Bilateral unicameral bone cyst of the calcaneum with unilateral symptoms: An unusual cause for heel pain

PP Sunil; KR Renjith; T Ajayakumar; P Vinod Kumar

doi:10.4103/joasis.joasis_7_20

CASE REPORT

Year : 2020 | Volume : 17 | Issue : 1 | Page : 15-17

Bilateral unicameral bone cyst of the calcaneum with unilateral symptoms: An unusual cause for heel pain

PP Sunil, KR Renjith, T Ajayakumar, P Vinod Kumar
Department of Orthopedics, Apollo-Adlux Hospital, Angamaly, Kerala, India

Date of Submission	20-Oct-2020
Date of Decision	03-Nov-2020
Date of Acceptance	27-Oct-2020
Date of Web Publication	16-Nov-2020

Correspondence Address:
K R Renjith
Department of Orthopedics, Apollo-Adlux Hospital, Near Adlux Convention Center, Cable Junction, Ernakulam District, National Highway 47, Karukutty, Angamaly - 683 576, Kerala
India

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/joasis.joasis_7_20

Abstract

Foot is an uncommon location for unicameral bone cyst, and it is widely believed that calcaneal cysts are typically asymptomatic. We report a case of a bilateral calcaneal cyst in a 65-year-old man which produced unilateral symptoms where open curettage and autogenous bone grafting provided a significant symptomatic relief. Our patient had complete symptomatic relief following surgical curettage without any perioperative complications. Calcaneal bone cyst, although rare, forms an important differential diagnosis in patients presenting with heel pain where surgical management can be a viable option in cases refractory to conservative treatment.

Keywords: Calcaneal cyst, heel pain, unicameral bone cyst

How to cite this article:
Sunil P P, Renjith K R, Ajayakumar T, Kumar P V. Bilateral unicameral bone cyst of the calcaneum with unilateral symptoms: An unusual cause for heel pain. J Orthop Assoc South Indian States 2020;17:15-7

How to cite this URL:
Sunil P P, Renjith K R, Ajayakumar T, Kumar P V. Bilateral unicameral bone cyst of the calcaneum with unilateral symptoms: An unusual cause for heel pain. J Orthop Assoc South Indian States [serial online] 2020 [cited 2023 Apr 1];17:15-7. Available from: https://www.joasis.org/text.asp?2020/17/1/15/300760

Introduction

Unicameral bone cysts (UBCs), otherwise known as simple bone cysts or juvenile bone cysts, are benign, fluid-filled lesions that constitute 3% of primary bone tumors.^[1] They characteristically affect children during the first two decades of life at the metaphyseal and diaphyseal regions of long bones, with spontaneous regression occurring after skeletal maturity. Foot is an uncommon location for UBC, and calcaneum ranks sixth among the most common locations, with proximal humerus and femur being the most frequently affected areas.^[2]

It is widely believed that calcaneal cysts are typically asymptomatic due to its anterolateral location away from the weight-bearing zone. Majority of them are diagnosed incidentally following minor trauma to the foot or ankle, and conservative treatment has been the mainstay in symptomatic cases. Surgical options following a failed conservative regimen include steroid injection, open or endoscopic curettage with or without bone grafting, bone substitutes, osseo-inductive materials or freeze-dried bone allografts, multiple drill holes, and cyst decompression.

Bilateral calcaneal bone cysts are extremely rare, and we report a case of bilateral calcaneal cyst in a 65-year-old man which produced unilateral symptoms where open curettage and autogenous bone grafting provided a significant symptomatic relief.

Case Report

A 65-year-old male, farmer by profession, presented to our outpatient department with insidious-onset left heel pain of 6 months' duration. He denied any history of trauma or other constitutional symptoms. The pain was progressively worsening, exacerbated on walking and running, and got relieved by taking rest. Clinical examination revealed tenderness at the calcaneum on deep palpation with preserved motion at the ankle and subtalar joints. He was provisionally diagnosed to have plantar fasciitis and was managed symptomatically with oral analgesics and footwear modification. One week later, he returned with exaggerated symptoms, and radiographs were taken which revealed a sharply demarcated radiolucent osteolysis surrounded by sclerotic borders anterolateral to the posterior facet of subtalar joint. Plain computed tomographic (CT) scan also showed similar findings with a minor cortical breach in the lateral wall [Figure 1]. Even though the patient denied contralateral foot symptoms, we took an opposite side radiograph to check for bilateralism and we found a similar lesion in his right calcaneum as well [Figure 2]. However, clinical examination was unremarkable. Considering the persistent symptoms which started affecting patient's daily activities and his demand for a quick recovery to get back to work, he was counseled for open curettage and bone grafting of the symptomatic side and this was performed through a lateral approach via a 3-cm mini-incision. A window measuring 2 cm × 1 cm was created in the lateral wall of the lesion identified under c-arm and the cyst was found empty. Curettage followed by extensive irrigation was performed, and the defect was filled with autogenous bone graft harvested from the ipsilateral iliac crest. The patient's limb was placed in a below knee soft splint, nonweight-bearing for 3 weeks postoperatively followed by gradually progressive weight-bearing with crutches. His histopathology report confirmed the diagnosis of UBC with the presence of marrow fat and cementum-like substance. At 3 months of follow-up, he was completely asymptomatic and got back to his normal daily activities. His follow-up radiographs showed no signs of cyst progression or recurrence.

Figure 1: Plain computed tomographic scan sagittal cut of the left calcaneum showing lytic lesion

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Figure 2: Plain radiograph of the bilateral ankle lateral view showing radiolucent lesion of calcaneum

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Discussion

Although UBCs are more common in the metaphyseal–diaphyseal region of the long bones such as humerus and femur in the growing child, calcaneal cysts are not as rare as once considered according to one of the largest series comprising 50 calcaneal cysts reported by Pogoda et al. in 2004.^[3] A review of 258 patients with UBCs by Polat et al. in 2008 also showed that calcaneal bone cysts were identified to be the third most common site.^[4] The average age at diagnosis has been found to be 15 years, with a calcaneal cyst being increasingly common after 17 years of age and a male-to-female ratio of approximately two.^[5],[6],[7] Bilateral lesions have been extremely rare as evidenced by the above-mentioned studies, which showed an incidence of 6.3% and 9.1%, respectively.

Most UBCs of the calcaneum are asymptomatic, incidental radiographic finding. Symptomatic patients may present with heel pain, especially those who are middle aged; however, pathological fracture is rare.^[4] Physical examination may elicit tenderness of calcaneum with normal ankle and subtalar motion. Plain radiographs alone are often sufficient for diagnosis which shows a well-demarcated radiolucent lesion with a unicameral structure of cystic formation. CT or magnetic resonance imaging can be useful in ambiguous lesions to exclude differential diagnoses such as lipomas, myxomas, or vascular malformations. Histopathological examination of the operative specimen can be used for the confirmation of diagnosis with the presence of hemosiderin deposits and fibrous tissues in the absence of cytological atypia.^[8]

In view of the negligible symptoms they produce and the least possibility for complications, conservative management has been advocated for majority of the patients. However, some authors prefer surgical management owing to the risk of pathological fracture. The general consensus is to reserve surgical treatment for those who remain symptomatic even after a trial of conservative management, including analgesic medications and heel support. Among the various surgical techniques described, open curettage and bone grafting was reported to be the most successful and curative with no reports of recurrence.^[9]

This is the second case report on the bilateral calcaneal bone cyst necessitating surgical management for symptomatic relief, the first being reported by Oliver et al. in 2014.^[10] Our patient had bilateral calcaneal cysts in which only the left side was symptomatic. We successfully performed an open curettage and bone grafting of the same side without any perioperative complications, and the patient returned to his normal activities by 12 weeks postoperatively.

Conclusion

Simple bone cysts should be kept in mind as one of the differential diagnoses for heel pain, especially in middle-aged adults where open curettage and bone grafting may be considered as a safe and effective surgical option in cases refractory to conservative management.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given his consent for his images and other clinical information to be reported in the journal. The patient understands that his name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1.	Mirra J. Simple Bone Cyst. In: Mirra J, editor. Bone Tumors: Clinical, Radiologic, and Pathologic Correlations. Philadelphia: Lea & Febiger; 1989. p. 1234-61.
2.	Glaser DL, Dormans JP, Stanton RP, Davidson RS. Surgical management of calcaneal unicameral bone cysts. Clin Orthop Relat Res 1999;360:231-7.
3.	Pogoda P, Priemel M, Linhart W, Stork A, Adam G, Windolf J, et al. Clinical relevance of calcaneal bone cysts: A study of 50 cysts in 47 patients. Clin Orthop Relat Res 2004;424:202-10.
4.	Polat O, Saǧlik Y, Adigüzel HE, Arikan M, Yildiz HY. Our clinical experience on calcaneal bone cysts: 36 cysts in 33 patients. Arch Orthop Trauma Surg 2009;129:1489-94.
5.	Kingsbery LB. Solitary cyst of the os calcis in adults and children; report of eight cases. J Int Coll Surg 1957;27:83-91.
6.	Smith RW, Smith CF. Solitary unicameral bone cyst of the calcaneus. A review of twenty cases. J Bone Joint Surg Am 1974;56:49-56.
7.	Norman A, Schiffman M. Simple bone cysts: Factors of age dependency. Radiology 1977;124:779-82.
8.	Takada J, Hoshi M, Oebisu N, Ieguchi M, Kakehashi A, Wanibuchi H, et al. A comparative study of clinicopathological features between simple bone cysts of the calcaneus and the long bone. Foot Ankle Int 2014;35:374-82.
9.	Smith SB, Shane HS. Simple bone cyst of the calcaneus. A case report and literature review. J Am Podiatr Med Assoc 1994;84:127-30.
10.	Oliver GD. A case of bilateral unicameral bone cysts. Orthopedic Muscul Sys 2014;2:S2-005.