First Clinical Medical College, Shandong University of Traditional Chinese Medicine, Jinan, Shandong Province, China.
Department of Orthopaedics, The 960Th Hospital of the PLA, Jinan, China.
World J Surg Oncol. 2023 May 31;21(1):164. doi: 10.1186/s12957-023-03047-0.
Tumor prostheses of the distal femur after revision surgery is associated with high rates of aseptic loosening, which has introduced great challenges to the survival of patients, but only a few studies have evaluated their X-ray imaging. The purpose of this study was to analyze the risk factors for recurrence of aseptic loosening and make recommendations to reduce the incidence of aseptic loosening after revision surgery of tumor prostheses in the distal femur.
A retrospective analysis was performed on 23 patients who had revision surgery for distal femur prostheses due to aseptic loosening between June 2002 and June 2021. They were divided into two groups based on the condition of the prostheses after revision surgery: loosening group (9 patients) and control group (14 patients). Following the initial replacement, the length and diameter of the prosthetic intramedullary stem were measured through the standard full-length anteroposterior X-ray imaging of both lower limbs. The osteotomy length, femoral length and diameter, femoral intramedullary stem diameter, hip-knee-ankle angle (HKAA), mechanical lateral distal femoral angle (mLDFA), mechanical medial proximal tibial angle (mMPTA), and so on were measured as well. Following that, statistical analysis was performed.
Patients in the loosening group had statistically significant differences in the ratio of prostheses length to femur length (71.89 ± 6.62) and the ratio of intramedullary stem diameter to femoral diameter (25.50 ± 6.90) (P < 0.05), when compared to the control group. The HKAA (175.58 ± 2.78), mLDFA (94.42 ± 2.57), and the deviation angle between the lower limb alignment and the tibial prostheses force line (2.23 ± 1.09) in the loosening group were significantly different from those in the control group (P < 0.05) on postoperative radiographs of the entire length of the lower limbs. The lowest score in intramedullary manubrium I indicated less osteolysis, while the highest score in intramedullary manubrium III indicated the most serious osteolysis, and the difference was statistically significant (P < 0.05).
Our study suggests that the use of longer and thicker intramedullary stems can effectively decrease the occurrence of aseptic loosening. Additionally, it is important to avoid using the original prostheses and reconstruct the standard line of lower limb force to further reduce the incidence of aseptic loosening. It is crucial to closely monitor the distal segment of the intramedullary stem for osteolysis after surgery.
肿瘤假体在翻修手术后出现无菌性松动的发生率较高，这给患者的生存带来了巨大挑战，但只有少数研究对其 X 射线影像学进行了评估。本研究旨在分析无菌性松动复发的危险因素，并提出减少肿瘤假体在股骨远端翻修手术后无菌性松动发生率的建议。
对 2002 年 6 月至 2021 年 6 月因无菌性松动行股骨远端假体翻修术的 23 例患者进行回顾性分析。根据翻修术后假体情况将患者分为两组：松动组（9 例）和对照组（14 例）。在初次置换后，通过下肢标准全长正侧位 X 线片测量假体髓内干的长度和直径。测量截骨长度、股骨长度和直径、股骨髓内干直径、髋膝踝角（HKAA）、机械外侧远端股骨角（mLDFA）、机械内侧近端胫骨角（mMPTA）等。然后进行统计学分析。
松动组患者假体长度与股骨长度之比（71.89±6.62）和髓内干直径与股骨直径之比（25.50±6.90）差异有统计学意义（P<0.05），与对照组相比。松动组患者术后全长下肢 X 线片 HKAA（175.58±2.78）、mLDFA（94.42±2.57）和下肢对线与胫骨假体力线偏差角度（2.23±1.09）与对照组相比差异有统计学意义（P<0.05）。髓内干隆突Ⅰ评分最低提示骨溶解程度较轻，髓内干隆突Ⅲ评分最高提示骨溶解最严重，差异有统计学意义（P<0.05）。
本研究表明，使用较长较粗的髓内干可以有效降低无菌性松动的发生。另外，避免使用原假体和重建下肢力线标准也可以进一步降低无菌性松动的发生率。术后密切监测髓内干远端骨溶解情况非常重要。
