Focal prosthetic inlay resurfacing has been proposed as a bridge between biological treatment and conventional joint arthroplasty. Promising short-term outcome is described but a high rate of revision to knee arthroplasty has been reported at mid-term follow-up It has been suggested that a more accurate implant positioning would enhance implant survival.
A customized prosthesis and guide system was designed to precisely fit the cartilage defect in location and size has the potential to improve implant positioning and thereby avoid damage to the opposing cartilage. We hypothesize that good subjective outcome is preserved and that risk of osteoarthritis development and need for revision to knee arthroplasty is low at a minimum 5-year follow-up.

Methods

Ten patients, focal chondral femoral injury and previous failed biological treatment.
Surgery with a customized Cr-Co femoral condyle implant. Minimum 5-year follow-up with clinical and radiological examination. Subjective outcome, KOOS. Data on re-surgery.

Results

Mean age at surgery 53 years. Mean 75 months follow-up (range 60-86 months). Two patients experienced limitation in range of motion. In one patient standing weight-bearing showed OA, Ahlbäck 1 at 84 months. Significant improvement in KOOS subscores pain (60-85), ADL (66-91), Sports (23-48), QoL (28-55) compared to pre-op. Tegner score from 3 to 4.

Conclusion

Good subjective outcome and low risk of progression of degenerative changes and need for subsequent surgery were seen at mid-term follow-up with this customized focal knee resurfacing implant.