P

Original Research

Prevalence of and Factors Associated With PosteriorTibial Tendon Pathology on Sonographic AssessmentNitin B. Jain, MD, MSPH, Imran Omar, MD, Armen S. Kelikian, MD,

Lodewijk van Holsbeeck, MD, Thomas H. Grant, DO

Objective: To assess the frequency of and factors associated with supramalleolar poste-rior tibial tendon (PTT) pathology that often may be missed on sonography because of thelimited field of view of ultrasound.Design: Retrospective cross-sectional study.Setting: Large academic center.

atients: Patients with medial ankle pain and tenderness and with normal radiographswho presented for sonographic assessment (n � 217).Methods: Two experienced musculoskeletal radiologists interpreted the studies by con-sensus.Main Outcome Measurement: PTT pathology.Results: Of the 217 patients, 33.2% had grade 1 PTT pathology (n � 72), 14.3% had grade2 pathology (n � 31), and 2.8% had grade 3 pathology (n � 6). When stratified by location,29.0% of patients (n � 63) had inframalleolar abnormalities, 11.5% had retromalleolarpathology (n � 25), and 11 patients had supramalleolar pathology (5.1%). Four patientshad PTT subluxation or dislocation. Age was significantly associated with PTT pathology(P � .02). A higher proportion of patients with supramalleolar (81.8%) and retromalleolar(72.0%) PTT pathology were women compared with patients who had inframalleolar(57.1%) PTT pathology. A higher proportion of patients with supramalleolar and retromal-leolar PTT pathology had grade 2 tears compared with those with inframalleolar PTTpathology (36.4% for supramalleolar, 44.0% for retromalleolar, and 22.2% for inframalleo-lar pathology).Conclusions: We present one of the largest studies on PTT pathology. PTT pathology canoccur in the supramalleolar area, a region that often is not assessed on imaging. Althoughdata are unavailable with regard to whether the natural history of supramalleolar PTT isdifferent from that of other regions, patients with supramalleolar PTT pathology had moresevere grades of tear and increased prevalence of tenosynovitis and were more often women.It is essential to recognize supramalleolar PTT pathology so that consequences of nontreat-ment such as medial arch collapse can be prevented.

PM R 2011;3:998-1004

INTRODUCTION

One of the most commonly dysfunctional tendons of the ankle and foot is the posterior tibialtendon (PTT). Early diagnosis and treatment of PTT dysfunction may prevent considerabledisability and surgery [1,2]. Presenting symptoms usually are pain in the region of themedial malleolus and the medial arch [3]. When PTT dysfunction is present, it is importantto determine whether the process is in an early stage, with only peritendinous involvement,or whether the tendon itself is involved, because treatment options differ [4].

The posterior tibial muscle originates from the interosseous membrane and adjacenttibial posterior surface in the proximal third of the leg [5]. Distally, the PTT lies beneath theflexor retinaculum, which is a strong and thin triangular-shaped fibrous band that extendsfrom the medial malleolus to the posterior aspect of the calcaneus and prevents the flexortendons from “bowstringing” as they curve around the malleolus [1]. The PTT has a

well-developed tendon sheath centered at the retromalleolar groove. The major site of

PM&R © 2011 by the American Academy of P1934-1482/11/$36.00

Printed in U.S.A.998

N.B.J. Department of Radiology, NorthwesternMemorial Hospital, Chicago, IL, Department ofPhysical Medicine and Rehabilitation, Spauld-ing Rehabilitation Hospital and Harvard Med-ical School, Boston, MA, Department of Ortho-pedics, Brigham and Women’s Hospital andHarvard Medical School, Boston, MADisclosure: nothing to disclose

I.O. Department of Radiology, NorthwesternMemorial Hospital, Chicago, ILDisclosure: nothing to disclose

A.S.K. Department of Orthopedic Surgery,Northwestern Memorial Hospital, Chicago, ILDisclosure: nothing to disclose

L.v.H. Department of Medicine, Wayne StateUniversity School of Medicine, Detroit, MIDisclosure: nothing to disclose

T.H.G. Department of Radiology, FeinbergSchool of Medicine, Northwestern University,676 North St Clair St, Suite 800, Chicago, IL60611 Address correspondence to T.H.G.;e-mail: t-grant@northwestern.eduDisclosure: nothing to disclose

An abstract of this study was presented at theRadiological Society of North America Scien-tific Assembly in November 2007.

Peer reviewers and all others who controlcontent have no relevant financial relation-ships to disclose.

Disclosure Key can be found on the Table ofContents and at www.pmrjournal.org

Submitted for publication January 20, 2011;accepted May 15, 2011.

hysical Medicine and RehabilitationVol. 3, 998-1004, November 2011

DOI: 10.1016/j.pmrj.2011.05.025

999PM&R Vol. 3, Iss. 11, 2011

insertion is the tarsal navicular tuberosity. The functions ofthe PTT include inversion of the foot (primary), plantarflexion, and stabilization of the hind foot to prevent excessivevalgus deflection of the tarsal bones [6].

PTT dysfunction (tendinosus or tear) has been describedmost often at its insertional site at the navicular tubercle(inframalleolar), and occasionally it has been described asadjacent to the medial malleolus (retromalleolar) [1,2,4,7-10] because of increased friction [11]. However, in ourexperience, the PTT also may be dysfunctional in the supra-malleolar region (ie, the region above the superior border ofthe medial malleolus), adjacent to the flexor retinaculum.Except for several case reports that describe patients withPTT dislocation, to our knowledge no published data havedescribed supramalleolar PTT dysfunction in a large cohortof patients. Unrecognized supramalleolar PTT pathology canlead to a delay in surgical or nonoperative treatment andultimately can cause midfoot changes and medial longitudi-nal arch collapse [1,2,7,12].

The objective of our study was to assess the frequency ofsupramalleolar PTT pathology in 217 patients with medialankle pain who presented for sonographic assessment at ourinstitution; to our knowledge, this is one of the largest reportson PTT pathology to date. We also assessed whether demo-graphic factors such as age and gender, flexor retinaculumabnormalities, grade of PTT tear, and PTT tenosynovitis wereassociated with the location (supramalleolar, retromalleolar,or inframalleolar) of PTT pathology. To date only 61 cases ofPTT subluxation or dislocation have been reported in themedical literature [3]. Therefore we also determined thefrequency of subluxation and dislocation of the PTT in ourpatient sample.

PATIENTS AND METHODS

Patient Sample

Between August 2003 and April 2007, patients who pre-sented to our institution for sonographic assessment of me-dial ankle pain were included in our study. The patients werereferred by 4 orthopedic surgeons and 3 physiatrists. Thepatients had an ultrasound examination within 2 weeks ofseeing their clinician. The patients were referred for sono-graphic assessment if they had medial ankle pain and poste-rior or medial ankle tenderness upon physical examination.These patients lacked other findings, such as weakness ofplantarflexion or inversion on manual muscle testing. Thepatients also had normal radiographs. No patients in ourcohort had pathologic flat foot or inflammatory arthritis. Inour clinical setting, patients with findings suggestive of PTTpathology such as weakness of plantar flexion-inversion andflat foot deformity are not referred for ultrasound or magneticresonance imaging (MRI) because a diagnosis is made on the

basis of clinical findings. PTT rupture has been associated

with valgus deformity of the hindfoot and abduction defor-mity of the forefoot, which produces a flat foot deformity[13]. A total of 217 consecutive records were retrospectivelyreviewed for inclusion in our study. The study was approvedby the institutional review boards at our institutions.

Ultrasonographic Assessment

Scanning was conducted according to a standardized tech-nique with a HDI 5000-Sono CT or an iU 22 ultrasoundmachine (Phillips Medical Systems, Bothel, WA) equippedwith a 12-5 or a 17-5 MHz multifrequency transducer. Thepatient was placed in a supine position with his or her footflush on the examining table. Longitudinal (long axis) andtransverse (short axis) images were then made, beginning atthe level of the myotendinous junction and proceeding dis-tally to the insertion at the navicular tuberosity. PTT pathol-ogy was assessed in 3 distinct anatomic regions: supramal-leolar (the region of the PTT above the superior border of themedial malleolus), retromalleolar (adjacent to the medialmalleolus), and inframalleolar (at the insertional site of thePTT on the navicular tubercle). The location of PTT pathol-ogy was noted as diffuse if more than one region was in-volved. The PTT sheath also was evaluated for signs oftenosynovitis. The hallmark of tenosynovitis is fluid collec-tion, hyperemia, and diffuse or focal thickening within thetendon sheath. Dynamic stress views (Figure 1) were per-formed by instructing the patient to lie on his or her side withthe ankle everted and then instructing the patient to activelycircumduct the foot with the transducer placed on the PTT atthe medial malleolus. Dynamic stress helps replicate stress onthe PTT during functional activities.

Two musculoskeletal radiologists (T.G., I.O.) retrospec-tively reviewed all of the studies, and a consensus on inter-pretation was reached between the 2 sonographers for allstudies. Data collected from sonographic assessment in-cluded whether the PTT was normal (Figure 2), the presence

Figure 1. Dynamic stress imaging of posterior tibial tendon(PTT), demonstrating subluxation. FDL � flexor digitorum longus;

MM � medial malleolus.

r

1000 Jain et al FACTORS ASSOCIATED WITH PTT PATHOLOGY

and grade of PTT pathology, the presence of PTT subluxationor dislocation (Figure 1), the appearance of the flexor reti-naculum (eg, normal, thickened, or tear) (Figure 3), and thepresence of tenosynovitis, which is characterized by fluid andhyperemia around the PTT (Figure 4). The presence of fluidand hyperemia around the PTT was used to characterizetenosynovitis [14]. A small amount of fluid in the tibialtendon sheath has previously been shown to be present inasymptomatic volunteers [15]. PTT subluxation was diag-nosed if the PTT was displaced anterior and medial to themedial malleolus. If PTT was displaced out of the retromal-leolar groove, then it was classified as dislocation.

Grades of PTT Pathology

PTT pathology was recorded in 3 grades, as described in themedical literature [2,4,16,17]: grade 1 (early): tenosynovitis,tendon thickening and surface irregularity, and roundedintrasubstance hypoechoic areas where the normal fibrillartendon architecture is disrupted (Figure 5); grade 2 (partial

Figure 2. Normal posterior tibial tendon (PTT) (left � medial;ight � lateral).

Figure 3. Retinacular thickening and demonstration of reti-nacular stripping and posterior tibial tendon (PTT) subluxation

on dynamic stress imaging.

tear): abnormal intrasubstance hypoechoic areas of disruptedtendon fibers that are generally linear or curvilinear and thatextend to the tendon surface (Figure 6); and grade 3 (com-plete tear): frank tendon disruption with fluid (anechoic) orgranulation tissue (hyperechoic debris) between the torntendon edges (Figure 7). The “empty groove sign” indicatescomplete disruption. If no abnormalities of the PTT were

Figure 4. (a) Tenosynovitis around an enlarged posterior tibialtendon (fluid in the tendon sheath). (b) Tenosynovitis aroundan enlarged posterior tibial tendon (hyperemia demonstratedin color Doppler). FDL � flexor digitorum longus; MM � medialmalleolus.

Figure 5. Grade 1 posterior tibial tendon (PTT) pathology

(arrow).

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1001PM&R Vol. 3, Iss. 11, 2011

found, it was recorded as normal. We are unaware of thevalidity and reliability of this grading system.

Statistical Analysis

We assessed baseline characteristics of patients includedin our study by using means and proportions. Thesecharacteristics include age and gender. We used the t-testand �2 test to assess differences in PTT pathology (anyrade) across age and gender. We also analyzed whetherharacteristics such as age, gender, grade of PTT pathol-gy, flexor retinaculum tear and/or thickening, and teno-ynovitis differed across locations (supramalleolar versusetromalleolar versus inframalleolar) of PTT pathology.

e used �2 and analysis of variance tests to determine

Figure 6. Grade 2 posterior tibial tendon (PTT) pathology.

Figure 7. Grade 3 posterior tibial tendon pathology. FDL � flexor

igitorum longus.

differences among groups. The continuous variable agewas normally distributed in our data. We used a P value of.05 to determine statistical significance.

RESULTS

A majority of patients in the entire sample of our study of 217subjects were women (63.6%), and the mean (standard de-viation [SD]) age of participants was 47.2 � 15.5 years (Table1). Most patients who underwent scanning had a normal PTT(49.8%). Grade 1 PTT pathology was most common(33.2%), followed by grade 2 pathology (14.3%). When ourentire sample was stratified by location of PTT pathology, 8cases of diffuse PTT pathology were found (Table 1). Theremainder of the cases were of pathology localized to aspecific region of the PTT. Sixty-three patients (29.0%) had

Table 1. Baseline characteristics of 217 participants undergo-ing sonography for posterior tibial tendinopathy and/or tear

Characteristics n (%) Mean � SD

Age (y) 47.2 � 15.5Women 138 (63.6)Side

Left 120 (55.3)Right 96 (44.2)Missing 1 (0.5)

Grade of tear*Normal 108 (49.8)Grade 1 72 (33.2)Grade 2 31 (14.3)Grade 3 6 (2.8)

LocationSupramalleolar 11 (5.1)Retromalleolar 25 (11.5)Inframalleolar 63 (29.0)Diffuse 8 (3.7)Unknown 1 (0.5)Not applicable† 108 (49.8)Missing 1 (0.5)

resence of tenosynovitis –Yes 81 (37.3)No 135 (62.2)Missing 1 (0.5)

lexor retinaculumNormal 207 (95.4)Thickening 7 (3.2)Tear 3 (1.4)

ubluxation or dislocationNone 213 (98.2)Subluxation 2 (0.9)Dislocation 2 (0.9)

urgical interventionYes 42 (19.2)No 172 (78.5)Missing 3 (1.4)

D � standard deviation.*Please refer to text for definitions of grades of tear and/or tendinopathy.†Not applicable because no tear or tendinopathy was present.

inframalleolar abnormalities, 25 patients (11.5%) had retro-

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1002 Jain et al FACTORS ASSOCIATED WITH PTT PATHOLOGY

malleolar pathology, and 11 patients (5.1%) had supramal-leolar pathology. A small percentage of patients had associ-ated findings of flexor retinaculum thickening or tear (4.6%),but a larger proportion (37.3%) had tenosynovitis. Of the217 patients in our study, 2 patients had subluxations and 2had dislocations (Table 1). These patients also had PTTpathology.

Age was significantly different across PTT pathology inour study. The mean age (SD) of the patients with PTTpathology was 49.6 � 16.1 years versus 44.8 � 14.6 yearsor those without PTT pathology (P � .02) (Table 2). Notatistically significant difference was found by gender in theresence of PTT pathology on ultrasound (P � .64).

When stratified by location of PTT pathology, a higherroportion of patients with supramalleolar and retromalleo-

ar PTT pathology were women compared with those withnframalleolar PTT pathology (81.8% for supramalleolar,2.0% for retromalleolar, and 57.1% for inframalleolar) (Ta-le 3). Similarly, a higher proportion of those with supramal-

eolar and retromalleolar PTT pathology had grade 2 tearsompared with those with inframalleolar PTT pathology36.4% for supramalleolar, 44.0% for retromalleolar, and

Table 2. Factors associated with posterior tibial tendinopathyand/or tear

Characteristics

Tendinopathy and/orTear*

P ValueYes, n (%) No, n (%)

Age 49.6 (16.1) 44.8 (14.6) .02Gender — — —

Women 71 (51.5) 67 (48.6) .64Men 38 (48.1) 41 (51.9) —

*All grades combined.

Table 3. Comparison of supramalleolar, retromalleolar, and in

Characteristic

Ten

Supramalleolar(n � 11), n (%)

Age 49.2 (19.8)Female gender 9 (81.8)Grade of tear†

1 6 (54.6)2 4 (36.4)3 1 (9.1)

resence of tenosynovitisYes 5 (45.5)

lexor retinaculumNormal 11 (100.0)Thickening 0 (0.0)Tear 0 (0.0)

All grades combined.

†Please refer to text for definitions of grades of tear and/or tendinopathy.

2.2% for inframalleolar). However, the differences amongroups did not achieve statistical significance.

DISCUSSION

We assessed the frequency of PTT pathology by its locationwith respect to the medial malleolus in 217 patients, whichrepresents one of the largest patient samples recruited to dateamong studies on PTT. We also assessed factors associatedwith PTT pathology and whether these factors differed whenstratified by location of PTT pathology. We report 11 cases ofsupramalleolar PTT pathology (5.1% of our patient sample)and 4 cases of PTT subluxation or dislocation. We alsoprovide data that suggest differences in demographics, gradeof the tear, and the presence of tenosynovitis among patientswith supramalleolar and retromalleolar PTT pathology com-pared with inframalleolar PTT pathology. Age was signifi-cantly different across the presence of sonographic evidencefor PTT pathology in our study.

PTT dysfunction and abnormalities on imaging have beenreported previously in the medical literature [2,7-9,14,16-25]. However, these reports focused on inframalleolar andretromalleolar PTT pathology. It is likely that the supramal-leolar PTT region is not evaluated by sonographers because ofthe limited field of view of ultrasound, although no data areavailable in this regard. Our study provides evidence forsupramalleolar PTT pathology that often may not be evalu-ated on imaging. Such patients may finally have chronic pain[1,7,12]. Thus a routine sonographic examination in a pa-tient presenting with medial ankle and/or foot pain shouldinclude supramalleolar PTT evaluation in addition to retro-malleolar and insertional PTT evaluation. Our protocol in-cludes evaluation of the PTT tendon in all 3 regions; someprotocols may not be similar. Our study does not provide

lleolar posterior tibial tendinopathy and/or tear

athy and/or Tear*

P Value

tromalleolar(n � 25),

n (%)

Inframalleolar(n � 63),

n (%)

49.1 (17.5) 49.0 (15.4) .6118 (72.0) 36 (57.1) .18

14 (56.0) 45 (71.4) .2111 (44.0) 14 (22.2)0 (0.0) 4 (6.4)

12 (48.0) 21 (33.3) .42

22 (88.0) 61 (96.8) .203 (12.0) 1 (1.6)0 (0.0) 1 (1.6)

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evidence that the natural history and complications of supra-malleolar PTT pathology are different from those of PTTpathology in other regions. We also are not aware of similarevidence in prior medical literature.

PTT subluxation and dislocation are rare. A recent system-atic review reported that only 61 cases had been published todate [3]. We add 4 more cases of subluxation or dislocation.

TT subluxation or dislocation is often seen in younger maleatients who have had a preceding trauma. Only 2 cases ofontraumatic PTT have previously been reported [9]. Patientsith PTT subluxation or dislocation often have associated flexor

etinaculum injuries or periosteal avulsion from the medialalleolus [9]. In our study, the median age of the patients with

TT subluxation or dislocation was 28.5 years (only one partic-pant was older than 35 years), 25% of the patients were womenn � 1), a flexor retinaculum tear was present in 2 cases, andenosynovitis was present in 1 of the 4 cases (data not presentedn tables because of the small sample size).

Age, os naviculare and/or cornuate navicular, rheumatoidrthritis and seronegative spondyloarthropathy, prior ankleracture, medial ankle surgery, diabetes, and enthesopathy pre-iously have been reported to be associated with PTT pathology2]. However, data that support these associations are limited bymall sample sizes. Our data provide evidence for a significantssociation between increasing age and PTT tendinopathynd/or tear. However, contrary to previous reports that PTTupture typically develops in women [11], we did not findemale gender to be associated with PTT pathology. It is possiblehat differences in the patient population recruited for our studynd in prior studies may explain the discrepancy in results. Theotential for selection bias exists in our study because patientsere selectively referred to us for sonographic assessment. Our

tudy also may be underpowered to detect differences, althought is the largest study to date.

Our study is the first to report on differences in characteris-ics of PTT pathology by location. Although our results did noteach conventional statistical significance because of the smallumbers of supramalleolar tendinopathies and/or tears, datarom our study suggest that supramalleolar and retromalleolarTT pathology is more common in women and is more oftenssociated with grade 2 tears (in comparison with grade 1 tears)nd is associated with tenosynovitis compared with inframalleo-ar PTT injuries. Thus retromalleolar PTT injuries are likely

ore similar to supramalleolar injuries. Our results contradictonventional thinking that inframalleolar PTT injuries closelyesemble retromalleolar PTT pathology. This observation is ofmportance to sonographers and to clinicians who treat patientsith medial ankle pain to prevent long-term consequences ofntreated PTT injuries, such as medial arch collapse [13,26,27].e cannot ascertain the cause of medial ankle pain in patientsith normal PTT from the data in our study, and it is alsoossible that asymptomatic PTT changes may be seen on ultra-

ound in some patients.

The diagnostic accuracy of ultrasound for detecting PTTathology has been demonstrated in previous studies2,7,8,17]. Sensitivities in the range of 80% and specificitiesn the range of 90% have been reported [17]. In the past 10ears, improvements in transducer technology and the grow-ng awareness of the technique as complementary or anlternative to MRI has been documented in the medicaliterature [28]. Although we cannot comment on the diag-ostic accuracy of ultrasound for the basis of our data, ournecdotal experiences have been that the anatomy of PTT andts surrounding structures can be well defined in the hands oftrained and experienced sonographer. Moreover, dynamic

tress examination can be performed to assess for PTT sub-uxation and dislocation, which is not possible with an MRI.ltrasound also is relatively inexpensive compared with MRI,nd bilateral comparisons can be performed easily. Thereforeltrasound can be a useful tool in early recognition of PTTathology.

CONCLUSION

In summary, we present one of the largest samples reportedto date of patients undergoing sonography for possible PTTpathology. We demonstrated that, along with the retromal-leolar and inframalleolar regions, the supramalleolar regionalso is a site for PTT pathology. Patients with supramalleolarPTT pathology have more severe grades of PTT pathology,have an increased prevalence of associated findings such astenosynovitis, and are more often women. Hence routinescanning of the supramalleolar region should be performedas part of standard ultrasound protocol. PTT subluxation ordislocation is uncommon, and ultrasound is an excellentmodality for demonstrating PTT subluxation or dislocationwith dynamic stress maneuvers.

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North Am 1994;25:109-121.2. Nallamshetty L, Nazarian LN, Schweitzer ME, et al. Evaluation of

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3. Lohrer H, Nauck T. Posterior tibial tendon dislocation. A systematicreview of the literature and presentation of a case. Br J Sports Med2010;44:398-406.

4. Johnson KA, Strom DE. Tibialis posterior tendon dysfunction. ClinOrthop Relat Res 1989(239):196-206.

5. Sarrafian SK. Anatomy of the Foot and Ankle: Descriptive, Topo-graphic, Functional. Philadelphia, PA: JB Lippincott; 1993.

6. Stranding S. Gray’s Anatomy: The Anatomical Basis of Clinical Practice.39th ed. New York, NY: Churchill Livingstone; 2004.

7. Chen YJ, Liang SC. Diagnostic efficacy of ultrasonography in stage Iposterior tibial tendon dysfunction: Sonographic-surgical correlation. JUltrasound Med 1997;16:417-423.

8. Hsu TC, Wang CL, Wang TG, Chiang IP, Hsieh FJ. Ultrasonographicexamination of the posterior tibial tendon. Foot Ankle Int 1997;18:

34-38.

1004 Jain et al FACTORS ASSOCIATED WITH PTT PATHOLOGY

9. Prato N, Abello E, Martinoli C, Derchi L, Bianchi S. Sonography ofposterior tibialis tendon dislocation. J Ultrasound Med 2004;23:701-705.

10. Trnka HJ. Dysfunction of the tendon of tibialis posterior. J Bone JointSurg Br 2004;86:939-946.

11. Rosenberg ZS, Beltran J, Bencardino JT. From the RSNA RefresherCourses. Radiological Society of North America. MR imaging of theankle and foot. Radiographics 2000;20:S153-S179.

12. Waitches GM, Rockett M, Brage M, Sudakoff G. Ultrasonographic-surgical correlation of ankle tendon tears. J Ultrasound Med 1998;17:249-256.

13. Funk DA, Cass JR, Johnson KA. Acquired adult flat foot secondary toposterior tibial-tendon pathology. J Bone Joint Surg Am 1986;68:95-102.

14. Bianchi S, Martinoli C. Ultrasound of the Musculoskeletal System.Berlin, Germany: Springer; 2007.

15. Nazarian LN, Rawool NM, Martin CE, Schweitzer ME. Synovial fluid inthe hindfoot and ankle: Detection of amount and distribution with US.Radiology 1995;197:275-278.

16. Khoury NJ, el-Khoury GY, Saltzman CL, Brandser EA. MR imaging ofposterior tibial tendon dysfunction. AJR Am J Roentgenol 1996;167:675-682.

17. Premkumar A, Perry MB, Dwyer AJ, et al. Sonography and MR imagingof posterior tibial tendinopathy. AJR Am J Roentgenol 2002;178:223-232.

18. Bencardino J, Rosenberg ZS, Beltran J, et al. MR imaging of dislocation ofthe posterior tibial tendon. AJR Am J Roentgenol 1997;169:1109-1112.

19. Feighan J, Towers J, Conti S. The use of magnetic resonance imaging inposterior tibial tendon dysfunction. Clin Orthop Relat Res 1999(365):23-38.

20. Khoury NJ, el-Khoury GY, Saltzman CL, Brandser EA. Rupture of theanterior tibial tendon: Diagnosis by MR imaging. AJR Am J Roentgenol1996;167:351-354.

CME QuestionWhich of the following is true regarding supramalleolar posterior tib

a. Routinely assessed with ultrasound imaging.b. Higher grades of tendon tears.c. Lower prevalence of tenosynovitis.d. Occurs more often in males.

Answer online at me.aapmr.org

21. Lim PS, Schweitzer ME, Deely DM, et al. Posterior tibial tendondysfunction: Secondary MR signs. Foot Ankle Int 1997;18:658-663.

22. Miller SD, Van Holsbeeck M, Boruta PM, Wu KK, Katcherian DA.Ultrasound in the diagnosis of posterior tibial tendon pathology. FootAnkle Int 1996;17:555-558.

23. Perry MB, Premkumar A, Venzon DJ, Shawker TH, Gerber LH. Ultra-sound, magnetic resonance imaging, and posterior tibialis dysfunction.Clin Orthop Relat Res 2003(408):225-231.

24. Rockett MS, Waitches G, Sudakoff G, Brage M. Use of ultrasonographyversus magnetic resonance imaging for tendon abnormalities aroundthe ankle. Foot Ankle Int 1998;19:604-612.

25. Stephenson CA, Seibert JJ, McAndrew MP, Glasier CM, Leithiser RE Jr,Iqbal V. Sonographic diagnosis of tenosynovitis of the posterior tibialtendon. J Clin Ultrasound 1990;18:114-116.

26. Downey DJ, Simkin PA, Mack LA, Richardson ML, Kilcoyne RF,Hansen ST. Tibialis posterior tendon rupture: A cause of rheumatoidflat foot. Arthritis Rheum 1988;31:441-446.

27. Mann RA, Thompson FM. Rupture of the posterior tibial tendoncausing flat foot. Surgical treatment. J Bone Joint Surg Am 1985;67:556-561.

28. Grant TH, Kelikian AS, Jereb SE, McCarthy RJ. Ultrasound diagnosis ofperoneal tendon tears. A surgical correlation. J Bone Joint Surg Am2005;87:1788-1794.

This CME activity is designated for 1.0 AMA PRA Category 1 Credit™ andcan be completed online at me.aapmr.org. Log on to www.me.aapmr.org,go to Lifelong Learning (CME) and select Journal-based CME from thedrop down menu. This activity is FREE to AAPM&R members and $25 fornon-members.

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