Uncemented Ceramic-on-Ceramic Bearing Couple for Dysplastic Osteoarthritis: A 5- to 11-Year Follow-up Study

The ceramic-on-ceramic bearing couple (CoC) has a potential to improve the longevity of hip arthroplasty. Dysplastic patients are relatively young and have high activity; therefore, the longevity of the implant is essential for them. Because of the anatomical property, adjusting the alignment of an uncemented implant may be sometimes difficult for them. We retrospectively evaluated 458 dysplastic hips with the primary uncemented third-generation alumina CoC followed up for 5-11 years. All cups were Spongiosa Metal II. Spongiosa Metal II stems were used for 325 hips, and SL Plus stems were used for 133 hips. The average cup angle was 39.9 degrees in inclination and 28.2 degrees in anteversion. The hip score was improved in all but 5 patients at the final follow-up. Two patients required revision surgery owing to the liner fracture caused by the metal shell damage during the initial surgery. At the final follow-up, all cups and stems were stable. The radiolucent line was observed in 4 acetabuli (2.4%) and in 43 femurs (9.4%). There was no osteolysis. No dislocation occurred in these alignments. The careful surgical technique enabled to adapt the uncemented CoC even for dysplastic hips.