Risk factors affecting bone healing in orthopedic surgery: A clinical review

The process of bone healing is a multicomponent, complex system, which depends on patient biology and the nature of the fracture but also surgical intervention and general health. Late or non-union still pose major issues in orthopedic surgery, causing long-term disability, overt medical cost and health related quality of life. This clinical review is designed to give an up-to-date summary of significant risk factors that contribute to bone regeneration and integrates the most current data from cellular, molecular and clinical aspects. We mention patient- related factors (age and sex, genetic predisposition, comorbidity, nutritional status) along with lifestyle-related factors (smoking habit, alcohol intake, physical activity). Factors relating to injury and fracture such as fracture location and type, soft tissue integrity, local vascular supply (including a re-evaluation of the role of avascular necrosis), and energy on injury are reviewed for their impact upon healing potential. Surgical and therapy-related parameters, including fixation methods, mechanical stability, and pharmacological modulation are also reviewed. Finally, advances in potential therapy and risk reduction strategies are reviewed focusing on regenerative medicine, growth factor therapies, tissue engineering and predictive analytics as the next horizons. Knowledge of the interrelations between these factors helps to risk stratify individually, and allows for preoperative planning as well as targeted intervention measures that may enhance outcome. Through an envelope of current biology and clinical practice, this review outlines how to optimize bone healing with its inherent personalized orthopedic care.