An Osteophyte in the Tibial Plateau Is a Risk Factor for Allograft Extrusion After Meniscus Allograft Transplantation

Background: Osteophytes can be observed on the tibial plateau during meniscus allograft transplantation (MAT). However, no studies to date have evaluated the effect of these osteophytes on meniscus allograft extrusion. Hypothesis: Osteophyte excision in the tibial plateau could reduce extrusion of the transplanted meniscus and improve short-term clinical outcomes with meniscus allograft transplantation. Study Design: Cohort study; Level of evidence, 3. Methods: Between October 2004 and July 2012, a total of 323 patients underwent MAT at a single institution. Of these, 88 patients had a peripheral osteophyte in their tibial plateau, and they were enrolled in the study retrospectively. The mean age of the patients was 35.3 years (range, 15-56 years); there were 57 male and 31 female patients. Forty-four patients underwent osteophyte excision concomitantly with MAT and 44 patients underwent MAT only. The 2 groups showed no difference in terms of age, body mass index, time after meniscectomy, and preoperative knee scores. A medial meniscus allograft was transplanted in 13 cases (15%) and a lateral meniscus in 75 (85%). The absolute extrusion and relative percentage of extrusion were measured to evaluate allograft extrusion 12 months after MAT. The modified Lysholm scoring system and the Hospital for Special Surgery score at 2 years after MAT were used to evaluate clinical outcomes. Results: The mean absolute extrusions at 1 year postoperatively in the excision and nonexcision groups were 3.5 1.5 and 5.5 +/- 1.6 mm, respectively. The mean relative percentages of extrusion were 34.1% +/- 15.9% and 54.7% +/- 20.7%, respectively. The rates of allograft extrusion (>3 mm) were 28 of 44 (63.6%) and 41 of 44 (93.2%) in the excision and nonexcision groups, respectively. The intergroup differences in absolute extrusion, relative percentage of extrusion, and rate of allograft extrusion were statistically significant (P < .001 for all 3 parameters). There were no significant differences in the clinical outcomes (modified Lysholm or Hospital of Special Surgery scores) at 2-year follow-up (P < .762 and < .298, respectively). Conclusion: The excision of a peripheral osteophyte larger than 2 mm in the proximal tibial plateau was associated with less allograft extrusion after MAT.