ObjectiveTo compare the clinical efficacy between deep medial collateral ligament (dMCL) repair and conservative treatment for complete MCL rupture. MethodsBetween August 2009 and December 2013, 36 patients with grade 3 MCL rupture underwent superior MCL (sMCL) reconstruction with tibial Inlay technique. Of 36 cases, 19 received dMCL repair (repair group), and 17 received conservative treatment (conservation group) after sMCL reconstruction. There was no significant difference in gender, age, knee sides, type of injury, disease duration and preoperative medial joint opening, knee Lysholm scores, and International Knee Documentation Committee (IKDC) score between 2 groups (P > 0.05). The Lysholm and IKDC scores, medial joint opening, range of motion (ROM), visual analogue scale (VAS) scores, and complications were used to assess the knee joint function. ResultsAll patients achieved primary incision healing without acute postoperative complications of incision infection and deep vein thrombosis in the lower limb. The patients were followed up 28-65 months (mean, 46.3 months) in the repair group, and 26-69 months (mean, 45.9 months) in the conservation group. No knee stiffness, vascular or nerve injury, and knee joint infection occurred in 2 groups. All the patients recovered medial stability at 2 years postoperatively. At 2 years after operation, no significant difference was shown in knee ROM between 2 groups (t=0.26, P=0.80); the VAS score of the repair group was significantly lower than that of the conservation group (t=5.22, P=0.00); medial joint opening, IKDC score, and Lysholm score were significantly improved when compared with preoperative ones in 2 groups (P < 0.05), but no significant difference was found between 2 groups (P>0.05). ConclusionWhether or not additional dMCL repair is performed can recover medial stability after sMCL reconstruction. However, the additional dMCL repair is better in relieving medial knee pain than the conservative treatment.