Bone grafting for spinal fusion.

At least 250,000 spinal fusions are performed in the United States each year, nearly all requiring implantation of bone graft material. The preferred technique for most of these operations is the transplantation of structured or morcellized autologous corticocancellous bone from the iliac crest. Further, because of the increasing frequency of spinal fusion surgery during the 1990s, arthrodesis of the spine has become the most common reason for autologous bone graft harvest. This article reviews the current clinical status of autogenous bone grafts and alternative materials in spinal fusion surgery.     

Bone grafting in rearfoot surgery

Bone grafting, especially in rearfoot surgery, is occasionally required. Two main morphologic types of bone may be grafted, namely cortical and cancellous. Each type of bone has its unique characteristics, which, when used properly, will ensure a good surgical result. Other factors also play an important role in decision making when using bone grafts. These factors include the characteristics of the host and site into which the graft will be placed, the fixation of the bone graft site, the metabolic state of the host, and the function of the graft. If careful surgical planning is exercised, a successful surgical result can be expected.     

Bone grafting and substitutes in spine surgery

The increase of spinal procedures over the last decades has made the long-term problems, such as pseudarthrosis, apparent. This demands optimized strategies, techniques and technologies. Modern fixation systems have been developed as an adjunct to spinal fusion, and several generations of different synthetic cages have proved to be reasonable alternatives to autologous bone or allografts. The development of recombinant bone morphogenetic proteins (BMPs) is of promise, because of their great osteoinductive capabilities. While spine surgeons are familiar with autologous and synthetic grafts as well as allografts, these comparably new evolving growth-factor-based technologies are of high interest. This was a selective literature review. Alternatives to autologous grafts include allograft bone, synthetic cages and growth-factor based bone substitutes, BMPs being the most-studied among them. Autologous iliac crest alone provides all of the required capabilities of an ideal bone graft, i.e. osteoconduction, osteoinduction, osteogenesis, but each of the alternatives can produce excellent results in a number of indications. If combined, these alternatives can cumulatively provide all required graft capabilities. Nevertheless, all of the available grafts have specific characteristics and can feature certain complications. Alternatives to autologous grafts circumvent donor-site morbidity and are available in a larger amount than autologous bone for extensive surgery. New technologies offer excellent possibilities of new bone formation, but there are also severe risks and high costs to be considered. The indication for bone grafting must be clearly defined, the graft selection should be individually adapted, and the risks, efforts and costs of the selected fusion procedure should be carefully considered.     

Complications of iliac crest graft and bone grafting alternatives in foot and ankle surgery

The ability to harvest iliac crest bone is a well-established skill in the surgical armamentarium of the orthopedic surgeon. As with any surgical procedure, this operation has its own set of complications. The surgeon must be aware of these potential problems in an effort to avoid them when possible. Other autologous sites for bone harvest are available to the surgeon, and s/he should be aware of these in terms of location, limitations of use, harvest technique, and potential pitfalls. The foot and ankle surgeon almost always needs less bone graft than our colleagues in spine surgery or joint revision surgery, so these other sites may be more suitable than the iliac crest for obtaining bone graft. Nonautogenous alternatives are becoming increasingly available to the orthopedist as a way to decrease morbidity and operating times. Scranton recently published an article about his success with several different bone substitute products that are used in foot and ankle reconstructive cases. As these options become more varied, it becomes more difficult to know which product to select. Understanding the biology of bone grafting with respect to osteoconduction, osteoinduction, and osteogenesis provides the surgeon with the knowledge that is needed to make an informed choice when selecting a bone grafting option. Before choosing an alternative graft material, the surgeon should also investigate how the graft material has performed in cases similar to his or her patient's needs. In the future, with continued research, the fields of tissue engineering and gene therapy will provide even better options for nonautogenous bone graft material.     

Bone grafting from the proximal tibia.

OBJECTIVE: A retrospective study was undertaken to analyze the results of proximal tibial bone grafts with immediate postoperative weight bearing. METHODS: Over a 2-year period, 54 patients underwent bone grafting harvested from the proximal tibia. Postoperatively patients were allowed to bear weight as tolerated on the donor site. Mean follow-up was 26.4 weeks, with a range of 6 to 80 weeks. Indications for bone grafting were fresh fractures with primary grafting and nonunions. RESULTS: The overall complication rate was 1.9%, with one patient suffering a local hematoma. No major complications such as fracture, sensory deficit, or wound infection were observed. Immediate postoperative weight bearing did not have any deleterious effects. Higher complication rates for iliac graft sites have been reported. The amount of bone that can be harvested is usually more than adequate. CONCLUSION: Complication rates are low without significant patient morbidity. Most importantly, the patients may start weight bearing immediately after surgery.     

Bone grafting in surgery about the foot and ankle: indications and techniques

Bone grafting is a common procedure in foot and ankle surgery. Historically, autogenous bone graft has most often been harvested from the ipsilateral iliac crest. However, other sites offer similar volumes of cancellous bone and are associated with fewer complications. The ipsilateral proximal tibia, distal tibia, and calcaneus provide adequate amounts of bone graft material for most arthrodesis procedures about the foot and ankle. Emerging techniques have enabled the development of a seemingly unlimited supply of alternative bone graft materials with osteoconductive properties. The osteoprogenitor cells in bone marrow aspirates can be concentrated by use of selective retention systems. These aspirate-matrix composites may be combined with allograft preparations, resulting in a product that promotes osteoconduction, osteoinduction, and osteogenesis with limited morbidity.     

Bone grafting in primary uncemented total knee arthroplasty.

Forty-two uncemented ICLH and Freeman Samuelson knee replacements that required bone grafting for tibial defects were studied before and after operation. The pattern of bone loss, the techniques of grafting, and the soft tissue releases required are described. Union of the graft was observed in 98% of cases, confirming the value of bone grafting in the reconstruction of the deformed, arthritic knee.     

Bone grafting. Principles and applications in the lower extremity

Bone grafting techniques have progressed in the twentieth century, leading to results that are more predictable. A complete understanding of the entire healing process has broadened indications while decreasing complications. Numerous possibilities are available to the foot and ankle surgeon for reconstruction or trauma scenarios. Combining the art (knowing when to use specific grafting techniques) with the science of graft healing will provide satisfactory results.     

Bone-fibrin mixture in spinal surgery.

When bone grafting is performed adjacent to the spinal cord, instability of the grafted bone can result in compression of the spinal cord. To prevent this complication, fibrin sealant was mixed with the fine fragments of autogeneic bone, and the resultant pastelike mixture was used as a graft material. Operative procedures performed were posterolateral fusion (11 cases), anterior fusion (seven cases), and grafting into the bone defect (one case). After solidification of fibrin sealant, the autogeneic bone grafts were found to be firmly fixed in place, resulting in good bony fusion, and there were none of the neurologic symptoms associated with graft instability. No neurotoxicity was observed in any of these patients. Fibrin sealant was found to be an effective material for spinal surgery.     

Headache after spinal puncture. Treatment alternatives: epidural blood patch

Headache is one of the most frequent complications of the subarachnoid puncture. Physiopathology and the different clinical factors involved in this type of headache are reviewed. The treatment is based in two types of procedures: those increasing cerebrospinal fluid production and those trying to decrease its leakage, like the epidural blood patch.     

Bone turnover in spinal osteoporosis

We have investigated biochemical indices of bone formation and bone resorption: serum alkaline phosphatase (sAP) plasma bone Gla protein (pBGP), fasting urinary hydroxyproline corrected for creatinine (FuHP/Cr), and fasting urinary calcium corrected for creatinine (FuCa/Cr) in 43 postmenopausal women with spinal fractures. Furthermore, histomorphometric indices of bone resorption and bone formation, as well as whole body retention (WBR) of 99m-technetium-diphosphonate (99mTc-DP), were determined. The results are compared to pre- and postmenopausal normal subjects. The results showed that indices of bone formation were mutually correlated except for sAP vs. WBR. sAP, WBR, and pBGP increased with age. sAP and WBR were not different between osteoporotics and age-matched controls, while pBGP and probably histological indices of bone formation were lower in osteoporotics than in age-matched controls. pBGP--and to a lesser extent sAP--were significantly correlated with all histological parameters reflecting bone formation. Finally, biochemical indices of bone resorption were high in osteoporotic patients and poorly correlated with histological bone resorption. The discrepancy between biochemical markers of bone formation may be related to the low sensitivity of sAP and WBR. Conversely, pBGP, sAP, and WBR may reflect different aspects of osteoblastic activity and bone mineralization. Finally, our data suggest that bone turnover increases with aging and that osteoporotic patients have higher bone resorption and probably lower bone formation than age-matched controls.     

Bone impactors. New instruments for spinal decompression

I have used these new instruments, designed for the reduction of nerve structure compression by the principle of impaction (driving inward of the outer surface), with success in well over 300 cases; they have proved to be useful, and often indispensible, in most cases having decompressions for lateral stenosis.