The position determination of“safe zone” in the treatment of radial head fracture with mini-plate

ZHUANG Yun-qiang; ZHANG Jun; ZHOU Long; JING Ling-yong; LIU Guan-yi

doi:10.3969/j.issn.1009-4237.2016.11.005

Abstract：Objective To study the position of the safe zone of radial head fracture with miniplate in order to avoid side effects on the forearm’ s rotating range and reduce damages of nerve and blood supply system,so as to real-ize the maximum function recovery of the forearm.Methods Totally 45 cases of radial head fracture from Jan.2012 to Nov.2014 treated in our hospital was retrospectively studied.Mini-plates were used in all 45 cases after determining the safe zone,among which 30 cases were Mason TypeⅡand 15 cases were Mason TypeⅢ,including 23 male cases and 22 female cases with an average of 41.5(18-69) years old.Four methods(the anatomical location of the radial head,the shape of articular cartilage,the methods of Caputo and the forearm rotation ) were used to confirm the influ-ence of plates position on the rotation of ulnar radial joints.Results All of the 45 patients were followed up for 12 to 18 months with an average of 15.1 months.The average postoperative elbow flexion arc was 135°(100 °-145 °),the average range of forearm rotation was 126°(120°-150°),the average pronation was 53°(45°-65°) and the average su-pination was 73°(65°-76°).According to the evaluation standards of Broberg-Morrey,the outcome was excellent in 32 cases,good in 10 cases,fair in 3 cases,and the excellent and good rate was 93.3%.During the follow-up,fixation fail-ure and loosened plate and screw occurred in two cases,restricting the activity of the proximal radio-ulnar joint.No case occurred nonunion,necrosis,infection or radial nerve injury.Conclusion There is no effect on the rotation of forearm when the plate is plated in the safe zone,and four methods can be used in determining the safe zone.