George Dyer, MD is a Hand and Upper Extremity surgeon at the Brigham & Women’s Hospital, Boston; Director of the Harvard Combined Orthopaedic Residency Program and a member of the Partners Orthopaedic Trauma Service.
Trevor Owen, MD, is our graduating trauma fellow. He is joining the faculty of the Carilion Clinic in Roanoke, VA, as an orthopaedic trauma surgeon.
In late October 2011, 22 rebels injured during the Libyan Civil War were admitted to Spaulding Hospital in Salem, MA. Our Trauma team provided care to six patients with complex nonunions, malunions, and nerve injuries. This opportunity allowed us to apply techniques we use for more routine care to severe wartime injuries and their sequelae. It showed us how the careful practice of surgical principles can be effective, even when treating devastating injuries.
One of the patients we treated had sustained multiple gunshot wounds from a battle three months prior to his admission to Spaulding. He presented with infected nonunions of his left distal femur and right diaphyseal tibia, as well as a complete left sciatic nerve palsy. We treated both of his infected nonunions with the Masquelet or “induced membrane” technique.
Figure 1: Initial films showing nonunion of distal femur (left), after debridement with antibiotic cement spacer and beads in place (center), final radiographs showing consolidation of nonunion site (right).
The French surgeon Alain-Charles Masquelet developed the Masquelet technique for the treatment of large bone defects in the 1980’s. Prior to the development of Masquelet’s technique the most common procedures for diaphyseal bone defects greater than six centimeters were bone transport using the Ilizarov method and vascularized bone transfer (1).
Bone grafting of large segmental defects leads to graft resorption and an unacceptably high rate of failure. Masquelet’s method (described below) involves staged reconstruction with a cement spacer to create an induced membrane followed by cancellous autografting of the cavity created after spacer removal. One of the major advantages of this technique is that the reconstruction time is independent of the length of the defect. The minimum treatment time to fix a 6 cm defect using the Ilizarov method is nearly 7 months in an external fixator (unless modified techniques are utilized), whereas with the Masquelet technique patients with defects of this size and larger have treatment times of 4-6 months. Case reports describe use of the Masquelet technique to treat defects caused by tumor, trauma, and infection.
Stage One: Implanting the Spacer
The first stage includes radical debridement, placement of an antibiotic spacer, and soft tissue coverage. During debridement all necrotic or infected bone is removed and the ends of remaining segments burred back to bleeding edges. A polymethyl methacrylate (PMMA) cement spacer is fashioned to completely fill the segmental defect and overlap the ends of the bone slightly to facilitate membrane elevation at the second stage of the procedure. The bone should be stabilized by either internal or external fixation prior to implantation of the spacer.
The cement spacer serves two purposes: (a) to create and preserve a cavity which can later be filled with cancellous autograft; and (b) to induce a foreign body reaction membrane around the spacer. In several animal and human studies, this membrane has been found to be highly vascular and secrete growth factors (i.e. VEGF, TGF-ß1, and BMP-2) with peak concentrations around the fourth week.
Stage Two: Cancellous Autografting
Six to eight weeks after the initial procedure the patient is brought back to the operating room. The induced membrane is meticulously elevated from around the cement spacer and the spacer removed with osteotomes. Cancellous autograft from the iliac crest is used to fill the cavity. The membrane is closed as a separate layer, acting as a containment unit around the graft.
Alternate forms of bone graft, such as cortico-cancellous graft obtained using the reamer-irrigator-aspirator, can be utilized or graft extenders can be used to expand the volume of the autograft in the event the void is very large. Once the membrane is closed, internal fixation is used to stabilize the bone.
Post-operative protocols involve an initial period of non- weight-bearing for 3-4 months followed by progressive weight bearing. In Masquelet’s initial cases, which included defect reconstructions as large as 25 cm, the average time until normal walking was 8.5 months.
We utilized the Masquelet technique in the treatment of our patient’s two infected nonunions. He underwent debridement until his wounds were considered “clean” with no growth from intraoperative cultures. His tibia was stabilized with a temporary antibiotic-impregnated PMMA intramedullary rod molded from a large chest tube with an additional cement spacer in the bony defect. After 4 weeks the temporary rod and spacer were removed and replaced with an interlocked antibiotic cement-coated titanium rod with iliac crest bone grafting within the induced membrane.
Figure 2: Initial films showing nonunion of diaphyseal tibia (left), after initial debridement with antibiotic cement rod and spacer (center), final radiographs showing consolidation of the nonunion site (right).
Similarly, his femur was treated with preservation of existing hardware with placement of an antibiotic coated spacer in the metadyaphseal defect and antibiotic beads along the lateral aspect of the plate. Eight weeks later the spacer and hardware were removed, the cavity filled with iliac crest autograft expanded with cancellous allograft and an allograft fibula for added stability. Revision locked fixation provided definitive stability.
We permitted immediate weight bearing on his tibia, but made him non-weight-bearing on his femur for 4 months. The patient is currently 8 months out from his first surgery and is able to bear weight on both legs with the assistance of a walker with minimal pain. There are no signs of recurrent infection. He recently underwent Achilles tendon lengthening and posterior capsule release because of an equinus contracture secondary to his sciatic palsy on his left leg. The patient is currently recovering from this surgery and making plans to return to Libya.
It is not often we have the opportunity to treat this type of severe problem with delays to treatment in a modern healthcare setting. The Masquelet technique allowed reconstruction of these difficult problems in relatively short time without the use of prolonged external fixation or vascularized tissue transfer. While this is a dramatic injury with an even more dramatic back-story, we present this case because the principles of debridement and delayed bone grafting with this technique are useful and applicable to any orthopaedic trauma practice.
George Dyer, MD, is a Hand and Upper Extremity surgeon at the BWH and Director of the Harvard Combined Orthopaedic Residency Program. Trevor Owen, MD, is our graduating trauma fellow. Dr. Owen is joining the faculty of the Carilion Clinic in Roanoke, VA, as an orthopaedic trauma surgeon.
Giannoudis P, Faour O, Goff T, et al. Masquelet technique for the treatment of bone defects: tips-tricks and future directions. Injury 2011; 42: 591-598.