OBJECTIVE: To analyze the impact of robot assistance on the restoration of limb length and offset distance in total hip arthroplasty (THA). METHODS: A retrospective analysis was conducted on the clinical data of 316 patients who underwent unilateral primary THA between September 2019 and August 2023. Among them, 117 patients underwent robot-assisted THA (group A), and 199 patients underwent conventional THA (group B). There was no significant difference between the two groups in the gender, age, or side of the hip replacement ( P>0.05); but there was a significant difference in the preoperative diagnosis ( P<0.05). The leg length discrepancy (LLD) and global offset (GO) dfference were measured on preoperative anteroposterior pelvic X-ray films, and absolute values were used for comparison between groups. RESULTS: The operations in both groups were successfully completed. Postoperative imaging measurements showed that the LLD and GO dfference in group A were significantly lower than those in group B ( P<0.05). Among them, group A had 32 cases (27.4%), 5 cases (4.3%), and 0 case (0) of LLD>3 mm, >5 mm, and >10 mm, respectively, while group B had 115 cases (57.8%), 75 cases (37.7%), and 22 cases (11.1%), respectively; and the differences in above indicators between groups were significant ( P<0.05). Group A had 40 cases (34.2%), 3 cases (2.6%), and 0 case (0) of GO dfference>5 mm, >10 mm, and >20 mm, respectively; group B had 103 cases (51.8%), 54 cases (27.1%), and 7 cases (3.5%), respectively. There was no significant difference in the proportion of patients with GO>20 mm between groups ( P>0.05), while there were significant differences in other indicators between groups ( P<0.05). CONCLUSION Compared with traditional THA, robot assisted THA has more advantages in restoration of limb length and offset distance.
Humans ; Arthroplasty, Replacement, Hip/methods* ; Retrospective Studies ; Robotic Surgical Procedures/methods* ; Leg Length Inequality/prevention & control* ; Male ; Female ; Treatment Outcome ; Middle Aged ; Aged ; Hip Joint/diagnostic imaging*

OBJECTIVETo introduce a new measuring tool for measuring postoperative limb length exactly, and to provide a convenient and effective method to control limb length after total hip replacement.

METHODSFrom January 2013 to September 2014, 102 patients undergoing primary unilateral hip replacement were divided into two groups: experimental group and control group. There were 51 patients in the experimental group, including 25 males and 26 females, ranging in age from 37 to 92 years old, with an average of 60.41 years old. The patients in experimental group were treated with new method to control limb length. Other 51 patients in the control group, including 27 males and 24 females, ranging in age from 35 to 87 years old, with an average of 61.00 years old. The patients in the control group were treated with normal methods such as shuck test or limb touching. All the patients were operated by the same experienced surgeon. In the experimental group,total hip arthroplasties (THA) were performed on 35 patients with avascular necrosis of the femoral head or femoral neck fracture, and 16 patients were treated with hemiarthroplasty (HA). In the control group, 38 patients received THA and 13 patients received HA. On the anterior-posterior X-ray radiograph, several indexes were measured as follows: the distance of bilateral femoral offset (a), the height from tip of great trochanter to the rotation center of the femoral head (b) and the vertical distance between the top of the minor trochanter and the two tear drops line (c). The leg length discrepancy can be assessed with three parameters as follows: d1, the absolute value of the difference between the bilateral a values; d2, the difference between the bilateral b values; d3, the difference between the bilateral c values. The SPSS 21.0 was applied for the statistical analysis.

RESULTSIn the experimental and control groups, d1 were 4.49 mm and 7.32 mm (P = 0.013); d2 were 2.37 mm and 4.32 mm (P = 0.033); d3 were 3.32 mm and 6.08 mm (P = 0.031). The values of d1, d2 and d3 in the experimental group were significant smaller than those in the control group.

CONCLUSIONThe new measuring tool and method can be used to control the limb length and offset effectively during operation.

Adult ; Aged ; Aged, 80 and over ; Arthroplasty, Replacement, Hip ; adverse effects ; methods ; Case-Control Studies ; Female ; Humans ; Leg Length Inequality ; prevention & control ; Male ; Middle Aged