Abstract
Introduction Considerable attention is focused on preoperative templating of radiological images
in patients undergoing total knee arthroplasty to obtain optimal alignment and outcome.
Several radiological measurements have been described.
Purpose In this study, we illustrate a new linear measurement: The linear coronal knee offset
(LCKO) that can be used to analyze the coronal configuration on long leg alignment
radiographs commonly undertaken during preoperative templating.
Methods A retrospective search was performed of our Picture Archiving and Communication System
and Radiology Information System to identify 100 lower limbs anteroposterior, weight
bearing, long leg alignment view radiographs of patients referred to knee clinics
over 1 year with knee pain.
Demographic details, clinical indication, standard radiological measurement of the
anatomical tibiofemoral angle, and the LCKO were measured and data were analyzed using
Student's t-test. In addition, intraclass correlation coefficient was used to analyze for intraclass
reliability.
Results The average age of patients was 36.3 years (range: 12–80 years) with a male predominance.
The LCKO was statistically significant between the three cohorts of patients. The
mean LCKO in normal cohorts was 0.24 cm, varus was −0.6 cm, and valgus was 1.72cm.
There was good inter and interobserver reliability (Kappa of 0.8 and 0.8, respectively).
Conclusion The novel LCKO measurement provides a simpler method in assessing coronal lower limb
malalignment and can easily identify a normal, varus, or valgus knee deformity.
Keywords
alignment - tibiofemoral angle - preoperative templating - total knee arthroplasty
- reliability
