Isolated Arthroscopic Partial Meniscectomy is More Effective at Improving Meniscal Symptoms in Comparison to Mechanical Symptoms in Patients with Concomitant Untreated Chondral Lesions.

Abstract Purpose The purpose of this study was to rank Knee Injury and Osteoarthritis Outcome Score (KOOS) questions from most to least improvement after arthroscopic partial meniscectomy (APM) and compare improvement of meniscal versus mechanical symptoms. Methods A secondary analysis of the Chondral Lesions and Meniscus Procedures (ChAMP) Trial was performed. Inclusion criteria were age 30 years or greater with degenerative meniscal tear failing non-operative management, with or without associated unstable chondral lesions. No chondral debridement was performed. Responses to the 42 KOOS questions ranged from 0 (extreme problems) to 4 (no problems), and were answered preoperatively and at 1-year after isolated APM. The 1-year mean change, or delta (Δ), was calculated for each KOOS question and the Δ for meniscal and mechanical symptoms were statistically compared. Results Greatest improvement in 135 eligible patients was observed for questions about: 1) awareness of knee problems (Δ = 1.93, SD=1.38), 2) frequency of knee pain (Δ = 1.93, SD=1.29), 3) degree of difficulty while twisting/pivoting on the injured knee (Δ = 1.88, SD=1.13), 4) degree of difficulty while running (Δ = 1.67, SD=1.30), and 5) being troubled by lack of confidence in the knee (Δ = 1.67, SD=1.11). Least improvement was observed for questions about: 1) degree of difficulty while getting on/off the toilet (Δ=0.94, SD=0.96), 2) feel grinding or hear clicking when the knee moves (Δ=0.90, SD=1.25), 3) degree of difficulty while getting in/out of the bath (Δ=0.88, SD=1.00), 4) knee catches/hangs up during movement (Δ=0.80, SD=1.09), and 5) the ability to straighten the knee fully (Δ=0.54, 1.44). There was greater improvement for the KOOS questions pertaining to meniscal versus mechanical symptoms (p Conclusion KOOS symptoms as reported by subjects’ responses to the questions pertaining to the frequency of knee pain, twisting/pivoting, running, squatting, and jumping showed the most improvement 1-year after isolated APM, while those relating to mechanical symptoms improved the least. Focusing on meniscal rather than mechanical symptoms may help surgeons better identify patients expected to benefit from APM.