Extended Curettage for Giant Cell Tumors of Bone
Authors: Gundavda Manit K. , Agarwal Manish G. 
Published: August 2021

Background:
The key to intralesional surgical treatment of giant cell tumor of bone (GCTB) is extended curettage. As GCTB is locally aggressive with a high propensity for local recurrence, a primary factor of surgical treatment is the ability to achieve local tumor clearance. GCTB commonly affects the epimetaphyseal region of the bone, which may compromise the integrity of the articular surface. With the exception of expendable bone that may be considered for resection without the challenge of reconstruction (e.g., the proximal aspect of the fibula or the distal aspect of the ulna), a large majority of cases of GCTB can be treated with joint-preserving techniques. In the present article, we share a video demonstration including the surgeon view of intralesional surgery for GCTB, with emphasis on the 360° visualization of the tumor cavity, dilemmas regarding use of adjuvants for extended curettage, and options in cavity reconstruction.

Description:
The surgical procedure involves 4 essential components.
(1) Surgical exposure and isolation of the soft tissues. The technique begins with a complete exposure that allows visualization of the entire tumor cavity. The initial part of the exposure involves getting to the bone and to the soft-tissue mass outside the bone, when present. The muscles are separated from the bone and retracted away from the soft-tissue component of the tumor. Soft tissue is adequately retracted to allow complete visualization of the tumor cavity. The tissues around the cavity are protected by placing hydrogen peroxide-soaked mops around the tumor cavity. The aim is to isolate the bone opening and avoid any contamination of soft tissue by the tumor, as hydrogen peroxide kills GCTB cells on contact
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. The soft-tissue mass of the tumor is removed en bloc with a cover of normal tissue in order to prevent spillage into uninvolved tissues. Ward and Li advise the use of cautery for this part of the exposure in order to minimize contamination because high-temperature cautery kills the tumor
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. The initial opening into the osseous tumor cavity is made smaller in order to control the tumor spillage, and then enlarged in order to gain complete visualization.
(2) Curetting and burring for tumor clearance. The walls are curetted, using the sharp edges of the curet. Good visualization is the key to meticulous and complete curetting. We recommend the use of a surgical loupe and headlight for adequate visualization
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. Tumor cavities often have overhanging osseous ridges with tumor hidden behind them. A curet may not be useful for breaking these hard osseous ridges; a burr is best utilized for this task. In addition to breaking the ridges, a high-speed burr helps to extend the curettage for a few millimeters beyond the grossly visible tumor margin
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.
(3) Use of adjuvants to achieve extended curettage. Various physical and chemical agents have been utilized to control the microscopic disease remaining in the walls following a thorough curettage. Liquid nitrogen, phenol, hydrogen peroxide, alcohol, electrocautery, bone cement, and argon plasma cautery have been utilized as adjuvants. Balke et al. showed that the rate of recurrence decreases with use of more adjuvants, with high-speed burring having the greatest effect on the rate of recurrence, likely as a result of the larger resection and the thermal effect of the burring
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. We suggest a case-by-case use of specific adjuvants, but in our experience, a high-speed burr is always utilized, hydrogen peroxide is utilized commonly when safe, and argon-plasma cautery is utilized judiciously.
(4) Reconstruction of the cavity. The defect may be filled with bone, cement, or a combination of both. We suggest an individual, case-by-case approach to the reconstruction. In cases in which >25% of the articular surface is undermined
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, subchondral bone grafting is recommended prior to cementing (i.e., a sandwich procedure).

Alternatives:
GCTB requires tumor clearance for local control. One alternative to intralesional surgical treatment performed around the knee is resection of the tumor-affected segment of bone and reconstruction with an endoprosthesis. This is a joint-sacrificing alternative and, in our experience, should be reserved for patients with joint involvement, multiply recurrent disease, or insufficient remaining wall to curet.

Rationale:
When adequate tumor clearance is possible, joint-salvaging intralesional surgical treatment remains the superior option to achieve physiological joint function
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. Indications for this procedure include maintained or restorable joint congruity and construct stability allowing early mobilization.

Expected Outcomes:
The rate of local recurrence following intralesional surgical treatment ranges from 16% to 25%
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. The use of a high-speed burr is an essential part of the curettage
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, and hydrogen peroxide is a safe choice for an adjuvant, if desired and when suitable, to provide greater local control
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. Reconstruction with bone, cement, or both is acceptable, but we recommend building up a few millimeters of subchondral bone with bone graft before cement filling
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.

Important Tips:

Illumination and magnification within the tumor cavity provide better visualization.Isolation of the soft tissue around the tumor with use of hydrogen peroxide-soaked mops can prevent seeding and contamination.Meticulous tumor clearance is more important to minimize recurrence than the use of adjuvants.Use of a C-arm helps to better guide extension of the curettage and avoid inadvertent joint penetration.Maintaining joint congruity is essential.