Newer Techniques in Treating Orthopaedic Cancers

Orthopedic oncology is a relatively newer orthopaedic field that involves managing and treating musculoskeletal tumors. The treatment of musculoskeletal tumors have undergone rapid developments over the years as amputation is no longer the only remaining option to treat malignant bone tumors. Newer alternatives aim to preserve mobility and function of the lesion-affected regions without compromising on treating the illness and thus overall quality of life of patients. 

Bone cancer and sarcoma require a combination of treatments and therapies. An orthopedic oncologist may use targeted procedures to remove tumors or reconstruct bone. These treatments and therapies are also designed to help restore limb mobility, enhance function and manage pain. Some of the therapies include: 

Amputation:

Amputation is the surgical removal of all or part of an extremity or limb. This surgical procedure may be used to remove cancerous bone tumors from the arm or leg. Since this is an extreme procedure, doctors typically consider other options first, such as limb-salvage surgery, which attempts to save the affected limb. Amputation for bone cancer is usually reserved for cases in which the limb would otherwise be left without good function. 

Limb-salvage surgery:

90% of limbs can be spared due to advancements in surgical techniques and in related cancer-fighting therapies. Limb salvage surgery, also called limb-sparing surgery, is a procedure intended to remove a tumor while still preserving the nearby tendons, nerves and blood vessels so the patient can maintain function in the affected limb. This option is used to treat cancers spreading at a slow rate.

In this procedure, the surgeon removes the tumor, affected tissue and one inch of healthy surrounding tissue. Sometimes a part of a bone is removed during this time which can be replaced using synthetic metal rods, prostheses, muscle implants or pieces of bone or tendon grafts. Over time, the replacement bone fuses with the original bone, making limb movement possible. Limb salvage surgery is often followed by conjunction with radiation therapy and/or chemotherapy. 

Cryotherapy

Curettage is a procedure where the surgeon scoops the tumor and any additional adjacent tissue out of the bone, leaving a hole in the bone. Following curettage, the surgeon may perform cryotherapy where they pour liquid nitrogen or specialized gas to freeze  and eliminate any tumor cells remaining within the tumor cavity. The technique is often used to treat benign (aneurysmal bone cysts), aggressive (giant cell tumor of bone), and certain low-grade malignant tumors (low grade chondrosarcomas). 

Jean-Emmanual Kurtz and his team analyzed the use of cryotherapy in 50 patients with non-abdominopelvic progressing desmoid tumors. The progression-free survival rate at 12 months was 86 % (complete response, 29 %; partial response, 6 %; stabilization, 31 %, with an objective response rate of 55 %) according to the modified response evaluation criteria for solid tumors. Cryotherapy improved functional outcomes and relieved pain, however the treatment results are poor for large tumors.

Implants and Prosthesis

Patients with primary bone cancers may require orthopedic implants, which are devices that replace or support damaged joints or bones in the body. Pins, rods, screws and plates are the most common implants. Metal rods may be used to prevent bones from breaking. Orthopedic implants are made of plastic, ceramic, stainless steel and titanium. Some of the implants are also 3-D printed. Orthopedic implants may be used to treat joint degeneration in the hip, knee, shoulder and elbow and can help restore normal function by increasing mobility and reducing pain.

Surgery is required to secure the implant where it’s needed. Non-surgical methods are often the first line of treatment. However, these implants may wear out after several years, hence they have to be replaced.

Percutaneous cementoplasty

Percutaneous cementoplasty is a new and minimally invasive technique to relieve pain in patients with osteoporosis, bone metastases and compression fractures of the spinal vertebrae. A special balloon is inflated inside the fractured bone to expand it to its normal height. The balloon is then deflated and removed and a cement-like material is injected directly into the remaining space through a hollow needle. The material, considered to be as strong as bone, doesn’t injure normal bone tissue. This procedure may help to relieve pain, restore height and mobility, reduce spinal deformity and stabilize these fractures.

The life expectancy of patients with metastatic bone disease appears to be the most important factor in determining the surgical method to be used. Bone cancer treatments are no longer limited to just getting rid of the disease and restoring limb function but also includes making these treatments affordable. 

Author: Parvathi Nair