Summary

Results of a novel technique to avoid extrusion in lateral meniscal transplantation

Abstract

Background

Extrusion is an intriguing phenomenon that is usually identified shortly after transplantation and seems to be stable over time. The aim of this study was to present the radiographic results (i.e. grade of graft extrusion) as well as the functional results in a series of lateral meniscal allograft transplantation (MAT) with a soft tissue fixation technique. That soft tissue technique would be when the meniscal horns are fixed with sutures through bone tunnels after a lateral capsular fixation (capsulodesis)

Methods

A prospective series of 14 consecutive lateral MAT was analysed. All the cases were performed with sutures through bone tunnels after lateral capsular fixation (capsulodesis). All patients were studied with standard supine magnetic resonance imaging to determine the degree of meniscal extrusion at an average of 18 months of surgery (range, 12-24 months). Meniscal extrusion was measured on coronal MRI's. To standardize the results, the percentage of meniscus extruded was also calculated. The functional results were analysed by means of standard knee scores (Lysholm, Tegner, KOOS and VAS). Categorical variables are presented as percentages and frequencies. Continuous variables are presented as mean +/- standard deviation. Interobserver agreement was analysed using the intraclass correlation coefficient. In those relevant cases, a 95% confidence interval was calculated. The relationships between categorical variables were described with contingency tables. Meniscal extrusion rates and functional scores were compared between the 2 groups using the Paired Student's t-Test. Multiple linear regression analysis was used to determine whether meniscal extrusion and functional evaluation were associated. The statistical analysis was performed using the SPSS 19 package (SPSS Inc, Chicago, Illinois). Statistical significance was set at .05

Results

10 knees (71.43%) showed a minor graft extrusion (<3 mm), while 4 (28.57%) had a higher extrusion. The final follow-up Lysholm score was 91.43 +/- 6.19 (p=0.00). An overall improvement was obtained in terms of the Tegner, KOOS and VAS scores. The median follow-up Tegner score significantly improved from 3.71 (SD 1.33) to 6.43 (SD 1.45) (p=0.00). The KOOS score improved from 51,98 (SD 2,84) to 90,88 (SD 7,53) (p = 0,00). The average VAS score dropped 7.29 points. There were no complications in this series.

Conclusions

The soft tissue fixation technique after capsulodesis in lateral MAT is effective at decreasing the degree of meniscal extrusion. Additionally, the functional results found were good and there were no complications recorded in this series