ASSESSING LOWER LIMB ALIGNMENT: COMPARISON OF STANDARD KNEE XRAY VS LONG LEG VIEW Biagio Zampogna, MD1-2, Sebastiano Vasta, MD1-2, Annunziato Amendola, MD1
Bastian Uribe-Echevarria Marbach MD1, Yubo Gao PhD1, Rocco Papalia MD PhD2, Vincenzo Denaro MD2
ABSTRACT Background: High tibial osteotomy (HTO) is a well-established and commonly utilized technique in medial knee osteoarthritis secondary to varus malalignment. Accurate measurement of the preoperative limb alignment, and the amount of correction required are essential when planning limb realignment surgery. The hip-knee-ankle angle (HKA) measured on a full length weightbearing (FLWB) X-ray in the standing position is considered the gold standard, since it allows for reliable and accurate measurement of the mechanical axis of the whole lower extremity. In general practice, alignment is often evaluated on standard anteroposterior weightbearing (APWB) X-rays, as the angle between the femur and tibial anatomic axis (TFa). It is, therefore, of value to establish if measuring the anatomical axis from limited APWB is an effective measure of knee alignment especially in patients undergoing osteotomy about the knee. Methods: Three independent observers measured preoperative and postoperative FTa with standard method (FTa1) and with circles method (FTa2) on APWB X-ray and the HKA on FLWB X-ray at three different time-points separated by a two-week period. Intra-obser ver and inter-obser ver reliabilities and the comparison and relationship between anatomical and mechanical alignment were calculated. Results: Intra- and interclass coefficients for all the three methods indicated excellent reliability, having all the values above 0.80. Using the mean of paired t-student test, the comparison of HKA versus TFa1 and TFa2 showed a statistically significant difference (p
Bastian Uribe-Echevarria Marbach MD1, Yubo Gao PhD1, Rocco Papalia MD PhD2, Vincenzo Denaro MD2
ABSTRACT Background: High tibial osteotomy (HTO) is a well-established and commonly utilized technique in medial knee osteoarthritis secondary to varus malalignment. Accurate measurement of the preoperative limb alignment, and the amount of correction required are essential when planning limb realignment surgery. The hip-knee-ankle angle (HKA) measured on a full length weightbearing (FLWB) X-ray in the standing position is considered the gold standard, since it allows for reliable and accurate measurement of the mechanical axis of the whole lower extremity. In general practice, alignment is often evaluated on standard anteroposterior weightbearing (APWB) X-rays, as the angle between the femur and tibial anatomic axis (TFa). It is, therefore, of value to establish if measuring the anatomical axis from limited APWB is an effective measure of knee alignment especially in patients undergoing osteotomy about the knee. Methods: Three independent observers measured preoperative and postoperative FTa with standard method (FTa1) and with circles method (FTa2) on APWB X-ray and the HKA on FLWB X-ray at three different time-points separated by a two-week period. Intra-obser ver and inter-obser ver reliabilities and the comparison and relationship between anatomical and mechanical alignment were calculated. Results: Intra- and interclass coefficients for all the three methods indicated excellent reliability, having all the values above 0.80. Using the mean of paired t-student test, the comparison of HKA versus TFa1 and TFa2 showed a statistically significant difference (p
