Smoking is a predictor of worse trabecular mechanical performance in hip fragility fracture patients

Abstract

Clinical risk factors (CRFs) are established predictors of fracture events. However, the influence of individual CRFs on trabecular mechanical fragility is still a subject of debate. In this study, we aimed to assess differences, adjusted for CRFs, between bone macrostructural parameters measured in ex-vivo specimens from hip fragility fracture patients and osteoarthritis patients, and to determine whether individual CRFs could predict trabecular bone mechanical behavior in hip fragility fractures. Additionally, we also looked for associations between the 10-year risk of major and hip fracture calculated by FRAX and trabecular bone mechanical performance. In this case-control study, a group of fragility fracture patients were compared with a group of osteoarthritis patients, both having undergone hip replacement surgery. A clinical protocol was applied in order to collect CRFs [body mass index (BMI), prior fragility fracture, parental history of hip fracture, long-term use of oral glucocorticoids, rheumatoid arthritis, current smoking, alcohol consumption, age and gender]. The 10-year probability of fracture was calculated. Serum bone turnover markers were determined and dual X-ray absorptiometry performed. Femoral head diameter was evaluated and trabecular bone cylinders were drilled for mechanical testing to determine bone strength, stiffness and toughness. We evaluated 40 hip fragility fracture and 52 osteoarthritis patients. Trabecular bone stiffness was significantly lower (p = 0.042) in hip fragility fracture patients when compared to osteoarthritic individuals, adjusted for age, gender and BMI. No other macrostructural parameter was statistically different between the groups. In hip fragility fracture patients, smoking habits (β = -0.403; p = 0.018) and female gender (β = -0.416; p = 0.008) were independently associated with lower stiffness. In addition, smoking was also independently associated with worse trabecular strength (β = -0.323; p = 0.045), and toughness (β = -0.403; p = 0.018). In these patients, the 10-year risk of major (r = -0.550; p = 0.012) and hip fracture (r = -0.513; p = 0.021) calculated using only CRFs was strongly correlated with femoral neck bone mineral density but not with mechanical performance. Our data showed that among fragility fracture patients active smoking is a predictor of worse intrinsic trabecular mechanical performance, and female gender is also independently associated with lower stiffness. In this population, the 10-year risk of fracture using CRFs with different weights only reflects bone mass loss but not trabecular mechanical properties.

Failure of femoral neck fracture fixation in younger patients

“…Smoking was the strongest predictor for fixation failure in younger adults (p=0.025). Nonetheless, the bone mineral density in smokers and non-smokers is comparable 10 , because bone mineral density only indicates a lower bone mass rather than reduced trabecular mechanical property. In addition, smoking may affect collagen and healing of bone and tissues.…”

The Effect of Tobacco Smoking on Musculoskeletal Health: A Systematic Review

“…Similar findings were reported in elderly women; former and current smokers compared to nonsmokers had increased risk for fracture [ 59 , 71 ], including nonvertebral fractures in patients with diabetes (OR = 3.47, 95%CI: 1.82-6.62, P = 0.001) [ 61 ]. Regardless of fracture site, six cohort studies and one case-control study examining both sexes found smoking was significantly associated with poor fracture outcomes, such as nonunion ( P < 0.01) [ 57 , 58 , 60 , 66 ], lower trabecular strength (beta = -0.323; P = 0.045) and toughness (beta = -0.403; P = 0.018) [ 68 ], and delayed mean healing time [ 64 ]. No significant association was found between fracture and delay in filling [ 69 ] work absenteeism (P = 0.1177) [ 66 ] or low mental and physical-function scores on the Short Form 36 (SF-36) [ 66 ].…”

Differential Impact of Cigarette Smoking on Fracture Risks in Subjective Cognitive Decline and Dementia: A Nationwide Longitudinal Study

“…29 Moreover, smoking was an independent predictor of worse trabecular strength in hip fracture patients. 30 As for the indirect effect of smoking on bone health, smoking was associated with decreased levels of parathyroid hormone 31 and vitamin D, 32 which could undermine bone integrity.…”

“…In a recent study, pernicious effects of smoking on bone mineralization and collagen synthesis were affected in a mouse model, demonstrating that mice exposed to cigarette smoke exhibited reduction of type I collagen deposition, which is critical for bone formation, which ultimately lead to slowed delayed bone formation rate [ 29 ]. Moreover, smoking was an independent predictor of worse trabecular strength in hip fracture patients [ 30 ]. As for the indirect effect of smoking on bone health, smoking was associated with decreased levels of parathyroid hormone [ 31 ] and vitamin D [ 32 ], which could undermine bone integrity.…”