In this article, Dr. Gurpal Singh from Farrer Park Hospital, specializing in Orthopedic Oncology & Joint Replacement (including robotic-assisted) and Sports Surgery, shares his insights on limb salvage surgery for bone tumors and post-operative patient care in cancer patients.
Limb salvage surgery describes the removal of a bone tumor without sacrificing the entire limb; no amputation is needed. In expert hands, limb salvage surgery offers better functional and psychosocial outcomes without increasing the risk of recurrence/spread of disease or compromising overall survival when compared to amputation.
Limb-salvage surgery involves two major steps: First, removal of the bone tumor and the soft tissue component of the tumor (if any), followed by reconstruction of the bone and soft tissue defect. It is a complex and technically challenging procedure that requires a highly specialized surgical team.
To achieve tumor-free margins, significant portions of the bone may need to be resected. This can result in large bone defects, which need to be reconstructed. Reconstruction of bone defects can be achieved by:
Studies show that the statistical chance of developing bone cancer parallels skeletal growth, meaning bone cancer is often found in children and young adults. Limb-salvage in children is particularly challenging when the growth plate needs to be resected during surgery. The growth plate is part of the long bone adding length to the bone during growth. Once removed, the bone won’t grow further. To avoid situations in young bone cancer patients where the operated limb stops growing and the other (non-operated) limb keeps growing, resulting limb length discrepancy, special “growing” implants can be used. With the help of strong magnets, these implants can be expanded in small increments in parallel with the child’s natural growth.
One of the most dreaded complications in any type of major surgery in cancer patients is infection. Cancer patients are particularly susceptible to infection as cancer treatment and cancer itself can weaken the body’s immune system. As a result, the body’s responses which are meant to protect against bacteria, viruses, fungi or parasites are less likely to be sufficient. Hence, cancer patients are prone to infection.
Infection can result in prolonged hospital stay necessitating the use of strong intravenous antibiotics and potentially multiple surgeries to remove the source of infection. In the worst-case scenario in the context of bone tumor patients, this can result in the need of amputation or spread of the disease to other parts of the body, which can be life-threatening. Risk of infection is particularly relevant in patients undergoing limb-salvage surgery with subsequent implantation of a megaprosthesis as research has shown that bacteria causing infections are more likely to grow on implants.
This explains why orthopedic tumor surgeons tend to be paranoid about infection control. Several measures are put in place to keep the risk of infection as low as possible. These include performing the limb salvage surgery in dedicated orthopedic surgery operating rooms with controlled laminar air flow, minimizing personnel in the operating room and the use of specialized “spacesuits” with internal ventilation to reduce the risk of pathogen transfer.
In view of the risk of infection in cancer patients, chemotherapy is stopped before surgery to allow the immune system to recover. As this means time off systemic cancer treatment, this period just before surgery is kept as short as possible. Once the wounds have healed after surgery, systemic cancer treatment can be re-started. Optimizing the timing of surgery and systemic treatment such chemotherapy or radiation therapy hence requires close collaboration between oncologists and orthopedic surgeons and highlights the need for teamwork among different specialties.
Most patients undergoing limb salvage surgery recover surprisingly quickly. Although every patient’s progress is different, assisted walking is typically allowed within a day or two after surgery. Orthopedic surgeons will also encourage their patients to gradually increase range of motion exercises. As tissues heal, patients can gradually transition to wider range of motion. Sometimes, a brace might be used to provide additional support in the immediate post-operative period.
Most patients can expect to regain mobility for basic activities within two weeks and may be reasonably independent by four weeks. Systemic cancer treatment after surgery can have several side-effects such as nausea and vomiting or the feeling of extreme tiredness. While this may set patients back on their path to full recovery, doctors and allied health professionals are working closely together to support cancer patients on every step of their journey.
Once fully healed, patients may resume normal physical activities and gentle exercising. Extreme sports or activities that exert major stress on the reconstructed limb, however, should be avoided to prevent failure of the construct/ implant fracture.
Limb-salvage surgery has significantly evolved in the past decade and continues to do so. Thanks to improved systemic cancer therapy, superior biomaterials and enhanced implant designs, surgeons today can operate safely on large tumours that were previously only amenable to amputation. Surgical techniques also become more and more refined enabling complex nervous and vascular reconstructions. For example, surgeons can reconnect severed blood vessels via bypass surgery, and thereby ensuring that the operated area still receives a healthy supply of blood flow.
Another example demonstrating that limb-salvage surgery is pushing the boundaries of what is feasible, are patients with pathological fractures. A pathological fracture is a bone break that can occur with minimal impact or even without obvious injury. It is related to the underlying disease (bone cancer) that weakens the bone, hence making it more prone to fracture. While amputations used to be the treatment of choice for these patients, more recent data show that limb-salvage surgery can be safely performed for patients with pathological fractures provided oncological principles are followed.
Despite all these advancements, there are still instances where limb-salvage surgery may not be feasible. The most common scenario in which amputation is the more valid option is a tumour that may not be completely removed due to contamination of nerves and bloods vessels as this may makes preservation of a functional limb after surgery impossible.
In summary, amputation, previously the gold standard for local treatment of bone cancers, is no longer the norm. Limb-salvage surgery can offer superior functional and psychosocial outcomes without compromising oncologic outcomes.