Rotating Hinge Revision Total Knee Arthroplasty With and Without Porous Cone Adjunct Fixation.

BACKGROUND

As the number of revision total knee arthroplasties (rTKAs) continues to rise, there is increasing interest in the use of contemporary rotating hinge prostheses. These devices often incorporate porous cones to fill bone defects and enhance long-term fixation. This study evaluated the clinical and functional outcomes and survivorship in rTKA patients utilizing a rotating hinge prosthesis with flexible titanium (FT) cones, porous tantalum (PT) cones, or no cones.

METHODS

From December 2014 to July 2023, 251 patients who underwent rTKA with a rotating hinge prosthesis were identified. Among them, 184 (73.3%) received cones: 93 tibial, 22 femoral, and 69 with combined cone fixation. Data were collected on demographics, surgical details, functional outcomes, complications, and implant survivorship. Statistical analyses were performed using a software program.

RESULTS

The average age of the cohort was 68 years (range, 34 to 98), the mean body mass index was 34.2 (range, 18.6 to 64), mean American Society of Anesthesiologists score was 2.97 (range, two to four), and the mean Charleson Comorbidity index 4.03 ± 1.88. The mean follow-up period was 1.85 years (range, zero to 7.9), with 97 (40%) men. Aseptic loosening of the hinge implant was observed in seven patients (2.8%) across the entire cohort. In patients who had cones, none were found to be loose despite loosening of the rTKA components. Postoperatively, wound complications were more common in the PT group (15.4%) compared to the FT (2.6%) and no-cone groups (14.9%, P = 0.017). There were no significant differences in reoperation rates across the groups.

CONCLUSIONS

The use of FT and PT cones with a novel rotating hinge prosthesis appears to be effective in achieving stable fixation and favorable early outcomes in rTKA. While aseptic loosening rates were low across all groups, the no-cone cohort had the highest proportion of cases. Long-term follow-up is necessary to validate these early findings and assess the durability and cost effectiveness of these implants over time.