To retrospectively explore the short-term clinical efficacy of RIO robotic arm interactive orthopedic system (MAKO robotic) assisted total hip arthroplasty (THA) through direct anterior approach (DAA) compared with traditional model.

The data of a total of 48 patients (24 patients for MAKO group and 24 patients for the traditional group) who underwent THA through DAA were analyzed retrospectively during the period of February 2020 to January 2021. Inclusion criteria: the patients undergoing unilateral TKA for the first time; no operation in this hip joint; no abnormality was found in preoperative hepatic and renal function, hemoglobin, and coagulation function. Exclusion criteria: operation in this hip; infection; cardiopulmonary insufficiency, anemia. The patients were divided into MAKO robotic assissted group (the MAKO group) and the tranditional group according to the opermtive method, 24 cases in each.The data of sex, age, hip diseases and body mass index (BMI) were collected. The operation time, post-operative volume of drainage, decline in hemoglobin, the anteversion and abduction angles of acetabular cup, lower leg discrepancy, lenghth of hospital stay, Harris score, postoperative analgesia drug score and complications were assessed between the two groups. The data were analyzed by independent sample t test, repeated measures ANOVA and chi-square test.

The follow-up time were (10.3±3.7) months in MAKO group and (10.9±2.7)months in the traditional group. There was no statistically significant difference between these two groups in the lenghth of hospital stay, pain drugs, volume of drainage, lower leg discrepancy, peri-operative hematocrit and decline in hemoglobin, postoperative analgesia drug score and Harris score in the last follow-up(all P>0.05). Compared with the traditional group, the MAKO group showed longer operation time [(133.1±26.3)min vs(103.1±25.0)min](t=4.050, P<0.001). The anteversion [(19.6±2.5)° vs(25.3±5.2)°](t=4.840, P<0.001) and abduction angles of acetabular cup[(40.6±4.0)°vs(36.9±7.0)°](t=2.248, P=0.029)were more consistent with predetermined values in the MAKO group than that in the traditional group. Compared with pre-operation, the patients in MAKO group had shorter difference between two hips in off-set. (t=2.668, P=0.011)

Compared with traditional THA, the prosthesis composition could achieve more corrective predetermined angles with the MAKO assisted arm and similar off-set at the cost of longer operation time. The short-term hip functions are similar in both surgical methods, but the long-term results should be further studied.