RESUMEN
Background: The Supratrochlear foramen (STF) is an important anatomical variation resulting from perforationof olecranon-coronoid septum present between two epicondyles of humerus.Material and methods: The study was conducted in 78 (41 left side and 37 right side) human dried humeri ofunknown sex and age. The topographical anatomy of the STF was studied in detail, morphometric measurementswere taken and specimens were photographed. Radiographs of humerus were taken to observe the translucencyof septum and the diameter of intramedullary canal was measured at three levels 1) below the surgical neck 2)junction between upper 2/3rd and lower 1/3rd of shaft 3) above the olecranon fossa.Results: Out of 78 bones studied,15 bones showed the presence of STF. The STF was oval, round and triangular inshape in 7, 5 and 3 bones respectively. The mean transverse and vertical diameters of supratrochlear foramenwere 5.46 mm,5.82 mm and 3.94mm, 3.82mm on the left and right sides respectively. The mean diameter of theintramedullary canal was 4.51mm for the humeri with STF and in the normal humeri it was 5.77mm.Conclusion: The knowledge of STF is essential in diagnostic orthopaedics, in intramedullary nailing of humerusin supracondylar fracture. STF is a radiolucent area in radiographs and this may be misinterpreted as osteolyticor cystic lesion
RESUMEN
PURPOSE: To evaluate the appropriate entry point of an intramedullary tibial cutting guide in total knee arthroplasty in Koreans by measuring the "intramedullary canal axis" of the proximal tibia in three dimensions. MATERIALS AND METHODS: Computed tomography was performed on 116 lower extremities from the hip to the ankle on 58 Korean cadavers. A three dimensional image of the tibia was reconstructed using the program, Bionix version 3.3. The location of intramedullary canal axis of proximal tibia passing through tibial plateau, canal axis center 1 (CAC 1), was measured. The beta' angle was defined as the angle between the tibial anatomical axis and a line perpendicular to the knee joint line. The correlations between the beta' angle and the CAC 1 mediolateral coordinates were analyzed. RESULTS: The CAC 1 is located on 56.3% from the medial cortex and 27.8% from the anterior cortex on the average. On average, the CAC 1 was located 1.2 mm medially and 15.9 mm anteriorly from the lateral tibial spine 1. The beta' angles and medial-lateral coordinates of the CAC 1 showed a significant positive correlation (r=0.418, p=0.000). CONCLUSION: When using an intramedullary guide for tibial cutting in total knee arthroplasty in Koreans, the entry point at the lateral and anterior positions from the surface center of the tibial plateau is appropriate. The lateralization of the entry point of intramedullary tibial cutting guide becomes necessary as the varus of the tibia becomes more severe. Because of the marked variability in the CAC 1, a preoperative evaluation of the CAC 1 needs to be carried out in order to properly locate the appropriate entry point of the intramedullary tibial cutting guide in total knee arthroplasty.