J Korean Bone Joint Tumor Soc.  2011 Dec;17(2):58-64. 10.5292/jkbjts.2011.17.2.58.

Pathologic Fracture of Unicameral Bone Cyst

• Choo SK
• Lee HD
• Oh HK

• KMID: 1444790
• DOI: http://doi.org/10.5292/jkbjts.2011.17.2.58

Abstract

PURPOSE
The purpose of this study is to observe unicameral bone cyst (UBC) outcome after the fracture has healed and if there is any identifiable prognostic factors.
MATERIALS AND METHODS
13 UBC patients with pathologic fracture from 2001 to 2010 were reviewed. The mean follow up were 26 months (3-90 months). There were 11 male and 2 female patients and the mean age of the patients were 10.2 years old (6-16 years). 9 involved proximal humerusand 2 involved humerus shaft and 1 involved proximal femur and 1 involved proximal tibia. The treatment of UBC fracture was conservative cast application to heal the fracture initially, and 1 patient was treated with primary auto bone graft and open reduction with internal fixation. 5 patients were treated with steroid injection during follow up period and 2 patients with auto bone graft. We analyzed the change of UBC during pathologic fracture healing period and prognostic factor about age, the size of UBC, the involvement of physis.
RESULTS
The mean duration of the fracture healing was 8.2 months. Complete healing were occurred at 4 patients (31%). No statiscal difference was checked with age about UBC healing (p=0.42). But, more larger size about UBC and more closer to physis, the healing was difficult (p=0.05, p=0.03).
CONCLUSION
While pathologic fracture of UBC was possibly healed, active treatment should be applied especially those cysts that involvescloser area of the physis or large size.

Keyword

simple bone cyst; pathologic fracture; prognostic factor

MeSH Terms

Bone Cysts
Female
Femur
Follow-Up Studies
Fracture Healing
Fractures, Spontaneous
Humans
Humerus
Male
Tibia
Transplants

Figure

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  Figure 1. Completely healed case. (A) It was initial x-ray. (B) After treatment, the cystic lesion was completely resolved after duration 46 months.

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  Figure 2. Partially healed case. (A) It was initial x-ray (B) After treatment, the cystic lesion was partially resolved after duration 4 months.

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  Figure 3. Recurrence case. (A) It was initial x-ray. (B) After treatment, the cystic lesion was partially resolved and fracture site was healed after duration 8 months. (C) But, after follow up 30 months, cystic lesion was recurred with another pathologic fracture.

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  Figure 4. The measurement of cyst size. The maxium length was measured from medial cortex of cyst to lateral cortex (A). The maxium height was measured from upper margin of cyst to lower margin of cyst (B). Size=1/4×3.14×A×B.

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  Figure 5. Involvement of physis. (A) Physis was not contacted (Grade I). (B) Physis was partially contacted (Grade II). (C) Physis was all contacted (Grade III).

Reference

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