Objective To assess the effectiveness of osteoperiosteal decortication and extracortical bone-bridging in the treatment of atrophic humeral nonunions.Methods Nineteen patients with atrophic humeral nonuninon were treated by osteoperiosteal decortication and extracortical bone-bridging between March 2008 and April 2016.They were 12 men and 7 women,aged from 23 to 68 years (mean,36.6 years).The fracture was located at the left side in 10 cases and at the right side in 9.Before admission to our hospital,8 had received surgery once,6 twice and 5 thrice.The time from fracture to hospitalization ranged from 12 to 106 months (average,26.3 months).Shoulder function was evaluated by Neer scoring and elbow function by Mayo elbow performance score (MEPS) at final follow-ups.Results All incisions healed by first intention.Two cases reported transient radial nerve symptoms of numbness.All the 19 patients were followed up for 28.9 months on average (range,from 13 to 78 months).Radiographic examinations showed signs of bone remodeling,disappearance of fracture lines and formation of extracortical bone bridge at 6 to 8 weeks after operation.All of them achieved radiographic union within 10 to 46 weeks (16.8 weeks on average).The Neer scores averaged 82.5 (range,from 70 to 98),giving 12 excellent cases,5 good ones and 2 fair ones.The MEPS averaged 84.4 (range,from 70 to 96),giving 11 excellent cases,5 good ones and 3 fair ones.Conclusion Osteoperiosteal decortication and extracortical bone-bridging in treatment of atrophic humeral nonunions can effectively induce osteogenesis and increase stability of broken ends,promoting bone healing.