Current trends in the management of adamantinoma of long bones. An international study.

BACKGROUND: Adamantinoma of long bones is a rare tumor. Published reviews of the orthopaedic management of adamantinoma have involved limited follow-up of small numbers of patients. The oncological aggressiveness of this tumor is unknown. Limb salvage is currently the treatment of choice for most adamantinomas. The purpose of this study was to evaluate the characteristics of adamantinoma of long bones as well as the oncological outcome and the complications of limb salvage operations.

METHODS: A retrospective study was designed to evaluate the clinical outcomes of limb salvage operations for the treatment of adamantinoma. Data on seventy biopsy-proven cases of adamantinoma treated between 1982 and 1992 at twenty-three different cancer centers in Europe and North America were obtained.

RESULTS: The median duration of follow-up was 7.0 years. The male:female ratio was 3:2, and the mean age was thirty-one years. Limb salvage was attempted in 91 percent (sixty-four) of the seventy patients, and the final rate of limb preservation was 84 percent (fifty-nine of seventy). Wide operative margins were obtained in 92 percent (fifty-eight) of sixty-three patients. An intercalary allograft was used to reconstruct the segmental bone defect in 51 percent (thirty-six) of the seventy patients. Reconstruction-related complications occurred in 48 percent (thirty) of sixty-two patients. Nonunion and fracture were the most common complications, occurring in 24 percent (fifteen) and 23 percent (fourteen) of sixty-two patients, respectively. Kaplan-Meier analysis demonstrated a rate of local recurrence of 18.6 percent at ten years. Wide operative margins were associated with a lower rate of local recurrence than marginal or intralesional margins were (p < 0.00005). Kaplan-Meier analysis showed a survival rate of 87.2 percent at ten years. There were no significant relationships between survival and the stage of the tumor (p = 0.058), duration of symptoms (p = 0.90), gender (p = 0.79), or wide operative margins (p = 0.14).

CONCLUSIONS: Current treatment of adamantinoma, including en bloc tumor resection with wide operative margins and limb salvage, provides lower rates of local recurrence than has been previously reported. In the present study, the limb preservation rate was 84 percent (fifty-nine of seventy), and the survival rate was 87.2 percent at ten years. The rate of complications related to the limb reconstruction was high.