Can Bone Grafts Provide An Advantage In Foot And Ankle Surgery?

Bone graft, whether it is cortical, cancellous or cortico-cancellous, has many applications in foot and ankle surgery. Most commonly, it is used to fill osseous defects or facilitate enhanced healing after surgery.15,16

Autograft continues to be the preferred choice due to its ability to develop mesenchymal cells into bone and cartilage forming cells; build pro-lattice for osteoblast and other support cells; and induce osteoprogenerative cells into new cells for bone production.15,17 However, the advantages of autogenous bone graft can sometimes be outweighed by problems such as donor site pain and morbidity, increased blood loss and the cost of graft harvest.17
Allograft has been shown to be advantageous in providing structural support for deformity and correction of deformities without complications of autogenous bone graft.18-20 However, allograft bone graft materials can incorporate at a slower rate, may induce an immune response and the techniques of preservation may affect the mechanical properties.21

Bone graft substitutes incorporate properties of the autogenous and allogenic bone graft via proprietary methods of merging different compounds into one material.17 Tissue engineered bone graft substitutes have been developed and possess both autogenous and allograft properties without most of their associated complications.
The OsteoCure bone graft substitute consists of polyglycolic acid (PGA) fibers, pores, surfactant, calcium sulfate and polylactide-co-glycolide. Poylactide-co-glycolide has shown to be effective in adhesion of osteoblast cells, calcium sulfate encourages bone growth and PGA provides strength to the graft material. In our experience, OsteoCure is a safe and effective bone graft alternative in foot and ankle reconstruction.
This report demonstrates the effectiveness of OsteoCure™ bone graft wedges in reconstructive surgery of the foot.

Case Study: A Patient With Progressive Arch Pain
A 36-year-old male presented with progressive pain in the arch of the right foot. The pain had been present for some time but had become progressively worse in the last six months. The patient had failed conservative treatment in the form of orthotics, oral steroids and antiinflammatory medications.

During the clinical examination, the patient had decreased arch height, forefoot abduction and heel valgus present in the left foot when compared with the right foot. The patient’s range of motion of the ankle joint was limited with a tight Achilles tendon. The patient had pain along the course of the posterior tibial tendon. Additionally, he displayed weakness on a single and double heel raise test, and plantarflexion inversion of the left foot.
Computerized gait analysis, using an EMED pedobarograph/pressure plate, revealed his left arch had abnormal loading, increased pressure to the left hallux, heel and right first metatarsals two through four and hallux. His left forefoot had minimal load and his left heel was loading more than the right. Magnetic resonance imaging (MRI) showed complete rupture of the posterior tibial tendon 2 mm distal to the medial malleolus.
The patient elected to undergo surgical correction via a tendo-Achilles lengthening, calcaneal Scarf osteotomy and Cotton osteotomy.

A Guide To Surgical Success With The OsteoCure Graft
Surgeons identified the superior edge and inferior aspect of the calcaneus. Utilizing an osteotomy guide, they made a Z-type osteotomy in the calcaneus. They directed the posterior vertical limb at a 45-degree angle from the lateral to the medial approximately 15 cm anterior to the posterior superior tuberosity, which extended 15 mm.

Following that, the surgeons directed the transverse cut anterior and plantar to an area 3 cm proximal to the calcaneocuboid joint. Surgeons made a distal vertical osteotomy directed at a 45-degree angle from the junction of the horizontal osteotomy to the plantar aspect of the calcaneus at this level. They used an osteotome to complete all three cuts through the lateral wall and the calcaneus was translated 10 mm laterally.
Surgeons opened a smooth laminar spreader at the posterior vertical limb in order to elongate the calcaneus. The distal portion of the vertical osteotomy measured 11 mm in length and placed a 10-mm/10-degree OsteoCure wedge in the defect as a positional graft. They then removed the laminar spreader from the superior aspect and inserted a smiliar bone graft superiorly under compression and tamped into place. Surgeons used an 8.0-mm cannulated screw to fixate the osteotomy under fluoroscopic imaging. They compressed and tamped the protruding medial wall.
The patient wore a non-weightbearing below-knee cast for five weeks. This was followed by partial weightbearing in a CAM Walker and physical therapy for an additional 10 weeks. Radiographs, which were taken along the postoperative course, showed alignment of the osteotomies remained while the bone graft underwent full resorption of the graft four months postoperatively. The patient denied any complication of infection following the procedure.
In the authors’ opinion, OsteoCure Bone Wedges appear to be a safe and effective bone graft alternative in foot and ankle reconstruction.