Table 1.

Evidence for arthroscopic partial meniscectomy

Study	Study description	Group 1	Group 2	Outcome measure	Results	Conclusion
Randomised control trials
Sihoven and colleagues, 2013 [18]	Multicentre with symptomatic medial meniscal tear	APM	Sham surgery	Symptoms	No significant between-group differences from baseline to 12 months in any primary outcome (LKS, WOMET and knee pain after exercise)	APM not superior to sham surgery in reducing knee symptoms at 12 months
Yim and colleagues, 2013 [16]	Degenerative horizontal tear of posterior horn of medial meniscus on MRI; mean age 53.8 years (range 43 to 62 years); follow-up 2 years	APM, n = 50	Strengthening exercises, n = 52	Symptoms	Both groups reported an improvement in knee pain, function and a high level of treatment satisfaction using VAS, LKS, Tegner activity scale, patient subjective knee pain and satisfaction. No significant between-group differences	APM not superior to strengthening exercises in terms of improved knee pain, function or treatment satisfaction
Katz and colleagues, 2013 [15]	Symptomatic meniscal tear; age ≥45 years; 6-month and 12-month follow-up	APM and postoperative PT, n = 161; mean age 59.9 ± 7.9	PT alone, n = 169; mean age 57.8 ± 6.8	Symptoms	WOMAC at 6 and 12 months improvement in both groups but no between-group differences; 30% crossover from PT alone within first 6 months	APM + PT not superior to PT for pain reduction
Herrlin and colleagues, 2013 [17]	Symptomatic medial meniscal tear and radiographic OA; 24-month and 60-month follow-up	APM followed by exercise therapy for 2 months, n = 47; median age 54 years	Exercise alone, n = 49; median age 56 years	Symptoms	Clinical improvement in both groups on all subscales of KOOS, LKS and VAS (P <0.0001). One-third of exercise-alone patients that failed to respond had a benefit from then having APM	APM + exercise not superior to exercise alone
Herrlin and colleagues, 2007 [14]	Knee pain and underlying OA with medial meniscal tear; mean age 56 years; 8-week and 6-month follow-up	APM and supervised exercise, n = 47	Supervised exercise alone, n = 43	Symptoms	Both groups reported decreased knee pain, improved function and high satisfaction. No between-group differences	APM + exercise not superior to exercise alone
Beidert, 2000 [10]	Painful intrasubstance medial meniscal tear; mean age 30.4 years (range 16 to 50 years); 26.5-month follow-up	Group D: APM, n = 11	Group A: PT and NSAIDs, n = 12	Symptoms	Normal/near-normal IKDC. Group A. 75%; Group D. 100%, P = 0.006	APM superior to conservative therapy
Cohort studies
Englund and Lohmander, 2004 [11]	Retrospective case–control study; meniscal Resection 15 to 22 years prior; mean age 54 years at follow-up (±11 years)	APM or total menisectomy, n = 317	Control group with no meniscal tear, previous surgery or cruciate pathology, n =68	Structure	Radiographic (RR 5.4, 95% CI 2.5 to 13) and symptomatic (RR 2.6, 95% CI 1.3 to 6.1) knee OA more common in operated knees than in controls. Total meniscectomy rather than APM had higher likelihood of knee OA (OR 3.6, 95% CI 1.4 to 9.4)	Menisectomy associated with higher risk of developing knee OA. APM associated with less radiographic knee OA than total menisectomy
Englund and colleagues, 2003 [12]	Retrospective analyses of patients who had undergone menisectomy in an orthopaedic hospital 16 years earlier; mean age 54 years at follow-up (±12 years)	APM or subtotal menisectomy, n = 155; mean age 54.3 years	Age, gender and BMI matched controls, n = 68; mean age: 56.3 years	Structure	Increased RR of knee OA (RR 4.8, 95% CI 2.2 to 12) and symptom development (RR 2.6, 95% CI 1.6 to 4.7) of knee OA in meniscectomy group. Subtotal menisectomy associated with significantly worse joint space narrowing and KOOS scores than APM	APM or subtotal associated with high risk of radiographic and symptomatic OA at 16-year follow-up. Outcomes worse in degenerative tears and extensive resection

APM, arthroscopic partial menisectomy; BMI, body mass index; CI, confidence interval; MRI, magnetic resonance imaging; NSAID, nonsteroidal anti-inflammatory drug; OA, osteoarthritis; PT, physical therapy; RR, relative risk. Western Ontario Meniscal Evaluation Tool (WOMET) is a disease-specific quality-of-life measurement tool for patients with meniscal lesions looking at symptoms (pain, giving way, swelling, stiffness, numbness, loss of motion), sports/recreation/lifestyle/work and emotion. Western Ontario and McMaster Universities Arthritis Index (WOMAC) evaluates the condition of patients with osteoarthritis of the knee and hip, including pain, stiffness, and physical functioning of the joints. Knee Injury and Osteoarthritis Outcome Score (KOOS) evaluates short-term and long-term patient-related outcomes following injury including pain, other symptoms such as catching/locking/swelling, activities of daily living, sport and recreation function, and knee-related quality of life. Lysholm knee scoring (LKS) scale for knee ligament injuries including pain, swelling, locking, limping, stair climbing, support and squatting. Visual analogue scale (VAS) is a subjective measurement of pain consisting of a line 10 cm long where on one end is ‘no pain’ and on the other is the ‘worst pain imaginable’. International Knee Documentation Committee score (IKDC) is a score to evaluate knee ligament injuries including three domains of symptoms (pain, locking, catching, swelling, stiffness), sports and daily activities and current knee function (compared with old knee function).