Retrospective Study
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Apr 6, 2020; 8(7): 1223-1231
Published online Apr 6, 2020. doi: 10.12998/wjcc.v8.i7.1223
Reconstruction of Paprosky type IIIB acetabular bone defects using a cup-on-cup technique: A surgical technique and case series
Yin-Qiao Du, Yu-Ping Liu, Jing-Yang Sun, Ming Ni, Yong-Gang Zhou
Yin-Qiao Du, Jing-Yang Sun, Ming Ni, Yong-Gang Zhou, Department of Orthopedics, Chinese People’s Liberation Army General Hospital, Beijing 100853, China
Yu-Ping Liu, Department of Orthopedics, Tengzhou Central People’s Hospital, Tengzhou 277500, Shandong Province, China
Author contributions: Du YQ wrote this paper; Liu YP and Sun JY analyzed the data; Ni M and Zhou YG designed this study; Zhou YG performed the operation; Ni M revised the paper.
Supported by National Key Research and Development Program of China, No. 2017YFB1104104.
Institutional review board statement: This study was reviewed and approved by the Institutional Review Board of General Hospital of Chinese People’s Liberation Army.
Informed consent statement: Patients were not required to give informed consent to the study because the analysis used anonymous clinical data that were obtained after each patient agreed to treatment by written consent.
Conflict-of-interest statement: We have no financial relationships to disclose.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Yong-Gang Zhou, MD, PhD, Doctor, Department of Orthopedics, Chinese People’s Liberation Army General Hospital, 28 Fuxing Road, Haidian District, Beijing 100853, China. ygzhou301@163.com
Received: December 29, 2019
Peer-review started: December 29, 2019
First decision: January 19, 2020
Revised: March 12, 2020
Accepted: March 19, 2020
Article in press: March 19, 2020
Published online: April 6, 2020
Processing time: 98 Days and 23.7 Hours
Abstract
BACKGROUND

Paprosky type IIIB acetabular bone defects are very difficult to reconstruct. For severe defects, we developed our own cup-on-cup technique. We defined the tantalum metal (TM) revision shell with the peripheral titanium ring removed as a TM-cup augment and the cementless hemispherical acetabulum component combined with a TM-cup augment as the cup-on-cup technique.

AIM

To report the short-term results of patients with type IIIB acetabular bone defects reconstructed using the cup-on-cup technique.

METHODS

We retrospectively reviewed six patients (six hips) with a mean age of 59 years who underwent acetabular reconstruction using our cup-on-cup technique between January 2015 and January 2017. All acetabular bone defects were classified as type IIIB without pelvic discontinuity using the system of Paprosky. All patients were followed both clinically and radiographically for a mean duration of 42 mo.

RESULTS

The mean Harris hip score improved from 32.4 pre-operatively to 80.7 at the last follow-up. The mean vertical position of the hip rotation centre changed from 60.9 mm pre-operatively to 31.7 mm post-operatively, and the mean horizontal position changed from 33.6 mm pre-operatively to 38.9 mm post-operatively. Greater trochanteric migration after extended trochanteric osteotomy occurred in one of six hips at 3 mo. There was no evidence of component migration at the last follow-up.

CONCLUSION

The short-term results suggest that our cup-on-cup technique could be considered an effective management option for Paprosky type IIIB acetabular bone defects without pelvic discontinuity.

Keywords: Total hip arthroplasty; Trabecular metal; Cup-on-cup; Bone defect

Core tip: Paprosky type IIIB acetabular bone defects are very difficult to reconstruct. We developed our own cup-on-cup technique. We defined the tantalum metal (TM) revision shell with the peripheral titanium ring removed as a TM-cup augment and the cementless hemispherical acetabulum component combined with a TM-cup augment as the cup-on-cup technique. The short-term results suggest that our cup-on-cup technique could be considered an effective management option for Paprosky type IIIB acetabular bone defects without pelvic discontinuity.