3 Cementless Size 4 Cementless Size 5 Cementless Size 6 Cementless Size 7 Cementless Size 8 Cementless Size 9 Cementless BIOLOX delta ceramic modular heads (12/14) from the Trinity acetabular system Short -3.5mm 28mm Short -4.0mm 32mm Short -4.0mm 36mm Short -4.0mm 40mm Stem extraction In the unlikely event that the stem needs to be removed the stem extractor set can be used. The extractor device is placed over the 12/14 trunnion and the slap hammer is rotated until the trunnion is securely clamped. Do not implant the stem with this instrument. Note: Do not overtighten the thread as this will cause damage to the plastic collar on the extractor. It should be tight enough to form an interference fit around the base of the neck to aid removal. The stem can then be extracted in conjunction with revision ancillary instruments. If the stem extractor is required it should be ordered separately prior to the operation 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 12

13 CoCr modular heads (12/14) from the Trinity acetabular system E Extra short -5.0mm 28mm E Extra short -6.0mm 32mm E Extra short -8.0mm 36mm E Extra short -8.0mm 40mm E Short -3.5mm 28mm E Short -4.0mm 32mm E Short -4.0mm 36mm E Short -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 28mm E Extra long +7.0mm 32mm E Extra long +8.0mm 36mm E Extra long +8.0mm 40mm X Ray Templates X-Ray Template - 100% X-Ray Template - 110% X-Ray Template - 115% X-Ray Template - 120% Instruments Broaches MiniHip Broach Size MiniHip Broach Size MiniHip Broach Size MiniHip Broach Size MiniHip Broach Size MiniHip Broach Size MiniHip Broach Size MiniHip Broach Size MiniHip Broach Size Finishing Broach Size Finishing Broach Size Finishing Broach Size Finishing Broach Size Finishing Broach Size Finishing Broach Size Finishing Broach Size Finishing Broach Size Finishing Broach Size 9 Handles Straight Lazy S Broach Handle MIAA Broach Handle Double O/S Broach Handle Right Male Double O/S Broach Handle Left Male Fin templates Fin Template - Size Fin Template - Size Fin Template - Size Fin Template - Size Fin Template - Size Fin Template - Size Fin Template - Size Fin Template - Size 9 Calcar cutters A mm Calcar Cutter - AO Drive A mm Calcar Cutter - AO Drive H mm Calcar Cutter - Hudson Drive H mm Calcar Cutter - Hudson Drive Z mm Calcar Cutter - Zimmer Drive Z mm Calcar Cutter - Zimmer Drive Responsible Innovation 13

14 Trial heads (12/14) E Modular Head Trial Ø28mm/-5/XS E Modular Head Trial Ø32mm/-6/XS E Modular Head Trial Ø36mm/-8/XS E Modular Head Trial Ø40mm/-8/XS E Modular Head Trial Ø28mm/-3.5/S E Modular Head Trial Ø32mm/-4/S E Modular Head Trial Ø36mm/-4/S E Modular Head Trial Ø40mm/-4/S E Modular Head Trial Ø28mm/0/M) E Modular Head Trial Ø32mm/0/M E Modular Head Trial Ø36mm/0/M E Modular Head Trial Ø40mm/0/M E Modular Head Trial Ø28mm/+3.5/L E Modular Head Trial Ø32mm/+4/L E Modular Head Trial Ø36mm/+4/L E Modular Head Trial Ø40mm/+4/L E Modular Head Trial Ø28mm/+7/XL E Modular Head Trial Ø32mm/+7/XL E Modular Head Trial Ø36mm/+8/XL E Modular Head Trial Ø40mm/+8/XL Additional instruments Neck Resection Template - Body Neck Resection Template - Neck Ø36 mm Sliding Head Universal Screw Handle Starter Awl Stem Impactor Head Impactor mm Allen Key Tommy Bar Curved Awl Long Curved Awl /14 Taper Trial Neck - Primary Broach /14 Taper Trial Neck - Finishing Broach Sizes 1 to /14 Taper Trial Neck - Finishing Broach Sizes 4 to /14 Taper Trial Neck - Finishing Broach Sizes 7 to /14 Stem Extractor Boxes Outer Box - Single Height Outer Box - Double Height Box Lid - Minihip Graphic Full Height Aesculap Box with Lid Single Height Aesculap Box with Lid Description MiniHip is a titanium femoral stem (Ti-6Al-4V) coated with a layer of hydroxyapatite applied over a layer of pure titanium. The distal section of the stem is polished. The device is available in a range of nine sizes each providing a 130 o CCD neck angle. The device is intended to be used with 12/14 modular taper heads. MiniHip is intended to provide increased patient mobility and reduce pain by replacing the damaged hip joint articulation in patients where there is evidence of sufficient sound bone to seat and support the components. Indications The indications for the MiniHip stem as a total hip arthroplasty include: Non-inflammatory degenerative joint disease including osteoarthritis and avascular necrosis Rheumatoid arthritis Correction of functional deformity Developmental dysplasia/congenital dislocation of the hip The MiniHip stem is indicated for cementless use only. Contraindications Active infection Poor bone quality Marked bone loss or bone resorption Metabolic disorders which may impair bone formation Vascular insufficiency Muscular atrophy or neuromuscular disease Allergy to implant material Uncorrectable deformity 14

15 Sizing guide offset References 1. Lombadi AV Jr, Berend KR, Ng VY. Stubby stems: good things come in small packages. Orthopaedics 2011;34: neck length medial stem length size medial stem length (mm) offset (mm) neck length (mm) Responsible Innovation 15

16 The Corinium Centre Cirencester, GL7 1YJ, UK t: +44 (0) f: +44 (0) e: 100% Printed on Cocoon 100 which contains 100% total recycled fibre and is produced at a mill which folds the ISO for Environmental Management Systems. The pulp is bleached using Elemental Chlorine Free processes. BIOLOX delta is a registered trademark of CeramTec 2013 Corin P No I1242 Rev2 09/2013 ECR 12825

Bone Conserving Hip Replacement Surgical technique

MiniHip Bone Conserving Hip Replacement Surgical technique MiniHip Contents Operative summary 4 Overview 5 Pre-operative templating 6 Operative technique 7 Neck resection 7 Femoral canal preparation 7