Midterm outcomes after meniscal allograft transplantation: comparison of cases with extrusion versus without...

Although graft extrusion is of concern after meniscal allograft transplantation (MAT), the correlation between extrusion and clinicoradiological outcomes remains unclear. Hypothesis Patients with graft extrusion after MAT have worse clinical outcomes and greater arthritic change than those without graft extrusion.

Cohort study; Level of evidence, 3.

Forty-three patients underwent MAT between 1999 and 2004. Grafts were classified as either nonextruded (<3 mm) or extruded (>or=3 mm) according to 1-year postoperative magnetic resonance imaging (MRI) findings. The mean patient age at the time of surgery was 33.5 years (range, 17-43 years), and the mean follow-up period was 5.1 years (range, 3.5-8.3 years). The Lysholm score was used to evaluate knee function. In addition, preoperative and postoperative (final follow-up) measurements were taken to determine the absolute and relative (affected side/normal side) joint space width (JSW) on a standing 45 degrees flexion posteroanterior view.

Magnetic resonance imaging at 1 year showed the mean graft subluxation was 3.03 +/- 0.872 mm across all patients. Twenty-six knees (60%) were classified as nonextruded and 17 (40%) as extruded. No statistical difference was found between these 2 groups regarding Lysholm score improvement after MAT. Overall, absolute and relative JSWs were slightly narrower postoperatively compared with preoperatively across all patients (mean absolute difference, 0.283 mm; mean relative difference; 4.79%; P <.001). However, extruded and nonextruded knees were similar in terms of absolute (P = .764) and relative (P = .482) JSW after MAT. The amount of extrusion did not correlate with Lysholm score or the relative difference between preoperative and postoperative JSW across all patients or in either group.

Joint space width was slightly narrower after MAT. Extrusion had no effect on 5-year clinical or radiological outcomes.