ORIGINAL ARTICLE

FS-3D-FISP for the diagnosis of ankle impingement syndromeand the evaluation of clinical outcomes of arthroscopic surgery

Shuijun Zhang • Chen Zhao • Bing Xia •

Danjie Zhu • Bingsong Qiu • Haifeng Gu •

Jianfei Hong • Qing Bi

Received: 14 May 2012 / Accepted: 25 August 2012

� Springer-Verlag 2012

Abstract This study aimed to assess the diagnostic value

of three types of MRI sequences and to observe the clinical

outcomes of arthroscopy surgery for ankle joint impinge-

ment syndrome. Ankle joint impingement syndrome was

confirmed by FSE-T2WI, FSE-PDWI, and FS-3D-FISP

MRI in 23 patients with arthroscopically proven ankle

impingement. All 23 patients underwent arthroscopic sur-

gery and the ankle joint function was evaluated before,

1 week after and 6 months after the operation. The patients

were followed-up for 12–64 months (average 28 months).

There was no significant difference in ankle function score

between preoperatively and 1 week postoperatively, but

86.96 % patients got overall excellent or good scores

6 months after the surgery, significantly higher than before

the surgery. The FS-3D-FISP MRI exhibited a good con-

sistency with arthroscopic examination and had higher

sensitivity and specificity for the diagnosis of ankle

impingement than FSE-T2WI and FSE-PDWI. In summary,

arthroscopy surgery for ankle impingement syndrome has

several advantages such as good efficacy, minimal trauma,

quick recovery, and much less complications. The preop-

erative FS-3D-FISP MRI allows accurate diagnosis and

positioning of ankle impingement syndrome.

Keywords Ankle joint impingement syndrome �Arthroscopy � MRI � FS-3D-FISP

Introduction

Ankle impingement syndrome is now accepted as a sig-

nificant cause of chronic injury. Ankle impingement is

derived from repetitive ankle sprains and its symptoms

include tenderness, swelling, and pain on ankle movement.

It is difficult to diagnose ankle impingement which has the

incidence of about 30 % in the general population and

40 % in athletes [1]. In general, nonoperative methods

should be chosen first for the treatment of ankle impinge-

ment. However, nonoperative treatment usually needs a

long recovery period and the results are sometimes unsat-

isfactory. When nonoperative treatment fails, significant

relief of ankle pain can be achieved by arthroscopic

debridement.

Magnetic resonance imaging (MRI) has been used to

assist the diagnosis of ankle impingement but the outcomes

are controversial [2–6]. In particular, three-dimensional

fat-saturated MRI has been shown to be more accurate than

conventional MRI in the detection of ankle impingement

[7–9]. Therefore, in this study we employed the fat-sup-

pressed three-dimensional steady-state rapid precession

imaging (FS-3D-FISP) MRI to investigate the efficacy of

this technique in the diagnosis of ankle impingement and

evaluate the clinical outcome of arthroscopic treatment.

Materials and methods

Patients

Between January 2003 and June 2009, 23 consecutive

patients (17 men and 6 women; age range 16–49 years with

the median age as 29 years) with the symptoms of ankle

impingement were enrolled in this study. Left ankle was

S. Zhang � C. Zhao � B. Xia � D. Zhu � B. Qiu � H. Gu �J. Hong � Q. Bi (&)

Department of Orthopedics and Joint Surgery,

Zhejiang Provincial People’s Hospital,

Hangzhou 310014, China

e-mail: biqing2@163.com

123

Eur J Orthop Surg Traumatol

DOI 10.1007/s00590-012-1078-9

involved in 9 cases and right ankle was involved in 14

cases. The duration of symptoms was 6–36 months with

the median duration as 14 months. All patients had history

of ankle sprain and complained of ankle pain and swelling,

and 10 cases had squat pain. Examination showed joint

swelling in 10 cases, limited dorsiflexion in 10 cases,

limited flexor in 3 cases, and no movement disorder in

other cases. All of the patients underwent preoperative

MRI examination including FS-3D FISP, FS 2D spin-echo

T2-weighted imaging (FSE-T2WI), and FS spin-echo

proton density-weighted imaging (FSE-PDWI). Ankle

arthroscopy was performed subsequently and the cartilage

damage was graded according to Mintz et al. [10]. The

grading system was as follows: 0, normal cartilage; 1,

abnormal signal but intact; 2, fibrillation or fissures not

extending to bone; 3, flap present or bone exposed; 4, loose

undisplaced fragment; 5, displaced fragment. The Ameri-

can Orthopaedic Foot and Ankle Society (AOFAS) ankle–

hindfoot score was assessed preoperatively, 1 week and

6 months postoperatively, and the efficacy was judged as

excellent for score of 85–100, good for score of 75–84,

normal for score of 65–74, and poor for score of less than

65, as described previously [11]. Written informed consent

was obtained from each patient and the study was approved

by the Ethics Committee of Zhejiang Provincial People’s

Hospital.

Operative procedures

The operation for ankle impingement was performed as

described previously [12]. Briefly, all patients were placed

in the lateral decubitus position under general anesthesia.

At the posterolateral aspect of the ankle joint, a 2.7-mm, 30

degree arthroscope was inserted into the subtalar joint

using posterolateral and accessory posterolateral portals.

During the initial inspection of the subtalar joint with this

approach, the posterolateral aspects of the ossicle and

surrounding inflamed synovial tissue were seen. A 3.5-mm

full-radius shaver was inserted, and a synovectomy of the

posterior subtalar joint was performed. When the impinged

fragment was visualized, it was carefully dissected from

the surrounding soft tissues using a banana knife and

removed with a grasper.

Statistical analysis

The sensitivity, specificity, and accuracy of MRI methods

for the diagnosis of ankle impingement were calculated by

using the arthroscopic results as the gold standard. The

differences in the sensitivities and specificities between

MRI methods were examined using a Kappa test and cat-

egorized as follows: j from 0 to 0.40, poor; j from 0.41 to

0.60, moderate; j from 0.61 to 0.80, good; and j from 0.81

to 1, perfect. Data were analyzed using the SPSS version

11.5 statistical analysis package (SPSS Inc., Chicago, IL,

USA). Examined data were assessed using the t test and v2

test. In each test, the data were expressed as the mean ± SD,

and p \ 0.05 was accepted as statistically significant.

Results

The signs of ankle impingement were examined by MRI as

described previously [10]. These included the articular

cartilage, fibrillation and fissures, flap, loose undisplaced

fragment, and displaced fragment. Both MRI and arthros-

copy could detect ankle impingement in all patients and

typical images in one patient were shown in Fig. 1. With

the arthroscopic findings as the gold standard, the sensi-

tivity for detecting ankle impingement was the highest for

FS-3D-FISP (92.86 %). The accuracy for detecting ankle

impingement was also the highest for FS-3D-FISP

(Table 1).

The mean follow-up duration of the assessment was 28

(12–64) months for all 23 patients. The incision was healed

within 7 days in all 23 patients and no serious complica-

tions such as vascular and tendon injuries, lower leg

compartment syndrome, infection, and deep vein throm-

bosis. One patient exhibited lateral dorsal skin numbness

that disappeared after half a year.

Ankle pain was relieved in most of the patients. The

surgical outcome was evaluated with the AOFAS ankle–

hindfoot score. Compared with the scores before the

operation, the scores got no significant improvement

1 week after the operation but were significantly improved

6 months after the operation (Table 2).

Discussion

Ankle impingement syndrome is common in clinical

practice, but its diagnosis rate is low mainly due to the

clinician’s lack of knowledge of the disease. Recently,

MRI has been accepted as an important approach for the

diagnosis of ankle impingement syndrome [2–6]. In our

preliminary studies, we found that conventional MRI

examinations including FSE-T2WI and FSE-PDWI could

not achieve a high accuracy for the diagnosis of cartilage

damage. Therefore, in this study we adopted the FS-3D-

FISP MRI for ankle cartilage imaging. The results showed

that FS-3D-FISP MRI exhibited a good consistency with

arthroscopic examination and had higher sensitivity and

specificity for the diagnosis of ankle impingement than

FSE-T2WI and FSE-PDWI.

Eur J Orthop Surg Traumatol

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Conservative treatment for ankle impingement is not

satisfactory. Open surgery could get rid of osteophytes,

but it is difficult to observe the damage of articular car-

tilage. In addition, it could destroy the local tissue, hin-

dering the recovery of joint function. Since the

development of arthroscopic minimally invasive surgery,

arthroscopic surgery has been proven the first choice for

the patients on whom the conservative treatment failed

[13]. Van et al. performed a prospective analysis of 62

patients who underwent arthroscopic surgery for ankle

impingement, after 2 years of follow-up 73 % of the

patients experienced overall excellent or good results and

90 % of those without joint space narrowing had good or

excellent results, demonstrating the efficacy of arthro-

scopic surgery [12]. In the present study, we followed-up

all 23 patients for an average of 28 (12–64) months and

found that 86.96 % patients got overall excellent or good

results 6 months after arthroscopic surgery, significantly

higher than before the surgery.

In summary, arthroscopy surgery for ankle impingement

syndrome has several advantages such as good efficacy,

minimal trauma, quick recovery, and much less compli-

cations. The preoperative FS-3D-FISP MRI allows accu-

rate diagnosis and positioning of ankle impingement

syndrome.

Conflict of interest None.

References

1. Coull R, Raffiq T, James LE, Stephens MM (2003) Open treat-

ment of anterior impingement of the ankle. J Bone Joint Surg Br

85:550–553

2. Ferkel RD, Karzel RP, Del Pizzo W, Friedman MJ, Fischer SP

(1991) Arthroscopic treatment of anterolateral impingement of

the ankle. Am J Sports Med 19:440–446

3. Rubin DA, Tishkoff NW, Britton CA, Conti SF, Towers JD

(1997) Anterolateral soft tissue impingement in the ankle: diag-

nosis using MR imaging. Am J Radiol 169:829–835

Fig. 1 A 28-year-old man with chronic ankle pain for 2 years. a FS-

3D-FISP image showed partial tibial cartilage thinning (grade III)

(indicated by arrow). b Arthroscopic findings confirmed the ankle

impingement. Cartilage flap was formed in the lower end of tibia with

the subchondral bone partially nude (grade III)

Table 1 Sensitivity and specificity of the fat-suppressed CE 3D-FISP for assessing ankle impingement

MRI Sensitivity (%) Specificity (%) Positive predictive

value (%)

Negative predictive

value (%)

Kappa Kappa 95 %CI

FSE-T2WI 71.43 92.31 95.24 60.00 0.4054 0.2267, 0.5840

FSE-PDWI 82.14 100 100 72.22 0.4802 0.2962, 0.6643

FS-3D-FISP 92.86* 100 100 86.67 0.7590* 0.6109, 0.9071

* p \ 0.05 versus FSE-T2WI and FSE-PDWI

Table 2 The outcomes of the operation for ankle impingement

Time AOFAS score Excellent Good Normal Poor Rate of good or

excellent score (%)

Before the operation 63.3 ± 14.2 0 10 8 5 43.47

1 Week after the operation 74..4 ± 12.3 7 8 6 2 65.22

6 Months after the operation 82.9 ± 12.1* 11 9 2 1 86.96*

* p \ 0.05 versus before the operation

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4. Liu SH, Nuccion SL, Finerman G (1997) Diagnosis of antero-

lateral ankle impingement: comparison between MRI and clinical

examination. Am J Sports Med 25:389–393

5. Farooki S, Yao L, Seeger LL (1998) Anterolateral impingement

of the ankle: effectiveness of MR imaging. Radiology 207:357–

360

6. Jordan LK III, Helms CA, Cooperman AE, Speer KP (2000)

Magnetic resonance imaging findings in anterolateral impinge-

ment of the ankle. Skelet Radiol 29:34–39

7. Lee JW, Suh JS, Huh YM, Moon ES, Kim SJ (2004) Soft tissue

impingement syndrome of the ankle: diagnostic efficacy of MRI

and clinical results after arthroscopic treatment. Foot Ankle Int

25:896–902

8. Notohamiprodjo M, Kuschel B, Horng A, Paul D, Baer P,

Li G, Garcia del Olmo JM, Reiser MF, Glaser C (2012) 3D-MRI

of the ankle with optimized 3D-SPACE. Invest Radiol 47:

231–239

9. Choo HJ, Suh JS, Kim SJ, Huh YM, Kim MI, Lee JW (2008)

Ankle MRI for anterolateral soft tissue impingement: increased

accuracy with the use of contrast-enhanced fat-suppressed 3D-

FSPGR MRI. Korean J Radiol 9:409–415

10. Mintz DN, Tashjian GS, Connell DA et al (2003) Osteochondral

lesions of the talus: a new magnetic resonance grading system

with arthroscopic correlation. Arthroscopy 19:353–359

11. Kitaoka HB, Alexander IJ, Adelaar RS et al (1994) Clinical rating

system for the ankle—hindfoot, midfoot, hallux, and lesser toes.

Foot Ankle Int 15:349–353

12. Van Dijk CN, Tol JL, Verheyen CC (1997) A prospective study

of prognostic factors concerning the outcome of arthroscopic

surgery for anterior ankle impingement. Am J Sports Med

25:737–745

13. Richardson AB, Deorio JK, Parekh SG (2012) Arthroscopic

debridement: effective treatment for impingement after total

ankle arthroplasty. Curr Rev Musculoskelet Med 5:171–175

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