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- What is bone histomorphometry?
Bone histomorphometry is the measurement and analysis of bone structure and
remodeling. This requires transiliac bone biopsy and histological examination
of undecalcified bone. The parameters which are examined for bone structure
include trabecular width, cortical width, and trabecular volume. The bone
remodeling parameters may be static or dynamic; static parameters include
osteoid volume and osteoid thickness, while the dynamic parameters include
mineralization lag time and mineral apposition rate. Double tetracycline label-
ing is required for the assessment of dynamic parameters of bone remodeling.
Normal values for some of the commonly used histomorphometric parameters
are summarized in the table given below.Parameters Male Female
Cortical thickness 915 μm 823 μm
Cancellous bone volume 19.7 % 21.8 %
Osteoid thickness 11.1 μm 12.3 μm
Osteoid volume 3.19 % 1.58 %
Mineral apposition rate 0.89 μm/day 0.88 μm/day
Mineralization lag time 27.6 days 21.1 days- What are the indications for bone histomorphometry?
Bone histomorphometry is indicated in patients with unexplained low bone
mineral density or unexplained fractures. In addition, patients with renal osteo-
dystrophy also require bone histomorphometry for evaluation of bone pain,
unexplained fractures, or before initiation of anti-osteoporotic therapy.- What are the characteristic findings of rickets/osteomalacia on bone
histomorphometry?
The histomorphometric characteristics of osteomalacia include osteoid volume
15 %, osteoid thickness >20 μm, and mineralization lag time>100 days.
- How to approach a patient with rickets–osteomalacia?
A detailed history and clinical examination usually provide clues to the diagno-
sis in patients with rickets/osteomalacia. Biochemical investigations include
serum calcium, albumin, phosphorous, alkaline phosphatase, parathyroid hor-
mone, 25(OH)D and renal function tests. The results of these investigations
help to guide further evaluation and management. An approach to a patient with
rickets–osteomalacia is given below (Fig. 5.11).5 Rickets–Osteomalacia