Concomitant Meniscal Allograft Transplantation and Autologous Chondrocyte Implantation: Minimum 2-year Follow-up

Background: Although recent studies have shown intermediate-term success of both meniscal allograft transplantation (MAT) and autologous chondrocyte implantation (ACI) performed separately, there have been no peer-reviewed studies focused prospectively on the combined procedure. By potentially reestablishing a compartment contact area closer to normal, MAT may allow a more optimal environment for ACI by reducing stress (stress =force/unit area). On the other hand, the literature suggests that MAT alone in the presence of extensive chondrosis performs poorly. Restoring the articular cartilage may allow the MAT to perform more similarly to series with nearly normal articular cartilage.

Hypothesis: Performed concomitantly, ACI and MAT will result in significant improvements in knee function as measured by functional scoring scales and visual analog pain scales.

Study Design: Case series; Level of evidence, 4.

Methods: Preoperative and postoperative comparisons of Browne modified Cincinnati functional levels, Lysholm, visual analog rest and maximum pain, and satisfaction scores were recorded. Thirty-six total procedures were performed between 1999 and 2004.

Results: Of the 36 patients entering the series, 29 had >2-year evaluation and scores. Four patients were recorded as failures before the 2-year follow-up and required revision surgery. Three patients were lost to follow-up. A total of 21 medial and 8 lateral MAT/femoral condyle ACIs were performed. Sixteen of 29 patients had concomitant procedures performed, including tibial tuberosity osteotomy, anterior cruciate ligament reconstruction, and high tibial osteotomy. Patients demonstrated statistically significant improvement in the standardized outcome surveys, visual analog pain, and satisfaction scores. The Browne Cincinnati (Patient and Clinician, respectively) showed an improvement from 3.9 (standard deviation [SD], 1.5) and 4.0 (SD, 1.4) preoperatively to 6.3 (SD, 1.9) postoperatively for both. The Lysholm also showed an improvement from 57.7 (SD, 16.2) preoperatively to 77.7 (SD, 19.3) postoperatively. There were no significant differences noted in any of the subgroups (medial vs lateral, isolated vs concomitant, or unipolar vs bipolar).

Conclusion: At a minimum of 2-year follow-up, MAT in combination with ACI demonstrates improvement in both symptoms and knee function. However, the improvements are less than literature-reported outcomes of either procedure performed in isolation.