Background

The collagen meniscus implant (CMI) was developed to treat patients with the clinical condition of post-meniscectomy syndrome. Particularly in the presence of a partial meniscal defects. The aim the study was to identify predictors of surgical failure after CMI implant a long term follow-up

Methods

A database search from a single center was conducted in order to identify all the CMI implanted from at a minimum 5 years of follow-up. Surgical failure was defined as partial or total scaffold removal, conversion to a meniscal transplant or unicompartmental/total knee arthroplasty. A logistic regression was performed by using sex, BMI, age at surgery, CMI laterality, Outerbridge grade (0-II vs III-IV), combined versus isolated procedure and "salvage procedure" (defined as Outerbridge grade III and an associated procedure to the CMI implant) as independent variables. Survival analysis was performed with Kaplan-Meier curve.

Results

156 patients (84%) with a mean age at surgery of 42.0 ± 11.1 were included in the final analysis at an average follow-up of 10.9 ± 4.3 years. The overall survival rate from surgical failure was 87.8%. When further evaluating the different subgroups of patients, an Outerbridge grade of III-IV (HR 3.8; P =.004), and lateral scaffold (HR, 3.2; P= .048) were identified as risk factors Finally, 42 patients (26.9%) were considered either a surgical or clinical failure. Risk factors were: an Outerbridge grade of III-IV (odds ratio [OR], 3.1; P =.000), and time from meniscectomy to scaffold greater than 10 years (OR, 2.7; P = .042)

Conclusion

The CMI showed a high surgical survival rate at a long-term follow-up. Lateral CMI, higher grade of cartilage degeneration and CMI implanted as a salvage procedure were found to be predictors of surgical failure. The results of this study are useful in the clinical setting to extimate the risk of failure and set patient's expectation.