[Short-term effectiveness of MAKO robot assisted complex total hip arthroplasty]

To investigate the short-term effectiveness of MAKO robot assisted complex total hip arthroplasty (THA).

The clinical data of 15 patients (17 hips) underwent MAKO robot assisted complex THA between May 2020 and June 2021 were analyzed retrospectively. There were 5 males and 10 females with the age ranged from 19 to 70 years (median, 49 years), included 9 cases (9 hips) of developmental dysplasia of the hip (Crowe type Ⅱ in 5 hips, type Ⅲ in 1 hip, and type Ⅳ in 3 hips), 1 case (2 hips) of rheumatoid arthritis, 2 cases (3 hips) of ankylosing spondylitis, 3 cases (3 hips) of secondary arthritis with a history of acetabular fracture and internal fixation. The acetabular cup abduction angle and anteversion angle were measured at 3 months after operation, and compared with those measured by MAKO robot system before and immediately after operation. The femoral offset and leg length discrepancy (LLD) were measured at 3 months after operation, which were compared with those before operation. Harris hip score (HHS) and visual analogue scale (VAS) score were used to evaluate hip function before operation and at 3 months after operation.

All 15 patients (17 hips) completed the operation successfully. The operation time was 75-175 minutes, with an average of 116.3 minutes; the intraoperative blood loss was 100-800 mL, with an average of 381.3 mL. Two patients were not included in the statistics because of intraoperative and postoperative complications, the remaining 13 patients (15 hips) had no serious complication such as vascular and nerve injuries, and 3 patients had intermuscular vein thrombosis. The 13 patients (15 hips) were followed up 3-15 months, with an average of 8 months. At last follow-up, the position of prosthesis did not change and there was no signs of loosening. There was no significant difference in acetabular abduction angle at immediate and 3 months after operation when compared with preoperative one ( P>0.05), and the acetabular anteversion angle was significantly lower than that before operation ( P<0.05). There was no significant difference in acetabular abduction angle and anteversion angle between at immediate and 3 months after operation ( P>0.05). The LLD, offset, HHS score, and VAS score were significantly improved at 3 months after operation when compared with preoperative ones ( P<0.05).

MAKO robot assisted complex THA can achieve good short-term effectiveness, improve the hip range of motion, reduce the length difference between bilateral lower limbs, and improve the quality of patients' life.