Process of clearing tumor contents after breaching the capsule (Intralesional Surgery)
- Benign bone tumors such as Giant cell tumor, Simple bone cyst, Aneurysmal bone cyst commonly.
- Metastasis to bone.
- Local recurrence in benign bone tumors.
- Rarely in malignant bone tumors (palliative).
- Depends on biopsy scar or previous surgery and localization of tumor bone.
- It is preferable to excise the biopsy scars during procedure.
- A tourniquet is almost always used in case of limb girdle tumor. This enables the surgeon to operate in a bloodless field. Also the risk of bleeding is negligible during surgery.
- A “Window” of sufficient size is created on the affected site of bone.
- A Curette is used to clear macroscopic tumor tissues from the host bone.
- Periodic regular saline wash is given to flush the tumor debris.
- Small pockets of tumor are cleared with help of “High speed Burr”, which can clear microscopic tumor tissues up to 2 mm depth. This procedure is called as “Extended Curettage”.
- The periosteum layer of bone is cleared of any tumor tissues.
- Adjuvants are used to help clear the tumor. Examples are hydrogen peroxide, absolute alcohol, phenol (85%) and liquid nitrogen.
- The walls of curetted host bone is then burnt or cauterized with “Argon laser cautery”.
- The resultant defect can be filled with cement (PMMA) or bone graft and substitutes depending on the size and type of defect.
- A suction drain is inserted into the cavity to drain and clear any post- operative fluid collection.
Reconstruction of cavity
PMMA (polymethyl methacrylate)
- Ideal filler after curettage of benign bone tumors with high risk of local recurrence.
- Also acts as tumoricidal (kills tumor cells) due to thermogenic (production of heat) effect.
- Ideally suited for cavities which have good host bone stock available.
- An advantage of using cement over bone graft is that recurrence is easily identifiable.
- Bone grafts are used for reconstructing a defect when the bone stock is less or the host bone needs structural support.
- Different types on bone grafts can be utilized to reconstruct the cavity/ defect, such as autograft, allograft in form of cancellous bone chips or strut grafts.
- Autograft is bone harvested by a separate incision from preferably the iliac crest.
- Allograft is cadaver or living donor harvested graft. This is treated and processed to reduce the chance of transmission of viral disease such as hepatitis, hiv and syphilis. They are stored under -70 degree Celsius to maintain viability.
- The advantage with utilizing bone graft is that remodeling occurs leaving host bone residue.
- Autogenous bone is preferred if a rapid and extensive bone growth is required, but has disadvantage of another procedure to harvest.
- Allogeneic bone graft are utilized more commonly as struts or block fillers providing structural integrity.
- Internal fixation in form of screws, plate and nails are fixed to host bone to support the graft or cement construct.
- Sandwich or “T” Construct Technique