Synthetic resorbable scaffolds for the treatment of isolated patellofemoral cartilage defects in young patients: magnetic resonance imaging and clinical evaluation.

BACKGROUND

Surgical management of patellar cartilage defects remains controversial. The ideal technique to regenerate hyaline cartilage is not yet defined. However, a synthetic resorbable osteochondral scaffold plug (TruFit CB) seems to offer a treatment option with good results at short-term follow-up, at least in the condylar setting.

HYPOTHESIS

A synthetic implant provides a simple and efficacious means of treating the cartilage defects of the patellofemoral joint in young patients.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A study was designed to evaluate prospectively short- and medium-term results in patients with osteochondral patellar defects treated with synthetic reabsorbable scaffolds. Patient outcome scores (Short Form 36 [SF-36] and Knee injury and Osteoarthritis Outcome Score [KOOS]), demographics, prior surgeries, and data from a physical examination were collected at baseline (before implantation) and at 6, 12, and 24 months after surgery. Defect characteristics were collected during implantation. Diagnosis and monitoring were performed by magnetic resonance imaging.

RESULTS

Ten patients with a mean age of 33.3 years (range, 16-49 years) were evaluated prospectively at 24 months' follow-up. The number of plugs used for each patient ranged from 1 to 4. At 1-year follow-up, the results were satisfactory in 8 of 10 patients, and poor in 2, according to clinical assessment (KOOS, visual analog scale, and SF-36). At 18 months of follow-up, all patients except one complained of pain and knee swelling. Reoperation rate for implant failure at final follow-up was 70%. Magnetic resonance imaging at final follow-up showed a cylindrical cavity of fibrous tissue instead of subchondral bone restoration.

CONCLUSION

A synthetic implant can improve symptoms and joint function, especially for small lesions, only for a short period of time. However, 2 years of monitoring has shown its failure in restoring the subchondral bone despite the formation of predominant hyaline cartilage from synthetic resorbable scaffolds. Under current conditions and according to our experience, we do not recommend TruFit synthetic implants for osteochondral patellar defects in active patients.