The chances of transplanted bone living, whether periosteum-covered or not, are increased when it is firmly contacted with living bone. These facts would seem to indicate that Murphy's theory is correct, in as far as ossification may take place from osteogenetic elements passing from the ends of the fragments into the substance of the graft. Magnesium as a graft, however, has had only fair success even in regions of greatest vascularity, such as the face.
The transplant does not need to be as heavy as the section of bone which it is to replace. If the operation is successful and the transplant lives, it will increase in diameter until it is capable of properly withstanding the full strain to which the bone is normally subjected. This increase in size, however, is more or less dependent on the use of the member after the graft has solidly united.
In obtaining a graft only a portion of the diameter of the shaft from which it is taken should be removed, since if a section of bone including the entire diameter with its periosteum is removed, repair of the defect with bony tissue cannot be expected. When a section of bone is taken from the tibia as shown in Figs. 846, 847 and 848, the space left in the crest of the shin is entirely repaired and filled in with living bone.
<Callout type="important" title="Critical Success Factors">The most favorable conditions for successful bone grafting include absolute asepsis, use of an autoplastic periosteum-covered transplant, solid contacting of the transplant with living bone at both ends if possible, viable soft tissue coverage, and avoidance of non-absorbable material in fixing the graft.</Callout>
Bone grafting is indicated to fill in defects in the skeleton, produce union between fragments where non-union has existed, and for immobilization of joints and support of diseased parts. The most satisfactory technique will usually be found to be the medullary graft or the inlay graft as described by Albee.
The manner in which this may be accomplished varies according to the region involved. First class operating room facilities should be available, and the surgeon must be experienced in bone work. These conditions and the observance of the most rigid asepsis are essential.
Key Takeaways
- Bone grafting is crucial for filling bony defects and correcting non-unions in fractures.
- Successful bone grafting requires solid contact with living bone, viable soft tissue coverage, and absolute asepsis.
- Medullary or inlay grafts are the most effective methods for bone transplantation.
Practical Tips
- Ensure that the transplanted bone is firmly contacted with living bone at both ends to maximize success rates.
- Use only autoplastic periosteum-covered transplants and avoid non-absorbable materials when fixing the graft in place.
- Gradually increase strain on the member after union has taken place to promote growth of the graft.
Warnings & Risks
- Do not attempt bone grafting if there is a discharging sinus or infection present; wait until these conditions have healed.
- Avoid removing an entire diameter of bone with its periosteum, as this can interfere with regeneration and healing.
- Failure rates are high when using foreign materials such as magnesium for grafts.
Modern Application
While the techniques described here are foundational to modern orthopedic surgery, advancements in sterile environments and surgical tools have significantly improved outcomes. Understanding these historical methods provides critical insight into bone biology and healing processes, which remain relevant today.
Frequently Asked Questions
Q: What is Murphy's theory regarding bone grafting?
Murphy's theory suggests that ossification can occur from osteogenetic elements passing from the ends of bone fragments into the substance of a graft.
Q: Why should magnesium be used with caution as a graft material?
Magnesium has had only fair success even in highly vascular regions like the face, indicating that it is not reliable for bone grafting and may lead to failure or complications.
Q: What are the key conditions necessary for successful bone grafting?
The key conditions include absolute asepsis, use of an autoplastic periosteum-covered transplant, solid contacting with living bone at both ends if possible, viable soft tissue coverage, and avoidance of non-absorbable material in fixing the graft.