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

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.

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.

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.

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.