Meniscal repair has become the treatment of choice for meniscus tears, especially in the subset of bucket-handle meniscal tears (BHMTs). However, a comprehensive estimate of the failure rate is missing, thus maintaining doubtful the effective healing potential of these tears. Furthermore, a wide number of predictive factors of higher failure rates have been reported, but with conflicting evidence.
The purpose of this study was to define the failure rate after arthroscopic repair of BHMTs, comparing it with the failure rate of simple meniscal tears extracted from the same studies, and to analyze the influence of factors previously stated as predicting of meniscal repair failure.
A systematic search was conducted by two independent reviewers on principal bibliographic databases (PubMed, Scopus, Cochrane library and EMBASE). After a stepwise exclusion process, 38 articles met the inclusion criteria. Failure rate data were analyzed with a random-effects proportion meta-analysis (weighted for individual study size), and a forest plot was constructed to determine any statistical significant difference between BHMTs and simple tears (longitudinal, radial or horizontal), medial and lateral BHMTs, isolated procedures and repairs with concomitant ACL reconstruction, tears in red-red and in red-white zone, respectively. Moreover, a meta-regression analysis was conducted, in order to evaluate the effect of patients’ age, gender, suture technique (in-out or all-inside), time from injury to surgery, mean number of stitches and length of follow-up on failure rates.
The pooled failure rate was 14.8% (95% CI, 11.3%-18.3%; I2 = 77.2%). Seventeen studies provided failure rates of both BHMTs repairs (46 out of 311 repairs) and other simple tears repairs (54 out of 546 repairs), demonstrating a significantly higher failure rate for BHMTs repairs (RR = 1.50, 95% CI, 1.05-2.15; I2 = 0%, p=0.03). Medial BHMTs (RR = 1.94, 95% CI, 1.25-3.01; I2 = 0%, p=0.03) and isolated repairs (RR = 1.77, 95% CI, 1.15-2.72; I2 = 0%, p=0.009) presented a statistically higher risk of failure, but no statistically significant difference was found between tears in red-red zone and in red-white zone. Among the other factors evaluated with meta-regression, only the mean number of stitches showed a statistically significant effect on failure rates.
Based upon the currently available literature, this systematic review provides a reasonably comprehensive analysis of failure rate after arthroscopic BHMTs repair, which is estimated in 14.8% of cases. Medial tears and isolated repairs were found to be the two major predictors of failure. Further studies are welcomed to update these data to a more accurate level.