Computed Tomography–Based Custom-Made Stem for Dysplastic Hips in Japanese Patients

• Published in: The Journal of arthroplasty Vol. 24; no. 1; pp. 65 - 70
• Main Authors: Kawate, Kenji, MD, Ohneda, Yutaka, MD, Ohmura, Tetsuji, MD, Yajima, Hiroshi, MD, Sugimoto, Kazuya, MD, Takakura, Yoshinori, MD
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 2009
• Subjects: Adult; Aged; Arthroplasty, Replacement, Hip - instrumentation; Biomechanical Phenomena - physiology; Bone Diseases, Developmental - ethnology; Bone Diseases, Developmental - surgery; canal flare index; Computer-Aided Design; cortical index; custom-made stem; Durapatite; dysplastic hip; Female; Follow-Up Studies; Hip Joint - diagnostic imaging; Hip Joint - physiology; Hip Joint - surgery; Hip Prosthesis; Humans; Japan; Longitudinal Studies; Male; Middle Aged; Orthopedics; Prosthesis Design; Radiography; stress shielding; Stress, Mechanical; Treatment Outcome; dysplastic hip; cortical index; stress shielding; canal flare index; custom-made stem
• ISSN: 0883-5403; 1532-8406
• DOI: 10.1016/j.arth.2007.12.021

Abstract We investigated 55 hips of 53 patients with dysplastic hips. Individual computed tomography data were used in the manufacturing of cementless custom-made stems made of Ti-6Al-4V. The proximal one third was coated using porous coating covered with hydroxyapatite coating. The average age at surgery was 60 years and the average follow-up was 7 years. Five patients (9%) complained of postoperative thigh pain. According to Engh's radiologic classification system, there was bone-ingrown fixation in all hips. The cortical index and canal flare index were lower, and stem diameter was greater in the 11 hips (20%) with severe stress shielding than in the remaining 44 hips. Although the results obtained with this custom-made stem system for dysplastic hips were excellent, stress shielding is still an issue.