Zimmer Patient Specific Instruments (PSI) for Reverse ... · Instruments (PSI) for Reverse Shoulder...

© Zimmer July 28, 2014 Page 1

Zimmer® Patient Specific

Instruments (PSI) for

Reverse Shoulder Arthroplasty

Ryan Krupp, M.D.

Norton Orthopaedic Specialists

Louisville, KY

Anand Murthi, M.D.

MedStar Union Memorial Hospital

Baltimore, MD



Reverse Shoulder Arthroplasty:

Rationale and Overview

Anand Murthi, M.D.


Baltimore, MD

Goals of Reverse Shoulder

Arthroplasty

• Pain relief

• Function restoration

• Stability

• Durability


Complications in Reverse Shoulder

Arthroplasty

• Radiolucencies*

• Instability*

• Infection

• Glenoid loosening*

• Hematoma

• Humerus fracture (in op)

• Acromio/Scap fracture * Directly

influenced by glenoid placement

(Boileau P, Old J, Pinedo M, Zumstein MA. Problems, complications, reoperations, and

revisions in reverse total shoulder arthroplasty: a systematic review . J Shoulder Elbow

Surg. 2011 Jan;20(1):146-57.)

Glenoid Component Malposition

• Common challenges– Glenoid bone loss, erosion and deformity

– Lack of visibility; challenging exposure

– Lack of reference; scapula movement

• Resulting difficulties– Pre-operative definition of pre-morbid anatomy

– Defining the optimal implant and its location

– Executing the surgery, bone preparation and implant placement

• Potential complications– Dislocation

– Loosening

– Notching

– Excessive poly wear

Glenoid Pathology - Value of 3D Imaging

• Assess version

• Assess OA posterior/inferior bone loss

• Assess CTA superior/central bone loss

• Assess revision cavitary bone loss

• X-rays and 2D imaging have many

problems with inaccurate assessment(Hoenecke HR Jr, Hermida JC, Flores-Hernandez C, D'Lima DD. Accuracy of CT-based

measurements of glenoid version for total shoulder arthroplasty. J Shoulder Elbow Surg.

2010 Mar;19(2):166-71.)


Longevity of a total and

reverse shoulder prosthesis

largely depends on correct

positioning and fixation of

the glenoid component.

Positioning• Location of the center (AP and SI dimensions)

• Location of joint line: avoiding medialization

• Version, inclination and rotation angles

• Post placement within glenoid vault

Fixation

• Support bone preservation

• Baseplate contact area

• Maximal screw length

• Bi-cortical purchase

• Avoidance of critical structures

• Focus on Reverse Shoulder Arthroplasty (RSA) due to:

– Addressing potential RSA

complication rates

– Increasing demand for RSA

procedures

– RSA patient population trending younger

Zimmer PSI Shoulder

• Goal of Zimmer PSI Shoulder:

– Improve accuracy of positioning and fixation of glenoid baseplate

– Maximize performance

Cleveland Clinic Results

Effect of PSI for Achieving Desired Location of the Glenoid Component 31 Pts RCT

(Note: This PSI study conducted with non-Zimmer glenoid components, primary TSA)

(Michael D. Hendel, MD, PhD; Jason A. Bryan, MS; Wael K. Barsoum, MD; Eric J. Rodriguez, BS; John J. Brems, MD; Peter J. Evans,

MD, PhD; Joseph P. Iannotti, MD, PhD. Comparison of Patient-Specif ic Instruments w ith Standard Surgical Instruments in Determining

Glenoid Component Position: A Randomized Prospective Clinical Trial. J Bone Joint Surg Am, 2012 Dec 05;94(23):2167-2175.)


• Zimmer PSI demonstrated to reduce variability in

baseplate component and

screw placement for RSA

– Base plate accuracy better

than 5°of variation to plan

for both inclination/version (69% PSI vs. 29% Non-PSI)

– Screws placed within 7°of

variation to plan compared to the non-PSI technique

(88% PSI vs. 22% Non-PSI)

Cadaveric Study Results

Aggregate analysis of cadaver studies on Zimmer f ile including 29 shoulders

using Zimmer PSI (TR-TG120709-01 Warsaw Cadaveric Lab 2012 and TR-

FB121026-01 Chicago PSI Shoulder Cadaver Lab November 2012).

Element One: 3D Planning SoftwareElement Two:

PSI Bone Model

Element Three:

Patient Specific Instrument Guides

Three Elements of Solution

CT Scan

1

Surgeon Plan

2

PSI Guides

3

Quality

4

Recovery

85 7

SurgerySterilizationShipping

5 6

PSI Shoulder Process


Preoperative Planning Overview




Surgical Technique

Ryan Krupp, M.D.


Louisville, KY

PSI Shoulder Pre-op Report:

Baseplate Planned Position

Baseplate Sagittal View Baseplate Transverse View



Glenoid Reaming

Glenoid Reamed Surface Sagittal View

Baseplate Post Length: 15mm


Fixation Screw Length

Screw Insertion Anterior View Screw Insertion Coronal View

PSI Shoulder Instrument Guides

Roll Guide

Screw GuideReam Guide

Pin Guide


Intraoperative Video




Case Study

Anand Murthi, M.D.


Baltimore, MD

PSI Shoulder Case Review

• 75 y.o. female chronic right shoulder

pain

• Pseudoparalysis

• VAS = 9

• Left RSA 1 year ago doing well

• Right stage 4 CTA


Imaging

PSI Shoulder Imaging















PSI Shoulder Surgery
















Case Study

Ryan Krupp, M.D.


Louisville, KY

60 Y/O RHD FEMALE

H/O POLIO > 50 YRS

SEVERE OSTEOPOROSIS

SEVERE PAIN AND WEAKNESS

LEFT REVERSE TSA 2011

FE 60/ER 20/IR LB

3/5 STRENGTH





Transverse view, superior part of baseplate

Measure = 4.46 mm

Sagittal view at contact area

with the base plateSagittal view of the 3D model




QUESTIONS?



Reverse Shoulder Arthroplasty

Ryan Krupp, M.D.


Louisville, KY

Anand Murthi, M.D.


Baltimore, MD

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