[Strategy of acetabular anteversion in total hip arthroplasty with lumbar degenerative kyphosis].

Objective: To investigate how to place the anteversion of acetabular prosthesis more reasonably in patients with lumbar degenerative kyphosis.

Methods: A total of 122 patients with degenerative kyphosis of lumbar spine who underwent total hip arthroplasty from December 2017 to October 2019 were included and divided into experimental group and control group, 61 cases in each group. In experimental group, there were 25 males and 36 females, with a median age of 67.0 years;the median course of disease was 46.0 months;the functional pelvic plane with acetabular anteversion was set according to different types of pelvic anterior plane bracket. In control group, there were 27 males and 34 females, with a median age of 67.0 years;the median course was 42.0 months;in control group, the anteversion was set by the traditional method. The patients were followed up for 3 months. The operation time and blood loss were recorded. The incidence of infection and dislocation within 3 months was counted. Harris score before and 3 months after operation was recorded. Functional anteversion angle of standing position was measured 3 months after operation.

Results: Compared with control group, there was no difference in operation time and blood loss between the two groups (P=0.918, 0.381);there was no infection between two groups within 3 months after operation;there was 1 case of hip joint dislocation in the control group and no dislocation in experimental group. There was no significant difference in Harris score before and after operation. Three months later, reexamination of pelvic standing radiographs showed that the number of patients with functional anteversion of acetabular prosthesis outside the safe area was less in experimental group thanin control group (=0.048), and the functional anteversion angle of acetabular prosthesis was more concentrated in the range of 15 ° to 20 ° in experimental group (<0.001).

Conclusion: According to the preoperative evaluation and classification of patients, better functional anteversion of acetabular prosthesis can be obtained with the help of pelvic anterior plane reference bracket in hip arthroplasty with lumbar degenerative kyphosis.