Chapter 7
Ultrasound-guided
procedures
205
Needle aspiration of synovial fluid and intra-
lesional injection of various compounds are very
common procedures in rheumatological practice.
Local steroid injection, in particular, is relatively
simple and cost-effective and may be alternative
or adjunctive to systemic drug therapy in several
rheumatological conditions [1-5]. Both efficacy
and side effects of the injection depend on the
correct placement of the tip of the needle inside or
around the lesion. Particular attention must be
taken to avoid direct needle contact with nerves,
tendons, articular cartilage and blood vessels [6].
Intra-articular and intra-lesional therapy is usu-
ally performed using palpation and bony land-
marks for guidance. Conventional blind inter-
ventional procedures may be particularly prob-
lematic when a small and/or deep target has to be
reached, or when an injection has to be carried
out into a dry joint.
It has been reported that 50% of conventional
joint injections are placed incorrectly [7-8].
US guidance during such procedures may min-
imize both the difficulty and margin for error dur-
ing intra-lesional therapy. This approach is, how-
ever, still very limited in rheumatological practice.
US-guided injections can be performed using the
method where the skin surface is marked after the
detection of the most appropriate entrance point
and the measurement of the depth of the target
area, or under direct visualization of needle place-
ment during real-time scanning [1, 2].
US-guided injection under direct visualization
should be performed according to the following
principles:
1. Baseline US assessment to explore the target
area and evaluate the indication for the planned
injection therapy.
2. Definition of the best US window to optimize
visualization of needle placement within the
target area.
3. Antiseptic swabbing of both the injection site
and the surface of the probe.
4. Placement of a thin layer of sterile gel on the
skin of the patient.
5. Continuous monitoring of the needle progres-
sion within the soft tissues on the screen with
particular attention to the tip of the needle,
which is placed within the target area.
6. Visualization of the steroid suspension during
and after the injection (Fig. 7.1).
Rheumatoid arthritis.US-guided injection of triamcinolone acetonide (5 mg) into a metacarpophalangeal joint with proliferative
synovitis.a Placement of the tip of the needle (arrowhead) in the target area.b Visualization of the steroid suspension (d) during
the injection. m = metacarpal head; * = synovial fluid; + = synovial proliferation
Fig. 7.1 a, b
a b
206 Musculoskeletal Sonography
On longitudinal scans, when the needle is per-
pendicular to the US beam it appears as a sharply
defined echoic band with strong posterior rever-
berations. On transverse scan, the needle appears as
a small hyperechoic round spot that can be easily
identified by dynamic assessment (fine movements
of the syringe).
Confirmation of the needle’s correct position-
ing can be obtained by direct observation by inject-
ing air or under power Doppler control (the inject-
ed fluid is visualized as a patch of color).
Needle placement is quick and easy to perform
when marked distension of the joint cavity is pres-
ent. Optimal visualization of the needle depends
on the correct alignment between the needle and
ultrasound beam.Accurate positioning of the probe
is critical to obtain a clearly defined image both of
the needle and the target site (Fig. 7.2).
Local injection therapy has a well-established
role in patients with tenosynovitis.
The cost/benefit ratio largely depends on the cor-
rect placement of the needle into the widened ten-
don sheath.An experienced rheumatologist should
be able to perform a safe and accurate intra-lesion-
al injection in most patients with tenosynovitis. The
main problem is taking care to avoid contact between
the tip of the needle and the tendon (Fig. 7.3).
The conventional blind approach to intra-lesion-
al injection cannot avoid the theoretical risk of caus-
ing damage to tendons and surrounding structures.
Joint effusion in knee osteoarthri-
tis. US-guided aspiration using a
supra-patellar transverse scan with
the knee extended. a, b Different
steps during synovial fluid (*) aspi-
ration. The arrowhead indicates
the tip of the needle. f = femur;
t = quadriceps tendon
Fig. 7.2 a, b
a b
Carpal tunnel syndrome due to rheumatoid tenosynovitis of the finger flexor tendons. Position of the tip of the needle is accu-
rately visualized both on transverse (a) and longitudinal (b) scans.arrowhead = tip of the needle; f = finger flexor tendons;n = medi-
an nerve; t = flexor carpi radialis tendon
Fig. 7.3 a, b
a b
Ultrasound-guided procedures 207Chapter 7
The injection of steroids within a widened tendon
sheath under US control appears to be very effective
in minimizing this risk. The progression of the nee-
dle can be accurately controlled “step by step” on
the monitor until the tip of the needle is properly
placed within the tendon sheath.
Bursitis is a very common problem in rheuma-
tological practice. Injection of steroid is an effec-
tive and safe procedure in non-responders to other
conservative therapeutic options, including rest,
local application of ice and anti-inflammatory
medication. The US approach to patients with sus-
pected bursitis serves three purposes: firstly, con-
firmation of the diagnosis; secondly, aspiration of
synovial fluid for microscopic examination and
thirdly, correct placement of the needle for steroid
injection.
US is very useful for the detection of popliteal
cysts and for careful assessment of their content.
Once the inner structure of the cyst is established,
it is possible to define an appropriate therapeutic
approach that depends on the cyst characteristics.
Needle aspiration of synovial fluid and steroid
injection within a popliteal cyst under US control
are indicated especially in patients with large cysts
due to a valve effect of the synovial tissue. US con-
trol is critical to avoid puncture wounds of nerves
and/or blood vessels and to ensure the correct posi-
tion of the tip of the needle especially in patients
with loculated cysts.
References
1. Koski JM (2000) Ultrasound guided injections in rheu-
matology. J Rheumatol 27:2131-2138
2. Grassi W, Farina A, Filippucci E, Cervini C (2001) Sono-
graphically guided procedures in rheumatology. Semin
Arthritis Rheum 30:347-353
3. Grassi W, Farina A, Filippucci E, Cervini C (2002) Intra-
lesional therapy in carpal tunnel syndrome: a sono-
graphic-guided approach. Clin Exp Reumatol 20:73-76
4. Qvistgaard E, Kristoffersen H, Terslev L et al (2001)
Guidance by ultrasound of intra-articular injections
in the knee and hip joints. Osteoarthritis Cartilage
9:512-517
5. Balint PV, Kane D, Sturrock RD (2001) Modern patient
management in rheumatology: interventional muscu-
loskeletal ultrasonography. Osteoarthritis Cartilage
9:509-511
6. Kumar N, Newmon RJ (1999) Complications of intra-
and peri-articular steroid injections. Br J Gen Pract
49:465-466
7. Jones A, Regan M, Ledingham J et al (1993) Importan-
ce of placement of intra-articular steroid injections. Br
Med J 307:1329-1330
8. Eustace JA, Brophy DP, Gibney RP et al (1997) Compa-
rison of the accuracy of steroid placement with clini-
cal outcome in patients with shoulder symptoms. Ann
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