Long Wu, Xin Zhao, Zhi-Dong Lu, Yong Yang, Long Ma, Peng Li

Department of Orthopedics, General Hospital of Ningxia Medical University, Yinchuan, China

Keywords: Acetabular cup positioning, artificial intelligence, lower-limb length discrepancy, prosthesis size, total hip arthroplasty, 3D preoperative planning.


Objectives: This study aims to assess the outcome of total hip arthroplasty (THA) using artificial intelligence (AI)-assisted three-dimensional (3D) preoperative planning technology in terms of predicting prosthesis size, acetabular cup positioning, and lowerlimb length restoration.

Patients and methods: Between January 2020 and July 2022, a total of 161 patients (101 males, 60 females; mean age: 57.6±10.5 years; range, 31 to 80 years) who underwent primary unilateral THA were retrospectively analyzed. The patients were divided into two groups as those who were treated with AI-assisted 3D preoperative planning technology (the observation group, n=95) and patients who were treated with traditional two-dimensional (2D) X-ray template planning technology (the control group, n=66).

Results: The accuracy of the planning was based on the consistency of the preoperative planning and intraoperative models. The difference between the observation group and the control group was statistically significant in terms of the accuracy of the preoperative planning of acetabular prostheses (54% vs. 38%, p=0.048) and femoral prostheses (64% vs. 44%, p=0.011), with both values significantly higher in the observation group. The mean inclination angle, anteversion angle, and limb length discrepancy (LLD) in the observation group were 36.85°±4.82°, 12.10°±5.33°, and 2.18±2.70 mm, respectively, while those in the control group were 35.06°±6.07°, 10.95°±5.09°, and 4.42±3.85 mm, respectively. There was a statistically significant difference between the two groups in terms of inclination angle and LLD (p<0.05 for both), but there was no significant difference in terms of anteversion angle (p>0.05). In the observation group, 86.3% (82/95) of acetabular cups were implanted within the Lewinnek safe zone (72.7% [48/66] in the control group), while 83.2% (79/95) were within the Callanan safe zone (69.7% [46/66] in the control group), with both values higher in the observation group (p<0.05).

Conclusion: Overall, AI-assisted 3D preoperative planning is superior to traditional 2D X-ray template planning for predicting prosthesis size, and it also has the advantage in terms of acetabular cup positioning and lower-limb length restoration.

Citation: Wu L, Zhao X, Lu ZD, Yang Y, Ma L, Li P. Accuracy analysis of artificial intelligence-assisted three-dimensional preoperative planning in total hip replacement. Jt Dis Relat Surg 2023;34(3):537- 547. doi: 10.52312/jdrs.2023.1059.

Ethics Committee Approval

The study protocol was approved by the General Hospital of Ningxia Medical University Ethics Committee (date: 08.11.2022, no: KYLL-2022-1278). The study was conducted in accordance with the principles of the Declaration of Helsinki.

Author Contributions

Conceived of the study: W.L., Z.X.; Participated in its design and coordination: L.Z.D., Y.Y.; Helped to draft the manuscript: M.L., L.P.; All authors read and approved the final manuscript.

Conflict of Interest

The authors declared no conflicts of interest with respect to the authorship and/or publication of this article.

Financial Disclosure

This work was supported by Scientific Research Project of Ningxia Health Commission (grant number 2023- NWKYP-042).


We would like to express our gratitude to all those who helped us during the writing of this manuscript.

Data Sharing Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.