Objective To evaluate the early effectiveness and summarize the initial application experiences of Mako robot-assisted total hip arthroplasty (THA) for developmental dysplasia of the hip (DDH) in adults. Methods Between August 2018 and January 2020, 55 cases of DDH (75 hips) were treated with Mako robot-assisted THA. There were 10 males and 45 females with an average age of 51 years (range, 30-73 years). There were 35 cases of unilateral hip and 20 cases of bilateral hips. The DDH was classified as Crowe type Ⅰin 29 hips, type Ⅱ in 20 hips, type Ⅲ in 6 hips, and type Ⅳ in 20 hips. The modified Harris score was 54.8±16.0, the hip joint range of motion was 90° (80°, 100°), and the leg length discrepancy (LLD) was 22.0 (10.5, 47.0) mm. The preoperative surgical plan was made in the robot system based on the CT data. The reaming and installation of the acetabular cup were completed with the assistance of the robot system. The distance between the rotation center of the hip joint and the teardrop (horizontal distance, vertical distance), inclination angle, and anteversion angle were measured on the pelvic X-ray film to evaluate the position of the acetabular prosthesis. The above indicators were compared with preoperative planning to evaluate the accuracy of robotic-assisted surgery. The modified Harris score, the range of motion, and the LLD were used to evaluate the early effectiveness. Results The 75 hips of THAs were completed with the assistance of Mako robots. There was no significant difference in the acetabular inclination angle, the horizontal distance and the vertical distance of the rotation center between the preoperative planning and the postoperative measurement values (P>0.05); the acetabular anteversion angle was significantly smaller than the postoperative measurement value (t=–2.482, P=0.015). Four hips located beyond the Lewinnek safety zone, and 71 hips located within the Lewinnek safety zone. All patients followed up 6-24 months (mean, 13 months). All incisions healed by first intention. At last follow-up, the modified Harris score was 85.5±11.2, the hip joint range of motion was 120° (110°, 120°), and the LLD was 3.8 (2.0, 8.1) mm; all improved significantly compared with preoperative ones (P<0.05). Except for one nerve injury case, there was no other complication. Conclusion Mako robot-assisted THA is a safe and effective method for adult DDH, which can optimize the acetabular cup positioning, hip function, and leg length, but the long-term effectiveness needs to be confirmed by further studies.
ObjectiveTo evaluate the early effectiveness of the robot-assisted total hip arthroplasty (THA) via direct superior approach (DSA).MethodsBetween March 2021 and April 2021, 11 patients (11 hips) were treated with a robot-assisted THA via DSA. There were 7 males and 4 females, with an average age of 55 years (range, 26-73 years). There were 5 patients of osteoarthritis secondary to hip dysplasia and 6 patients of osteonecrosis of femoral head. Preoperative hip Harris score was 55.8±6.3. The operation time, volume of blood loss, length of incision, postoperative blood transfusion and hospital stay, and the incidence of surgical complications were recorded. The visual analogue scale (VAS) score and Harris score were used to evaluate hip joint pain and function. The leg length discrepancy (LLD) was measured on the X-ray films. The inclination angle and anteversion angle of the acetabular component were also measured, and the difference between the planned and actual values were compared.ResultsOne THA was performed via conventional posterolateral approach finally because of poor exposure. The rest of 10 THAs were performed with assistance of robotic arm via DSA. The average operation time was 89 minutes (range, 65-120 minutes); the average length of incision was 10.5 cm (range, 9-13 cm); and the average blood loss was 400 mL (range, 110-740 mL). One patient was given a blood transfusion for 2 unit. All incisions healed by first intention and no neurovascular injury, deep vein thrombosis, or fracture occurred. The length of hospital stay after operation was 2-6 days (mean, 4.4 days). The duration of follow-up was 1-3 months (mean, 2.1 months). The VAS score was 0 in 9 patients and 2 in 1 patient at the day of discharge. At last follow-up, the hip Harris score was 84.9±6.7, showing significant difference when compared with that before operation (t=−8.717, P=0.000). The inclination and anteversion angles were (37.4±2.0)° and (17.1±4.5)°, respectively, and there was no significant difference when compared with the planned values [(38.2±1.6)°, (16.6±3.7)°] (t=1.809, P=0.104; t=–1.103, P=0.299). The LLD ranged from –2 to 4 mm. No complication such as dislocation, aseptic loosening, or periprosthetic joint infection occurred. ConclusionThe robot-assisted THA via DSA has encouraged early effectiveness.
ObjectiveTo explore the short-term effectiveness of Mako robot-assisted total hip arthroplasty (THA) via posterolateral approach.MethodsThe clinical data of 64 patients (74 hips) treated with Mako robot-assisted THA via posterolateral approach (robot group) between May 2020 and March 2021 were retrospectively analyzed and compared with the clinical data of 52 patients (55 hips) treated with traditional THA via posterolateral approach (control group) in the same period. There was no significant difference in general data such as gender, age, side, body mass index, disease type, and preoperative Harris score between the two groups (P>0.05). The operation time, intraoperative blood loss, and complications were recorded and compared between the two groups. Acetabular inclination angle, acetabular anteversion angle, and lower limbs discrepancy were measured after operation. At last follow-up, the improvement of hip pain and function was evaluated by visual analogue scale (VAS) score, Harris score, and forgetting joint score (FJS-12).ResultsIn the robot group, 3 patients (including 1 patient with acetabular fracture during operation) were converted to routine THA because the pelvic data array placed at the anterior superior iliac spine was loose, resulting in data error and unable to register the acetabulum; the other patients in the two groups completed the operation successfully. The operation time and intraoperative blood loss in the robot group were significantly higher than those in the control group (P<0.05). All patients were followed up 1-10 months, with an average of 4.6 months. In the robot group, 1 patient with ankylosing spondylitis had acetabular prosthesis loosening at 2 days after operation, underwent surgical revision, and 10 patients had lower limb intermuscular vein thrombosis; in the control group, 1 patient had left hip dislocation and 5 patients had lower extremity intermuscular vein thrombosis; there was no complication such as sciatic nerve injury, incision exudation, and periprosthetic infection in both groups. There was no significant difference in the incidence of complications between the robot group and the control group (17.2% vs.11.5%) (χ2=0.732, P=0.392). At last follow-up, the acetabular anteversion angle and FJS-12 score in the robot group were was significantly greater than those in the control group, and the lower limbs discrepancy was significantly less than that in the control group (P<0.05); there was no significant difference in acetabular inclination angle and VAS score between the two groups (P>0.05). The Harris scores of the two groups were significantly improved when compared with those before operation (P<0.05), but there was no significant difference in the difference of pre- and post-operative score between the two groups (t=1.632, P=0.119).ConclusionCompared with traditional surgery, Mako robot-assisted THA can optimize the accuracy and safety of acetabular cup implantation, reduce the length difference of the lower limbs, and has a certain learning curve. Its long-term effectiveness needs further research to confirm.