ABSTRACT
PURPOSE: To describe and quantify a radiological phenomenon where the distal tibial plafond appears in valgus malalignment in intra-operative fluoroscopy owing to 15 degrees craniocaudal angulation of the X-ray beam. METHODS: The lateral distal tibial angle (LDTA) of 14 male and 9 female skeletally mature patients was measured by a single reviewer using 2 types of anteroposterior radiographs, in which the X-ray beam was projected at 0 (orthogonal to the ankle) and then at 15 (in a craniocaudal direction) degrees. The LDTA was the angle between the long axis of the tibia and a line drawn across the most radiodense part of the tibial plafond. The paired t-test was used to compare the LDTA of the 2 measurements. RESULTS: The mean LDTA on the 0-degree orthogonal radiographs was 89 (range, 87-92) degrees, whereas the mean LDTA on the 15-degree craniocaudal radiographs was 79 (range, 77-81) degrees. The mean difference was 10 degrees (range, 9-12; p<0.0001). In the 15-degree craniocaudal radiographs, the ankle joint appeared to have valgus malalignment. CONCLUSION: During intramedullary nailing of the tibia, the knee is usually flexed and the image intensifier may not swing over far enough. This can result in well-aligned reduction being incorrectly viewed as having valgus malalignment or a varus-malaligned fracture being incorrectly viewed as reduced.
Subject(s)
Coxa Valga/diagnostic imaging , Fracture Fixation, Intramedullary/methods , Tibia/diagnostic imaging , Tibial Fractures/diagnostic imaging , Adult , Coxa Valga/etiology , Coxa Valga/surgery , Female , Follow-Up Studies , Fracture Healing , Humans , Male , Radiography , Tibia/surgery , Tibial Fractures/complications , Tibial Fractures/surgery , Young AdultABSTRACT
We compared 47 patients with groin pain following hip resurfacing to a matched control group. Functional scores and plain radiographs were assessed along with measurement of whole blood cobalt and chromium by inductively coupled mass spectrometry. Symptomatic patients underwent ultrasound scan of the affected hip. Mean functional outcomes were poor in those with pain and good in the control group. Groin pain was associated with valgus stem positioning and lower neck:head ratio (relatively narrow neck) (p=0.03, p=0.04 respectively). We classified patients with groin pain into two groups: biological and mechanical. The biological group had soft tissue abnormalities on USS and higher levels of cobalt and chromium (p=0.04, p=0.05 respectively). The mechanical group had normal USS, lower metal ion levels and more retroverted femoral components (p=0.01).
