Unicondylar Knee System Surgical Technique · about 1 to 2 cm tilted from the medial into the...

univation™ XUnicondylar Knee System Surgical Technique

Aesculap Orthopaedics

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univation™ X Unicondylar Knee SystemSurgical Technique

Table of Contents

I. System Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

II. Indications, Contraindications, Warnings and Potential Risks & Precautions . . . . . 4

III. Preoperative Planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

IV. Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

V. Instrument Assembly Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

1 . Extramedullar Tibial Alignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

2 . Femur Trial Insertion Instrument . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

VI. Workflow Synopsis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

VII. Surgical Technique . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

1 . Tibia Alignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

2 . Tibia Resection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

3 . Measuring Flexion and Extension Gaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

4 . Femur Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

a . Distal Cut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

b . Chamfer and Posterior Cuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

5 . Tibia Sizing and Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

6 . Implant Sizing and Final Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

7 . Trial Reduction and Implant Final Components . . . . . . . . . . . . . . . . . . . . . . . . . . 26

8 . Trial and Final Implant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

9 . Cementing Technique . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

10 . Closure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

VIII. Implants Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

IX. Femur/Tibia Compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

X. Instrument Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Saw Blades . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Table of Contents

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The univation™ X Unicondylar Knee System was designed with a fixed platform to treat medial knee defects . The system offers streamlined, user-friendly instrumentation to optimize surgical time and allow for intra-operative flexibility . The univation X system is an enhanced design with efficient instrumentation to help restore natural knee kinematics .

Design Advantages:

■ Advanced Surface Technology: All univation X knee components are created with the 7-layer Advanced Surface technology, which makes the system the first choice for surgeons and patients alike .

■ Anatomic Implant Fit and Design: With 5 femoral sizes and 6 tibial sizes there are over 30 possible implant combinations . The design of each component addresses the various needs of the natural anatomy of the patient while providing optimal bone coverage and minimal bone resection .

■ Gap Balancing Technique: Aesculap’s innovative gap balancing instrumentation allows the surgeon to manage the gap before the distal cut is made . The instrumentation and technique also permits gap management by resecting the posterior condyles as well .

■ Stability and Bone Preservation: univation X is a fixed platform with a peg design that offers optimal primary stability with minimal cuts to preserve bone . There are three sizes that have identical cuts allowing the surgeon intra-operative flexibility .

■ IQ Instrumentation Platform: Instrumentation is part of the Intuitive & Quick (IQ) platform, which is designed to create efficiency in the operating room (OR) through a streamlined workflow, improved ergonomics and familiar instrumentation, all with reproducible results . This is accomplished through:

Reduced instrumentation

Ergonomic handles

Fast-acting lock mechanisms

Color-coded instruments and trays

■ Efficient Reprocessing: univation X IQ instruments are stored in modern and simple wash trays for efficiencies in reprocessing . Instruments can remain in the tray during cleaning for fast sterilization intended to save time and money in the Central Sterile Supply Department (CSSD) . Note: Complex instruments such as incision guides require manual precleaning.

I. System Overview

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Indications for UseThe univation X Unicompartmental Knee System is indicated for cemented use only in patients undergoing surgery for a severely painful and/or disabled joint damaged as a result of osteoarthritis, traumatic arthritis, or a failed previous implant when only one condyle of the knee (medial) is affected .

Contraindications

Contraindications include, but are not limited to:

■ Presence of fever, infection or inflammation (systemic or localized);

■ Morbid obesity;

■ Pregnancy;

■ Mental illness or drug abuse

■ Severe osteopenia (or any medical or surgical condition) which would preclude potential benefits of implants;

■ Suspected or documented metal allergy or intolerance;

■ Mixing of implant components from other manufacturers;

■ Any case not listed in the indications; and

■ Patients unwilling or unable to follow post-operative care instructions .

Warnings

■ The univation X implants are designed for single patient use only and must never be reused . As with all other orthopedic implants, the univation X components should never be re-implanted under any circumstances .

■ The mixing of different manufacturer implant components is not recommended due to metallurgical, mechanical and functional reasons . Dissimilar metals in contact with each other can accelerate the corrosion process due to galvanic corrosion effects . Do not use implants or instruments from other systems or manufacturers, and do not mix cobalt-chromium and titanium implant components together in a total knee system .

■ The univation X implants can become loose or break if subjected to increased loading . Factors such as the patient’s weight, activity level and adherence to weight-bearing or load-bearing instructions can affect the implant’s longevity . Damage to the weight-bearing bone cement and/or bone structures caused by infection can give rise to loosening of the components and/or fracture of the bone .

■ The univation X Unicompartmental Knee System has not been evaluated for safety and compatibility in the MR environment . The univation X Unicompartmental Knee System implants have not been tested for heating or migration in the MR environment .

■ These warnings do not include all adverse effects which could occur with surgery, but are important considerations specific to metallic devices . The risks associated with orthopedic surgery, general surgery and the use of general anesthesia should be explained to the patient prior to surgery . See the complete indications for use provided with the product .

II. Indications, Contraindications, Warnings and Potential Risks & Precautions

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Precautions

■ The univation™ X Unicompartmental Knee System is intended to be used by surgeons specializing in orthopedic surgery who have a thorough knowledge of knee arthroplasty, joint morphology and the biomechanical principles of the knee .

■ Pre-operative assessment of the suitability of the patient’s anatomy for accepting implants is made on the basis of X-rays, CT scans and other radiological studies .

■ Only patients that meet the criteria described in the Indications for Use section should be selected .

■ Correct selection of the implant is extremely important. The morbidity as well as patient weight height, occupation and/or degree of physical activity should be considered .

■ Proper implant handling before and during the operation is crucial. Handle the implant components properly . Ensure packaging integrity for implant sterility . Do not use any implant where the packaging has been breached . Do not resterilize an implant . Do not allow the implants surfaces to be damaged .

■ Adequately instruct the patient. The physician should inform the patient about knee implant advantages and disadvantages, post-operative limitations, weight/load bearing stresses which could affect bone healing, implant limitations, and the fact that premature physical activity and full weight/load bearing stresses have been implicated in premature loosening, damage and/or fracture of knee prosthesis .

II. Indications, Contraindications, Warnings and Potential Risks & Precautions (continued)

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For every knee arthroplasty, careful pre-operative X-ray planning is recommended .

The size of the femoral component is determined in the X-ray before the surgery . To do this, X-ray templates are available in different scales .

The contours of the implant partly project up to 2 mm over the bony edge and therefore replace the cartilage .

The tibial component should also be determined, but the size of the tibia can easily be determined intra-operatively .

The tibial slope of the tibial component should correspond as closely as possible to the natural slope of the patient . For this reason, it is also determined from the X-ray image .

The following images are required for X-ray analysis:

■ Knee joint in AP projection (Fig . 1)■ Knee extended■ Centered over the distal patella■ Knee joint in lateral projection (Fig . 2)■ Knee 30° flexed■ Centered over the distal patella .■ Ideally for tibial slope: long leg image in lateral

projection .

The results of preoperative planning should be documented in the patients file and available during the operative procedure for reference .

Fig . 2Fig . 1

III. Preoperative Planning

Note: Place the dotted line of the femoral template in parallel to the longitudinal axis of the femur. The femoral templates are designed so that the dotted line is parallel to the lengthwise axis of the femur. Please note that the femoral pegs do not run parallel to the longitudinal axis. The posterior edge of the implant should not project over the posterior edge of the condyle.

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IV. Approach

At 90° flexion, make a paramedial skin incision from the medial edge of the patella to a point 2 to 3 cm distal of the joint line . (Fig . 3) The incision point descends through the joint capsule . At its cranial end, extend the capsule incision about 1 to 2 cm tilted from the medial into the musculus vastus medialis . For a better view, remove part of the retropatellar fat pad (Hoffa’s fat pad) . The surgeon should decide the overall length of the incision based on each patient and what is required for proper visualization of the knee anatomy .

All osteophytes must be removed from the medial edge of the medial condyle as well as from the intercondylar notch and in the posterolateral area of the medial condyle . Different flexion positions of the leg can be used to reveal all the remaining osteophytes through the moving incision window .

Fig . 4Fig . 3

Caution: Careful consideration must be made to not damage the suprapatellaris recess/bursa

Medial parapatellar Arthrotomy

With the knee in flexion or extension, the arthrotomy is performed starting proximal to the superior pole of the patella, incising the rectus femoris tendon longitudinally . (Fig . 4) Continuing the arthrotomy distally around the medial aspect of the patella, and ending medial to the tibial tubercule is then carried out .

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■ Press and hold the button on the bimalleolar clamp .

■ Guide the holder for the bimalleolar clamp into the groove .

■ After the neutral position has been reached, release the button .

■ Turn the wheel on the tibial alignment handle to the open position, in which it shows 'OPEN' .

■ Place the handle onto the holder for the bimalleolar clamp .

■ Adjust to the neutral position .

■ Press and hold the handle adjustment wheel to release the locking mechanism .

■ Insert the holding rod for the resection block into the handle .

■ After reaching the desired height, release the wheel .

■ Turning the wheel will allow a fine adjustment to the height .

1 2 3

■ Connect the support rod to the right or left tibial resection block .

■ Lock the assembly using the front wheel .

■ Insert the rod into the sleeve and tighten the fixation screw .

4 5

V. Instrument Assembly Instructions

1. Extramedullar Tibial Alignment

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1 2 3

■ Insert the implant holder with the thread into the sleeve of the femoral holder .

■ Place the insertion instrument with both pins parallel to the trial implant . Place firm pressure on the implant and click it into place .

■ The femoral trial holder is fixated to the trial using a rolling motion . Using firm pressure, start with the lower pin and roll upward .

■ Tighten the holder onto the femoral trial .

2. Femur Trial Holder Instrument

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VI. Workflow Synopsis

1 2 3

4 5 6

7 8 1 . Tibial alignment and proximal tibia resection

2 . Measuring flexion and extension gaps3 . Femur preparation4 . Femur anterior and posterior cuts5 . Tibia sizing6 . Implant sizing and final preparation7 . Trial reduction and implant final

components8 . Trial and final implant

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Fig . 6Fig . 5

VII. Surgical Technique

1. Tibia AlignmentExtramedullary Alignment

■ The extramedullary (EM) alignment system assembly is placed parallel to the front of the tibia with the leg in flexion .

■ The bimalleolar clamp, previously placed in the neutral position, is fixed around the lower leg just above and centered around the ankle joint .

Height Adjustment

■ Using the cutting check plate, the height and posterior slope of the resection can be checked .

■ If necessary, the resection height can be adjusted using the wheel for the height adjustment . The goal is to remove any defect of the tibial plateau so that the tibial implant lays on intact bone for optimal implant support .

■ Depending on the resection method, either through the sawing slit or on the block, the resection height must be appropriately adjusted .

A: Bimalleolar clamp NS345R, B: Holder for bimalleolar clamp NS344R, C: Tibial alignment system NS342R, D: Holding rod for tibial resection block NM583R, E: Tibial resection block right/left NM585R/NM584R, F: Cutting depth check plate NS850R

A B C D E F

Note: When aligning it parallel to the axis of the tibia (2 and 3 finger rule), a tibial slope of 5° is pre-adjusted.

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1. Tibia Alignment (continued)Varus-valgus Alignment■ Push the knob (1) on the bimalleolar clamp and slide

the alignment system medially or laterally to adjust the varus/valgus of the proximal tibial resection . The distance between the laser-marked lines on the scale corresponds to a deviation of 1° for a tibia length of 40 cm .

Alignment of the tibial slope■ Releasing the fixation wheel (2) on the lower part of

the alignment system (by turning the screw to OPEN) allows the alignment system to be shifted in the anterior direction to increase the slope of the proximal tibial resection . The distance between the laser-marked lines on the scale corresponds to a deviation of 1° for a tibia length of 40 cm .

Fig . 8Fig . 7

1

2

A: Bimalleolar clamp NS345R, B: Holder for bimalleolar clamp NS344R, C: Tibial alignment system NS342R, D: Holding rod for tibial resection block NM583R, E: Tibial resection block right/left NM585R/NM584R

A B C D E

■ Fasten the tibial cutting guide with two headless pins through the two lowest marked pinholes to the bone . To secure the resection block, a third pin can be inserted in the convergent pin holes .

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2. Tibia ResectionStep 1:■ The horizontal tibia cut is made either through the

cutting guide (Fig . 9) or on top of the cutting guide (Fig . 10) . In either approach ensure the blade reaches the back of the joint .

Step 2:■ Using the reciprocating saw blade, make the vertical

tibial cut . The cut should be made slightly medial to the origin of the anterior cruciate ligament .

■ Point the saw blade towards the femoral head in the direction of the femoral axis as shown in (Fig . 11) .

Fig . 10Fig . 9

A: Headless pins 63 mm NP583R, B: Pin driver NP613R, C: Acculan® drill, D: Acculan saw, E: Acculan reciprocating sawA B DC E

Note: The difference in height from the top of the cutting guide to the cutting guide slot is 4 mm.

Caution: The protection of the surrounding soft tissue of the knee joint is critical. Special attention and necessary retractor instruments should be used to protect this during the tibia resection. Fig . 11

■ Tip: The vertical/sagittal cut should not extend below the transverse/horizontal cut .

■ You can now use the necessary instrumentation to excise the resected tibial plateau .

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3. Measuring Flexion and Extension GapsMeasurement with Spacers

■ The flexion gap is measured with the spacers . Please note that the flexion gap is measured with the leg hanging . To do this, an assistant must lift the upper thigh slightly . The thickness of the spacer is correct if it can no longer be shifted and pushed in and out while holding it with two fingers .

Fig . 12 Fig . 13

A: Trial Spacer NM651R – NM653R, B: Gap distractor for femoral-tibial distractor NP609R, C: Femoral alignment guide NP894RA B C

■ The minimum height for the tibial plateau and meniscus component is 7 mm . If the 7 mm spacer does not fit, the tibia must be resected again .

Caution: Before extending the leg for measurement of the extension gap, remove the spacer to avoid injury to the ligaments.

Optional: Instead of the spacer, a distractor can be used to measure the gaps. To do this, use the spreader in flexion and extension and apply the same force. The size of the gap can be read off the instrument.

Note: In some cases, the cement thickness causes the meniscus components to be inserted about 1 mm higher than planned. Therefore, it is recommended that the joint gap is resected to at least 8 mm.

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■ Flexion and extension gaps must be balanced for optimal post-operative results .

■ The resection height can be adjusted either through the distal cut (distal cutting block) or through the posterior/chamfer cut (2-in-1 cutting block), by setting the blocks to the corresponding level on the spacer . At “0”, the gaps are not changed . At +1, +2, the cut is increased . At -1, -2, the cut is decreased .

Gap Balancing Strategies

Scenario Option 1 Option 2Flexion Gap = Extension Gap

Both resection blocks are set to ‘0’ . The implant thickness is resected .

Extension Gap > Flexion Gap

The extension gap is adjusted to the flexion gap . There is less resection in the distal cut . The distal cutting guide is set at -1 or -2 .

The flexion gap is adjusted to the extension gap . There is more resection in the posterior cut (2-in-1 cutting guide) . The 2-in-1 cutting block is set to +1 or +2 .

Extension Gap < Flexion Gap

The extension gap is adjusted to the flexion gap . There is greater resection distally than posteriorly . Cutting block is set to +1 or +2 .

On the 2-in-1 cutting guide, that is the posterior cut, no less can be resected .

Fig . 15Fig . 14

A: Distal cutting guide NM540R, B: Femur 2-in-1 cutting guide left/right NM006R – NM011RA B

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4. Femur Preparationa. Distal Femur Cut■ Place the distal femur cutting guide onto the trial spacer

with the leg placed in extension .

■ For alignment to the mechanical axis, the rod and the adapter are attached to the spacer . The rod points towards the femoral head .

Fig . 17Fig . 16

A B CA: Trial Spacer NM651R – NM653R, B: Distal femur cutting guide NM540R, C: Femoral alignment guide NM560R, D: Alignment check rod with sleeve NE331R, E: Alignment check rod NP471R

ED

■ Fasten the cutting guide with two headless pins . Be sure that the cutting guide is in contact with the distal and anterior condyle .

Note: The distal cutting guide should slide easily along the spacer tool.

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■ Before resection, remove the spacer and bring the knee to 90° flexion .

Fig . 19Fig . 18

A B C D E FA: Headless pins 63 mm NP583R, B: Pin driver NP613R, C: Acculan® drill, D: Tibial preparation plateau T1-T6 NM591R – NM596R, E: Acculan reciprocating saw, F: Femoral size determination guide NM667R

Caution: The tibial plateau must be protected during resection using the tibia preparation plate.

Femoral Sizing

■ It is recommended to measure the femur size on the X-ray . The posterior part is difficult to assess intra-operatively . The femur sizer is used to determine the size of the femur component .

■ Place the femoral sizer onto the spacer with the side marked “F” for fixed version (facing outward) . The sizer is placed onto the previously planned level of the spacer .

■ The femur sizing instrument measures the anterior section of the femoral component shield . The distal resection should also be covered as much as possible .

Note: The spacer contains ridges on the side which corresponds to the femoral size. The sizer should be placed at “0” and slide forward. Careful attention should be made to ensure the femoral size guide is placed on the same groove on both sides of the spacer.

Note: Please make sure you can read “F” on the femoral sizer.

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Fig . 20

4. Femur Preparation (continued)b. Femur Chamfer and Posterior Cuts

■ Place the 2-in-1 cutting guide onto the spacer with the knee in 90° flexion .

■ The 2-in-1 cutting guide is placed flush against the distal surface and posterior condyle .

Fig . 21

A: Trial Spacer NM651R – NM653R, B: Femur 2-in-1 cutting guide left/right NM006R – NM011RA B

■ Based on the tibia cut, the rotation of the femur is adjusted . In the case of a medial or lateral overhang of the cutting guide, translation in the medial/lateral plane can be adjusted .

Note: Protection of the surrounding soft tissue of the knee joint is imperative! We recommend the use of Hohmann or collateral retractors for protection.

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■ The resection block is fastened with two headed pins . The anterior pin is 30 mm long (NP585R), and the posterior pin is 50 mm long (NP586R) .

Fig . 23Fig . 22

A: Headed pins 30 mm NP585R, B: Headed pin 50 mm NP586R, C: Pin driver NP613R, D: Acculan® drill, E: Tibial preparation plateau T1-T6 NM591R – NM596R, F: Acculan saw

A B C FD

■ Make the posterior cut first, then the chamfer cut is made .

Note: Either the trial spacer or tibia preparation plateau should be used to protect the tibia.

E

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Fig . 24 Fig . 25

5. Tibia Sizing and Preparation■ Use the hook to measure the AP dimension of the tibia

and tibia implant size .

A: Tibial size measurement instrument AP NM903R, B: Tibial preparation plateau T1-T6 NM591R – NM596RA B

■ Place the corresponding size tibial plate on the tibial cut . The plate should not overhang on the sides . If necessary, a new sagittal cut should be performed to enlarge the ML surface . It is important during this process to keep the footprint of the cruciate ligament intact .

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■ With the longer end of the tibial hook, the tibial plateau should be placed even with the posterior edge of the tibia .

Fig . 27Fig . 26

A: Headed pin 50 mm NP586R, B: Pin driver NP613R, C: Acculan® drill

A B C

■ Fixate the tibia plateau with a pin .

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■ The tibial peg hole is prepared using the tibial drill . Leave the peg in place for additional stabilization .

■ The peg hole can be prepared at an angle up to 10° .

Fig . 29Fig . 28

A: Tibial preparation plateau T1-T6 NM591R – NM596R, B: Headed pins 30 mm NP585R, C: Tibial peg drill NM597R, D: Pin driver NP613R, E: Acculan® drill

A B C ED

■ The fin is prepared using a reciprocating saw, then finished using the tibial osteotome .

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■ Connect the fin punch to the handle and then hit it into place .

Fig . 30

A: Acculan® saw, B: Osteotome for tibial fin NM598R, C: Handle for impactors NM590R, D: Tibial fin punch NM599RA B C DA

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Fig . 31

6. Final Femur Preparation■ Refer to page 9 for the Femur Trial Insertion Instrument -

Assembly Instructions .

■ Connect the femoral trial with the insertion instrument .

■ If the medium 2-in-1 resection block was used (sizes 2-3-4), the appropriate femoral size can now be chosen .

■ Remove the handle

Fig . 32

A: Tibial preparation plateau T1-T6 NM591R – NM596R, B: Headed pins 30 mm NP585R, C: Femoral trial, D: Femoral trial holder NM609R, E: Femoral peg drill NM587R, F: Pin driver NP613R, G: Acculan® drill

B C D E F G

■ Before drilling, align the femoral trial in the ML position so it sits centrally above the tibial plateau and there is no anterior, medial, or lateral overhang .

■ The femoral trial is fixated using a headed pin .

V - 2. Femur Trial Insertion Instrument - Assembly Instructions

A

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■ Use the femoral drill pegs to prepare the two parallel peg holes . Leave the first drill peg in place until the second peg hole is drilled .

■ Remove the drill pegs and insert the femoral trial fixation holder into the peg holes .

Fig . 34Fig . 33

A: Fixation trial-Femur F1-F5 holder: NM687R – NM689R, B: Osteophyte osteotome NM001RA B

Note: This step is particularly important, since osteophytes could interfere with the meniscus component during extension.

■ Use the osteophyte osteotome to remove osteophytes from the posterior edge for the femoral implant .

Recommendation: To eliminate micro movements when drilling the peg holes, start with the bottom hole first .

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Fig . 36

7. Trial Reduction and Implant Final Components■ For the trial reduction, the trial meniscus components

should match the height of the spacer used previously .

■ The side of the meniscus probe that is labeled trial tibia should be used . The other side is for the final implant . The trial meniscus component is inserted until it stops .

Fig . 35

A: Tibial preparation plateau T1-T6 NM591R – NM596R, B: Head pins 30 mm NP585R, C: Meniscus test spacer, NM620 – NM624, D: Femoral trial F1-F5 NM610R – NM619R, E: Fixation trial femur NM687R - NM659R, F: Tibial test component, fixed, T1-T6 NM1056R – NM1067R

A B C D E F

■ Check the range of motion, the ligament tension, and the stability of the joints .

■ Optional: Trial reposition with the tibial trial implant and size-specific meniscus component .

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Fig . 38Fig . 37

Microfracturing

■ Remove the tibia trial .

■ Remove the femoral trial by first removing the clamp then use the handle to take off the femoral trial .

■ For unicondylar systems, a bone-preserving resection is typically used, so that the subchondral plate is often retained after preparation .

■ For better anchoring of the cement, it is recommended to prepare additional anchor holes on both the tibia and the femur .

■ For the tibia, a special microfracture punch is used that is connected to the impactor handle . Alternatively, the drill (2 .7 mm) can be used to drill holes .

A: Handle for impactors NM590R, B: Tibial perforation plate NM586R, C: Drill Ø 2 .7 mm GC316R, D: Pin driver NP613R, E: Acculan® drillA B C D E

■ For the femur, the drill (2 .7 mm) is used to drill holes .

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Fig . 40Fig . 39

8. Trial and Final ImplantFinal Implant

■ The implants are implanted in the following order: 1 . Tibia 2 . Femur 3 . Meniscus component

■ The femoral implant is inserted by hand and positioned with the femoral impactor .

A: Handle for impactors NM590R, B: Driver for femur NM894, C: Driver for tibial, mobile, NM893, D: Femur, cemented, fixed, F1-F5 NO180Z – NO189Z, E: Tibia, cemented, fixed T1-T6 NO156Z – NO167Z

A C D EB

■ All cement residue must be thoroughly removed before the femoral component is implanted .

■ The tibia is inserted by hand and positioned in with the tibial impactor .

■ All cement residue must be thoroughly removed .

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9. Cementing Technique■ Regardless of what fixation method is utilized, it is

critical that correct techniques are employed to help avoid complications and early failure . Also, even with accurate cuts it is important to ensure that components are fully seated, as it is easy for this to be obscured when cementing is taking place . Varus-valgus alignment can be significantly affected by unequal medial-lateral cement mantles and poorly seated components and there can be a tendency to place femoral components in relatively flexed positions if specific care is not taken .

■ It should also be noted that when definitive components are cemented in, they may prove more stable and seat better than the trials, which are often a little loose . It is therefore worthwhile to recheck the balancing and stability at this point so that further adjustments can be made if necessary . It has been possible to relate poor cementing techniques to early and continuous component migration, which in turn is of positive prognostic significance when predicting aseptic loosening so proper attention to the cementation steps must be taken .

■ Preparation of the bony surfaces and cancellous bone should be performed with pulsatile type lavage with the knee under a pressure tourniquet . This step allows for optimal cement penetration and interlocking to the bony

prepared surfaces and also removes bone debris that can serve as third body particles that increase polyethylene wear after surgery . The surfaces should be properly dried prior to cementation and appropriate exposure of all bony surfaces achieved . All of the surfaces should be pressurized for optimal cement penetration . Emphasizing the importance of effective cementation of the posterior femoral condylar surfaces is also recommended since it can have a significant effect on the longevity of the fixation of the femoral implant . A further point worth noting is that holding the knee out in full extension while cement is hardening is used to compress components down and possibly improve cement intrusion .

■ Care should be taken to completely remove all excess cement that protrudes from the implant bone interface . Any remnants of overhanging cement can impinge on surrounding soft tissue or can provide a source of debris that can serve as a generator of third body wear and may contribute to the demise of the fixation earlier than expected .

10. ClosureAfter cement polymerization and removal of all excess cement, thoroughly irrigate the joint . If a tourniquet is used, hemostasis is achieved after its deflation .

Close soft tissue in the normal layered fashion .

30


Overview of Instrument Options

Item No. Description Consisting of the following trays

NM601 univation XF Tibia Basic Femur Basic Femur FNM604 univation XF Tibia F

univation XF Meniscus Component

H* (in mm) 7 8 9 10 11

Thickness 4 5 6 7 8

univation XF Tibia

Dimensions ML AP

T1 25 .0 41T2 26 .5 44T3 28 .0 47T4 29 .5 50T5 31 .0 53T6 32 .5 56

*H = height of the tibial implant plus meniscus component . H is the dimensional specification on the packaging of the meniscus component .

univation XF Femur

Size Width Radius Distal Cut Post Cut

F1 18 22 6 .0 5 .5F2 19 23 6 .5 6 .5F3 20 24 6 .5 6 .5F4 21 25 6 .5 6 .5F5 22 26 7 .0 7 .0

All dimensions are in mm .

X. Instrument Overview

VIII. Implant Overview

All femur sizes are compatible with each tibia size.

IX. Femur/Tibia Compatibility

31

TF082

Qty. Item No. Description

1 NM583Runivation™ X support rod for tibia saw blade

1 NM584R univation X Tibial resection block LM

1 NM585R univation X Tibial resection block RM

1 NM586R univation X Tibial perforation plate

1 NM592Runivation X Tibial preparation plateau T2





1 NM597R univation X Tibial peg drill

1 NM598R univation X Osteotome for tibial fin

1 NM599R univation X trial instr . for tibial fin

1 NS342R IQ Tibial alignment system handle

1 NS344RIQ Tibial alignment system holder, bimalleolar clamp

1 NS345RIQ Tibial alignment system holder, bimalleolar clamp


1 GB414R Hexagonal chuck triangle shank

1 GC316RSpiral drill D 2 .7 mm L100/75 mm A0-shaft

1 NM1092Runivation X storage for general tibial instruments

1 NM590Runivation X Handle for modular impactors

1 NM903R univation X Tibia sizing instrument AP

1 NP580R Pin holder box (use for storage)

5 NP583R Headless pin 3 .2 mm x 63 mm

2 NP585R Headed pin 3 .2 mm x 30 mm

2 NP586R Headed pin 3 .2 mm x 50 mm

1 NP613R Driver for fastening pins, motor-driven

1 NS850R IQ cut control plate

1 TF082 Graphic template for NM1092R

1 JA455R Cover for Orthotray

Tibia Basic

32


TF085


1 NM001R univation X osteophyte osteotome

1 NM006Runivation X 2-in-1 cutting guide F1 LM

1 NM007Runivation X 2-in-1 cutting guide F1 RM

1 NM008Runivation X 2-in-1 cutting guide F2/F3/F4 LM

1 NM009Runivation X 2-in-1 cutting guide F2/F3/F4 RM

1 NM010Runivation X 2-in-1 cutting guide F5 LM

1 NM011Runivation X 2-in-1 cutting guide F5 RM

1 NM540R univation X distal cutting guide

1 NM609Runivation X holder femoral trial/prep . instrument

1 NM894 univation X femoral impactor



1 NE331R Alignment check rod w/ sleeve

1 NM1095Runivation X storage for general femoral instruments

1 NM560R univation X femoral alignment guide

2 NM587R univation X femoral peg drill

1 NM651R univation X trial spacer 7 & 8 mm

1 NM652R univation X trial spacer 9 & 10 mm

1 NM653R univation X trial spacer 11 mm

1 NM667R univation X femoral sizing guide

1 NP471R Alignment check rod

Femur Basic

33


1 NM610R univation™ X trial femur component F1 LM

1 NM611R univation X trial femur component F1 RM

1 NM612R univation X trial femur component F2 LM









1 NM620univation X meniscus trial spacer 7 mm





1 NM687R univation X trial femur fixation holder F1

1 NM688Runivation X for trial femur fixation holder F2-F4

1 NM689R univation X trial femur fixation holder F5

1 NM892 univation X for tibia impactor

1 TF085Graphic template for NM1095R+NM1096R

1 NM1096Runivation X for use of instruments, femur F

Femur

34


TF083


1 NM1056R univation XF tibia trial component T1 RM







1 NM1062R univation XF tibia trial component T1 LM




1 Nm1066R univation XF tibia trial component T5 LM

1 Nm1067R univation XF tibia trial component T6 LM

1 NM1093R univation XF storage for Instr . Tibia F

1 TF083 Graphic template for NM1093R


Tibia F (optional)

35

10

20

30

50

40

60

70

80

90

10

20

30

40

50

60

70

80

90

10

20

30

40

50

60

70

80

90

100

Saw blades: Sterile delivery, disposal items, packaging with 1 unit

■ Thickness: 1 .27 mm

19 mm GE271SU GE241SU GE249SU GE331SU

Aesculap

Length 90 mm

Aesculap Acculan 3 Ti

Length 90 mm

Aesculap Acculan 3 Ti

Length 100 mm

StrykerConnector

Width

Reciprocating saw blade 75/10/1 .0/1 .2 mm Reciprocating saw blade 75/12/1 .0/1 .2 mm

GC769R GC771R

FULLINSERT

10

20

30

40

50

60

70

80

XX01

23

GE3

32SU

1,27

Saw Blades

36


References1 Santana AE, Karimi A, Derflinger VG, Schütze A . Relating hardness-curve shapes

with deformation mechanism in TiAlN thin films indentation . Materials Science and Engineering . 2005;406(1-2):11-8 .

2 Reich J, Hovy L, Lindenmaier HL, Zeller R, Schwiesau J, Thomas P, Grupp TM . Präklinische Ergebnisse beschichteter Knieimplantate für Allergiker . Orthopäde . 2010 Mai;39(5):495-502 .

3 Jung KA, Kim SJ, Lee SC, Hwang SH, Ahn NK . Accuracy of implantation during computer-assisted minimally invasive Oxford unicompartmental knee arthroplasty . Knee . 2010 Dec;17(6):387-91 .

4 Perlick L, Bäthis H, Tingart M, Perlick C, Lüring C, Grifka J . Minimally invasive unicommpartmental knee replacement with a nonimage-based navigation system . Int Orthop . 2004 Aug;28(4):193-7 . Epub 2004 Mar 6 .

5 Jenny JY . Navigated unicompartmental knee replacement . SportsMed Arthrosc . 2008

Jun;16(2)103-7 .

6 Buckup K . Die unikondyläre Schlittenprothese Pro&Contra, Steinkopff Verlag, Darmstadt . 2005, Seite 51 .

7 Malchau H, Herberts P, Wang YX, Kärrholm J, Romanus B . Long-term clinical and radiological results of the Lord total hip prosthesis . A prospective study . J Bone Joint Surg Br . 1996 Nov;78(6):884-91 .

8 Krause WR, Krug W, Miller J . Strength of the cement-bone interface . Clin Orthop Relat Res . 1982 Mar;(163):290-9 .

9 MacDonald W, Swarts E, Beaver R . Penetration and shear strength of cement-bone interfaces in vivo . Clin Orthop Relat Res . 1993 Jan;(286):283-8 .

10 Maistrelli GL, Antonelli L, Fornasier V, Mahomed N . Cement penetration with pulsed lavage versus syringe irrigation in total knee arthroplasty . Clin Orthop Relat Res . 1995 Mar;(312):261-5 .

11 Alho A, Lepistö J, Ylinen P, Paavilainen T . Cemented Lubinus and Furlog total hip endoprosthesis: a 12-year follow-up study of 175 hips comparing the cementing technique . Arch Orthop Trauma Surg . 2000;120(5-6):276-80 .

12 Ebramzadeh E, Sarmiento A, McKellop HA, Llinas A, Gogan W . The cement mantle in total hip arthroplasty . Analysis of long-term radiographic results . J Bone Joint Surg Am . 1994 Jan;76(1):77-87 .

13 Huiskes R . Some fundamental aspects of human joint replacement . Analyses of stresses and heat conduction in bone-prosthesis structures . Acta Orthop Scand Suppl . 1980;185:1-208 .

14 Kawate K, Maloney WJ, Bragdon CR, Biggs SA, Jasty M, Harris WH . Importance of a thin cement mantle . Autopsy studies of eight hips . Clin Orthop Relat Res . 1998 Oct;(355):70-6 .

15 Grupp TM, Pietschmann MF, Holderied M, Scheele C, Schröder C, Jansson V, Müller PE . Primary stability of unicompartmental knee arthroplasty under dynamic compression-shear loading in human tibiae . Clin Biomech (Bristol, Avon) . 2013 Nov-Dec;28(9-10):1006-13 . doi: 10 .1016/j .clinbiomech .2013 .10 .003 . Epub 2013 Oct 10 .

16 Hauptmann SM, Weber P, Glaser C, Birkenmaier C, Jansson V, Müller PE . Free bone cement fragments after minimally invasive unicom partmental knee arthroplasty: an underappreciated problem . Knee Surg Sports Traumatol Arthrosc . 2008 Aug;16(8):770-5 . doi:10 .1007/s00167-008-0563-5 . Epub 2008 May 31 .

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38

Notes

39

All rights reserved. Technical alterations are possible. The information provided in this leaflet is distributed by Aesculap Implant Systems, LLC for educational purposes and not for the purpose of rendering medical advice. The material in this leaflet is not instructional and should NOT be relied upon by surgeons and staff as adequate training for performing the surgeries illustrated. This brochure is intended for health care professionals and employees, not for patients. The information presented is not a substitute for a medical examination and opinion by a licensed physician regarding a patient’s diagnosis or recommended course of treatment. This leaflet may be used for no other purposes than offering, buying and selling of our products. No part may be copied or reproduced in any form. In the case of misuse we retain the rights to recall our catalogs and price lists and to take legal actions.

©2014 AESCULAP. ALL RIGHTS RESERVED. PRINTED IN THE USA.Aesculap is an equal opportunity employer

Aesculap Implant Systems, LLC | 3773 Corporate Parkway | Center Valley, PA | 18034Phone 866-229-3002 | Fax 610-984-9096 | www.aesculapimplantsystems.com

Aesculap Implant Systems, LLC - a B. Braun company SOP-AIS-5001041 Rev. 01 DOC1156 1M 9/14

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Unicondylar Knee System Surgical Technique · about 1 to 2 cm tilted from the medial into the...

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