Clinical assessment of tibial torsion differences. Do we always need a computed tomography?

Abstract

Background: Tibial torsional malalignment presents a well-known complication of intramedullary nailing for tibial shaft fractures. Purpose: Objective of this study was to investigate the ability to clinically assess tibial torsion differences. Computed Tomography (CT) was used here as the gold standard. Further, intra- and inter-observer reliability of the clinical examination, and radiological measurements were calculated. Methods: Fifty-one patients with torsion-difference CTs, obtained for various reasons, were asked to kneel on an examination couch with free hanging feet. All patients are positioned with 90° flexed knee and neutral ankle. A picture of the lower extremities was obtained from the back of the patient. Two blinded orthopedic surgeons were asked to look at the pictures and measure the tibial torsion with a digital goniometer, based on the axis of the femur in relation to the second ray of the foot. To determine the intra-observer variation, the torsional angles were calculated again after 4 weeks. To be able to compare values, two blinded radiologists calculated torsional differences based on computed tomography. Results: All patients were able to be positioned for clinical assessment (n = 51). Clinical assessment of torsional difference revealed 4.55° ± 6.85 for the first, respectively, 4.55° ± 7.41 for the second investigator. The second measurement of the first investigator revealed a value of 4.57° ± 6.9. There was a good intra-observer agreement for clinical assessment (ICC 0.993, p < 0.001). Also, the inter-observer agreement showed a good inter-observer agreement (ICC 0.949, p < 0.001). Evaluation of radiological inter-observer assessment could also show a good inter-observer agreement (ICC 0.922, p < 0.001). The clinical method showed a good correlation to the CT method (0.839, p < 0.001). Additionally, the Bland–Altman plot was used to compare graphically both measurement techniques, which proved the agreement. Conclusion: In summary, computed tomography-assisted measurement of tibial torsion and clinical assessment correlated significantly good. In addition to that, clinical measurement has a good intra- and inter-observer reliability. Clinical examination is a reliable and cost-effective tool to detect mal-torsion and should be part of the repertoire of every surgeon.