Systematic Review Medial Soft-Tissue Realignment Versus Medial Patellofemoral Ligament Reconstruction for Recurrent Patellar Dislocation: Systematic Review Jae-Gwang Song, M.D., Seung-Baik Kang, M.D., So-Hee Oh, Ph.D., Jae-Hwi Han, M.D., Daivesh Shah, M.S.Ortho., Hyung-Joon Park, M.D., Umid T. Kholmurodov, M.D., and Kyung-Wook Nha, M.D. Purpose: To compare the clinical outcomes between medial soft-tissue surgery and medial patellofemoral ligament (MPFL) reconstruction for recurrent patellar dislocation without any evident predisposing factors. Methods: A literature search was performed on the established medical databases MEDLINE, EMBASE, and the Cochrane register. The inclusion criteria were as follows: English-language papers for recurrent patellar dislocation without any evident predisposing factors, clinical trial(s) with clear description of surgical technique, adult subjects, medial soft-tissue surgery or MPFL reconstruction without combined surgery, and a follow-up longer than 2 years. The methodological quality of all articles was assessed by 2 authors according to the Coleman methodology score. Results: Thirteen studies (mean Coleman methodology score value, 74.1; standard deviation, 11.5) were included in the analysis. Five studies reported the out- comes of patients undergoing medial soft-tissue surgery, compared with 7 studies reporting MPFL reconstruction. Overall, 109 patients underwent medial soft-tissue surgery with a minimum 2-years follow-up, compared with 308 patients of MPFL reconstruction. There was one direct comparative study between medial soft-tissue surgery and MPFL recon- struction. Of the patients who received medial soft-tissue surgery, 0 to 9.7% experienced redislocation, compared with 0 to 10.7% of the MPFL reconstruction group. The ranges of differences in Kujala scores were 23.6 to 31.7 points in patients who underwent medial soft-tissue surgery and 23.11 to 38.8 points in patients who underwent MPFL recon- struction. The ranges of postoperative congruence angles were 14.4  to 8.2  for medial soft-tissue surgery and 7.7  to 5.2  for MPFL reconstruction. The ranges of postoperative lateral patellofemoral angles were 7.9  to 9.4  for medial soft-tissue surgery and 5  to 5.3  for MPFL reconstruction. Conclusions: All studies on medial soft-tissue surgery and MPFL reconstruction for recurrent patellar dislocation without predisposing factors showed satisfactory outcomes despite the use of numerous surgical techniques, graft types, and follow-up periods. Level of Evidence: Level IV, Systematic Review. P atellar instability is often multifactorial, with osseous and soft-tissue abnormalities leading to recurrent lateral dislocations. According to the causes of dislocation, different surgeries are adopted. In cases of severe trochlear dysplasia, trochleoplasty may be indi- cated. 1-3 If extensor mechanism disorders such as increased distance from the tibial tubercle to the trochlear groove (TT-TG) or patellar alta are present, proximal realignment, distal realignment, or combined surgery follow. For lower-limb malalignment (high Q- angle) or patella alta, distal realignment surgery is indicated. Ideal candidates for proximal soft-tissue procedures have a normal Q-angle, insufficient medial structures, and initial instability resulting from a trau- matic event. 2,3 Proximal soft-tissue procedures seek to balance the medial and lateral soft tissues. The rationale behind these procedures is that recurrent patellar From the Department of Orthopedic Surgery, Aerospace Medical Center, Republic of Korea Air Force (J-G.S.), Cheongju-si; Department of Orthopedic Surgery (S-B.K.) and Department of Biostatistics (S-H.O.), Seoul National University Boramae Hospital, Seoul; Department of Orthopedic Surgery, Inje University, Ilsan Paik Hospital (J-H.H., H-J.P., K-W.N.), Ilsan, Republic of Korea; Department of Orthopaedic Surgery, B. J. Medical College and New Civil Hospital (D.S.), Ahmedabad, India; and Department of Orthopaedic Surgery, Tashkent Medical Academy (U.T.K.), Tashkent, Uzbekistan. The authors report that they have no conflicts of interest in the authorship and publication of this article. J-G.S. and S-B.K. contributed equally to this work as co-first authors. Received December 10, 2014; accepted August 7, 2015. Address correspondence to Kyung-Wook Nha, M.D., 2240, Daehwa-dong, Ilsan-Segu, Koyang-Si, Ilsan 411-706, Korea. E-mail: kwnhamj@hotmail. com Ó 2015 by the Arthroscopy Association of North America 0749-8063/141035/$36.00 http://dx.doi.org/10.1016/j.arthro.2015.08.012 Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol -, No - (Month), 2015: pp 1-10 1