Age / Sex : 46 / M

Chief complaint: left foot pain (10 months ago)

1) What is your impression?

Two weeks later, you can see the final diagnosis with a brief discussion of this case.

(Quiz는 quiz일 뿐이오니 답안은 한개만 보내주시기 바라오며, 복수의 답안을 보내주시는 분은 정답이 포함되어 있더라도 부득이 semi-correct answer로 처리토록 하겠습니다.)

Courtesy: 양익(Ik Yang), 한림대학교강남성심병원(Hallym University College of Medicine, Kangnam Sacred Heart Hospital)

Sinus tarsi syndrome (=Tarsal sinus syndrome)

Discussion

Findings:

Simple X-ray: within normal limit.

MRI

T1W sagittal MR image shows obliteration of fat by an area
of fluid like signal intensity in the subtalar joint.

Fat suppression proton density coronal MR image well
demonstrates high signal intensity of fluid at subtalar joint area with
adjacent diffuse bone marrow edemas.

Those findings are consistent with sinus tarsi syndrome.

Bone scan: A focal hot uptake at left foot, subtalar area

Post operative simple X-ray; subtalar arthrodesis with a
screw fixation

Differential Diagnosis:

   Joint effusion from
subtalar joint

   Bifurcate ligament
tear

   Talar neck stress
fracture

Diagnosis:  Sinus tarsi syndrome (=Tarsal sinus syndrome)

Discussion:

l  Sinus tarsi : conical shaped cavity located between
anterosuperior surface of calcaneus and neck of the talus

l  Etiology

- First described by O’Connor
in 1949

- He suggested that
excessive post traumatic scarring of the superficial ligament floor was
responsible for the symptoms

- Other cause –
hypertrophy of synovial membrane, ganglion cyst, entrapment of superficial
peroneal nerve & exostosis associated with DJD

- Etiology of sinus
tarsi syndrome is thought to be associated with post traumatic complications
following lateral ankle sprain

l  Symptom

- Pain over the lateral aspect of the foot,
with increased tenderness over the sinus area

l  MRI

- Obliteration of fat in the sinus tarsi
space

- The space itself is replaced by either
fluid or scar tissue, and the ligaments may be disrupted

- Osteoarthritis of the subtalar joint and
subchondral cysts may be present in advanced cases

* Normal recesses from the posterior subtalar
joint may frequently extend into the sinus tarsi and should not be misinterpreted
as pathologic conditions.

l  Treatment : relative rest, Ice, NSAID,
Electrotherapeutic modalities, surgery

References:

Sonin, Manaster. AMIRSYS. Diagnostic
imaging, Musculoskeletal : Trauma 7:174-177

Zehava S. et al. MR Imaging of the
Ankle and Foot. RadioGraphics 2000;20:S153-S179