Objective To compare the efficacy of tibial tuberosity osteotomy (TTO) combined with medial patellofemoral ligament reconstruction (MPFLR) with simple TTO in treatment of recurrent patella dislocation associated with patella alta.Methods From July 2010 to December 2015,50 patients with recurrent patella dislocation and patella alta were included in this study.There were 15 males and 35 females with an average age of 20.6 years.These patients received surgical treatment and their clinical data were collected and retrospectively analyzed by case-control study.According to surgical methods,patients were divided into TTO group (32 cases) and MPFLR + TTO group (18 cases).The differences between preoperative status and postoperative status were evaluated by knee function scores including Tegner,international knee documentation committee (IKDC),Kujala scores,knee injury and osteoarthritis outcome score (KOOS).Patellar stability was checked at the last follow-up visit.Results The TTO group and MPFLR + TTO group were followed up for (50.9 ± 17.8) months and (22.3± 10.1)months,respectively.Two patients occurred recurrent dislocation in TTO group,who showed positive in both extrapolation test and extrapolation apprehension test at 0°flexions of knee.All patients in MPFLR + TTO group did not occur recurrent dislocation,who showed negative in both extrapolation test and extrapolation apprehension test at 0° flexions of knee.There was no significant difference between preoperative and postoperative results in TTO group in Tegner score (P ＞ 0.05),KOOS scores in pain and daily life activities subdomains (P ＞ 0.05),while differences in the rest of scores were statistically significant (P ＜ 0.05).Compared with TFO group,the differences of all scores were statistically significant (P ＜ 0.05) and KOOS scores in the pain and daily life activities subdomains were significantly improved postoperatively in MPFLR + TTO group P ＜0.05).Conclusions For patients with recurrent patellar dislocation associated with patella alta,both surgical methods are found to be effective.Postoperative improvements in pain and daily life activities are less obvious in TTO.While postoperative improvements in pain and daily life activities in MPFLR + TTO are superior to those of TTO.