BACKGROUND: There is a variety of treatment modalities for unicameral bone cysts, with variable outcomes reported in the literature. Although good initial outcomes have been reported, the success rate has often changed with longer-term follow-up. We introduce a novel, minimally invasive treatment method and compare its clinical outcomes with those of other methods of treatment of this lesion.
METHODS: From February 1994 to April 2008, forty patients with a unicameral bone cyst were treated with one of four techniques: serial percutaneous steroid and autogenous bone-marrow injection (Group 1, nine patients); open curettage and grafting with a calcium sulfate bone substitute either without instrumentation (Group 2, twelve patients) or with internal instrumentation (Group 3, seven patients); or minimally invasive curettage, ethanol cauterization, disruption of the cystic boundary, insertion of a synthetic calcium sulfate bone-graft substitute, and placement of a cannulated screw to provide drainage (Group 4, twelve patients). Success was defined as radiographic evidence of a healed cyst or of a healed cyst with some defect according to the modified Neer classification, and failure was defined as a persistent or recurrent cyst that needed additional treatment. Patients who sustained a fracture during treatment were also considered to have had a failure. The outcome parameters included the radiographically determined healing rate, the time to solid union, and the total number of procedures needed.
RESULTS: The follow-up time ranged from eighteen to eighty-four months. Group-4 patients had the highest radiographically determined healing rate. Healing was seen in eleven of the twelve patients in that group compared with three of the nine in Group 1, eight of the twelve in Group 2, and six of the seven in Group 3. Group-4 patients also had the shortest mean time to union: 3.7 ± 2.3 months compared with 23.4 ± 14.9, 12.2 ± 8.5, and 6.6 ± 4.3 months in Groups 1, 2, and 3, respectively.
CONCLUSIONS: This new minimally invasive method achieved a favorable outcome, with a higher radiographically determined healing rate and a shorter time to union. Thus, it can be considered an option for initial treatment of unicameral bone cysts.
LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions to Authors for a complete description of levels of evidence.
ORIGINAL ABSTRACT CITATION: “Treatment of Unicameral Bone Cyst. A Comparative Study of Selected Techniques” (2010;92:855-62).
Investigation performed at the Department of Orthopaedics, National Taiwan University Hospital, Taipei, Taiwan
The original scientific article in which the surgical technique was presented was published in JBJS Vol. 92-A, pp. 855-62, April 2010
The line drawings in this article are the work of Joanne Haderer Müller of Haderer & Müller ().
DISCLOSURE: The authors did not receive any outside funding or grants in support of their research for or preparation of this work. Neither they nor a member of their immediate families received payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity.
- Copyright © 2011 by The Journal of Bone and Joint Surgery, Incorporated
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