The Radiological Anatomical Observation Of The Calcaneum And The Determination Of Calcaneal Width On The Calcaneal Tangential View

Objective: Calcaneal fracture is one of the most common clinical fractures, accounting for 2% of all fractures, accounting for about 60% of the tarsal bone injury cases, and 75% for intra-articular fractures, and for 80% to 90% occurred in young men, some of the cases are disabling injury, which are great impact for the community and family. Factors affecting the efficacy of intra-articular calcaneal fractures include: changes in the width and height of the calcaneus, calcaneal valgus deformity, articular surface stepped shift, changes of B?hler angle and Gissan angle. For previous calcaneal fractures,we will take the conservative treatment more, but long-term follow-up showed that conservative treatment will make a higher disability rate, because calcaneal fractures can not reset,which will leave the malformation and widens of calcaneus. In recent years, along with the extensive research on the mechanism of fractures and fracture type, orthopedic surgeons experience of diagnosis and treatment of calcaneal fractures has been greatly improved. As a effective treatment of displaced calcaneal fractures,particularly of intra-articular fractures, surgery has been widely recognized. Therefore, most scholars suggested that we should take Open reduction and internal fixation surgery for displaced of intra-articular calcaneal fracture, but in calcaneal fracture surgery,we often use routine axial fluoroscopy of calcaneus to ensure the recovery of the width of the calcaneus.The ankle of patient usually needed to be hold by hands of surgeon. Both doctors and patients receive a large number of X-ray radiation. And with different radiate angles, the axial images change more. To the disadvantage of evaluating the width of calcaneus. Thus we design X-ray radiation of tangential position of calcaneus and on the basis of it we can observe the anatomy of radiological anatomy of calcaneal. On this basis, we can ensure the relationship of calcaneus lateral wall and anatomic landmark and measure calcaneal width, and provide a new approach for the clinical treatment of calcaneal fractures and evaluation of the deformation.Methods: Use SIEMENS Axiom Aristos FX DR X-ray machine. The ligature between the middle of the forth and the fifth metatarsal bone and the lateral border of calcaneus is the incident direction of X-ray, the foot is pronated 15-20° at this point(Fig.1), conditions of exposure is 71.5kv; 4.0m As. Place scaleplate at parallel of central calcaneal and examinating couch, and wearing protective clothing for gonad and other sensitive areas of patients. 57 cases of normal calcaneal tangential view X-ray photographs were selected.10 cases(12sides) calcaneal fractures were taken calcaneal tangential view X-ray examination. The radiological anatomical observation were made on the calcaneal tangential view X-ray photographs.The determination method of the calcaneal width was found.Results: On the calcaneal tangential view, the projection of the sustentaculum tali likes a duck beach. The superior arc was the middle subtalar joint. The projection of the calcaneal body likes an ellipse. The superior arc of this ellipse is the posterior subtalar joint. The outer surface of the calcaneum does not exceed the vertical line tangential to the malleolar fossa of lateral malleolus(Z line). The longitudinal axis of the ellipse(a) is 3.52±0.41 cm in nomal calcaneus. The transverse axis of the ellipse(b) is 2.56±0.28 cm. The ratio of a/b is 1.40±0.11. A is 3.22±0.61 cm, b is 3.88±0.71 cm and a/b is 0.91±0.24 after calcaneal fracture. 57 cases(57 sides) of normal calcaneus and 10 cases(12sides) calcaneal fractures of this group showed statistical significance in comparation between height and width of calcaneus(P<0.01). If the outer surface of the calcaneum exceeds the Z line, it indicates the calcaneum has been widened. The ratio of a/b can indicate the degree of calcaneal deformation.Conclusion: Using calcaneal tangential X-ray view to ensure the width of the calcaneus. The scaleplate of view is unaffected. Z-line is the watershed to measure the calcaneus widen or not. This way is convenient, accurate and reproducible. It can be used to the efficacy of preoperative and postoperative, and a/b can be used to quantitatively evaluate the deflection of the calcaneus, it is a new index to evaluate the deformation condition after calcaneal fracture.Conclusion: Calcaneal tangential view can be used in the radiological anatomical evaluation of the calcaneum.