Aims Adaptative changes on the lumbar spine and knee following total hip arthroplasty (THA) for severe congenital dislocation of the hip (CDH) can affect patients outcome. We sought to analyse these changes at a mean follow-up of ten years. Methods We identified 84 patients (100 hips) undergoing THA due to severe CDH at a single institution from 2002 to 2019: 45 hips had a low dislocation (group 1), and 55 a high dislocation (group 2). Changes in the Harris Hip Score (HHS), lumbar back pain (LBP) and knee complaints were compared. Radiological analysis included changes in hip reconstruction, spinal curvature, pelvic obliquity (PO) and the coronal plane alignment of the knee (CPAK). Results At latest follow-up, the mean HHS improved in group 1 from 45.2 to 91.2 and in group 2, from 43.2 to 88.2. 1 Ten hips required reoperation for aseptic loosening (8 hips, 2 in group 1, 6 in group 2), and periprosthetic femoral fracture (2 in group 2). Four patients had postoperative LBP, whereas 10 out 35 patients with a compensatory spinal curve corrected their PO. No patient required further spinal surgery. Twelve out 27 patients having knee pain required knee surgery including 5 total knee arthroplasties and 4 osteotomies. Eleven out 58 patients with a CPAK phenotype type 3 changed to a type 5 after THA. The 15-year survival for any hip reoperation was 97.2% (95% CI, 95–100) in group 1 and 85.0% (95% CI 74.5–99.5) in group 2, whereas of both hips and knees decreased to 91.5% (95% CI, 82–99) in group 1 and 69.8% (95% CI 51–88) in group 2. Conclusions Most patients undergoing THA due to severe CDH improved spinopelvic deformities and lower limb misalignment. Decreased survival rates for any reoperation over time considering hips and knees in the high dislocation group are noteworthy.
Eduardo García del Rey (Thu,) studied this question.