Mechanical failure begins preferentially near resorption cavities in human vertebral cancellous bone under compression

• Published in: Bone (New York, N.Y.) Vol. 50; no. 6; pp. 1281 - 1287
• Main Authors: Slyfield, C.R, Tkachenko, E.V, Fischer, S.E, Ehlert, K.M, Yi, I.H, Jekir, M.G, O'Brien, R.G, Keaveny, T.M, Hernandez, C.J
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 01.06.2012; Elsevier
• Subjects: Age; Aged; Aged, 80 and over; Biological and medical sciences; Biomechanical Phenomena; Biomechanics; Biomechanics. Biorheology; Bone (cancellous); Bone imaging; Bone remodeling; Bone Remodeling - physiology; Bone Resorption - pathology; Bone Resorption - physiopathology; Bone strength; Bone turnover; Cancellous bone; Compression; Compressive Strength; Female; Fractures; Fractures, Compression - pathology; Fractures, Compression - physiopathology; Fundamental and applied biological sciences. Psychology; Humans; imaging; Imaging, Three-Dimensional; In Vitro Techniques; Loading; Male; Microdamage; Middle Aged; Orthopedics; Resorption cavities; Risk assessment; Skeleton and joints; Spinal Injuries - pathology; Spinal Injuries - physiopathology; Spine - pathology; Spine - physiopathology; Stress, Mechanical; Tissues, organs and organisms biophysics; Vertebrae; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Vertebrates: osteoarticular system, musculoskeletal system; Biomechanics; Resorption cavities; Bone remodeling; Microdamage; Cancellous bone; Human; Compression; Resorption; Vertebra; Cavity; Morphology; Spongious bone; Failure
• ISSN: 8756-3282; 1873-2763
• DOI: 10.1016/j.bone.2012.02.636

Abstract The amount of bone turnover in the body has been implicated as a factor that can influence fracture risk and bone strength. Here we test the idea that remodeling cavities promote local tissue failure by determining if microscopic tissue damage (microdamage) caused by controlled loading in vitro is more likely to form near resorption cavities. Specimens of human vertebral cancellous bone (L4, 7 male and 2 female, age 70 ± 10, mean ± SD) were loaded in compression to the yield point, stained for microscopic tissue damage and submitted to three-dimensional fluorescent imaging using serial milling (image voxel size 0.7 × 0.7 × 5.0 μm). We found the resulting damage volume per bone volume (DV/BV) was correlated with percent eroded surface ( p < 0.01, r2 = 0.65), demonstrating that whole specimen measures of resorption cavities and microdamage are related. Locations of microdamage were more than two times as likely to have a neighboring resorption cavity than randomly selected sites without microdamage (relative risk 2.39, 95% confidence interval of relative risk: 2.09–2.73), indicating a spatial association between resorption cavities and microdamage at the local level. Individual microdamage sites were 48,700 (40,100; 62,700) μm3 in size (median, 25th and 75th percentiles). That microdamage was associated with resorption cavities when measured at the whole specimen level as well as at the local level provides strong evidence that resorption cavities play a role in mechanical failure processes of cancellous bone and therefore have the potential to influence resistance to clinical fracture.