A Report on Three Consecutive Cases using Computer Tomography 3D Preoperative Planning for Conversion of Arthrodesed Hips to Total Hip Replacements

HSS Journal Volume 11, Number 1 February, 2015

Yutaka Kuroda, MD, PhD

Department of Orthopaedic Surgery, Graduate School of Medicine, Kyoto University, Japan

Haruhiko Akiyama, MD, PhD

Department of Orthopaedic Surgery, Gifu University, Japan

Manabu Nankaku, BS, MS

Rehabilitation Unit, Kyoto University Hospital, Kyoto, Japan

Kazutaka So, MD, PhD

Department of Orthopaedic Surgery, Graduate School of Medicine, Kyoto University, Japan

Koji Goto, MD, PhD

Department of Orthopaedic Surgery, Graduate School of Medicine, Kyoto University, Japan

Shuichi Matsuda, MD, PhD

Department of Orthopaedic Surgery, Graduate School of Medicine, Kyoto University, Japan

Abstract

Background

Conversion of an arthrodesed hip to a total hip arthroplasty (THA) is a technically demanding procedure with high complication rates. One important issue is that determining the amount of correction for a leg length discrepancy (LLD) can be difficult at the planning stage.

Questions/Purposes

The aim of this study is to assess the reliable use of computer tomography (CT)-based three-dimensional (3D) preoperative planning for the conversion of arthrodesed hips to THAs.

Patients and Methods

CT-based preoperative 3D planning was used to convert three arthrodesed hips to THAs. The efficacy of the planning was evaluated with postoperative radiographic measurements involving the amount of correction for LLD, position of components, difference between targeted and actual values, and ratio of the moment arms. The clinical assessment was performed with the Japanese Orthopaedic Association (JOA) hip score before and after THA.

Results

The mean amount of LLD correction and median LLD after THA were 16 mm (range, 15–17 mm) and 4 mm (range, 1–10 mm), respectively. The components were implanted close to the positions recommended by the preoperative simulation. The ratio of the moment arms indicated that the converted hips were reconstructed in a biomechanically correct manner. The implants for the conversion to THA were successfully positioned with respect to anatomy and functional outcome. The median JOA hip score improved from 50 points (range, 30–66 points) preoperatively to 79 points (range, 72–86 points) at the latest follow-up.

Conclusions

CT-based preoperative 3D planning could be a powerful guidance tool for conversion of arthrodesed hips to THAs.

Work performed at the Department of Orthopaedic Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan, and Department of Orthopaedic Surgery, Gifu University, Rehabilitation Unit, Kyoto University Hospital, Kyoto, Japan.

This article appears in the HSS Journal: Volume 11, Issue 1.
View the full HSS Journal at springerlink.com.

About the HSS Journal

HSS Journal, an academic peer-reviewed journal published three times a year, February, July and October. The Journal accepts and publishes peer reviewed articles from around the world that contribute to the advancement of the knowledge of musculoskeletal diseases and disorders.

 

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