Custom-made total knee arthroplasty with mechanical alignment achieves 94% patient satisfaction at mid-term follow-up.

PURPOSE: A notable proportion of patients remain dissatisfied following a total knee arthroplasty (TKA), often due to issues like prosthetic implant overhang, overstuffing, ligament imbalance and paradoxical motion. Custom made implants (CMI) aim to improve this condition by providing patient-specific solutions tailored to individual knee joint characteristics. The purpose of this prospective study is to evaluate the clinical and radiological outcomes of patients undergoing CMI TKA.

METHODS

This prospective study evaluated clinically and radiologically 31 patients (33 knees) undergoing TKA with custom-made prostheses implanted using mechanical alignment. Pre- and post-operative assessments included patient-reported outcome measures (PROMs), radiographic evaluations, and analysis of intraoperative and postoperative data. The mean follow-up period was of 39 ± 22.6 months (range: 9-66 months).

RESULTS

Clinical outcomes, including functional scores and range of motion, showed significant improvements over time. Specifically, at a mean follow-up of three years after the custom TKA, the Oxford Knee Score (OKS) improved from a preoperative value of 24.3 ± 8.5 to a postoperative value of 41.2 ± 5.9 (p < 0.01), and the Knee Society Score (KSS) (functional) increased from 54.4 ± 14.2 to 89.8 ± 14.6 (p < 0.01). Similarly, it was observed an increase in the Forgotten Joint Score (FJS), reaching an average value of 85.8 ± 27.0 (range: 15-100) three years post-surgery. The radiographic analysis showed an increase in the mechanical Lateral Distal Femoral Angle (mLDFA) from 89.2 ± 4.4 to 90.6 ± 2.5 (p = 0,03). No significant complications were observed, with the exception of one patient who was diagnosed with aseptic loosening. The overall satisfaction rate was 94%.

CONCLUSIONS

CMI demonstrate good clinical and radiological outcomes at mid-term follow-up, encouraging further studies to support the potential implementation of this type of implant.

LEVEL OF EVIDENCE: Level II, prospective cohort study.