Ultrasound Guided MSK Procedures in Children

Mahesh Thapa, MD Associate Professor

Seattle Children’s University of Washington School of

Medicine

ANDREW KISHORE THAPA * - BORN APRIL 14, 2012

*NAUGHTIER THAN THIS PICTURE SUGGESTS

Disclosures

Under contract with Lippincott Williams and Wilkins (LWW) for Pediatric Radiology - A Teaching File Textbook

Simulation workshop for Ultrasound-guided MSK procedures

Acknowledgment

• William Shiels, DO

• Nationwide Children’s Hospital

Objectives

• At the end of this lecture the audience will be able to:

reiterate three basic US techniques to increase needle conspicuity.

define the key steps in performing arthrograms of the shoulder, hip, elbow, and ankle.

explain the concept of hydrodisection and how to remove a foreign body.

Needle Visualization

Direct visualization is most important for success & safety

Insertion angle and needle gauge

Steeper the angle of insertion, the more difficult it is to visualize the needle.

Large bore needle has larger surface of reflection and less flexible (resists bending out of plane of US beam)

If background echogenic, lower gain

Small Angle = Better Visualization

Cyst Aspiration/Mass Bx

Cyst Aspiration/Mass Bx

Better Visualization

Better Visualization

Advancing Needle

DON’T advance blindly

Always know where needle tip is

Jiggling the needle slightly may help identify the tip, but only make tiny movements

In general hold probe hand steady; try to move only the needle

Reverberation Artifact

Sound waves keep getting reflected back and forth between two parallel smooth surfaces.

Looks like several “copies” of the same object.

Occurs w/in core of the needle

Tip Scatter

Before the procedure

Review prior imaging

Obtain informed consent

Time-out

Ready US machine; choose appropriate probe

Scan area and plan approach. Make marks as needed

Prep and drape

A GODDESS AMONG MORTALS - LESCHI, SEATTLE

LIGHT OF MY LIFE - CARKEEK PARK, SEATTLE

US guided arthrograms Is it just as effective as as fluoro guided arthrograms?

Choudur, et. al. Ultrasound Guided Gadolinium Joint Injections for Magnetic Resonance Arthrography. Journal of Clinical US. 2010.

99/100 joints successfully injected under US (shoulder, hip, knee, wrists)

1 patient has vasovagal reaction after local anesthetic and procedure aborted.

No studies in kids, AFAIK

US guided arthrograms

How to know the needle is in the joint

Visualize and feel needle tip “hitting” bone/cartilage

Visualize contrast solution flowing away from needle tip.

Minimal resistance to injection

Until comfortable with technique, I suggest using fluoro to verify contrast is in joint

US guided arthrograms Shoulder

Elbow

Wrist - I prefer fluoro

Hip

Knee

Ankle

My Arthrogram Cocktail

15 cc NS

5 cc Optiray (isoversol) 320 - if fluoro used for verification

0.1 cc Magnevist (.5 mol/L solution)

? Lidocaine: Although less profound than the effects of bupivacaine, lidocaine 1% and lidocaine 2% also exhibit dose-dependent and time-dependent toxic effects on bovine articular chondrocytes.*

Karpie JC, Chu CR. Lidocaine exhibits dose- and time-dependent cytotoxic effects on bovine articular chondrocytes in vitro. Am J Sports Med 2007;35:1622-7

Shoulder arthrogram

Patient positioning

Similar to conventional arthrogram

Supine, elbow extended, forearm supinated

22 G Spinal needle (20 G if very muscular)

Shoulder arthrogram

Shoulder Arthrogram

Shoulder arthrogram

Landmarks

Identify Coracoid process

Aim for humeral head just inferior and lateral to Coracoid process

Best to place needle between subscapularis and biceps tendons

DISCOVERING THE LIGHT - DISCOVERY PARK, SEATTLE

Elbow arthrogram Patient positioning

Whichever position is most comfortable for patient and operator (eg, prone with with elbow flexed by head; sitting with elbow on table)

Visualize the radial head/capitellum joint as best you can

25 G Injection needle adequate for both local anesthesia and contrast injection

Elbow arthrogram

Elbow Arthrogram

Elbow Arthrogram

Elbow arthrogram

Landmarks

I prefer to approach from the lateral aspect of the radio-capitellar joint

Carefully examine radiographs, especially if hx of fracture. Look for osteophytes

Remember joint is very superficial.

THE RED BRIDGE OF COURAGKUBOTA GARDEN, SEATTLE

Hip arthrogram

Patient positioning

Leg fully extended with foot in slight internal rotation

22 G Spinal needle (20 G if very muscular)

Hip arthrogram/tap

Hip arthrogram

Hip arthrogram

Hip arthrogram Landmarks

Locate the femoral artery and stay at least 3 finger widths lateral to it.

Method 1: Locate the Greater Tuberosity in transverse plane

Aim for femoral neck at level of the mid aspect of the greater tuberosity

Method 2: Parallel to femoral neck and aim for neck “concavity”

GOING, GOING, GOING... - RIZAL PARK, SEATTLE

Ankle arthrogram

Patient positioning

I find the “mortise view” (extension and slight adduction of foot) position best opens up the lateral tibiotalar joint.

22 G spinal needle

Ankle arthrogram

Ankle arthrogram

Ankle arthrogram

Landmarks

Must locate dorsalis pedis and avoid it.

Aim for the lateral gutter of the tibiotalar joint

I find it easiest to find the lateral malleolus with the US probe and work medially until the joint space is observed.

Pitfalls How easy it is to find the needle tip depends on

Body habitus

e.g. obese patients

Type of joint injected

e.g. Shoulder: difficult to localize needle between biceps and subscapularis tendons

Capacity of the joint

Presence of intra-articular fluid

Benefits of US guided arthrograms

No radiation to patient or radiologist

Realtime visualization of needle tip entering joint space

Plane of orientation of joint space varies in different individuals. With US, probe and needle can be tailored to individual joint orientation.

Benefits of US guided arthrograms No need to inject radiopaque contrast prior to Gad

Avoids rare complication of allergic reaction to inadvertent venous injection of iodinated contrast *

Jordan RM, Mintz RD. Fatal reaction to gadopentetate dimeglumine. AJR Am J Roentgenol 1999;172: 1141.

If intra-articular fluid present, US guided injection much easier

Can be performed in any room

Disadvantages of US guided arthrograms

Entire joint is not depicted on a single image

Only subchondral surfaces are visualized

Learning curve longer with MSK US than with fluoro

Narrowed joint space & presence of osteophytes better assessed with fluoro, but these are not common issues in pediatric population.

US guided arthrograms Personal Experience at Seattle Children’s (December 2010 - June 2012)

Shoulder: 22/22. Average 15 min

Elbow: 12/12. Average 5 min

Hip: 19/19. Average 15 min

Ankle (tibio-talar) 3/3. Average 10 min

Subtalar: 0

SI: 0

EACH FOR THE SKY - POINT OF ARCHES, OLYMPIC NATIONAL PAR

Foreign Body Removal

Can be very time intensive & fruitless - set a time limit

Make sure to visualize the longest axis of foreign body

Look carefully for small FB

Pre-scan to visualize important structures to avoid

Foreign body appearance

TX OBLIQUE LONGITUDINAL

Foreign Body Removal (Hydrodisection)

Foreign Body Removal (Hydrodisection)

Foreign Body Removal (Hydrodisection)

Foreign Body Removal (incorrect method)

Foreign Body Removal (correct method)

Foreign Body Removal

Workshop

AKA FOREIGN BODY

AKA MASS

AKA JOINTS

AKA CYST

AKA PATIENT

FREED WILLIES - SAN JUAN ISLANDS, WATHANK YOU thapamd@uw.edu