Determination of zones of different osteogenesis capabilities at the fracture ends for bone grafting to treat bone nonunion

Abstract

Objective To explore the feasibility and clinical value of determining zones of different osteogenesis capabilities at the fracture ends for bone grafting to treat bone nonunion.Methods Between January 2012 and September 2013,138 patients with nonunion were treated in our department.They were 102 men and 36 women,12 to 73 years of age (38.6 years on average).The bone nonunion was located at the humeral shaft in 20 cases,the tibiofibula in 45,and the femoral shaft in 73.The nonunion was of atrophic type in 42 cases,of ischemic type in 86,and of pseudarthrosis type in 10.Intraoperatively,the fracture ends were determined as one osteogenesis deactivation zone (scar tissue and hardened sequestrum) and 2 osteogenesis activation zones (normal porosis tissue).Bone grafting was conducted across the osteogenesis deactivation zone to bridge the osteogenesis activation zones.All patients were fixated by locking compression plate.When the graft size ＞ 2 cm,a reconstruction plate was added on the anterior of the graft.The time for nonunion healing and complications were recorded.The postoperative function was assessed according to corresponding criteria.Results The average follow-up time was 12.4 months (from 6 to 24 months).Bone union was achieved in 134 cases after an average of 6.3 months (from 5 to 10 months).For the 20 cases of humeral shaft nonunion,the average Constant score was 91.2 points and the average Mayo elbow performance score 90.7 points; for the 45 cases of tibiofibular nonunion,the excellent to good rate of knee function was 100％ by American Knee Society Score and the excellent to good rate of ankle function 93.3％ (42/45) by Kofoed evaluation system; for the 73 cases of femoral shaft nonunion,the excellent to good rate of the hip was 96.0％ (24/25) by the Sanders evaluation system and 95.8％ (46/48) by the American Knee Society Score.No such complications occurred as infection,bilateral leg length discrepancy,or pain at the bone donation area.Conclusion Since the bone deactivation and activation zones have significantly different osteogenesis capabilities,autologous bone grafting should span the deactivation zone to bridge the activation zones to take the most advantage of active osteogenesis when it is used in combination with locking plate to cure bone nonunion. Key words: Fractures, ununited; Osteoblasts; Bone plates; Grafting