Table 4.

Level IV Studies

Study	Intervention	Mean Follow-up	Laterality	Radiographic Outcomes	Clinical Outcomes	Comments
Han et al., 201020	Partial meniscectomy (46)	78 mo	Medial	35% showed progression of K-L grade	Significant improvement in modified Lysholm score	56% improvement in pain 67% patient satisfaction 19% underwent reoperation
Ahn et al., 201021	Repair, all inside (27)	18 mo	Lateral	Significant improvement in extrusion in sagittal plane only	Improvement in IKDC and Lysholm scores	—All patients underwent concomitant ACL reconstruction —8 of 9 patients showed complete healing on second-look arthroscopy
Lee et al., 201822	Repair, pull-out (56)	40.6 mo	Medial	–23% Progression of K-L grade —Narrowed medial joint space: 3.52 to 3.17 mm	Improved Lysholm, IKDC, and HSS functional scores	Significant prognostic factors were age, BMI, K-L grade, medial joint space width, meniscal extrusion, type of tear, grade 3 or greater chondral lesion
Krych et al., 201723	Conservative (52)	62 mo	Medial	Significant progression of K-L grade	13% with abnormal IKDC, 56% had severely abnormal score	Female sex associated with worse outcomes
Chung et al., 201824	Repair, pull-out (91)	84.8 mo	Medial	All failures were K-L grade I and Outerbridge grade 2 or 3	Significant improvement in Lysholm score	All failures were female
Tjoumakaris et al., 2015∗,25	Repair, pull-out (9)	Unknown	Medial	Mean meniscal extrusion: 1.5 mm	Mean Lysholm: 81.6 Mean WOMAC: 11.2	—Recurrence of tear in 4 patients
Alaia et al., 2017∗,26	Repair, transtibial (18)	24.9 mo	Medial	—Significantly worsened ICRS grades —Meniscal extrusion increased: 4.74 to 5.98	Significant improvement in IKDC (45.9-76.8) and Lysholm (50.9-87.1)	Only 1/18 achieved complete healing

ACL, anterior cruciate ligament; BMI, body mass index; HSS, Hospital for Special Surgery; ICRS, International Cartilage Repair Society; IKDC, International Knee Documentation Committee; K-L, Kellgren–Lawrence; WOMAC, Western Ontario and McMaster Universities Arthritis Index.

^∗Abstract presentation.