Advances in the management of soft-tissue and bone sarcomas—referred to collectively as “musculoskeletal sarcomas” hereafter—have resulted in significant improvements in survival and quality of life.1–3 Several factors have likely contributed to these advances, including improved surgical technique and the development of referral centers for sarcoma treatment that have embraced a multidisciplinary approach.1,2
The goal of treatment for musculoskeletal sarcomas is to optimize oncologic outcome and maximize functional restoration.2,3 Surgical resection has been the mainstay of therapy,1–7 as detailed earlier in this supplement. In patients with musculoskeletal sarcomas of the extremities, limb-sparing resection has been shown to be significantly superior to amputation.1,7–9 Wide local excision of the tumor along with its muscle compartment, followed by adjuvant chemotherapy and radiation therapy, has allowed limb salvage without an increased risk of recurrence in many patients.3 However, wide tumor resection can leave large defects that are not amenable to coverage by mobilization of the surrounding tissues, particularly if those tissues have been irradiated. As a result, resection can expose neurovascular structures, bone without periosteum, alloplastic materials, and internal fixation devices.
GOALS OF RECONSTRUCTION
Reconstructive surgery after musculoskeletal sarcoma resection aims to provide adequate wound coverage, preserve function, and optimize the cosmetic outcome.1–3 Tumors can be found on areas crucial to limb movement or may involve tissues vital to limb function. Reconstruction to repair these deficits can take many forms. In certain situations, amputation is still inevitable. In those cases, the reconstruction should provide stable stump coverage with durability and the ability to fit well with an external prosthesis.3
TIMING OF RECONSTRUCTION
Immediate reconstruction should be pursued if possible
Immediate reconstruction after a negative margin should always be considered and should be attempted when possible. Immediate reconstruction allows the reconstructive surgeon to benefit from better evaluation of the defect and exposed structures, as no scar tissue is present to distort the anatomy. Likewise, patients benefit from faster recovery and can receive adjuvant treatment (if necessary) sooner, as well as earlier rehabilitation. Patients may also benefit psychologically from immediate reconstruction.1,3
Indications for delayed reconstruction
Delayed reconstruction is primarily indicated when there are wound healing problems or there is uncertainty about the tumor margins. Secondary indications for delayed reconstruction are wound dehiscence and unstable soft-tissue coverage. If hardware is exposed, the recommendation is for early intervention and wound coverage with well-vascularized tissue to protect and cover the implant or prosthesis.
What about radiation therapy?
A very important consideration in reconstruction is the need for neoadjuvant or adjuvant radiation therapy.3,10,11 Irradiated wounds have a higher incidence of complications, including a tendency to dehisce. In patients who have been previously irradiated, the best practice is to perform immediate reconstruction with well-vascularized tissue, most likely a free tissue transfer.4,6,11,12 This practice reduces hospital stay, costs, and morbidity and increases limb salvage and patient satisfaction.13
SYSTEMATIC PREOPERATIVE PLANNING NEEDED
Reconstruction after musculoskeletal sarcoma resection should be planned systematically within a process that involves preoperative anticipation of the defect size and the resulting functional and cosmetic deficits that might need to be addressed. A preoperative visit to the reconstructive surgeon can be very helpful for presurgical planning.
During surgery it is usually preferable to allow the surgeon doing the tumor resection (eg, surgical oncologist or orthopedic oncologist) to complete the resection because the dimensions of the defect are not certain until negative margins are obtained.14 If tumor margins are unclear at the time of initial resection, the surgeon should consider delaying the definitive reconstruction until the permanent sections confirm negative margins. Temporary closure can be achieved with wound dressings, skin grafts (either allograft or autograft), or negative-pressure wound therapy. In the same context, if neurovascular structures are exposed it is reasonable to use a muscle flap without “tailoring” the flap to the defect. This approach allows the flap to be advanced or repositioned in case of positive margins, and the skin graft can be applied to the muscle surface in a second procedure.3
RECONSTRUCTIVE METHODS: A BRIEF OVERVIEW
Several methods can be used to close musculoskeletal sarcoma excision defects. Smaller defects can be closed primarily, although most defects are large and not amenable to primary closure. If fascia or muscle is preserved with only the skin coverage missing, the wound can be covered with either split-thickness or full-thickness skin grafts.1,4,6 Split-thickness skin grafts can be obtained in larger amounts and often heal faster than full-thickness skin grafts. However, most resections will require durable tissue coverage, particularly if adjuvant radiation therapy is planned.
In the case of long bone sarcoma resection, the resulting defect is usually large and complex and the traditional reconstruction is based on avascular allografts and local tissue flaps. However, allografts are associated with high rates of infection, nonunion, and fracture, leading to failure in about 50% of cases. Microvascular free flaps that contain bone, such as free fibula flaps, have been used instead of allografts with good success rates.2
Lately there has been growing interest in the use of the vacuum-assisted closure device (a form of negative-pressure wound therapy) to promote wound healing. It has been shown to improve the granulation and healing of open wounds by absorbing moisture, as well as to promote adherence after skin grafting, thereby reducing the risk of graft displacement.1,3 This device can be used immediately after musculoskeletal sarcoma resection while definitive tumor margin results are pending. It also can be used to prepare the wound bed for grafting in high-risk patients who would not tolerate more complex reconstructions.
Local or adjacent fascial, fasciocutaneous, and dermal flaps can also be used in lower-extremity reconstruction. However, muscle or musculocutaneous flaps are the mainstay of reconstruction after resection of musculoskeletal sarcomas. This group also includes perforator flaps, which have grown in popularity in the last few years.1,3