The innovative features of the Score? prosthesis, most notably patellar replacement with a highly constrained femoral component, do not jeopardize implant survival.
In a pilot study, we retrospectively evaluated outcomes of 19?patients treated with Score? knee replacement between February and October?2006 (mean age, 66.8 years; range, 58-82 years). The evaluation criteria were the International Knee Society (IKS) scores and prosthesis survival rate estimated using Kaplan-Meier plots with failure defined as revision need to change the prosthesis.
Mean follow-up was 35.3 months. The IKS knee score increased from 27.4 (5-60) preoperatively to 81.4 (45-99) at last follow-up (P < 0.0001). Mean mechanical axis was 181.2??180-186?? with 16 between 180??nd 183??Revision surgery was required in five cases (for patellar complications with combined motion-range limitation in flexion (< 90??and extension (5-20??in three cases, isolated motion-range limitation in one case, and recurvatum deformity with instability in one case). Prosthesis survival was 82 % (73-91 % ) after 24 months and 65 % (51-78 % ) after 44 months.
The deep trochlear groove femoral component resulted in patellar complications, which were the most common reasons for revision surgery, together with motion-range limitation and instability possibly related to improper use of the navigation system. This small retrospective case-series study showed an unusually low prosthesis survival rate probably related to the implant design. We no longer use the Score? prosthesis, despite the availability of a dedicated navigation system, and we recommend careful monitoring of patients who have this prosthesis.
Level IV, retrospective study.