Arthroscopic partial meniscectomy for a degenerative meniscus tear: a 5 year follow-up of the placebo-surgery controlled FIDELITY (Finnish Degenerative Meniscus Lesion Study) trial

Sihvonen R, Paavola M, Malmivaara A, Itälä A, Joukainen A, Kalske J, Nurmi H, Kumm J, Sillanpää N, Kiekara T, Turkiewicz A, Toivonen P, Englund M, Taimela S, Järvinen TLN · British Journal of Sports Medicine

At 5 years, 48 of 67 knees (72%) in the meniscectomy group and 44 of 74 (60%) in the placebo group had progressed at least one Kellgren-Lawrence grade, an adjusted absolute risk difference of 13% (95% CI -2% to 28%); the adjusted difference in OARSI sum score was 0.7 (95% CI 0.1 to 1.3), with more progression after meniscectomy. No patient-reported outcome differed: WOMET -1.7 (95% CI -7.7 to 4.3), Lysholm -2.1 (-6.8 to 2.6), knee pain after exercise -0.04 (-0.81 to 0.72). Mechanical symptoms were reported by 20 of 68 (29%) after meniscectomy and 9 of 74 (12%) after placebo surgery, a risk difference of 18% (95% CI 5% to 31%).

Population

The 146 FIDELITY participants, mean age 52, followed to 5 years with weight-bearing radiographs read by two blinded musculoskeletal radiologists

Intervention

Arthroscopic partial meniscectomy

Comparator

Placebo surgery

Limitations

The osteoarthritis estimate is imprecise — the confidence interval on the Kellgren-Lawrence risk difference crosses zero — and eight participants crossed over, which the authors note would bias the structural difference towards the null. Radiographic grading is subjective, which is why two readers were added; consensus and single-reader analyses agreed.