DOI:10.2214/AJR.05.0345
AJR 2006; 187:1432-1435
© American Roentgen Ray Society
A Novel Approach to Flexor Hallucis Longus Tenography
Michael S. Gelbart1,
Ashesh Parikh2,
Wincha Chong2 and
Louis A. Gilula2
1 Mallinckrodt Institute of Radiology, Washington University School of Medicine,
510 S. Kingshighway Blvd., St. Louis, MO 63110.
2 Washington University School of Medicine, St. Louis, MO 63110.
Received February 28, 2005;
accepted after revision November 10, 2005.
Presented at the 89th Scientific Assembly and Annual RSNA Meeting, 2003,
Chicago, IL.
Address correspondence to L. A. Gilula.
Abstract
OBJECTIVE. This article presents a technically simple and more
accurate approach to flexor hallucis longus (FHL) tenography than any we found
reported in the literature.
CONCLUSION. Tenography is used to evaluate and treat tenosynovitis.
Standard FHL tenography protocol involves either direct percutaneous access of
the FHL synovial sheath posterior to the medial malleolus or indirect filling
of the FHL sheath from an injection of the flexor digitorum longus (FDL)
tendon sheath, which often communicates with the FHL tendon sheath. However,
with these methods, difficulty entering the FHL sheath may be encountered. We
adapted our technique to access the FHL sheath as it courses below the
sustentaculum talus. Our early experience with five cases using this technique
reflects a 100% success rate with accurate needle placement within the FHL
tendon sheath, thereby improving procedural efficiency.
Keywords: ankle • flexor hallucis longus • tenography
Introduction
Tenography, first described in 1970
[1], is a minimally invasive
technique in which the synovial sheath surrounding a tendon is opacified with
percutaneously administered contrast. Tenography is highly accurate in showing
tendon sheath blockage, various tendon sheath abnormalities of tenosynovitis,
and, rarely, masses in the sheath
[2,
3]. In addition, tenography
enables the diagnostic or therapeutic injection of an anesthetic or steroid
into the tendon sheath, a useful adjunct to nonoperative management of
tenosynovitis [4,
5].
Posttraumatic and chronic inflammatory conditions of the ankle tendons can
be diagnostically challenging sources of ankle pain
[2-8].
Although flexor hallucis longus (FHL) dysfunction is an uncommon cause of
ankle pain [1,
9], its accurate diagnosis is
important for clinical treatment. With chronic, repetitive injury, the FHL
tendon may develop stenosing tenosynovitis or tendinosis. Patients present
with posteromedial ankle pain or pain at the distal medial arch that is
exacerbated by ankle motion. In particular, flexion of the great toe
exacerbates the pain. Occasionally there is clicking or popping with movement
of the first toe. This clinical presentation encompasses an extensive spectrum
of possible causes. Not surprisingly, patients are frequently misdiagnosed and
effective treatment is delayed. Because stenosing tenosynovitis cannot be
confirmed by conventional radiographs, sonograms, or CT images, and MR images
may be associated with high false-positive rates for abnormal tendon effusions
[9], the diagnostic evaluation
of suspected FHL disease in chronic ankle pain may require tenography. We
present a technically simple and more accurate approach to FHL tenography that
has not been previously reported in the literature.
Anatomy
The FHL tendon originates in the distal two-thirds of the fibula, extends
from the posterior aspect of the FHL muscle to course in the groove of the
distal tibia posteriorly, and then passes below the flexor retinaculum (Figs.
1A,
1B, and
1C). At the level of the medial
malleolus, the neurovascular bundle of the posterior tibial artery and nerve
is medial to the FHL. The tendon continues within the groove of the posterior
talus and passes along the inferior surface of the sustentaculum talus of the
calcaneus, where the FHL is anatomically isolated from the posterior tibial
(PT) and flexor digitorum longus (FDL) tendons. On the plantar aspect of the
foot, the FHL passes superior to the FDL. In 50% of patients, a communication
is present between the FHL and FDL tendon sheaths at this level, allowing
simultaneous filling of these sheaths during tenography
[7]. The FHL tendon continues
along the inferior aspect of the first metatarsal to insert at the base of the
distal phalanx of the first toe. FHL contraction flexes the first toe and
plantar flexes and inverts the foot.
View larger version (109K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 1A —MR images show relationship of flexor tendons to each other,
sustentaculum talus, and neurovascular bundle in 35-year-old man. Axial T1 =
weighted (TR/TE, 500/15) weighted image of ankle at level of midportion of
sustentaculum talus (star). Neurovascular bundle (gray
arrow) shown anteromedial to flexor hallucis longus (long arrow)
tendon at level of sustentaculum talus. Posterior tibialis tendon (short,
thick arrow) and flexor digitorum longus tendon (short, thin
arrow) are shown.
|
|
View larger version (114K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 1B —MR images show relationship of flexor tendons to each other,
sustentaculum talus, and neurovascular bundle in 35-year-old man. Coronal T1 =
weighted (TR/TE, 500/15) weighted image of ankle at level of sustentaculum
talus (star) and mid subtalar facet joint. Flexor hallucis longus
tendon (long arrow), posterior tibialis tendon (short, thick
arrow), and flexor digitorum longus tendon (short, thin arrow)
are shown.
|
|
View larger version (152K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 1C —MR images show relationship of flexor tendons to each other,
sustentaculum talus, and neurovascular bundle in 35-year-old man. Sagittal T1
= weighted (TR/TE, 500/15) weighted image of ankle at level of sustentaculum
talus (star). Flexor hallucis longus (arrow) is shown.
|
|
Materials and Methods
Between May 31, 1985 and June 6, 2003, 927 ankle tenograms were performed
at our institution. All cases were reviewed to identify those that were
performed for FHL tenography. The cases performed for FHL tenography were
analyzed as to the approach used, whether directly into the FHL tendon sheath
posterior to the medial malleolus, through retrograde filling from injection
of the FDL tendon sheath, or by placement of the needle inferior to the
sustentaculum talus (the approach is described below). A tenogram was
considered successful when contrast filled the FHL tendon sheath and
unsuccessful when the sheath was missed because of extravasation or not filled
because of failure to fill the FHL retrograde from an FDL sheath
injection.
Our new approach to FHL tenography is as follows. The patient is placed in
a lateral decubitus position with the symptomatic medial side of the ankle
facing up and the rectangular-shaped sustentaculum talus profiled in the
lateral position under fluoroscopy (Fig.
2A). The skin is aseptically prepared and draped, and local
anesthetic (1% lidocaine) is injected for superficial anesthesia. A 25-gauge,
1-inch needle is introduced under fluoroscopic control along the inferior mid
surface of the sustentaculum talus until firm resistance is felt with the
needle tip against the osseous calcaneus
(Fig. 2B). Contrast material in
a 10-mL syringe with a flexible connecting tube is then attached to the
25-gauge needle. We use a preparation of two parts of iothalamate meglumine
(Conray 43, Tyco Health Care/Mallinckrodt) to one part of 1% lidocaine for the
injectate. Injection usually results in prompt filling of the FHL tendon
sheath with contrast flowing away from the needle
(Fig. 2C). If immediate filling
is not seen, the needle tip can be placed closer to the undersurface of the
sustentaculum talus. Alternatively, the needle can be withdrawn 1-2 mm and
contrast injected again to check intrasheath placement of contrast. The final
step of a therapeutic tenogram is to in-still 1 mL of a long- or medium-acting
steroid into the tendon sheath to assist in reducing or eliminating
inflammation and pain. We used 1 mL of methylprednisolone, 40 mg/mL
(Depo-Medrol, Pharmacia & Upjohn, Inc.) or 1 mL of triamcinolone acetonide
(Kenalog 40, Bristol-Myers Squibb). The intrasheath placement of the
nonradiopaque steroid can be confirmed by observing contrast dilution within
the tendon sheath under fluoroscopy. Fluoroscopic radiographs of the ankle are
then obtained during and after filling of the tendon sheath at different
degrees of obliquity to evaluate for abnormalities of the tendon and tendon
sheath (Figs. 2D and 2E).
View larger version (90K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 2A —Fluoroscopy of a 41-year-old woman. Lateral view of foot with
under surface of sustentaculum talus (arrows) in profile. Tip of
metal clamp points to undersurface of sustentaculum talus.
|
|
View larger version (114K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 2B —Fluoroscopy of a 41-year-old woman. Twenty-five-gauge, 1-inch
(2.54-mm) needle (white arrow) passed in a "bull's-eye"
fashion to midportion of the undersurface of sustentaculum talus (black
arrows).
|
|
Results
This new approach to FHL tenography has been used at our institution since
December 12, 2000. Of the 927 tenograms performed at our institution, 15
tenograms were dedicated to FHL examination, five of which were performed by
our new technique of percutaneously accessing the tendon sheath inferior to
the sustentaculum talus. Six tendon sheaths were accessed through the FDL and
four were unsuccessful. Using one of the two traditional approaches for FHL
tenography, only six of 10 percutaneous injections showed filling of the FHL
tendon sheath, yielding a 60% success rate. Failures occurred either because
of an inability to directly palpate the FHL tendon or a lack of communication
between the FHL and FDL tendon sheaths. By comparison, FHL tenography was
performed successfully on initial percutaneous puncture in all five instances
with our method of access at the inferior surface of the sustentaculum talus.
Two staff radiologists and one fellow performed the five tenograms with this
new technique.
Discussion
Accurately determining the source of chronic ankle pain can be
diagnostically challenging. Repetitive tendon injuries may progress to chronic
tendon derangement and the development of tenosynovitis. Although various
imaging techniques such as sonography, MRI, and CT are commonly used to assess
ankle dysfunction, tenography remains the imaging technique of choice for
evaluation of tenosynovitis, particularly if intrasheath pathology such as
adhesions is suspected. Sonography of ankle tendons permits a close look at
tendon fibers for tears through the entire tendon and for intrasubstance
tears. We routinely perform sonography of suspect tendons before tenography to
exclude such tears. If such a tear is identified, usually tenography is
canceled; we do not want to place steroids into a tendon sheath with a torn
tendon. Anecdotally, in our department, many cases with marked synovial
irregularities that are consistent with synovitis are seen on a tenogram but
are not seen on a sonogram. MRI has the major advantage of displaying
surrounding soft tissue and osseous anatomy other than just the tendon or
tendons of interest. Often the MRI diagnosis of tenosynovitis is made by the
presence of increased fluid in a tendon sheath rather than small tears within
the substance of a tendon. It is not clearly answered in the literature as to
whether MRI can show the small intrasubstance tendon tears that can be seen
with sonography. Finally, neither sonography nor MRI offers the opportunity to
effectively treat a patient with intrasheath steroid placement who is
debilitated by tenosynovitis; such treatment, however, can be accomplished
using tenography [5].
Prior standard protocols for FHL tenography in a small percentage of cases
may be associated with inadvertent access of adjacent structures, including
the tibial neurovascular bundle or synovial sheath of the PT
[5,
9]. In addition, these
techniques rely on the accurate physical assessment of all three medial ankle
tendons. We altered our technique to access the FHL tendon sheath as it passes
inferior to the sustentaculum talus. In this location, the FHL is isolated
from both the PT tendon sheath, which continues toward the tarsal navicular
bone, and the FDL tendon sheath, which passes medial to the sustentaculum
talus. The sustentaculum talus itself is an easily palpable and
fluoroscopically distinct landmark. In the region of the sustentaculum talus,
the FHL tendon is easily isolated from adjacent structures, including the
tibial neurovascular bundle and synovial sheaths of the FDL and PT. It is
theoretically possible that a needle placed toward the inferior surface of the
sustentaculum talus could touch a vessel or nerve in this area. However, use
of a needle as small as 25 gauge should not present a problem with respect to
the neurovascular bundle. If a nerve would be touched when the needle is
passed slowly and carefully, the needle tip could be angled slightly to pass
by that nerve. If any vascular structure were traversed in a fashion similar
to elsewhere in the body, it can be managed by direct compression. We had no
difficulty using fluoroscopy to place the needle along the undersurface of the
sustentaculum talus, especially in a "bull's-eye" technique
(Fig. 2B) at its midportion for
FHL tenography. This is in contrast to use of traditional techniques with
which it was difficult to access and evaluate the FHL.
Because of the referral nature of our practice, the series presented here
is small. Indeed, before developing this new approach to FHL tenography, we
discouraged its performance because of the frequent unsatisfactory filling of
the FHL tendon sheath that resulted when using other techniques. Although some
radiologists perform tenography regularly, some never perform it. Radiologists
who regularly perform FHL tenography may be more comfortable performing this
new technique. Our early experience with this technique of FHL tenography is a
100% success rate and no complications. Consequently, we expect to increase
the number of FHL tenographies we perform.
References
- Palmer DG. Tendon sheaths and bursae involved by rheumatoid disease
at the foot and ankle. Australas Radiol1970; 14:419
-428[Medline]
- Destouet JM, Monsees B, Gilula LA. Ankle tenography. In: Goldman
AB, ed. Procedures in skeletal radiology (multiple imaging
procedures). Orlando, FL: Grune and Stratton, 1984;679
-699
- Haller J, Resnick D, Sartoris D, Mitchell M, Howard B, Gilula L.
Arthrography, tenography, and bursography of the ankle and foot.
Clin Podiatr Med Surg 1988;5
: 893-908[Medline]
- Gilula LA, Oloff L, Caputi R, Destouet JM, Jacobs A, Solomon MA.
Ankle tenography: a key to unexplained symptomatology. Part II. Diagnosis of
chronic tendon disabilities. Radiology1984; 51:581
-587
- Schreibman KL, Gilula LA. Ankle tenography. A therapeutic imaging
modality. Radiol Clin North Am 1998;36
: 739-756[CrossRef][Medline]
- Reinus WR, Gilula LA, Lesiak LF, Blair VA, Winer M. Tenography in
unresolved ankle tenosynovitis. Orthopedics1987; 10:497
-504[Medline]
- Teng MM, Destouet JM, Gilula LA, Resnick D, Hembree JL, Oloff LM.
Ankle tenography: a key to unexplained symptomatology. Part I. Normal
tenographic anatomy. Radiology 1984;151
: 575-580[Abstract/Free Full Text]
- Cheung Y, Rosenberg ZS, Magee T, Chinitz L. Normal anatomy and
pathologic conditions of ankle tendons: current imaging techniques.
RadioGraphics 1992;12
: 429-444[Abstract]
- Schulhofer SD, Oloff LM. Flexor hallucis longus dysfunction: an
overview. Clin Podiatr Med Surg 2002;19
: 411-418[CrossRef][Medline]
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
Top
Abstract
Introduction
