[Alteration of X-ray measurements in proximal humerus osteosynthesis with intramedullary nail].

Introduction: The quality of reduction in proximal humerus fractures is valuable with radiographic criteria (Neck-shaft angle [NSA]; medial offset [MO]; distance head tuberosity [DHT] and subacromial space [SS]) that predict functionality. These criteria set for other implants are not described for the intramedullary nail.
Material and Methods: Observational cohort study, retrospective, with patients 18 years, with osteosynthesis with intramedullary nail (2014 to 2017), evaluating demographic characteristics, severity of injury (Neer classification), progressive radiographic measurements and complications.
Results: 84 cases with an average age of 65 ± 2 years and an average follow-up of 13.9 months were analyzed. By Neer rating 40.4% were grade II, 29.7% grade III and 29.7% grade IV. Consolidation in varus increases to 10.7% at the end of follow-up, with Neer III and IV patients. The 140° deformity is prevalent for Neer II (n = 15/34). 30.9% have a change of neck-shaft angle of 10°. Overall 86.9% has HTD changes 5 mm. Cases Neer III/IV 32% has alteration of SS 5 mm. The most common complication is avascular necrosis (AVN) with 44% of cases.
Conclusions: Radiographic measurements have changes in long-term follow-up. Alterations in NSA ( 10o) and SS ( 5 mm) occur in higher proportion of Neer III/IV patients, according to the severity of the fracture, favoring vicious consolidations in varus or valgus and increased presence of AVN.