Introduction
A unicameral bone cyst (UBC) is a common, benign, fluid-filled lesion found almost exclusively in children. Much has been written about the diagnosis and management of these lesions, and evidence of a variety of successful treatment strategies can be found in the literature.
The orthopedic entity called a UBC is not believed to be a new phenomenon. Lagier et al identified a UBC in the femur from the remains of a child from medieval times.1 Virchow also recognized such bone cysts in humans in the late 1870s.2
In 1942, Henry Jaffe and Louis Lichtenstein published their classic paper concerning solitary UBCs.3 In their article, the authors emphasized the distinctiveness of UBC by saying:
"Solitary unicameral bone cyst is a lesion sui generis. It bears no relation whatever to giant cell tumor of bone, and in particular it does not represent a cystic-healing phase of this tumor. Nor is it to be linked with enchondroma, fibroma or focus of fibrous dysplasia of bone that has undergone partial or extensive cystic degeneration. Further, it should not be regarded as representing cystic expression of osteitis fibrosa, since to throw it into this wastebasket category (one which to us is also meaningless) is to obliterate its distinctiveness. Correspondingly, solitary unicameral bone cyst ought no longer to be classed as an expression of localized fibrocystic disease of bone or localized fibrous osteodystrophy—likewise blanket designations dating from a more primitive era of bone pathology."2
Despite abundant clinical confidence in managing these lesions, many basic questions still remain concerning the etiology and pathophysiology of UBCs.
This article offers a comprehensive review of the present state of knowledge of a UBC, highlighting aspects of its pathophysiology, clinical presentation, and the most commonly used treatment strategies.
History of the Procedure
For history of the surgical procedures used to treat UBCs, see Surgical therapy.
Problem
A UBC is a benign, fluid-filled, radiolucent lesion that may appear in virtually any bone, but typically, it is found in either the proximal humerus or proximal femur. Illustrations of such lesions can be seen in Images 1-2. A UBC often leads to thinning of adjacent areas of bone, such that fracture or pain from microfracture may occur. When such cysts are immediately adjacent to a growth plate, they are referred to as active cysts, and when they have achieved some distance from the growth plate, they are considered to be latent cysts. This distinction has been used in the past, as it was believed to have prognostic significance. A UBC usually presents as a unifocal (one bone) problem, affecting patients who are skeletally immature.
The rarity of the lesion in adults supports a hypothesis of spontaneous resolution. In the absence of fracture through the cyst (or impending fracture), UBCs are asymptomatic. They are, at times, found serendipitously when radiographs are taken for other reasons. In the absence of symptoms and in the absence of mechanical compromise of the involved bone (eg, extensive cortical thinning), no treatment may be necessary other than observation.
However, treatment should be strongly considered for lesions that have resulted in a fracture or marked weakening of bone. Some evidence exists that spontaneous healing of a UBC may occur following fracture. Such healing occurs in only a minority of cases. Growth disturbance secondary to a UBC is also a concern.4
At least 2 case reports exist in which a chondrosarcoma was found to arise within the same area of a previous histologically proven UBC.5 In a separate case, an 8-year-old boy was reported to have sustained a pathologic fracture of the distal fibula that was believed to have resulted from a Ewing sarcoma infiltrating a UBC.6 The precise relationship between such rare instances of apparent malignant transformation and the thousands (if not millions) of UBCs that have not demonstrated such behavior remains unclear. At any rate, a UBC is not considered to be a malignant or premalignant lesion, and as such, routine biopsy or other treatment of asymptomatic and nonproblematic lesions based on a patient's or family's fear of cancer should not be undertaken.
Frequency
A UBC occurs most frequently in children aged 5-15 years, with an average age of approximately 9 years.7,8 Many authors consider cysts that present in the first decade of life to be more aggressive.7,8 A UBC affects males approximately twice as often as females. These lesions constitute approximately 3% of all bone tumors. A UBC probably represents the third or fourth most common benign bone tumor that the orthopedic surgeon confronts (osteochondromas are commonly considered to be the most frequently encountered benign bone tumors in children, followed by fibromas and/or fibrous cortical defects). The lesion may occur in conjunction with other benign bone tumors such as a nonossifying fibroma.9
By far, the most common location for the lesion is the proximal humerus, followed by the proximal femur. The proximal humerus and femur together account for nearly 90% of all UBC sites.7,8 However, virtually any bone may be affected, with the calcaneus being one of these notable alternate locations.10,11,12,13,14,15
Etiology
The specific etiology of a UBC has not been elucidated. Many theories have been proposed. One commonly quoted theory was proposed by Cohen in 1960.16 He studied the cyst fluid from 6 children undergoing treatment for UBCs and found 4 to resemble plasma and 2 to resemble blood. Cohen proposed that the principal etiologic factor is blockage of the drainage of interstitial fluid in a rapidly growing and rapidly remodeling area of cancellous bone.16
Chigira and a group of Japanese researchers studied the internal pressure of 7 patients with UBCs and found them to be higher (2-7 mm Hg range) as compared to the contralateral normal bone marrow pressures.17 The partial pressure of oxygen (PaO 2 ) found in the fluid from these same cysts was found to be impressively lower than venous or arterial samples taken at the same time. These authors suggested that venous obstruction within the bone appears to be a likely cause of such simple bone cysts.
Such vascular theories have been supported by other authors.18 Mirra et al suggested that a UBC represents an area of a congenital rest of synovial tissue and has supported this by demonstrating both synovial type A (macrophagelike) and type B (fibroblastlike) cells in the lining of such cysts.19 This description resembles that of an intraosseous synovial cyst. Yu et al also demonstrated how methylprednisolone influences the cellular physiology of synovial cells in culture, thus establishing a theoretic basis for steroid injection treatments for a UBC.20
Shindel et al reported increased prostaglandin E2 levels in the cyst fluid from 7 of their patients and theorized that this may help explain the beneficial effect of steroid injection of such lesions.21 Gerasimov led a group of Russian researchers who stressed that the fluid from UBCs possesses increased lysosomal enzyme activity regardless of the UBCs' status as active or latent.22 These authors emphasized the role such enzymatic activity might play in permanent corrosion of the cyst cavity, as well as increasing osmotic pressure within the cyst.
High levels of cytotoxic oxygen free radicals have also been found in the fluid from UBCs.23 Such free radicals are not only cytotoxic; they might be generated during the ischemic state following blockage of interstitial fluid drainage from UBCs. The Japanese researchers suggested that such oxygen scavengers may contribute to the bone destruction associated with UBCs. Reproduction of these results in other centers has not yet occurred.
In the past several years, a group of Brazilian researchers have reported specific genetic abnormalities in a pediatric patient with a UBC of his right distal femur. Vayego and her colleagues made their first report in 1996.24 Cytogenetic analysis of the resected cyst initially demonstrated complex aberrations of chromosomes 4, 6, 8, 12, 16, and 21. Further study of the same patient (following bone cyst recurrence) later revealed specific mutations associated with amino acid substitutions (arginine for tryptophan, arginine for serine).25 More study in this area clearly is indicated, and the potential for future gene-based therapies is seemingly apparent.
Pathophysiology
Komiya and Inoue have the only longitudinal study (with serial radiographs over 6 y) that documents the development of a UBC over time.26 Initially, a small erosive lesion of the endosteal humeral metaphysis appeared, and over time, the lesion progressively enlarged into a typical UBC.26 The lesion analyzed by these authors was somewhat unusual in that it was located in the distal humerus. In addition, the lesion appeared following notation of a previous UBC in the proximal aspect of the same bone.
Presentation
Most patients with a UBC present to the orthopedic surgeon after sustaining a pathologic fracture. Such fractures most commonly involve either the proximal humerus or the proximal femur. The events leading up to the fracture may vary from fairly trivial, such as throwing a ball, to more substantial, such as a hard fall while playing soccer. As with all patients who have sustained a fracture, a careful physical examination of the patient should include efforts to exclude the possibility of an open fracture and a neurocirculatory insult.
In other instances, patients may present to emergency department physicians, their primary care physicians, or orthopedic surgeons for other reasons, and radiographs obtained in the workup of other complaints may identify asymptomatic UBCs. Such incidental diagnosis of "a bone tumor" may be quite disconcerting to the child's parents and family. Random bone tumor discussions with such a child's family is contraindicated. Medical personnel who eagerly deliver well-intentioned but inaccurate discussions of bone tumors often needlessly terrify families.
In either of these scenarios, a review of the patient's past history, as well as their family's past history relative to fractures, rheumatologic conditions, bone tumors, endocrine disease, and cancer, is appropriate. Physical examination of the patient should also include a screening examination of the axial skeleton and the uninvolved extremities. Any other identified abnormalities may require further plain radiographs. Palpation of major lymph node areas, such as the axillary and inguinal fields, is also appropriate, as infection and malignancy are part of the differential diagnosis.
Indications
The decision to pursue surgical intervention in patients with UBCs is a highly individualized one. An asymptomatic lesion with satisfactory maintenance of cortical thickness may require only observation. A lesion with precarious cortical thinning (with or without insufficient pain) may demand surgical intervention. In addition, factors such as an upper extremity (lower stress) versus a lower extremity (higher stress) and younger children (more amenable to cast immobilization) versus older adolescents (less amenable to cast immobilization) may strongly influence surgical decisions. Simple treatment of the pathologic fracture may result in cyst resolution in up to 25% of cases.27
Some authors have suggested the use of a cyst index aimed at predicting the future risk of a pathologic fracture. Andre Kaelin and Dean MacEwen discussed this concept and defined their cyst index as the area of the UBC measured via its widest dimensions divided by the diameter of the diaphysis of the same bone.28 Based on their statistical analysis of 57 patients with UBCs, these authors recommended mainly observation for humeral cysts with an index of less than 4 and for femoral cysts with an index of less than 3.5.28 When either of these thresholds was exceeded, stronger consideration regarding surgical intervention was believed to be appropriate.
Relevant Anatomy
Anatomy that is relevant to UBCs is mainly that of the proximal humerus and proximal femur. Percutaneous approaches to the proximal humerus require the surgeon to avoid injury to the biceps tendon as well as the axillary nerve as it innervates the deltoid musculature. The standard delta-pectoral approach is the most common open surgical approach for proximal humeral lesions.
Key points of this approach include preservation of the cephalic vein as well as careful medial retraction of the conjoined tendon (coracobrachialis and short head of the biceps) to avoid injuring the musculocutaneous nerve. Dissection in the region of the bicipital groove should be minimized, as this may injure the anterolateral ascending branch of the anterior humeral circumflex artery. This artery provides the bulk of the blood supply for the humeral head.
Contraindications
The main contraindication for surgical treatment of a UBC is a patient who otherwise meets indications for surgery but is unable to tolerate anesthesia. Another relative contraindication for surgery is a patient with a small asymptomatic latent cyst with a low likelihood of a pathologic fracture.
More on Unicameral Bone Cyst |
 Overview: Unicameral Bone Cyst |
| Workup: Unicameral Bone Cyst |
| Treatment: Unicameral Bone Cyst |
| Follow-up: Unicameral Bone Cyst |
| Multimedia: Unicameral Bone Cyst |
| References |
| Next Page » |
References
Lagier R, Kramar C, Baud CA. Femoral unicameral bone cyst in a medieval child. Radiological and pathological study. Pediatr Radiol. 1987;17(6):498-500. [Medline].
Virchow R. [On the formation of bony cysts] [German]. Ueber die bildung von knochencysten. Berlin, Germany: Monatsber d Kgl Akad D Wissenschaften. Sitzung der Phisikalischen-mathemat Klasse vom; 12 Juni 1876:369-81.
Jaffe HL, Lichtenstein L. Solitary unicameral bone cyst with emphasis on the roentgen picture, the pathologic appearance and the pathogenesis. Arch Surg. 1942;44:1004-25.
Stanton RP, Abdel-Mota'al MM. Growth arrest resulting from unicameral bone cyst. J Pediatr Orthop. Mar-Apr 1998;18(2):198-201. [Medline].
Grabias S, Mankin HJ. Chondrosarcoma arising in histologically proved unicameral bone cyst. A case report. J Bone Joint Surg Am. Oct 1974;56(7):1501-9. [Medline]. [Full Text].
Steinberg GG. Ewing's sarcoma arising in a unicameral bone cyst. J Pediatr Orthop. Jan-Feb 1985;5(1):97-100. [Medline].
Lokiec F, Ezra E, Khermosh O, Wientroub S. Simple bone cysts treated by percutaneous autologous marrow grafting. A preliminary report. J Bone Joint Surg Br. Nov 1996;78(6):934-7. [Medline]. [Full Text].
Lokiec F, Wientroub S. Simple bone cyst: etiology, classification, pathology, and treatment modalities. J Pediatr Orthop B. Oct 1998;7(4):262-73. [Medline].
Godette GA, Rooney RJ. Two different non-neoplastic lesions in the same long bone. Contemp Orthop. 1995;30:395-98.
Park IH, Micic ID, Jeon IH. A study of 23 unicameral bone cysts of the calcaneus: open chip allogeneic bone graft versus percutaneous injection of bone powder with autogenous bone marrow. Foot Ankle Int. Feb 2008;29(2):164-70. [Medline].
Glaser DL, Dormans JP, Stanton RP, Davidson RS. Surgical management of calcaneal unicameral bone cysts. Clin Orthop Relat Res. Mar 1999;360:231-7. [Medline].
Zenmyo M, Komiya S, Hamada T, Inoue A. A solitary bone cyst in the spinous process of the cervical spine: a case report. Spine. Mar 1 2000;25(5):641-2. [Medline].
Chaudhary D, Bhatia N, Ahmed A, et al. Unicameral bone cyst of the patella. Orthopedics. Dec 2000;23(12):1285-6. [Medline].
Abdelwahab IF, Hermann G, Norton KI, et al. Simple bone cysts of the pelvis in adolescents. A report of four cases. J Bone Joint Surg Am. Aug 1991;73(7):1090-4. [Medline]. [Full Text].
Smith RW, Smith CF. Solitary unicameral bone cyst of the calcaneus. A review of twenty cases. J Bone Joint Surg Am. Jan 1974;56(1):49-56. [Medline]. [Full Text].
Cohen J. Simple bone cysts. Studies of cyst fluid in six cases with a theory of pathogenesis. J Bone Joint Surg Am. Jun 1960;42-A(4):609-16. [Medline]. [Full Text].
Chigira M, Maehara S, Arita S, Udagawa E. The aetiology and treatment of simple bone cysts. J Bone Joint Surg Br. Nov 1983;65(5):633-7. [Medline]. [Full Text].
Gebhart M, Blaimont P. Contribution to the vascular origin of the unicameral bone cyst. Acta Orthop Belg. Sep 1996;62(3):137-43. [Medline].
Mirra JM, Bernard GW, Bullough PG, Johnston W, Mink G. Cementum-like bone production in solitary bone cysts (so-called "cementoma" of long bones). Report of three cases. Electron microscopic observations supporting a synovial origin to the simple bone cyst. Clin Orthop Relat Res. Sep 1978;135:295-307. [Medline].
Yu CL, D'Astous J, Finnegan M. Simple bone cysts. The effects of methylprednisolone on synovial cells in culture. Clin Orthop Relat Res. Jan 1991;262:34-41. [Medline].
Shindell R, Huurman WW, Lippiello L, Connolly JF. Prostaglandin levels in unicameral bone cysts treated by intralesional steroid injection. J Pediatr Orthop. Sep-Oct 1989;9(5):516-9. [Medline].
Gerasimov AM, Toporova SM, Furtseva LN, et al. The role of lysosomes in the pathogenesis of unicameral bone cysts. Clin Orthop Relat Res. May 1991;266:53-63. [Medline].
Komiya S, Tsuzuki K, Mangham DC, et al. Oxygen scavengers in simple bone cysts. Clin Orthop. Nov 1994;(308):199-206. [Medline].
Vayego SA, De Conti OJ, Varella-Garcia M. Complex cytogenetic rearrangement in a case of unicameral bone cyst. Cancer Genet Cytogenet. Jan 1996;86(1):46-9. [Medline].
Vayego-Lourenco SA. TP53 mutations in a recurrent unicameral bone cyst. Cancer Genet Cytogenet. Jan 15 2001;124(2):175-6. [Medline].
Komiya S, Inoue A. Development of a solitary bone cyst--a report of a case suggesting its pathogenesis. Arch Orthop Trauma Surg. 2000;120(7-8):455-7. [Medline].
Farber JM, Stanton RP. Treatment options in unicameral bone cysts. Orthopedics. Jan 1990;13(1):25-32. [Medline].
Kaelin AJ, MacEwen GD. Unicameral bone cysts. Natural history and the risk of fracture. Int Orthop. 1989;13(4):275-82. [Medline].
Capanna R, Campanacci DA, Manfrini M. Unicameral and aneurysmal bone cysts. Orthop Clin North Am. Jul 1996;27(3):605-14. [Medline].
Lodwick GS, Wilson AJ, Farrell C, Virtama P, Dittrich F. Determining growth rates of focal lesions of bone from radiographs. Radiology. Mar 1980;134(3):577-83. [Medline]. [Full Text].
Sundaram M, Totty WG, Kyriakos M, McDonald DJ, Merkel K. Imaging findings in pseudocystic osteosarcoma. AJR Am J Roentgenol. Mar 2001;176(3):783-8. [Medline]. [Full Text].
Reynolds J. The "fallen fragment sign" in the diagnosis of unicameral bone cysts. Radiology. Apr 1969;92(5):949-53 passim. [Medline].
Struhl S, Edelson C, Pritzker H, Seimon LP, Dorfman HD. Solitary (unicameral) bone cyst. The fallen fragment sign revisited. Skeletal Radiol. 1989;18(4):261-5. [Medline].
McGlynn FJ, Mickelson MR, El-Khoury GY. The fallen fragment sign in unicameral bone cyst. Clin Orthop Relat Res. May 1981;156:157-9. [Medline].
Maas EJ, Craig JG, Swisher PK, Amin MB, Marcus N. Fluid-fluid levels in a simple bone cyst on magnetic resonance imaging. Australas Radiol. Aug 1998;42(3):267-70. [Medline].
Margau R, Babyn P, Cole W, Smith C, Lee F. MR imaging of simple bone cysts in children: not so simple. Pediatr Radiol. Aug 2000;30(8):551-7. [Medline].
Sullivan RJ, Meyer JS, Dormans JP, Davidson RS. Diagnosing aneurysmal and unicameral bone cysts with magnetic resonance imaging. Clin Orthop Relat Res. Sep 1999;366:186-90. [Medline].
Campanacci M, Capanna R, Picci P. Unicameral and aneurysmal bone cysts. Clin Orthop Relat Res. Mar 1986;204:25-36. [Medline].
Neer CS 2nd, Francis KC, Marcove RC, Terz J, Carbonara PN. Treatment of unicameral bone cyst. A follow-up study of one hundred seventy-five cases. J Bone Joint Surg Am. Jun 1966;48(4):731-45. [Medline]. [Full Text].
Oppenheim WL, Galleno H. Operative treatment versus steroid injection in the management of unicameral bone cysts. J Pediatr Orthop. Jan 1984;4(1):1-7. [Medline].
Bovill DF, Skinner HB. Unicameral bone cysts. A comparison of treatment options. Orthop Rev. Apr 1989;18(4):420-7. [Medline].
Carrata A, Garbagna P, Mapelli S, Zucchi V. The treatment of simple bone cysts by topical infiltrations of methylprednisolone acetate: technique and results. Eur J Radiol. Feb 1983;3(1):3-8. [Medline].
Clayer M. Injectable form of calcium sulphate as treatment of aneurysmal bone cysts. ANZ J Surg. May 2008;78(5):366-70. [Medline].
Hecht AC, Gebhardt MC. Diagnosis and treatment of unicameral and aneurysmal bone cysts in children. Curr Opin Pediatr. Feb 1998;10(1):87-94. [Medline].
[Best Evidence] Wright JG, Yandow S, Donaldson S, Marley L. A randomized clinical trial comparing intralesional bone marrow and steroid injections for simple bone cysts. J Bone Joint Surg Am. Apr 2008;90(4):722-30. [Medline].
Altermatt S, Schwöbel M, Pochon JP. Operative treatment of solitary bone cysts with tricalcium phosphate ceramic. A 1 to 7 year follow-up. Eur J Pediatr Surg. Jun 1992;2(3):180-2. [Medline].
Spence KF Jr, Bright RW, Fitzgerald SP, Sell KW. Solitary unicameral bone cyst: treatment with freeze-dried crushed cortical-bone allograft. A review of one hundred and forty-four cases. J Bone Joint Surg Am. Jul 1976;58(5):636-41. [Medline]. [Full Text].
Neer CS, Francis KC, Johnston AD, Kiernan HA Jr. Current concepts on the treatment of solitary unicameral bone cyst. Clin Orthop Relat Res. Nov-Dec 1973;97:40-51. [Medline].
Fahey JJ, O'Brien ET. Subtotal resection and grafting in selected cases of solitary unicameral bone cyst. J Bone Joint Surg Am. Jan 1973;55(1):59-68. [Medline]. [Full Text].
McKay DW, Nason SS. Treatment of unicameral bone cysts by subtotal resection without grafts. J Bone Joint Surg Am. Jun 1977;59(4):515-9. [Medline]. [Full Text].
Scaglietti O, Marchetti PG, Bartolozzi P. Final results obtained in the treatment of bone cysts with methylprednisolone acetate (depo-medrol) and a discussion of results achieved in other bone lesions. Clin Orthop Relat Res. May 1982;165:33-42. [Medline].
Komiya S, Minamitani K, Sasaguri Y, et al. Simple bone cyst. Treatment by trepanation and studies on bone resorptive factors in cyst fluid with a theory of its pathogenesis. Clin Orthop. Feb 1993;(287):204-11. [Medline].
Capanna R, Dal Monte A, Gitelis S, Campanacci M. The natural history of unicameral bone cyst after steroid injection. Clin Orthop Relat Res. Jun 1982;166:204-11. [Medline].
Fernbach SK, Blumenthal DH, Poznanski AK, Dias LS, Tachdjian MO. Radiographic changes in unicameral bone cysts following direct injection of steroids: a report on 14 cases. Radiology. Sep 1981;140(3):689-95. [Medline]. [Full Text].
Mitchell EP, Fugle MJ, Limbert AB. The treatment of unicameral bone cysts with injections of methylprednisolone acetate: a case study and review of the literature. J Am Osteopath Acad Orthop. 1983;2:19-23.
Scaglietti O, Marchetti PG, Bartolozzi P. The effects of methylprednisolone acetate in the treatment of bone cysts. Results of three years follow-up. J Bone Joint Surg Br. May 1979;61-B(2):200-4. [Medline]. [Full Text].
Rosenborg M, Mortensson W, Hirsch G, Sisask G, Karlsson A. Considerations in the corticosteroid treatment of bone cysts. J Pediatr Orthop. Mar-Apr 1989;9(2):240-3. [Medline].
Capanna R, Albisinni U, Caroli GC, Campanacci M. Contrast examination as a prognostic factor in the treatment of solitary bone cyst by cortisone injection. Skeletal Radiol. 1984;12(2):97-102. [Medline].
Garg NK, Carty H, Walsh HP, Dorgan JC, Bruce CE. Percutaneous Ethibloc injection in aneurysmal bone cysts. Skeletal Radiol. Apr 2000;29(4):211-6. [Medline].
Adamsbaum C, Kalifa G, Seringe R, Dubousset J. Direct Ethibloc injection in benign bone cysts: preliminary report on four patients. Skeletal Radiol. 1993;22(5):317-20. [Medline].
Killian JT, Wilkinson L, White S, Brassard M. Treatment of unicameral bone cyst with demineralized bone matrix. J Pediatr Orthop. Sep-Oct 1998;18(5):621-4. [Medline].
Yandow SM, Lundeen GA, Scott SM, Coffin C. Autogenic bone marrow injections as a treatment for simple bone cyst. J Pediatr Orthop. Sep-Oct 1998;18(5):616-20. [Medline].
Wientroub S, Goodwin D, Khermosh O, Salama R. The clinical use of autologous marrow to improve osteogenic potential of bone grafts in pediatric orthopedics. J Pediatr Orthop. Mar-Apr 1989;9(2):186-90. [Medline].
Delloye C, Docquier PL, Cornu O, et al. Simple bone cysts treated with aspiration and a single bone marrow injection. A preliminary report. Int Orthop. 1998;22(2):134-8. [Medline].
Köse N, Göktürk E, Turgut A, Günal I, Seber S. Percutaneous autologous bone marrow grafting for simple bone cysts. Bull Hosp Jt Dis. 1999;58(2):105-10. [Medline].
Moreau G, Letts M. Unicameral bone cyst of the calcaneus in children. J Pediatr Orthop. Jan-Feb 1994;14(1):101-4. [Medline].
Imhäuser G. [Management of juvenile bone cysts using intramedullary nailing?] [German]. Z Orthop Ihre Grenzgeb. Oct 1968;105(3):110-1. [Medline].
Roposch A, Saraph V, Linhart WE. Flexible intramedullary nailing for the treatment of unicameral bone cysts in long bones. J Bone Joint Surg Am. Oct 2000;82-A(10):1447-53. [Medline].
Santori F, Ghera S, Castelli V. Treatment of solitary bone cysts with intramedullary nailing. Orthopedics. Jun 1988;11(6):873-8. [Medline].
Catier P, Bracq H, Canciani JP, Allouis M, Babut JM. [The treatment of upper femoral unicameral bone cysts in children by Ender's nailing technique] [French]. Rev Chir Orthop Reparatrice Appar Mot. 1981;67(2):147-9. [Medline].
Gupta AK, Crawford AH. Solitary bone cyst with epiphyseal involvement: confirmation with magnetic resonance imaging. A case report and review of the literature. J Bone Joint Surg Am. Jun 1996;78(6):911-5. [Medline].
Malawer MM, Markle B. Unicameral bone cyst with epiphyseal involvement: clinicoanatomic analysis. J Pediatr Orthop. Mar 1982;2(1):71-9. [Medline].
Bensahel H, Jehanno P, Desgrippes Y, Pennecot GF. Solitary bone cyst: controversies and treatment. J Pediatr Orthop B. Oct 1998;7(4):257-61. [Medline].
Atar D, Lehman WB, Grant AD. Unicameral bone cysts. Contemp Orthop. 1991;23:249-53.
Capanna R, Van Horn J, Ruggieri P, Biagini R. Epiphyseal involvement in unicameral bone cysts. Skeletal Radiol. 1986;15(6):428-32. [Medline].
Choong PF, Pritchard DJ, Rock MG, et al. Low grade central osteogenic sarcoma. A long-term followup of 20 patients. Clin Orthop Relat Res. Jan 1996;322:198-206. [Medline].
Cohen J. Simple bone cysts treated by injection of autologous bone marrow. J Bone Joint Surg Br. Sep 1997;79(5):877. [Medline]. [Full Text].
de Palma L, Santucci A. Treatment of bone cysts with methylprednisolone acetate. A 9 to 11 year follow-up. Int Orthop. 1987;11(1):23-8. [Medline].
Delling G, Sopta J. [Solitary bone cysts of the pelvis : A frequently misinterpreted entity.] [German]. Pathologe. Mar 7 2008;[Medline].
Gakuu LN. Solitary unicameral bone cyst. East Afr Med J. Jan 1997;74(1):31-2. [Medline].
Galey JP. Ten year retrospection of the treatment of unicameral bone cysts. J Bone Joint Surg [Br]. 1986;68-B:675.
Gartland JJ, Cole FL. Modern concepts in the treatment of unicameral bone cysts of the proximmal humerus. Orthop Clin North Am. Apr 1975;6(2):487-98. [Medline].
Gitelis S, Wilkins R, Conrad EU 2nd. Benign bone tumors. Instr Course Lect. 1996;45:425-46. [Medline].
Göktürk E, Köse N. Simple bone cysts treated by percutaneous autologous marrow grafting [letter]. J Bone Joint Surg Br. Jul 1997;79(4):695. [Medline]. [Full Text].
Haims AH, Desai P, Present D, Beltran J. Epiphyseal extension of a unicameral bone cyst. Skeletal Radiol. Jan 1997;26(1):51-4. [Medline].
Inoue O, Ibaraki K, Shimabukuro H, Shingaki Y. Packing with high-porosity hydroxyapatite cubes alone for the treatment of simple bone cyst. Clin Orthop Relat Res. Aug 1993;293:287-92. [Medline].
Kiesler TW, Kling TF, Rougraff BT. Unicameral bone cysts. Curr Opin Orthop. 1994;5:75-81.
Lin PP, Brown C, Raymond AK, Deavers MT, Yasko AW. Aneurysmal bone cysts recur at juxtaphyseal locations in skeletally immature patients. Clin Orthop Relat Res. Mar 2008;466(3):722-8. [Medline].
Madhavan P, Ogilvie C. Premature closure of upper humeral physis after fracture through simple bone cyst. J Pediatr Orthop B. Jan 1998;7(1):83-5. [Medline].
Makley JT, Joyce MJ. Unicameral bone cyst (simple bone cyst). Orthop Clin North Am. Jul 1989;20(3):407-15. [Medline].
Mirzayan R, Panossian V, Avedian R, Forrester DM, Menendez LR. The use of calcium sulfate in the treatment of benign bone lesions. A preliminary report. J Bone Joint Surg Am. Mar 2001;83-A(3):355-8. [Medline].
Peltier LF, Jones RH. Treatment of unicameral bone cysts by curettage and packing with plaster-of-Paris pellets. J Bone Joint Surg Am. Sep 1978;60(6):820-2. [Medline]. [Full Text].
Robbins H. The treatment of unicameral or solitary bone cysts by the injection of corticosteroids. Bull Hosp Jt Dis Orthop Inst. Spring 1982;42(1):1-16. [Medline].
Schreuder HW, Conrad EU 3rd, Bruckner JD, Howlett AT, Sorensen LS. Treatment of simple bone cysts in children with curettage and cryosurgery. J Pediatr Orthop. Nov-Dec 1997;17(6):814-20. [Medline].
Schreuder HW, Veth RP. Simple bone cysts treated by injection of autologous bone marrow. J Bone Joint Surg Br. Sep 1997;79(5):877. [Medline]. [Full Text].
Spence KF, Sell KW, Brown RH. Solitary bone cyst: treatment with freeze-dried cancellous bone allograft. A study of one hundred seventy-seven cases. J Bone Joint Surg Am. Jan 1969;51(1):87-96. [Medline]. [Full Text].
Wilkins RM. Unicameral bone cysts. J Am Acad Orthop Surg. Jul-Aug 2000;8(4):217-24. [Medline].
Further Reading
Keywords
UBC, simple bone cyst, solitary bone cyst, bone cyst, solitary unicameral bone cyst, benign bone cyst, essential bone cyst, aneurysmal bone cyst
