Bone structure and turnover in the distal radius and iliac crest: a histomorphometric study

Area of Science:

• Orthopedic Surgery
• Bone Biology
• Histomorphometry

Background:

• The iliac crest is the conventional donor site for bone grafts in wrist surgery.
• The distal radius presents a more accessible alternative donor site.

Purpose of the Study:

• To compare the structural and dynamic properties of bone from the distal radius and iliac crest for wrist bone grafting.
• To evaluate the suitability of the distal radius as a bone graft donor site.

Main Methods:

• Undecalcified bone biopsies from the distal radius and iliac crest of 18 patients were analyzed.
• Histomorphometry was used to assess bone structure, turnover, and marrow cellularity.

Main Results:

• Distal radius bone exhibited thinner cortices, lower bone volume, thinner trabeculae, and greater trabecular separation compared to iliac crest bone.
• Bone from the distal radius showed significantly lower marrow cellularity, osteoid parameters, osteoblast activity, and bone formation rates.
• Mineralization lag time was longer in the distal radius, attributed to reduced osteoblast activity rather than osteomalacia.

Conclusions:

• Bone from the distal radius is structurally inferior and has lower turnover than iliac crest bone.
• The iliac crest is the preferred donor site when immediate structural integrity is crucial.
• Distal radial bone may be a viable alternative for grafting small cavitary defects, pending further clinical studies.