Unfavorable Results of Partial Meniscectomy for Complete Posterior Medial Meniscus Root Tear With Early Osteoarthritis: A 5- to 8-Year Follow-Up Study

Purpose The aim of this retrospective study was to evaluate the clinical and radiographic outcomes of arthroscopic partial meniscectomy for complete posterior medial meniscus root tear (PMMRT) in patients with early radiographic evidence of knee osteoarthritis at a minimum follow-up of 5 years. Methods Forty-six cases had complete PMMRT with follow-up of at least 5 years and were treated with arthroscopic partial meniscectomy. On the basis of medical records, we reviewed the arthroscopic findings of joint degeneration (Outerbridge grading), clinical results using the modified Lysholm (ML) knee score and a patient questionnaire, and radiographic evaluation of degeneration using Kellgren-Lawrence (KL) grading. Results The incidence of complete PMMRT in the study population was 15%. At a mean follow-up of 78 months (range, 60 to 103 months), the mean ML score significantly improved from 72 (range, 62 to 78) preoperatively to 77 (range, 70 to 98) at final follow-up ( P < .01), 16 patients (35%) showed progression of degeneration from KL grade 0 to 2 preoperatively to KL grade 2 to 4, 56% of patients indicated improvement in pain, 67% of patients were satisfied with the results of the procedure, and 19% of patients underwent reoperation. There was a significant negative correlation between chondral wear during arthroscopy (ρ = −0.516, P = .002) and preoperative KL grade (ρ = −0.429, P = .004) with ML score at final follow-up. Conclusions Although arthroscopic partial meniscectomy for complete PMMRT significantly improved ML scores postoperatively, only 56% of patients had improvement in pain, 67% were satisfied with the outcome of the procedure, and 35% showed radiographic progression of osteoarthritis at a mean follow-up of 77 months. Level of Evidence Level IV, therapeutic study.