Lateral meniscus allograft transplantation: Clinical and anatomic outcomes after arthroscopic implantation with tibial tunnels versus open implantation without tunnels

Meniscus allograft transplantation (MAT) is used to treat patients with knee pain after total or subtotal meniscectomy. The graft can be inserted during open or arthroscopic surgery. The objectives are anatomic horn positioning and strong fixation to the bone and capsule of an appropriately sized graft.HypothesisArthroscopic MAT with trans-tibial bone fixation ensures better mid-term functional outcomes and limits allograft extrusion.Patients and methodsWe conducted a retrospective single-centre study of 23 consecutive patients who underwent MAT between 2001 and 2010. Among them, 11 had open surgery and anchoring of the horns without tunnels and 12 had arthroscopically-assisted surgery with bony fixation of the horns through trans-tibial tunnels. The two groups were comparable at baseline. Mean follow-up was 66.1 months. Post-operative outcomes were assessed using the IKDC score and KOOS, standard radiographs of both knees, and either magnetic resonance imaging or computed arthrotomography. We measured joint space narrowing, meniscal extrusion in the sagittal and coronal planes; and the degree of cartilage coverage by the graft using an index developed for this study.ResultsThe overall failure rate was 17.4% (4/23, two cases each of complete and partial graft removal). Joint space narrowing increased by 28% versus the pre-operative value (P = 0.009). IKDC and KOOS values were not significantly different between the two groups. Absolute meniscus extrusion was greater in the arthroscopy group (4 mm vs. 3 mm, P = 0.03).DiscussionOsteoarthritis of the transplanted compartment is unavoidable. Open surgery is associated with less meniscal extrusion. The clinical outcomes are independent from the technique used. Other factors require investigation, including graft rehabilitation, quality peripheral suturing, and intermeniscal ligament reconstruction.Level of evidenceIV, retrospective study.