Prospective morphometric study of the distal humerus region applied to clinical practice

Abstract

IntroductionThe anatomical knowledge of bone depressions and elevations of the distal humerus region is important for planning surgical procedures. The supratrochlear septum, located superiorly to the trochlea, can be perforated, originating an anatomical variation known as supratrochlear foramen (STF). The occurrence rate of this variation is between 0% and 60% and reaches different ethnicities. The STF is commonly associated with the presence of a narrow medullary cavity, which could complicate some surgical procedures to correct fractures of the distal humerus region. In radiological evaluations, the presence of the STF can cause a wrong interpretation, being confused with a cystic or osteolytic lesion.ObjectiveMeasure anatomical structures present in the humerus distal region to determine the morphology of this region, in human adult humeri. Detect the presence of the STF and calculate its size.Material and methods48 dried humeri of brazilian male adult cadavers, were selected from the collection of the Department of Morphology of Santa Casa de São Paulo School of Medical Sciences. All humeri were submitted to several measurements, with the help of two digital calipers. The measurements taken are represented in figure 1. The study was performed by two independent observers, who did three measurements of each of the evaluated items, at different times and blindly, totaling six measurements per bone. The values obtained by the observers were submitted to statistical analysis (SPSS 21.0) in order to determine the intraobserver and interobserver correlations. The intraclass correlation coefficient (ICC) and the Pearson's correlation coefficient were used, respectively.ResultsOf the 48 dried humerianalized, 28 (58,33%) were right side and 20 (41,67%) were left side. The results of the measurements taken are presented in table 1. The Intraobserver and interobserver correlations are represented in tables 2 and 3, respectively. About the STF, it was found in 13 (27,09%) of 48 studied bones, six (46,15%) on right side and seven (53,85%) on left side. Our presence of STF was similar to the results found by 13 authors in the literature, variating from 19,20% to 39,00%. As demonstrated in tables 2 and 3, the measurements whose values are highlighted in green had intraobserver and interobserver correlation coefficients very high (r ≥ 0,9), unlike depression measurements (mainly the olecranon fossa), probably because of the difficulty to stipulate which is the exact location of its beginning and end.ConclusionThe interepicondylar distance, supretrochlear septum thickness and diameters of the STF, when present, were reproducible by the two observers, being considered the best measurements to describe this region. The presence of the STF in the analyzed humeri was relevant, showing that it is an anatomical variation relatively frequent. This fact should be known by all professionals who are involved in the diagnosis and treatment of affections of the humerus distal region, in order to choose the best therapeutic option to be followed.Support or Funding InformationPiBic CNPq 2018This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.