Abstract
Introduction
An aneurysmatic bone cyst (ABC) is a benign cystic lesion of bone composed of blood-filled spaces separated by connective septa.
The most common treatment is curettage with or without bone grafting. Curettage with bone grafting and Ethibloc injection therapy have a comparable recurrence rate. Ethibloc is a radiopaque alcohol solution of corn protein which is percutaneously injected in the ABC.
Objective
To compare percutaneous Ethibloc injection (ETHI) with curettage with bone grafting (CUBG) in the treatment of ABC.
Methods
We conducted a retrospective cohort study of 73 treatments on 56 patients with ABC, between 1985 and 2007. The number of treatments were divided in two groups, one consisting of treatments with ETHI (n=35) and the other of treatments with CUBG (n=38).
Both groups are comparable for the number of primary lesions; ETHI (n=17) and CUBG (n=21) or recurrences; ETHI (n=18) and CUBG (n=17).
Radiological and clinical outcomes were assessed pre- and post-operatively. We evaluated the outcome measures of ETHI and of CUBG during a mean of 24.7 (range: 2–48) months. We evaluated the recurrence rate in both groups for a maximum period of 4 years to prevent the influence of outliers. Recurrence was defined as a radiological progression/recurrence of the lesion or progression/persistence of symptoms (pain, tumor, function impairment). Statistical analysis included a Kaplan Meier survival analysis, a cox-regression analysis to account for potential confounders and a chi-square test.
Results
A survival analysis showed no difference in recurrence rate between both groups. A cox regression analysis showed that type of treatment, after correcting for size of tumor, location and previous treatment, had no influence on recurrence rate.
There was no significant difference in clinical outcome in both groups; complete relief of all symptoms was found after ETHI and CUBG n=30 (86%) and n=33 (87%) respectively.
Radiologically, 24 (69%) of the treatments with ETHI were effective (no recurrence) in 24 months (range: 3–48) and 28 (74%) of the treatments with CUBG in 23 months (range: 2–48).
There was no significant difference between the ETHI vs. CUBG in the number of effective treatments in both primarily treated ABC's (10 vs. 15, p=0.3) as in ABC's with previous treatments (14 vs. 13, p=0.6).
Complications after ETHI consisted of 2 fistulas and after CUBG of an AVN and failure of reconstruction.
Discussion
This study shows that the relatively simple, percutaneous Ethibloc injection is comparable to curettage with bone grafting, regarding both clinical and radiological outcome. Recurrence rate was not influenced by type of treatment, location or size of tumour.
We recommend Ethibloc injection as the first-choice treatment of primary and recurrent ABC's.
