Femoral Bone Remodeling in Revision Total Hip Arthroplasty with Use of Modular Compared with Monoblock Tapered Fluted Titanium Stems: The Role of Stem Length and Stiffness. (20th March 2019)

• Record Type: Journal Article
• Authors: Huang, Yong; Shao, Hongyi; Zhou, Yixin; Gu, Jianming; Tang, Hao; Yang, Dejin
• Is Part Of: Journal of bone and joint surgery. Volume 101:Number 6(2019)
• Publication Date: 2019-03-20
• Subjects: Bones -- Surgery -- Periodicals; Joints -- Surgery -- Periodicals; Orthopedics -- Periodicals; Orthopedics; General Surgery; Bone Diseases; Joint Diseases; Bones -- Surgery; Joints -- Surgery; Orthopedics; Bot (anatomie); Gewrichten; Chirurgie (geneeskunde); Periodicals; Electronic journals; Periodicals; 617.47005
• DOI: 10.2106/JBJS.18.00442
• Languages: English
• ISSNs: 0021-9355

Abstract

Abstract : Background: To our knowledge, no previous studies have compared periprosthetic bone remodeling around monoblock versus modular tapered fluted titanium stems with different stem length and thickness. Methods: A retrospective comparative study was performed on 139 consecutive total hip arthroplasties (THAs) revised with a tapered fluted modular titanium stem and 114 consecutive THAs revised with a tapered fluted monoblock titanium stem. The latest follow-up radiographs were compared with immediate postoperative radiographs to assess bone restoration in residual osteolytic areas, femoral stress-shielding, spot-welds, and radiolucent lines. Diameter and medullary canal filling of the 2 stems were measured. Results: More patients in the monoblock group demonstrated osseous restoration than in the modular group (p = 0.009), and the modular stem exerted more severe stress-shielding on the femur (p < 0.001). Stem tip spot-welds developed in 88.5% of modular stems compared with 47.4% of the monoblock stems (p < 0.001). Spot-welds developed in 38.8% of modular stems at the modular junction. Partial or circumferential radiolucent lines were observed at the proximal segment of 30.9% of modular stems, compared with 14.0% of monoblock stems (p = 0.002). Conclusions: Compared with the longer and thinner monoblock stems, modular stems had less proximal osseous restoration in residual osteolytic areas and more severe femoral stress-shielding, stem tip spot-welds, and radiolucent lines around the stems, which were stiffer and had a shorter distal section. The stem diameter and stiffness (which were influenced by stem length, curvature, and modularity) determined bone remodeling patterns. Level of Evidence: TherapeuticLevel III . See Instructions for Authors for a complete description of levels of evidence.