Outcome of meniscal allograft transplantation related to articular cartilage status: advanced chondral damage should not be a contraindication.

PURPOSE: Advanced chondral damage (bare bone) at presentation is considered a contraindication to meniscal allograft transplantation (MAT), yet there are few other options for young patients where arthroplasty is not appropriate. This study hypothesis is that MAT in patients with advanced chondral damage can obtain good clinical outcomes, equivalent to patients with minimal chondral damage.
METHOD: A prospective longitudinal study of 99 consecutive patients who underwent MAT between May 2005 and Feb 2013, with a minimum of 1-year follow-up. Patients were categorised into two groups: 60 in Group A (Good) up to ICRS Chondral grade 3b involving <1 cm(2) and 39 in Group B (Bare) ICRS grade 3b involving >1 cm(2) or worse. Outcomes were assessed by PROMS (KOOS, IKDC, Lysholm, Tegner Activity Scale), with an endpoint of meniscal allograft failure.
RESULTS: Mean follow-up was 2.9 years (range 1.1-9.1, SD 1.23), with a similar male to female and lateral to medial ratios between the groups (n.s). The age of Group B was significantly older than Group A (35 vs 29 years, p = 0.002). The status of the articular cartilage at the time of transplant was directly related to the number of years since index meniscectomy [(A) Mean 6.9 years, SD 6.3; (B) 11.9 years, SD 7.4; p = 0.001]. Pre-operatively, patients in Group B had significantly worse pain and functional outcome scores (KOOS p = 0.022, Lysholm p = 0.025, IKDC pain subset p = 0.035). The mean increase PROMs was significant in both groups at 1 year (KOOS p < 0.05, IKDC p < 0.001, Lysholm p < 0.001), and the pain and functional scores were no longer significantly different between groups (n.s.). The outcome measures continued to improve in both groups at 2 and 3 years, with slightly greater improvement in Group A. Failure of the meniscal allograft occurred in 9 patients (A:1, B:8) at a mean time of 1.1 years (SD 0.55). Kaplan-Meier survival at 2 years was 97.9% (A) and 78% (B) (p = 0.002). Logistic regression analysis demonstrated a relationship between survival and chondral grade (p = 0.001) and number of concomitant procedures (p < 0.001).
CONCLUSION: Patients with advanced chondral damage should not be excluded from MAT. Though there is a higher initial failure rate, these patients obtain a similar therapeutic benefit to the traditional, ideal patient group. LEVEL OF EVIDENCE: III.