PATH™

“Percuntaneous Assisted Total Hip Arthroplasty”

What is PATH®?

• PATH is an acronym that stands for Percutaneous Assisted Total Hip

• Why would a surgeon want to perform the PATH technique?– Benefits include

• Tissue Sparing – that minimizes functional tissue trauma that allows quick patient recovery

• Less Blood loss• Less Pain medication• Piriformis Release only technique that saves short external

rotators

• What does all this mean for the patient?– Quicker recovery and return to functional mobility

Why do MIS or TS techniques?(Minimally Invasive or Tissue Sparing)

To minimize functional tissue trauma for immediate post-op

mobility!!

What are the benefits for the Patient?

• No blood donation• No blood transfusion

– Reduces the risk of catching an infectious disease

• More functioning tissue for immediate post-op mobility

– Short external rotators spared– Abductors (medius and minimus) are

spared– Piriformis release only

• Reduced dislocation rate• Quicker rehabilitation• Quicker release from hospital• Shorter recovery back to an active

lifestyle

Pain Management Protocol• Medication Regimen for PATH® MIS StudyPre Op Hct and Hgb2 hours Pre operative • Oxycontin 10 mg. P.O.• Celebrex 200 mg. P.O.• Tylenol 1 gram P.O.General, spinal or epidural anesthesia can be utilized

Injection # 1: Into capsule and greater trochanter • Marcaine 30cc 0.5% (.25% each hip for bilateral cases)• Depo Medrol 80 mg *not in diabetics, immune-compromised or history of infection• Toradol 30 mgInjection #2: *change to a second syringe and needle• SQ: Marcaine 20 to 30 cc 0.5 % (0.25% each hip for bilateral) • Marcaine 30 cc ½ %Post Operative medications may be offered to patient as needed and as tolerated post operative for 48 to 72 hours:• Oxycontin 10mg-20mg Bid P.O.• Oxycodone 5mg PO Q. 2 hrs• Celebrex 200 mg PO BID• Tylenol 1 gram 6AM, Noon, 6 PM P.O.• Morphine Sulfate or Dilaudid as needed I.M. No Drain Mobilize Patient 4-6 hours weight bearing as tolerated

A-Class™ Advanced Metalwith

BFH® Technology

A-Class™ Advanced Metal

A-Class Advanced Metal innovation is a patent-pending process that is the solution to the reduction of wear and potentially the reduction of metal ions.

A-Class™ SUPERIOR PRODUCT

• Reduction of wear– 90% reduction in initial

(run-in) wear– 68% reduction in lifetime

wear of the implant

Run-In versus Steady State Wear• Run-In: Surface carbides

dislodged, 3rd-body abrasion, high wear rate

• Steady state: High polish, large contact area, smooth surface, low wear rate

New Implant

Run-In Wear

Steady State

A-Class™ SUPERIOR PRODUCT

• Optimized Bearing System– Surface Hardness– Component Clearances– Sphericity– Surface Finish– Surface Velocity

Optimized Bearing – Key Points• Surface Hardness

– The femoral head is responsible for 80-95% of the wear in a hip bearing system.

– The differential hardness between the head and the cup reduces metal wear. (the head is harder than the cup)

• Surface Finish– Extremely tight tolerance promotes a reduction in metal wear.

• Surface Velocity– Increased head size creates increased surface velocity.

• Greater Surface Velocity = Greater Fluid Film Separation– Increased fluid film separation decreases metal wear.

A-Class™ Advanced Metal Comparison(Tested under different conditions)

Company/Brand Size Volumetric Wear Rate

WMT - LINEAGE® 28mm .063 mm3/million cycles

DePuy - ULTIMA® 28mm .10 mm3/million cycles

Zimmer - METASUL™ 28mm .12 mm3/million cycles

Biomet 28mm .73 mm3/million cycles

Biomet 32mm .15 mm3/million cycles

Corin 40mm .48 mm3/million cycles

WMT - BFH™ 44mm .084 mm3/million cycles

WMT - BFH™ 54mm .143 mm3/million cycles

WMT - A-Class™ BFH™ 54mm .0625 mm3/million cycles

A-Class™ SUPERIOR PRODUCT

• Advanced Metal with BFH™ Technology– Reduction of dislocation– Increased range of

motion– Increased jump distance

A-Class™ SUPERIOR PRODUCT

A-Class™ SUPERIOR PRODUCT

Head Diameter Jump Distance Short Neck ROM Medium NeckROM

Long Neck ROM

36 mm 16.0 mm 147° 151° 155°

38 mm 17.0 mm 148° 152° 156°

40 mm 17.9 mm 150° 153° 157°

42 mm 18.8 mm 151° 154° 157°

44 mm 19.7 mm 152° 155° 155°

46 mm 20.7 mm 154° 156° 158°

48 mm 21.6 mm 157° 156° 159°

50 mm 22.5 mm 161° 157° 159°

52 mm 23.4 mm 164° 158° 160°

54 mm 24.4 mm 167° 159° 160°

56 mm 25.3 mm 169° 162° 160°

A-Class™ SUPERIOR PRODUCT

• An increase of 9.3 mm in jump distance from 36mm to 56mm heads.

• A range of motion that is substantially greater than the typical competitor’s 130° to 135° range of motion for smaller diameter heads.– WMT’s range of motion is 150° to 165 °

A-Class™ EASE OF USE

• Multiple BFH® Technology head sizes– 36mm – 56mm

• Long, medium, and short BFH® Technology neck options– Long = +3.5mm– Medium = 0mm– Short = -3.5mm

• Multiple PROFEMUR® stem options

A-Class™ EASE OF USE

Multiple cup options provideIntraoperative flexibility

6mm HA Cup with BFH®

6mm Cup 10mm Cup 6mm Spiked Cup 14mm SUPER-Fix™

A-Class™ INNOVATION

• A-Class™ Advanced Metal

• BFH® Technology• Modular Necks –

optimal restoration of normal hip biomechanics– Leg length– Varus, Valgus– Anteversion, Retroversion

Your Philosophy,

Our Modular Necks.

Patient Positioning

Peg is positioned proximal to the sacrum

Final peg is positioned on lower chest

Preliminary leg length is checked using relative knee height

Move patient anteriorly on table

to permit maximum adduction

Pre-operative Planning

Pre-op X-ray evaluation

Surgical TechniqueHip Exposure

Initial Incision• Place the hip in 20 to 30 degrees

of flexion• Foot resting on Mayo to facilitate

maximum internal rotation• Internal rotation will facilitate

maximum exposure of piriformis and conjoined tendon

• Outline the greater Trochanter• Mark the incision posterior to the

corner of the greater Trochanter, overlapping 1cm and extending obliquely 30º to 50º to the axis of the patient

Expose the fascia over the gluteus maximus • Cobb is used to tease apart

gluteus maximus muscle fibers

POST

ANT

A cobb elevator separates the muscle for reduced trauma

• Deeper dissection is continued proximal and posterior to the greater Trochanter

• Try not to disturb the Iliotibial band/tensor

The piriformis tendon is palpated

• On some occasions the piriformis is difficult to identify

• Internally rotate the leg for help identification of the piriformis

• The tip of the greater Trochanter should also be noted

The piriformis tendon is released

• Place blunt Hohmann just above piriformis tendon – deep to the capsular minimus muscle

• Then release piriformis as close to the attachment of the greater Trochanter as possible

• Preserve maximum piriformis length

Hohmann Retractor

Capsular incision • Continue to release soft tissues under piriformis to access the capsule

• After the Piriformis is released a J shaped capusular incision is made– Make the capsular

incision parallel to the neck axis and obturator internus tendon

• Intertrochanteric attachments are released

J IAnterior

Posterior

The neck is resected • The hip is adducted, flexed, and maximally internally rotated to dislocate the head

• An anterior acetabulum retractor is placed along inferior neck

• Hohmann is placed on superior neck

• The hip is in 45º of flexion and 60º-70º of internal rotation for neck resection

HEADFOOT

Anterior Acetabular Retractor

Neck Resection • Penetrate the anterior cortex to center of the femoral neck with oscillating saw

• Complete cut with reciprocating saw to minimize soft tissue damage

A schantz screw is threaded into the femoral head and used to extract the femoral head

Retractor positioning for acetabular exposure • Return to

approximately 30º flexion, 20º adduction and approximately 30º internal rotation

• Anterior retractor is placed on anterior rim

• This retractor should lever on the tip of the greater Trochanter and anterior rim of the acetabulum

Anterior Act. Retractor

Anterior Rim

Superior Pin

PINPOINT™ retractor placement

• PINPOINT™ Posterior Acetabular Retractor is placed posteriorly on the ischium between the capsule and labrum

PINPOINT™ retractor placement

• Insert two Steinmann pins to hold the PINPOINT™ retractor in place

• Complete the removal of the labrumSuperior

Posterior

PINPOINT™ Retractor & Pins are secured to the ischium

SUPERIOR

POSTERIOR

Conventional reamers have angular constraints

preventing optimal bone preparation

Percutaneous Portal Hole Location is Determined

• Find femur and mark with pen• Acetabulum Alignment guide

should be placed in main incision into socket

• The handle should be perpendicular to the table

• Abduction angle is approximately 40º to 45º when alignment guide is straight up out of the wound

• Cannula should be loaded on the Trocar / cannula inserter

• Mark entrance point and make initial stab with scalpel with #11

FOOTHEAD

ExternalAlignment Guide

Sharp Trocar

Cannula Placement

• Trocar is removed and cannula is left in the incision Superior

Cannula

Cannula location is behind the femur

FOOT

HEAD

FEMURPosterior

Anterior

Reaming the Acetabulum

Reamer basket is introduced through main incision

FOOT

HEAD

Reaming begins medially to remove any articular cartilage

Direct visualization to the acetabulum

Abducting (how much?) the leg allows medialization

FOOT

Reaming at a 40 to 45 degree angle for final socket sizing

HEAD

FOOT

Cup Placement

Conventional impactors prevent optimal implant positioning

Acetabular component is introduce in-line with incision (just like reamers)

Insertion is parallel to the incision then rotated into the acetabulum

Rotate cup into position

• Cup impaction is 40º of abduction and 20º -25º of anteversion using the alignment guide

• Special consideration should be directed to the patient positioning and bony landmarks for cup placement

Version and abduction are verified

20°

• With the crossbar portion of the handle perpendicular to the patient’s torso, anteversion is approximately 20º

40°20°

Cup Impaction

Need another image here of cup impaction

Femoral Retractor Placement

Retractors are positioned for femoral preparation

• Remove soft tissue from lateral neck and intertrochanteric wall

• The gluteus offset retractor is placed over the tip of the greater Trochanter

• The anterior acetabular retractor is placed over the medial calcar and under the remaining short external rotators

HEAD

Starting punch / Chisel is impacted lateral to the piriformis

• The leg should be in 45º -80º of flexion and 45-80º of internal rotation

• Chisel’s are inserted at the tip of the Greater Trochanter for maximum lateralization of the canal

It is important to maintain axial alignment

Reamer sleeve prevents skin trauma

PROFEMUR® Z Broach design preserves endosteal blood flow potential around the stem

Axial inline broaching is performed sequentially

Outrigger guide allows alignment check

• Alignment guide can be used to ensure proper alignment during broaching

Modular neck and femoral ball is inserted and the hip is reduced

• Key note – Metal trial necks can only be used with broaches

• Plastic trial necks are to be utilized with the final implant

Position is checked using tip of the Trochanter and lateral top of trial

Inter op x-ray to check position and leg lengths (recommended

for first 5 cases)

• A bump should be put under the ankle to keep the leg parallel to the table

• The hip should be stable in full extension and 70-80º external rotation with pressure applied to the posterior aspect of the Greater Trochanter

• In addition, hip should be stable between 30º and 90º flexion, 30º-50 adduction, 70º-80º internal rotation, as well as 120º flexion in neutral rotation and neutral adduction

Implant stability

!

Stability relies on STEM positioning…

…and NECK geometry!!!

Leg is positioned for closure

Post Op Events

• Straight leg raise in recovery room• Weight bearing – day one• Walking halls unassisted day two• Leave hospital day two or three• No morphine pain pump

THANK YOU