Augmented Glenoids are Here Now Wake Up Young Guys!!! Thomas W. - - PowerPoint PPT Presentation

Augmented Glenoids are Here Now – Wake Up Young Guys!!!

Thomas W. Wright MD University of Florida Department of Orthopaedics and Rehabilitation Gainesville, Fl.

Disclosure

• Design surgeon - Exactech
• Institutional Research support -

Exactech

The Problem – B2 Glenoid!

• TSA - Posterior worn B2 glenoid

–Worse functional results –Increased rate glenoid loosening –Increased failure rate –Many now recommend giving up TSA - for RTSA

Posterior Glenoid Wear

• Technically difficult to treat
• glenoid faces away from

surgeon – deltopectoral approach

• Worse clinical results

Posterior Glenoid Wear

Treatment Options

• Eccentric reaming
• Bone grafting
• Leaving glenoid retroverted
• Augmented glenoids
• RTSA

Eccentric Reaming

Literature conclusion for posterior wear:

• Farron article = 10° limit
• Gillespie article = 10° limit
• Clavet article = 15° limit
• Nowak article = 12°to 18° limit

Avg Consensus: ~12° posterior wear limit correct by eccentric reaming

• Worn > 12° then different method/solution required

How much can I correct it?

• Posterior wear humeral head translates posteriorly

–

Increased contact pressure

– Increased stresses in bone and cement – Increased implant micromotion – And potentially aseptic glenoid loosening…

What happens if I don’t correct it?

Can we do Better?

• Posterior augmented glenoid

–Decrease reaming saving valuable bone –Eliminate need bone graft –Rebalance joint

• Direct forces down glenoid neck
• Change shear forces to compressive

forces

Posterior Augmented Glenoid

• Wedge – Equinoxe Exactech
• 8 and 16 degree augmentation

–Correction on non articular side

• Pegs directed down axis glenoid
• Joint is rebalanced
• Step – Depuy
• Half Wedge – Tornier/Wright

• Posterior Augmented design – full wedge
• Minimize removal of anterior cortical bone – removing

ridge only

Posterior Augment Glenoid

Posterior Augmented Wedge - Composite

• Due to central peg being off-axis from the backside curvature, the

reaming axis and the peg axis are different.

• Off-axis cannulated reaming conserves bone by removing less than

would occur ordinarily during eccentric reaming to correct for the defect.

Bone Conservation

Glenoid Defect Off Axis Reaming w/ Augmented Implant Eccentric Reaming

The Question?

• Full wedge posterior

augmented glenoid - OA B2 glenoids

• TSA non-

augmented concentric non boney deficient glenoids

VS

Posterior Augment Glenoid Demographics

• > 100 shoulders to date

performed at University of Florida

–First prototype - 2010

Posterior Augment 2 Yr min F/U – Consortium Data Base

• 47 patients – Posterior Augmented Glenoid

(PAG)

– 31 male shoulders – 16 female shoulders

• Age – 66
• 47 control shoulders – Non augmented

glenoids (NAG) – Age, Diagnosis, Sex, and f/u matched

– NAG – standard all poly glenoid

SST UCLA ASES

Constant SPADI

Active Abduction Active Forward Flexion Internal Rotation Score Active External Rotation

Post Aug Avg ± St Dev 11.3 ± 1.2 32.3 ± 2.7 92.5 ± 10.2 76.7 ± 8.7 8.9 ± 13.4 138.9 ± 27.1 144.4 ± 18.8 5.4 ± 1.4 54.7 ± 21.1 Poly Peg Avg ± St Dev 10.8 ± 2.3 31.6 ± 4.6 87.5 ± 18.1 75.8 ± 13.6 13.1 ± 19.7 135.4 ± 28.3 152.7 ± 27.7 5.5 ± 1.2 48.6 ± 16.3 P value

0.1836 0.4312 0.1836 0.7394 0.2354 0.5492 0.1049 0.9855 0.1313

Comparison of Average and Post-op, Posterior Augmented Peg vs UHMWPE Peg aTSA Patients

Radiographic Lucent Lines

• PAG –

–Lucent line – 59% –Lucent line score (Lazarus) – 1.1

• NAG –

–Lucent line – 38% –Lucent line Score – 0.74

Radiographic Lines

• Composite/cage glenoids

have 1/3 lucent line incidence as all poly

– Now using mostly composite/cage posterior augmented glenoids – Too early to say if PAG lucent line issue will be solved

Shoulder Arthroplasty Subluxation Index (SASI)

• PAG Grashey –

–38 centered –2 superior subluxated –7 AWOL

• PAG Axillary –

–37 centered –3 anterior subluxated

Complications

• 2 – loose glenoids –

– Patient 1 happy – head centered in both planes – AEL 125 – AER 35 – Constant 72 – SPADI 11 – Patient 2 MVA - revised

• Stay tuned not sure we know the final story

• 1 reoperations to date – short term

f/u

• Improved ROM
• Improved Functional Outcomes
• No repeat posterior subluxation of

humeral head to date

Conclusion Short Term Results

Conclusion – Posterior Augmented

• Posterior

Augmented Glenoid

–Balances joint short term –Saves bone –Makes procedure

easier