Surgery of Malignant Osteosarcoma
Amputation
- 手術時間快
- 手術較容易
- 功能恢復差
- 腫瘤侵犯重要神經血管的選擇
- < 5% 病友需要
Limb salvage
- 手術時間長
- 較困難
- 功能恢復佳
- 一般狀況下的選擇
- >95 % 病友需要
In contrast to amputation, ‘Limb salvage’ is the remaining surgery for osteosarcoma and other malignant bone tumors. As the name implies, limb salvage is to remove only the tumor from the patient and then reconstruct the defected bone rather than remove the patient's limb entirely. Almost all patients and physicians want to conduct limb salvage for patients with malignant osteosarcoma, but the key determinator is the degree of their tumor invasion and the extent of their disease. Generally, if the tumor is quite large and has invaded the entire important limb nerves and blood vessels, retaining the dilapidated limb will bring greater distress.
It will require the physician to take about five to ten times more surgery time and more concentration to perform limb salvage surgery, comparing to amputation. It takes a considerable amount of time to carefully remove the tumor, avoid damage to important nerve vessels, and spend much more effort on reconstructing the limb. As a result, physicians who are able to perform this surgery are required to undergo a considerable amount of time for double specialist training (including trainings for osteosarcoma and artificial joints). Also, since in Taiwan, the amount of osteosarcoma patients is small and most of them concentrate in some hospitals, the physicians specializing in osteosarcoma are really scarce. (Note: Although hard as it is, it's worth it to see the patients gradually recover from surgery!)
The missions of limb salvage surgery are two:
First: Remove tumor (Wide Excision)
Second: Restore limb function (Limb Reconstruction)
Both are indispensable and are must-to-have. If the tumor is not removed completely, even if the postoperative limb function is excellent, after a few months, the tumor will recur. If the tumor is cleaned up thoroughly, but the limb reconstruction is incorrect, the patient is still unable to walk (or move the upper limb), it’d be better to conduct a direct amputation.
The definition of wide excision is to remove the tumor from the edge of the tumor along with two to three centimeters of normal tissues. Simply put, it indicates that removing the tumor completely and integratedly without a break and slicing some normal tissue nearby to create a safe margin. It is not allowed to pull, scrape, or grind the tumor; otherwise, it is easy to cause local recurrence. There is no firm definition of how many centimeters of normal tissues should be removed. Articles decades ago recommended that the edge should be at least 3 centimeters or more (See figure below, second left). Because of the good pre-operative chemotherapy and the accurate imaging equipment, it is generally believed that one to three centimeters of the safe range is sufficient (See figure below, the light right, part two).
Intralesional curettage (See figure below, first right) is not considered in malignant osteosarcoma surgery since it increases the chance of a fairly high tumor recurrence. Hence, this practice is not considered except for special considerations.
In the figure below, the osteosarcoma is significantly large and locates above the knee (distal femur), where the patient has pathological fractures. The range of tumor invasion is quite large, and it suppressed the popliteal artery and vein and popliteal nerve. We conducted the surgery to remove the entire tumor completely and to reconstruct the blood vessels.
When we successfully remove the tumor, the next challenge the osteosarcoma physicians will face is how to make a proper reconstruction of this significant bone defect (the yellow dotted line in the figure below). If the reconstruction is not successful, the operation can only be considered half the success. Although the tumor has been removed, the patient's limb function is relatively poor.
Remote femur sarcoma
The range circulated by solid yellow line indicates the tumor range
After tumor removal
The range circulated by dotted yellow line indicates the bone defects after tumor removal
we have three methods of bone reconstruction clinically, which we will describe in the following articles.