Truncal Changes in Patients After Total Hip or Knee Arthroplasty: A Surface Topography Study.

Introduction Total hip and knee arthroplasty (THA/TKA) are among the most successful orthopedic operations performed, aiming at the alleviation of osteoarthritic pain. This report is a surface topography study that assesses the mechanism by which THA or TKA influences truncal parameters. This study represents the first time that surface topography has been used for the assessment of truncal parameters. Methods In total, 15 patients with THA, including nine women and six men, with a mean age of 65.07 ± 9.73 years (range: 47-80 years), and 23 patients with TKA were assessed preoperatively and four and 12 months postoperatively. These patients were also compared with a control group (CG) that included 25 individuals, including 12 women and 13 men, with a mean age of 69.28 ± 10.11 years (range: 55-86 years). The Diers Formetric four-D analysis system was used to calculate several truncal parameters in all planes. Results Data analysis revealed statistically significant differences in the kyphotic angle (°; 56.50→63.57, p < 0.05) and the pelvic obliquity (°; 3.40→1.93, p < 0.05) between measurements at baseline and 12 months after THA. Statistically significant differences were noted for the pelvic obliquity (°; 2.74→1.43, p < 0.05) between measurements at baseline and 12 months after TKA. Conclusions THA and TKA are causes of truncal morphological alterations. THA and TKA improved pelvic obliquity, contributing to correct the posture in the patients.