MiniHip™ - Corin Group€¦ · Representing a natural progression in hip joint replacement, MiniHip™ offers all the advantages of traditional total hip replacement, with the added

Surgical techniqueCombined broaches

MiniHip™

ContentsOperative 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. Trial reduction 9

6. Calcar reaming (optional step) 9

7. Implantation of the stem 10

8. Final reduction 10

Appendix: Stem extraction 11

Ordering information 12

Description 14

Indications / Contraindications 14

Sizing guide 14

References 15

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MiniHip™

3 |Responsible Innovation

Operative summary

a. Intra-operative templating b. Neck starter awl c. Curved starter awl d. Femoral canal preparation

e. Trial reduction f. 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 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.

* Ceramic liner and Ceramic-on-Ceramic coupling are available in the USA for investigational use only. 5 |Responsible Innovation

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

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2

3

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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 awlUsing 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.

Operative technique


4. Femoral canal preparationThe 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.

3. Curved starter awlThe 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.

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5. Trial reductionA trial reduction may then be performed by selecting the correct trial neck and head trial on the final broach.

6. Calcar reaming (optional step)The 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.

A/P including fins

M/L

A/P excluding fins

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

580.0004 4 18.3 20.2 27.6

580.0005 5 19.8 21.8 29.5

580.0006 6 21.4 23.6 31.4

580.0007 7 22.9 25.2 33.3

580.0008 8 24.5 27.0 35.1

580.0009 9 26.0 28.6 37.0

*Not for use in the USA 9 |Responsible Innovation

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.

8. Final reductionOnce 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.

7. Implantation of the stemThe final broach indicates the size of the definitive implant, which is inserted by hand.

If the definitive stem seats by more than 5mm 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.

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Stem extractionIn 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.

Appendix


Ordering informationMiniHip™ standard tapered stem

580.0001 Size 1* Cementless

580.0002 Size 2* Cementless

580.0003 Size 3 Cementless







CoCr modular heads (12/14)from the Trinity™ acetabular system

E321.428 Extra short -5.0mm 28mm




E321.028 Short -3.5mm 28mm

E321.032 Short -4.0mm 32mm

E321.036 Short -4.0mm 36mm

E321.040 Short -4.0mm 40mm

E321.128 Medium 0.0mm 28mm




E321.228 Long +3.5mm 28mm

E321.232 Long +4.0mm 32mm

E321.236 Long +4.0mm 36mm

E321.240 Long +4.0mm 40mm

E321.328 Extra long +7.0mm 28mm




BIOLOX® delta ceramic modular heads (12/14)from the Trinity™ acetabular system

104.2800 Short -3.5mm 28mm

104.3200 Short -4.0mm 32mm

104.3600 Short -4.0mm 36mm

104.4000 Short -4.0mm 40mm

104.2805 Medium 0.0mm 28mm

104.3205 Medium 0.0mm 32mm

104.3605 Medium 0.0mm 36mm

104.4005 Medium 0.0mm 40mm

104.2810 Long +3.5mm 28mm

104.3210 Long +4.0mm 32mm

104.3610 Long +4.0mm 36mm

104.4010 Long +4.0mm 40mm

104.3215 Extra long +7.0mm 32mm



InstrumentsBroaches

580.9431 MiniHip Broach Size 1*(Male spigot connection)


580.9433 MiniHip Broach Size 3(Male spigot connection)







X Ray Templates

580.9090 X-Ray Template - 100%




*Not for use in the USA12

InstrumentsBroaches










Handles

340.450 Straight Lazy S Broach Handle

340.353 MIAA Broach Handle

340.544 Double O/S Broach Handle Right Male

340.545 Double O/S Broach Handle Left Male

Calcar cutters

3997040 Ø40 Calcar Cutter (A/O Drive)

3997045 Ø45 Calcar Cutter (A/O Drive)

3997140 Ø40 Calcar Cutter (Hudson Drive)

3997145 Ø45 Calcar Cutter (Hudson Drive)

3997240 Ø40 Calcar Cutter (Zimmer Drive)

3997245 Ø45 Calcar Cutter (Zimmer Drive)

Trial heads (12/14)

E922.428 Modular Head Trial Ø28mm/-5/XS




E922.028 Modular Head Trial Ø28mm/-3.5/S

E922.032 Modular Head Trial Ø32mm/-4/S



E922.128 Modular Head Trial Ø28mm/0/M)

E922.132 Modular Head Trial Ø32mm/0/M



E922.228 Modular Head Trial Ø28mm/+3.5/L

E922.232 Modular Head Trial Ø32mm/+4/L



E922.328 Modular Head Trial Ø28mm/+7/XL




Additional instruments

580.9145 Neck Resection Template - Body

580.9150 Neck Resection Template - Neck

580.9155 Ø36 mm Sliding Head

580.9041.03 Universal Screw Handle

580.9063 Starter Awl

580.9400 Stem Impactor

340.400 Head Impactor

340.308 2.5 mm Allen Key

340.328 Tommy Bar

580.9300 Curved Awl

580.9310 Long Curved Awl

580.9611 12/14 Taper Trial Neck Sizes 1 to 3



Boxes

399.013.003 Outer Box - Single Height

399.014.001 Outer Box - Double Height

399.007.001 Box Lid - Minihip Graphic

496.028 Full Height Aesculap Box with Lid

496.027 Single Height Aesculap Box with Lid


DescriptionMiniHip™ 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 130o 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.

IndicationsThe 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

Sizing guide

*Not for use in the USA14

offset

size lateral stem length (mm)

offset (mm)

neck length (mm)

1* 79.5 32.2 25.0

2* 84.2 33.3 26.0

3 89.0 34.5 27.0

4 93.8 35.6 28.0

5 98.5 36.8 29.0

6 103.3 37.9 30.0

7 108.0 39.1 31.0

8 112.8 40.2 32.0

9 117.5 41.4 33.0

lateral stem length

neck length

References1. Lombadi AV Jr, Berend KR, Ng VY. Stubby

stems: good things come in small packages. Orthopaedics 2011;34:464-466.

Notes


The Corinium CentreCirencester, GL7 1YJ, UKt: +44 (0)1285 659 866f: +44 (0)1285 658 960e: [email protected]

BIOLOX delta is a registered trademark of CeramTec©2017 Corin P No I1329 Rev1 10/2017 CR 216

Documents

MiniHip™ - Corin Group€¦ · Representing a natural progression in hip joint replacement, MiniHip™ offers all the advantages of traditional total hip replacement, with the added