Department of General Surgery and Medical Surgical Specialties - Section of Orthopaedics and Traumatology, University Hospital "Policlinico-Vittorio Emanuele", University of Catania, Via Santa Sofia 78, 95123, Catania, Italy.
II Clinic, Biomechanics Laboratory, Rizzoli Orthopaedic Institute, Bologna, Italy.
Int Orthop. 2019 Jan;43(1):71-75. doi: 10.1007/s00264-018-4187-1. Epub 2018 Oct 3.
Bone remodeling around the femoral component after total hip arthroplasty (THA) is considered to be an important factor in long-term stability and seems to be strictly related to the stem design, coating, and fixation. Stress shielding, micro-movement, and high intra-articular fluid pressure might activate macrophages and osteoclasts, causing progressive bone density decreases. Here we analyze the bone mineral density (BMD) around a cementless femoral stem during a 20-year period to better understand the adaptive bone changes around such implants during long-term follow-up.
In this retrospective study, 14 patients treated by THA were reviewed from a cohort of 84. Clinical evaluation with Harris Hip Score and radiographic assessment were performed throughout a 20-year follow-up. To evaluate the bone remodeling around the stem, we monitored the femoral BMD in four regions of interest with a dual-energy X-ray absorptiometry (DEXA) post-operatively and at one, two, three, five and 20 years of follow-up.
The main BMD changes between the post-operative examination and the 20-year follow-up varied between + 11.19% and + 24.30%. Patients with signs of loosening, low Harris Hip Scores, and pain showed decreasing BMD values.
The correlation between the clinical result and BMD values could suggest DEXA results as a predictor of implant loosening or longevity.
全髋关节置换术后股骨假体周围的骨重塑被认为是长期稳定性的一个重要因素，似乎与假体的设计、涂层和固定方式密切相关。应力遮挡、微动和高关节内压可能会激活巨噬细胞和破骨细胞，导致骨密度逐渐下降。在此，我们分析了 20 年内无骨水泥股骨柄周围的骨矿物质密度（BMD），以更好地了解此类植入物在长期随访过程中周围适应性骨变化。
在这项回顾性研究中，对 84 例患者队列中的 14 例接受全髋关节置换术的患者进行了回顾。通过 Harris 髋关节评分进行临床评估，并在 20 年的随访中进行影像学评估。为了评估假体周围的骨重塑，我们在术后以及 1、2、3、5 和 20 年的随访中使用双能 X 线吸收法（DEXA）对四个感兴趣区域的股骨 BMD 进行监测。
术后检查与 20 年随访之间的主要 BMD 变化在+11.19%至+24.30%之间。有松动迹象、Harris 髋关节评分低和疼痛的患者 BMD 值下降。
临床结果与 BMD 值之间的相关性提示 DEXA 结果可作为假体松动或寿命的预测指标。
