Abstract
Aims and Objectives:
The treatment of focal (osteo-)chondral lesions of the knee in middle-aged patients with previous frustane cartilage regeneration is challenging. This prospective study presents clinical 2 years results after implantation of patient-specific mini-metal implants.
Materials and Methods:
Based on a three dimensional MRI planing 7 patient-specific mini-metal implants (Episealer, Episurf, Stockholm, Sweden) were produced for 4 patients (2 men, 2 women). In one patient a single implant was implanted to the trochlea, the other 3 patients received each a trochlea and a medial condyle implant. Corresponding cartilage lesions in the tibia plateau or retropatellar surface were excluded by a detailed specific MRI resulting in a so called “damage report”. MRI data was used to manufacture patient-specific implants and guide instruments, to fit the unique anatomy of each individual knee. Demographic, operative and clinical scores (VAS of pain and patient satisfaction, KOOS and Forgotten Joint Score) were collected preop and at 6 months, 1 and 2 years postoperatively.
Results:
Mean age was 51.5 (47-57) years. All patients had failed previous cartilage surgery. All mean KOOS domain scores were improved at 1 and 2 years. Mean preoperative aggregated KOOS (35) improved to 60 at 12 months and remained at 60 also at 24 months. Mean VAS score (pain) improved from 7.4 preoperatively to 2.1 at 24 months, mean VAS score (patient satisfaction) improved from 3.1 to 8.5 postoperatively at 24 months. The forgotten joint score reached a mean of 24 points. No revisions or complications were detected.
Conclusion:
Despite a very small patient number and leck of statistical power the new patient-spedific mini-metal implant seems to be a good options fort he treatment of middle-aged patients who already underwent frustane cartilage surgery. In these relatively rare caes early unicompartimental arthroplasty can be prevented. Further clinical studies with larger patient collectives have to prove the effectiveness of this new technique.