Tumour Service

At the Department of Orthopaedic Surgery in Singapore General Hospital, our Musculoskeletal Tumour Service focuses on the reconstruction of severe bone and tissue loss due to tumour, degenerative and surgical conditions. We are the only Bone and Soft Tissue Tumour and Orthopaedic Oncological Service within the Singapore Health Services cluster. Limb salvage reconstructions are performed whenever possible.

As a patient, you can be assured of receiving state-of-the-art treatment, as well as the best post-surgical care, to help you on your way to a speedier recovery. Collaborating with the National Cancer Centre and backed by a team of highly qualified and experienced specialists, our goal at the Musculoskeletal Tumour Service is to ensure that each patient returns to living a quality life.

Our physicians are also experts in microsurgery. Microsurgery restores limb function by repairing tiny, delicate vessels, and nerves. It also enables the transfer of muscles and large segments of skin, fat, and bone from one part of the body to reconstruct another. Advances in microsurgery often mean that patients may avoid amputation.

Listed below are some of the conditions treated by our specialists:

• Benign bone tumours 

• Malignant bone tumours 

• Metastatic bone tumours 

• Bone fractures without significant trauma

• Soft tissue sarcomas

Benign bone tumors do not metastasize or spread to other areas. Though they can occur in any bone in the skeleton, some types of tumors are most common in specific locations such as the spine or near the growth plates of the largest bones (femur, tibia, humerus and pelvis). Others can be very aggressive and destroy bone quickly.

Common benign bone tumours that require treatment include:

Aneurysmal bone cysts (ABC) are benign expansile tumour-like bone lesions of uncertain aetiology, composed of numerous blood-filled channels. They are mostly diagnosed in children and adolescents. Although benign, the ABC can be locally aggressive. Its expansile nature can      cause pain, swelling, deformity, disruption of growth plates or joint surfaces, neurologic symptoms (depending on location) and pathologic fracture.

Chondroblastoma is a relatively rare, benign cartilaginous tumour, accounting for approximately 1% of the benign tumours of bone. The peak incidence is in the second decade of life and is slightly more common in males than females. In addition to long bones, chondroblastoma also occurs in the acetabular region of the pelvis, scapula, spine, and ribs. It can also occur in the patella, tarsal bones, and occasionally in craniofacial bones.

Chondromyxoid fibroma (CMF) is one of the rarest of bone tumors, accounting for less than 1% of all bone tumours. It is a benign tumour that most often develops in older children and young       adults under the age of 30. CMF is found equally in both males and females.

A giant cell tumour of bone is a type of benign tumour that grows at the ends of the body’s long bones. Most often, the tumours develop at the lower end of the femur (thighbone) or upper end of the tibia (shinbone), close to the knee joint.

Giant cell tumours typically occur in young adults and are slightly more common in females. They are quite rare, occurring in only about one out of every one million people per ear.  

 

Although giant cell tumours are not cancerous, they are aggressive and can destroy the surrounding bone.

Osteoblastoma is a benign bone tumour that often develops in the bones of the spine, as well as the legs, hands and feet. They destroy healthy bone and can grow to a large size.

Adolescents and young adults are most often affected by osteoblastoma. The tumours typically appear between the ages of 10 and 30 years. They are twice more common in males than in females.

An osteoid osteoma is a benign bone tumour that usually develops in the long bones of the body such as the femur (thighbone) and tibia (shinbone). Although osteoid osteomas can cause pain and discomfort, they do not spread throughout the body. Osteoid osteomas can affect people of all ages but they occur more frequently in children and young adults.

Common benign tumors that may require treatment include:

o Fibrous dysplasia

o Metaphyseal fibrous defect

o Osteochondroma

o Unicameral bone cyst

All malignant bone tumours require treatment. The likelihood of treatment success increases   when these tumours are diagnosed and treated early.

Types of malignant bone tumours include the following:

Chondrosarcoma is a rare type of cancer called a sarcoma, which develops in the bones and soft tissues of the body. Most chondrosarcomas begin in the bones. A small number develop in the soft tissues away from bones (extraskeletal chondrosarcomas).

Many chondrosarcomas are low-grade tumours that grow slowly and rarely spread (metastasize) to other areas of the body. However, some chondrosarcomas are intermediate and high-grade tumours that behave more aggressively.

Chondrosarcomas often affect middle-aged and older adults and most commonly occur in the pelvis or thigh (femur) bones.

Ewing’s sarcoma is a very rare form of cancer in adults. It is a cancerous tumor that grows in your bones or the soft tissue around your bones, such as cartilage or the nerves. Although it can occur in any bone, it most often begins in the leg bones and hipbones, as well as the bones in the arms, chest, skull and spine. This cancer most often occurs in children and young adults between the ages of 10 and 20. More males are affected than females.

Osteosarcoma is a type of bone cancer that begins in the cells that form your bones. It is most often found in the long bones in your arms and legs, though it can occur in any bone. It is most common among people aged 10 to 25, although it can occur at any age.

Lymphoma of bone affects adults, usually in their 40s and 50s. It may arise in any bone. It can develop as an isolated primary bone tumour, in association with similar tumours in other tissues, or as a metastasis from known soft-tissue lymphomatous disease.

Bone metastatis occurs when cancer cells spread from their original site to a bone. Nearly all types of cancer can spread (metastasize) to the bones, but some types of cancer are particularly likely to spread to bone, including breast cancer and prostate cancer. Bone metastatis can occur in any bone but more commonly occurs in the spine, pelvis and thigh.

Fractures through abnormal bone are called ‘’pathological fractures’’. Probably the most common cause of this is an underlying tumour, either benign or malignant. However, almost any underlying process of bone that weakens the bone can lead to a pathological fracture. It could be due to osteoporosis as well to other pathologies such as cancer, infection (eg. osteomyelitis), inherited bone disorders, or a bone cyst.  

Soft tissue sarcomas are very rare. As the name implies, soft tissue sarcomas develop in soft tissues, such as muscle or fat, rather than bone. They mostly occur in the extremities or pelvic area. There are many types of soft tissue sarcomas, but most are treated in the same way. Some common soft tissue sarcomas include:

• Fibrosarcoma

• Liposarcoma

• Malignant Fibrous Histiocytoma (MFH)

• Leiomyosarcoma

• Rhabdomyosarcoma

• Synovial Sarcoma

• Angiosarcoma

• Malignant Schwannoma (Neurofibrosarcoma)

Our team of specialty-trained orthopaedic surgeons has extensive experience and expertise in musculoskeletal tumours.

They specialize in:

 

Some of these surgical techniques are explained in greater detail below:

Depending on the site and stage of a sarcoma, surgery might be able to remove the cancer and some of the nearby tissue. The goal of surgery is to remove the entire tumour along with at least 1 to 2 cm (less than an inch) of the normal tissue surrounding the tumour. This is to make sure that no cancer cells are left behind. Most patients can be treated with surgery to remove the tumour without amputation. This procedure is known as a limb-sparing surgery, which is usually followed by radiation therapy.

Endoprosthetic replacement of segmental skeletal defects is the preferred technique of reconstruction after resection of bone sarcomas. It is the most frequently used surgical method for skeletal reconstruction in limb salvage surgery for malignant bone tumours. Today, all of the major anatomic joints with their adjacent segmental bone can be reconstructed safely and reliably with a modular endoprosthetic replacement. 

In this procedure, the diseased bone is replaced with a metal implant. This metal implant is called an Endoprosthetic Replacement (or an EPR). The EPR is made of titanium alloy and is the same shape and size as the bone that has been remove.

Common endoprosthetic replacement surgeries include:

• Distal Femoral Endoprosthetic Replacement

• Helmipelvic Endoprosthetic Replacement

• Proximal Femoral Endoprosthetic Replacement

• Proximal Humeral Endoprosthetic Replacement

• Proximal Tibial Endoprosthetic Replacement

Endoprosthetic replacement following resection is a good treatment option for proximal   femoral tumours due to the low complication rate and achievement of good postoperative function.

Endoprosthetic knee replacement is associated with good functional, cosmetic and psychological   outcomes, resulting in significantly better walking efficiency and musculoskeletal tumor society scores (MSTS) in comparison to major amputation or arthrodesis.

The procedure is also known as Van Ness rotationplasty and involves the removal of the tumor plus the joint. This always involves the distal femur and proximal tibia, or the knee joint. After removing the bone tumor, the distal limb (the part of the limb farthest away from the body’s center) is attached to the proximal limb (the part of the limb closest to the body’s center) with the foot facing backward. The foot then acts like the knee joint and a prosthesis is attached to it. 

Rotationplasty is a satisfactory treatment option in selected patients. A prerequisite for this type of surgery is an intact sciatic nerve. Rotationplasty is a satisfactory treatment option in selected patients. The procedure is suitable for young patients (<8-10 years of age) with a tumoral lesion above the knee, for older patients with large lesions that are not candidates for limb salvage as an alternative to above-knee amputation, as well as a salvage procedure for chronically infected prosthetic implants.

Patients are able to control the movement of the prosthesis much better. Furthermore, they are able to have a functioning knee joint and have a better quality of life, with less limitations doing daily activities.

Hemipelvectomy is the surgical removal of half of the pelvis usually for the treatment of localized tumours and, rarely, for cancer that has metastasized to the area.

Half pelvis removal may be classified as external or internal. The former involves the resection of the bones of the pelvis and the amputation of the leg on the same side, which is usually followed up by the fitting of prostheses. The latter, on the other hand, spares the limb but removes the diseased bones and tissues.

Surgical reconstruction is a standard after hemipelvectomy and involves the use of flap procedure or graft technique that recreates the pelvis and protects the remaining structures as well as the attached metal screws and plates from exposure. Reconstruction surgery is also performed to reduce the possibility of a hernia from developing.

Computer-assisted orthopaedic tumour surgery, also known as CAOTS, with image fusion offers preoperative three-dimensional surgical planning and allows our surgeons to reproduce the intended bone resections in musculoskeletal tumors. The technique is useful in technically demanding resections, such as in pelvic and sacral tumors; joint-preserving intercalated and multiplanar tumor resection. It allows for complex reconstruction with custom computer-aided design prostheses or allografts.

Limb salvage surgery has become a standard practice without compromising the oncological   outcome. Patients generally will benefit with superior function and a better quality of life compared with definitive amputation. 

For patients with metastatic bone disease, treatments help to relieve pain, improve function and ambulation, as well as improve their psychological wellbeing. Aggressive treatment results in the restoration of function and diminution of pain. Multimodality treatment, which includes surgical stabilisation and replacement, radiation and medical treatment, helps to preserve limb function. As a result, the patients’ quality of life is enhanced significantly.

For patients with malignant bone tumours, function preserving alternatives in these lesions have now become the norm without compromising on overall disease survival and have resulted in a documented improvement in overall quality of life for these patients.