SLR - March 2011 - Johnathan Deming
Reference: Innami K, Takao M, Miyamoto W, Abe S, Nishi H, Matsushita T. Am J of Sports Med. Published online ahead of print, Jan 6 2011.
Scientific Literature Review
Reviewed by: Jonathan Deming, DPM
Residency Program: St. John Hospital & Medical Center, Detroit MI
Podiatric Relevance:
Unicameral bone cysts are typically associated with long bones such as the humerus or femur. They are rarely encountered in the calcaneus, of which about 60% are symptomatic. The most common surgical intervention for symptomatic unicameral bone cysts has been open curettage and bone graft. Although good results have been reported with this method, it is highly invasive with large lateral cortical fenestration required to achieve good visualization of the lesion. The authors propose a less invasive endoscopic treatment offering earlier return to full activity which is particularly of interest for the younger or more athletic population.
Methods:
Sixteen athletes with symptomatic unicameral bone cysts were followed (none were incidental discoveries without symptoms). Thirteen were surgically treated by means of endoscopic curettage and percutaneous injection of calcium phosphate cement. Of those, ten patients (three were dropped who did not meat the minimum follow-up requirements) were included in the analysis.
Surgical Technique:
Two guide wires were inserted at the most anterior and posterior points of the cyst directed toward the center. The lateral calcaneal wall was fenestrated with a drill over the guide wires and a 2.7 mm arthroscope was inserted via the posterior portal and fluid was aspirated from the cyst via the anterior portal. A small suction shaver and abrader were used to resect the inner bony septum and curettage of the fibrous inner surface was performed circumferentially using a small curette through either of the two portals. Following irrigation, calcium phosphate cement was injected percutaneously via either of the two portals. Prior to the procedure saline was injected into the cyst to measure the capacity and that amount minus 1 mL of calcium phosphate was injected.
Results:
The mean follow-up period after surgery was 36.2 months (minimum 24 months). The mean AOFAS (ankle-hindfoot scale) score improved from 78.7 +/- 4.7 pre-operatively to 98.0 +/- 4.2 post-operatively. No recurrence or pathologic fracture occurred in any patient. No surgery complications such as infection, delayed wound healing, or sural nerve injury were noted. All patients could return to their initial levels of sport activity within 8 weeks after surgery (mean 7.1 weeks; range 4-8 weeks).
Conclusions:
Endoscopic curettage and percutaneous injection of calcium phosphate cement is a useful treatment for young athletes with symptomatic unicameral calcaneal bone cysts.