Increased Joint Space Narrowing After Arthroscopic Partial Meniscectomy: Data From the Osteoarthritis Initiative

Santana DC, Oak SR, Jin Y, Rothy A, Lee LL, Katz JN, Winalski CS, Duryea J, Jones MH · The American Journal of Sports Medicine

Baseline joint space width was 4.33 to 4.38 mm in all three groups. The meniscectomy group lost 0.083 mm per month over the first 12 months, roughly 27 times the rate in the untreated-tear group (0.003 mm/month) and 5 times the no-tear group (0.015 mm/month); from 12 to 72 months the three rates converged (0.014, 0.009 and 0.010 mm/month). Adjusted joint space width at 72 months was 2.57 mm after meniscectomy, 3.73 mm with an untreated tear and 3.54 mm with no tear.

Population

144 Osteoarthritis Initiative patients who underwent arthroscopic partial meniscectomy, each matched by sex, age, Kellgren-Lawrence grade and follow-up time to a patient with an untreated meniscal tear and to a patient with no tear

Intervention

Automated measurement of minimum medial compartment joint space width on annual radiographs, modelled piecewise

Limitations

Observational and matched rather than randomised, so confounding by indication applies. The shape of the finding is its most useful part: the loss is concentrated in the first postoperative year and the rates then equalise, leaving a gap that does not close. Full text was not retrievable.