Changes in Bone Mass and Bone Turnover Following Distal Forearm Fracture

Abstract

Bone loss occurs close to a fracture and is associated with increased bone turnover. Fracture healing itself results in increased markers of bone turnover. But the exact patterns of these changes after different fractures are unclear. We aimed to investigate the changes in bone density and biochemical markers following distal forearm fracture. Twenty women (mean age 63 years) were recruited following fracture of the distal radius and ulna. Bone mineral density (BMD) of the hand and forearm were measured by dual-energy X-ray absorptiometry (DXA) and quantitative ultrasound (QUS) of the fingers was measured at 0, 6, 12, 26 and 52 weeks after fracture. Serum and urine samples were collected at 0, 3 and 7 days and at 2, 4, 6, 12, 26 and 52 weeks after fracture to measure markers of bone turnover. For bone formation we measured: bone alkaline phosphatase (iBAP), osteocalcin (Oc), procollagen type I N-terminal propeptide (PINP); and for bone resorption: tartrate-resistant acid phosphatase (TRAcP), free deoxypyridinoline (iFDpd), N-telopeptides of type I collagen (NTx). We used the nonfractured limb to calculate values for baseline BMD and amplitude-dependent speed of sound (AD-SoS). There was a decrease in BMD at the hand and in AD-SoS of the fingers after forearm fracture (p<0.001). This bone loss was maximal for BMD by 6 weeks at 9% (p<0. 001) and remained decreased at 52 weeks. AD-SoS decreased at 12 weeks by 3% (p<0.01) and recovered completely by 52 weeks. Bone formation markers increased between 2 and 4 weeks by 13-52% (p<0. 001), and were still elevated at 52 weeks. Bone resorption markers increased between 2 and 6 weeks by 18-35% and returned to baseline at 52 weeks (TRAcP remained elevated). We conclude that BMD decreased distal and immediately proximal to the fracture line when measured with DXA and QUS. Bone loss after distal forearm fracture did not recover by 52 weeks and most bone turnover markers did not return to baseline.

Premenopausal Women with a Distal Radial Fracture Have Deteriorated Trabecular Bone Density and Morphology Compared with Controls without a Fracture

“…Furthermore, we were unable to explore whether poor bone microarchitecture was related to low bone formation and/or high resorption. Although this could be examined using serum markers of bone turnover, these are known to increase after a fracture, remain elevated for up to a year, and may not have been helpful in our cohort 50 . We did explore clinical factors that may have been related to poorer bone microarchitecture in the patients with a fracture, but we found no differences between groups with respect to common risk factors for low bone mineral density and fracture.…”

Role of subchondral bone in osteoarthritis development: A comparative study of two strains of guinea pigs with and without spontaneously occurring osteoarthritis

“…In light of the fact that increased bone turnover has been reported after fracture (35)(36)(37)(38)(39)(40), it is possible that microfracture of subchondral bone is involved in OA development in Hartley guinea pigs. In our study, only the levels of bone formation markers were high before the onset of cartilage degeneration, unlike the findings reported by Huebner et al Subchondral cancellous bone had a rod-like and convex structure before the onset of cartilage degeneration, indicating low mechanical 3372 MURAOKA ET AL strength, but the structure became plate-like and concave with the progression of cartilage degeneration, indicating that the mechanical strength increased.…”

Biochemical markers of bone turnover – uses and limitations

“…This increase is estimated to be around 20-50% and may persist for up to six months. 32,56,57 . Immobility: The bone resorption markers, but not formation markers, tend to increase after 2-4 days of bed rest and return to normal after remobilization.…”