Knee–Hip–Spine Syndrome: Improvement in Preoperative Abnormal Posture following Total Knee Arthroplasty

Figure 4

Age-related global postural changes. (a) The center of the acoustic meati, (b) the center of the hip, (c) the center of the knee, and (d) the center of the ankle. The vertical line shows the plumb line from the center of the acoustic meati. (1) The global alignment of the healthy subject. The plumb line from the center of the acoustic meati is close to the gravity line. The cervical and thoracic vertebrae are posterior to the gravity line. The lumbar vertebrae show lordosis, and L4 is anterior to the gravity line. The sacrum is posterior, and the hip center is anterior to the gravity line. The knee joint and ankle joint are posterior to the gravity line. (2) TK increases, LL decreases, and the pelvis tilts posteriorly while the hip, knee, and ankle flex. Consequently, the sagittal balance sifts anteriorly with age. (3) Older subjects show spinal kyphosis with the severe anterior shift of the sagittal balance. Consequently, the body balance is better maintained with support. (4) As the knee becomes extended and the lower extremity alignment is corrected with TKA, the global alignment and the sagittal balance can be improved.