Limits...
Inter-trabecular bone formation: a specific mechanism for healing of cancellous bone

View Article: PubMed Central - PubMed

ABSTRACT

Background and purpose: Studies of fracture healing have mainly dealt with shaft fractures, both experimentally and clinically. In contrast, most patients have metaphyseal fractures. There is an increasing awareness that metaphyseal fractures heal partly through mechanisms specific to cancellous bone. Several new models for the study of cancellous bone healing have recently been presented. This review summarizes our current knowledge of cancellous fracture healing.

Methods: We performed a review of the literature after doing a systematic literature search.

Results: Cancellous bone appears to heal mainly via direct, membranous bone formation that occurs freely in the marrow, probably mostly arising from local stem cells. This mechanism appears to be specific for cancellous bone, and could be named inter-trabecular bone formation. This kind of bone formation is spatially restricted and does not extend more than a few mm outside the injured region. Usually no cartilage is seen, although external callus and cartilage formation can be induced in meta­physeal fractures by mechanical instability. Inter-trabecular bone formation seems to be less sensitive to anti-inflammatory treatment than shaft fractures.

Interpretation: The unique characteristics of inter-trabecular bone formation in metaphyseal fractures can lead to differences from shaft healing regarding the effects of age, loading, or drug treatment. This casts doubt on generalizations about fracture healing based solely on shaft fracture models.

No MeSH data available.


Photograph of a micro-dissected biopsy taken 4 weeks after knee arthrodesis, comprising the junction between the femur and tibia. Note the spatially limited bone formation. From Charnley and Baker (1952) with permission.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC5016903&req=5

Figure 0001: Photograph of a micro-dissected biopsy taken 4 weeks after knee arthrodesis, comprising the junction between the femur and tibia. Note the spatially limited bone formation. From Charnley and Baker (1952) with permission.

Mentions: Bone formation after injury in cancellous bone is usually strictly localized to the injured region and appears not to spread away from it (Figure 1). The filling of a defect in cancellous bone of a few millimeters width can therefore be slow or incomplete. This is quite different from shaft fracture healing, which can fill up considerable gaps. Already in the 1950s, John Charnley showed that human knee arthrodeses could heal in as little as 4 weeks if the cancellous resection surfaces fitted perfectly together, but not at all if there was a small gap. The cancellous bone formation response to trauma rarely extended more than 2 mm from the traumatized area (Figure 1) (Charnley and Baker 1952).


Inter-trabecular bone formation: a specific mechanism for healing of cancellous bone
Photograph of a micro-dissected biopsy taken 4 weeks after knee arthrodesis, comprising the junction between the femur and tibia. Note the spatially limited bone formation. From Charnley and Baker (1952) with permission.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5016903&req=5

Figure 0001: Photograph of a micro-dissected biopsy taken 4 weeks after knee arthrodesis, comprising the junction between the femur and tibia. Note the spatially limited bone formation. From Charnley and Baker (1952) with permission.
Mentions: Bone formation after injury in cancellous bone is usually strictly localized to the injured region and appears not to spread away from it (Figure 1). The filling of a defect in cancellous bone of a few millimeters width can therefore be slow or incomplete. This is quite different from shaft fracture healing, which can fill up considerable gaps. Already in the 1950s, John Charnley showed that human knee arthrodeses could heal in as little as 4 weeks if the cancellous resection surfaces fitted perfectly together, but not at all if there was a small gap. The cancellous bone formation response to trauma rarely extended more than 2 mm from the traumatized area (Figure 1) (Charnley and Baker 1952).

View Article: PubMed Central - PubMed

ABSTRACT

Background and purpose: Studies of fracture healing have mainly dealt with shaft fractures, both experimentally and clinically. In contrast, most patients have metaphyseal fractures. There is an increasing awareness that metaphyseal fractures heal partly through mechanisms specific to cancellous bone. Several new models for the study of cancellous bone healing have recently been presented. This review summarizes our current knowledge of cancellous fracture healing.

Methods: We performed a review of the literature after doing a systematic literature search.

Results: Cancellous bone appears to heal mainly via direct, membranous bone formation that occurs freely in the marrow, probably mostly arising from local stem cells. This mechanism appears to be specific for cancellous bone, and could be named inter-trabecular bone formation. This kind of bone formation is spatially restricted and does not extend more than a few mm outside the injured region. Usually no cartilage is seen, although external callus and cartilage formation can be induced in meta­physeal fractures by mechanical instability. Inter-trabecular bone formation seems to be less sensitive to anti-inflammatory treatment than shaft fractures.

Interpretation: The unique characteristics of inter-trabecular bone formation in metaphyseal fractures can lead to differences from shaft healing regarding the effects of age, loading, or drug treatment. This casts doubt on generalizations about fracture healing based solely on shaft fracture models.

No MeSH data available.