CASE REPORTS

Removal of an Unusual Pedal Ossicle in anElite Distance Runner: A Case Report

Amol Saxena, DPM, FACFAS

A 24-year-old female national champion 5000-meter runner presented with an approximately 1-yearduration of left foot pain localized to the medial arch. She had received multiple diagnoses and hadundergone many different treatments, all of which had failed to relieve her symptoms. Careful review ofher radiographic studies revealed an unusual ossicle in the region of her symptoms. Surgical excision ofthe not previously described ossicle localized within the posterior tibial tendon distal to the navicularadjacent to the first cuneiform resulted in complete resolution of the patient’s longstanding symptoms,and allowed her to return to competition at an elite level. Level of Clinical Evidence: 4 (The Journal ofFoot & Ankle Surgery 48(2):191–195, 2009)

Key Words: accessory ossicle, runner, tarsal navicular, tibialis posterior tendon

Pedal ossicles occur in various locations within the footand ankle, and they can cause symptoms that may necessi-tate their removal when nonsurgical treatment methods failto satisfactorily alleviate pain and disability. In this article,we describe the case of an elite athlete who suffered withrecalcitrant pain caused by a heretofore-undescribed pedalossicle that responded well to surgical excision and resump-tion of her high level of athletic activity.

Case Report

A 24-year-old female national champion 5000-meter run-ner presented with an approximately 1-year duration of leftfoot pain localized to the medial arch. She had receivedmultiple diagnoses and treatments, including navicular andfirst cuneiform stress fracture, and posterior tibial tendontear, with 2 sessions of immobilization with non–weightbearing for 8 weeks, combined with electrical bone growth

Address correspondence to Amol Saxena, DPM, FACFAS, Departmentof Sports Medicine, Palo Alto Medical Foundation, 795 El Camino Real,Palo Alto, CA 94301. E-mail: Heysax@aol.com.

Podiatrist, Department of Sports Medicine, Fellowship Director, PaloAlto Medical Foundation, Palo Alto, CA.

Financial Disclosure: None reported.Conflict of Interest: None reported.Copyright © 2009 by the American College of Foot and Ankle Surgeons

1067-2516/09/4802-0015$36.00/0doi:10.1053/j.jfas.2008.12.002

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stimulation. She had also undergone numerous sessions ofphysical therapy, and she used foot orthotic devices, onepair of which had been prescribed by the author of thisarticle. All of these interventions had failed to relieve hersymptoms.

The clinical exam was relatively unremarkable other thanthe patient’s location of pain. She had mildly pronated feetthat were symmetrical without any medial prominence orswelling, and she displayed equal limb length, no evidenceof Tinel’s sign upon percussion of the posterior tibial nerveand its branches, absence of any lumbosacral radicular painpatterns, full muscle strength, and she used appropriate shoegear and foot orthoses. There was no evidence of hyperes-thesia, hyperemia, or hypohidrosis that could have beenindicative of complex regional pain syndrome. The patientconsistently stated that her pain emanated from the medialarch, and she pointed to the area of her foot just distal to thetuberosity and body of the tarsal navicular, dorsal to theplantar fascia, distal to the tarsal tunnel, and these find-ings seemed to be inconsistent with all of the previousdiagnoses that were historically ascertained. At the timeof her presentation to our clinic, she was in possession ofa number of diagnostic images that had been previouslyobtained.

The patient presented with radiographic studies includinga magnetic resonance image (MRI), which, as reported bythe radiologist who interpreted the images, showed signal

change consistent with rupture of the distal fibers of the

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posterior tibial tendon distal to the navicular attachment andirregularity of proximal plantar aspect of the first cuneiform.There was no signal change within the body of the navicularconsistent with stress fracture, nor any abnormality of theplantar fascia and musculature (Figure 1). A technetium(99Tc) bone scan showed increased uptake in the medialnavicular area and was interpreted as either a fracture or

FIGURE 1 (A) Sagittal T1-weighted magnetic resonance image scuneiform. (B) Short TI inversion recovery (STIR) axial magnetic resoposterial tibial tendon. (C) Axial T2-weighted magnetic resonance i

enthesiopathy of the posterior tibial tendon. A computerized

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tomographic (CT) scan report was also read as negative fornavicular and first cuneiform stress fracture, but did notstate any other abnormalities (Figure 2). The author’s inter-pretation of the radiographic studies was of a sesamoidlikeossicle of the posterior tibial tendon within the distal attach-ment to the plantar-proximal aspect of the first cuneiform(exactly at the patient’s pain location), with tearing of the

g a bony ossicle at the plantar-medial aspect of the first (medial)e image showing inflammation around the ossicle and surroundingshowing increased signal of the accessory ossicle.

howinnanc

surrounding posterior tibial tendon fibers. This did not ap-

pear to be an avulsion fracture because the margins of theossicle were smooth and there was no adjacent signalchange at the first cuneiform as viewed with MRIs.

Despite having undergone multiple radiographic stud-ies, including plain radiographs, she had yet to be imagedwith an oblique view of the symptomatic foot. The authorwas able to demonstrate this ossicle on a lateral obliqueview of the foot (Figure 3). Interestingly, review of theliterature failed to reveal an eponym for this ossicle.Because of the patient’s lack of relief from nonsurgicaltreatment and worsening symptoms such that she couldnot train effectively, the decision was made to proceedwith surgical excision of the ossicle and repair of the

FIGURE 2 (A) Sagittal computerized tomographic image showinga bony ossicle at the plantar-medial aspect of the first (medial)cuneiform. (B) Axial computerized tomographic image showing abony ossicle just distal to the tarsal navicular.

posterior tibial tendon insertion.

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Surgical Technique

A curvilinear incision was created on the medial aspect ofthe left foot to expose the navicular tuberosity and thearticulation with the first cuneiform. The posterior tibialtendon was identified and explored. The attachment to thenavicular tuberosity appeared relatively secure but distallyinferior to the navicular-cuneiform articulation; there wastearing noted of the tendon’s fibers; and a firm, smooth,rounded ossicle was visualized (Figure 4). The ossicle wasexcised (Figure 5), and close inspection failed to reveal any

FIGURE 3 Lateral oblique radiographic view showing a bony os-sicle at the plantar-medial aspect of the first (medial) cuneiform.

FIGURE 4 Intraoperative view showing a bony ossicle at the plan-tar-medial aspect of the first (medial) cuneiform, and tearing of theposterior tibial tendon at its insertion.

jagged or irregular margins that would be suggestive of a

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fracture. The plantar ligamentous and tendinous fibers wererepaired with 2–0 Fiberwire (Arthrex, Inc., Naples, FL)with the foot in a supinated position. To further add to thestability of the posterior tibial tendon, a bone anchor wasplaced in the inferior aspect of the navicular, since she wasa high-level athlete and optimum strength would be required(Figure 6). Thereafter the wound was closed in anatomicallayers.

Postoperatively, the patient was placed in a below-the-knee cast-boot, with the foot immobilized in a slightlysupinated position and the ankle at 90°. She remainednon–weight bearing on the operated foot for 3 weeks, andthen bore weight in the cast-boot for 2 more weeks, at whichtime she was pain-free. The patient initiated range-of-mo-tion exercises with her foot at 3 weeks postoperative, andused a stationary bike with the cast-boot, beginning at 2weeks postsurgery. The patient removed the cast-boot toswim at 4 weeks postsurgery. At 5 weeks following theoperation, she discontinued use of the cast-boot and re-turned to an athletic shoe with a foot orthosis and sheinitiated formalized physical therapy, including single-

FIGURE 5 Excised ossicle.

FIGURE 6 Postoperative weight-bearing lateral radiograph show-ing anchor for reinforcement of posterior tibial tendon repair.

legged strengthening. At 7 weeks postsurgery, she was able

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to run on a special treadmill (Alter-G, Alter-G Inc., MenloPark, CA) that allows patients to “reduce” their bodyweight(Figure 7). This specialized treadmill uses a pressurizedchamber to provide a counterforce to the patient’s bodyweight, thereby unweighting the individual during the train-ing regimen. In effect, the counter pressure reduces thepatient’s effective weight on the running surface of thetreadmill. Our patient ran on this treadmill initially at 70%of her bodyweight, progressively increasing to 95% over a3-week period. Although the precise protocol for use of thisequipment is still being established, patients should notexhibit any “limping” or antalgic postural guarding of theinjured extremity, while running. At 10 weeks postsurgery,she was able to begin training outdoors. At 7 months post-surgery, she won her first competition following the oper-ation. At 9 months postsurgery, she broke her first Americanrecord indoors, and by 1 year postsurgery, she had brokenthe American 5000-meter record outdoors. Thereafter, shewent on to win the national championships and finishedeighth in the world championships. After 2 years of post-operative follow-up, she won a medal in the 2008 Olympics.After the Olympics she had mild posterior tibial tendonsymptoms that resolved with physical therapy, taping, andmild additional orthoses correction. She is currently trainingat full capacity with no limitations.

Discussion

Accessory ossicles of the foot are common. They canoccur as osseous, incompletely ossified, and cartilaginous

FIGURE 7 A runner using the Alter-G Treadmill (Menlo Park, CA),which was used by the patient described in this report when sheresumed running. Use of this pressurized treadmill allowed thepatient to gradually increase her effective body weight from aninitially reduced weight, up to her actual body weight, from 7 to 10weeks postsurgery.

forms (1, 2). Authors have reported good results with exci-

sion of the commonly found accessory navicular and ostrigonum (3, 4). The rehabilitation component for the treat-ment of excised accessory bones of the foot and ankletypically takes 3 or more months postsurgery before indi-viduals can comfortably to return to their preoperative ac-tivity level (4, 5). The accessory bone excised in the patientpresented in this case study did not appear to have beenpreviously described in the published biomedical literature,and because of this, there was no information available toguide our choice of treatment and her subsequent rehabili-tation efforts. Furthermore, the symptomatic bone appearedto be an ossicle, as it was embedded within the distal slip ofthe posterior tibial tendon. Even further, the smooth, roundmargins of the excised bone suggested ossicle, as comparedwith an avulsion fracture fragment that would have mostlikely presented with sharp and irregular margins withoutbeing embedded.

Coughlin (2) described 3 accessory bones associated withthe first cuneiform. One medial ossicle, known as os para-cuneiforme, occurs near the medial aspect of the naviculo-cuneiform joint, and not plantar, as was the case in thepatient described in this report. The second, termed oscuneometatarsale I tibiale, occurs near the medial aspect ofthe first metatarsocuneiform joint. An ossicle known as oscuneo-I metatarsale-I plantare occurs on the plantar aspectof the first metatarsocuneiform joint. Coughlin’s extensiveand thorough review of accessory ossicles fails to reveal abone similar in location to the one described in this case

study. A small bipartite first cuneiform could possibly be

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mistaken for the bony lesion observed in the patient de-scribed in this article; however, involvement of the insertionof the posterior tibial tendon is not described in associationwith a bipartite first cuneiform.

In conclusion, elite and nonelite athletes may have atyp-ical causes for foot pain. When patients with atypical andprolonged symptoms fail to respond to standard means, thepractitioner should be alerted to the possibility of an unusualor anomalous skeletal structure. In this case report, surgicalexcision of a previously undescribed pedal ossicle associ-ated with the insertion of the tibialis posterior tendon distalto the tarsal navicular, and adjacent to the first cuneiform,resulted in complete resolution and a full recovery in anelite runner.

References

1. Champagne IM, Cook DL, Kestner SC, Pontisso JA, Siesel KJ. Ossubfibulare. Investigation of an accessory bone. J Am Podiatr MedAssoc 89:520–524, 1999.

2. Coughlin MJ. Sesamoids and accessory bones of the foot. In Surgery ofthe Foot & Ankle, ed 8, pp 531–610, edited by MJ Coughlin, RA Mann,CA Saltzman, Mosby, St. Louis, MO, 2006.

3. Abramowitz Y, Wollstein R, Barzilay Y, London E, Matan Y, Shabat S,Nyska M. Outcome of resection of a symptomatic os trigonum. J BoneJoint Surg Am 85-A:1051–1057, 2003.

4. Kopp FJ, Marcus RE. Clinical outcome of surgical treatment of thesymptomatic accessory navicular. Foot Ankle Int 25:27–30, 2004.

5. Requejo SM, Kulig K, Thordarson DB. Management of foot pain withaccessory bones of the foot: two clinical case reports. J Ortho Sports

Phys Ther 30:580–594, 2000.

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