Capsulodesis Versus Bone Trough Technique in Lateral Meniscal Allograft Transplantation: Graft Extrusion and Functional Results.

PURPOSE: To compare the radiographic results (in terms of graft extrusion) and the functional results of lateral meniscus allograft transplantations (MAT) performed with a bony fixation technique or with a soft tissue fixation technique after capsulodesis.

METHODS: A prospective series of 29 consecutive lateral MAT was analyzed. The inclusion criterion for MAT was lateral joint line pain due to a previous meniscectomy. Malalignment, patients who had an Ahlback grade greater than II, and patients with a body mass index over 30 were considered as the exclusion criterion to prevent confounding results. Fifteen of the grafts were fixed with a bony fixation technique (group A). The remaining 14 cases (group B) were fixed with sutures through bone tunnels after lateral capsular fixation (capsulodesis). All patients were studied with magnetic resonance imaging to determine the degree of meniscal extrusion at an average of 18 months of surgery (range, 12-48 months). Meniscal extrusion was measured on coronal magnetic resonance imaging. To standardize the results, the percentage of meniscus extruded for each group was also calculated and compared. The functional results were analyzed by means of standard knee scores (Lysholm, Tegner, and visual analog scale).

RESULTS: If we consider the first 4 cases of group B as the learning curve of the new technique, we observe that group A had 8 cases (53.3%) of major extrusion, whereas group B had 1 case (7.1%) (P = .02). When comparing the degree of meniscal extrusion with the type of fixation employed, an even lower percentage of extruded menisci was found in group B (P = .01). The final follow-up Lysholm score in group A was 94.33 ± 5.96 (P < .001) and 91.43 ± 6.19 (P < .001) in group B. The median follow-up Tegner score significantly improved from 4 (range, 2-5) to 7 (range, 6-9) in group A (P < .001) and from 4 (range, 3-5) to 7 (range, 6-8) in group B (P < .001). The average visual analog scale score dropped down 5.87 and 7.29 points in groups A and B, respectively (P < .001). The Knee Injury and Osteoarthritis Outcome Score improved from 51.98 ± 2.84 to 90.88 ± 7.53 in group A (P < .001) and from 50.44 ± 2.32 to 92.01 ± 6.71 in group B (P < .001). Patient satisfaction with regard to the procedure stood at a mean of 3.6 ± 0.2 points out of a maximum of 4 in group A and 3.8 ± 0.4 in group B. There were no complications in this series.

CONCLUSIONS: The capsulodesis technique in lateral MAT proved not to be statistically different at decreasing the degree of meniscal extrusion with respect to the bone-bridge fixation. If the first 4 cases using the new capsulodesis technique had not included in the results, the capsulodesis technique would have effectively presented better results relative to the degree of meniscal extrusion compared with the bone-bridge fixation technique. In addition, the functional results were similar.

LEVEL OF EVIDENCE: Level II, prospective comparative study.