{"title":"Modular Femoral Stem for Hartofilakidis Type C Hip Dysplasia: Is It Necessary for 1-mm Increment of Distal Stem Diameter?","authors":"Jiafeng Yi, Hongbin Xie, Yubo Liu, Yijian Huang, Wei Chai, Xiangpeng Kong","doi":"10.1111/os.70092","DOIUrl":null,"url":null,"abstract":"<p><strong>Background: </strong>S-ROM prosthesis, one well-used femoral prosthesis in the patients with developmental dysplasia of the hip (DDH), has a skipping size of the distal stem diameter. The purpose of this study was to investigate whether its 2-mm incremental diameter could meet clinical needs for high-riding DDH patients.</p><p><strong>Methods: </strong>Between July 2018 and December 2022, the Hartofilakidis type C DDH patients with S-ROM stem (9 or 11 mm) were retrospectively enrolled according to the inclusion criteria and exclusion criteria in our institute. The intraoperative femur fractures, the diameter of the femoral medullary cavity, the canal filling ratio of the S-ROM stem, the closure conditions of the stem slot, and the healing rate of subtrochanteric osteotomy were analyzed to evaluate the effect of stem design on clinical outcomes. Statistical analyses were conducted using independent samples t-tests, chi-square test, and logistic regression analysis with a significance threshold of p < 0.05.</p><p><strong>Results: </strong>A total of 95 patients (109 hips) were included in this study, including 60 hips with 9 mm S-ROM and 49 hips with 11 mm S-ROM. Compared with the 9 mm S-ROM group, the 11 mm S-ROM group presented nearly 5 times the intraoperative fracture rate (16.3%, 3.3%, p < 0.05). The mean diameter of the femoral medullary cavity in the 9 mm S-ROM group was 0.84 ± 0.20 mm and in the 11 mm S-ROM group was 1.03 ± 0.18 mm. The canal filling ratio in the 9 mm S-ROM group is significantly lower than that of the 11 mm S-ROM group. In the 11 mm S-ROM group, the filling ratio of the femoral medullary cavity of fracture hips was significantly higher than that in non-fracture hips.</p><p><strong>Conclusion: </strong>The S-ROM design with a distal stem diameter increment of every 2 mm would increase the risk of intraoperative periprosthetic femoral fractures in high-riding DDH patients. It is necessary for a 1-mm increment of distal stem diameter in such patients.</p><p><strong>Level of evidence: </strong>Level III, retrospective comparative study.</p>","PeriodicalId":19566,"journal":{"name":"Orthopaedic Surgery","volume":" ","pages":""},"PeriodicalIF":1.8000,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Orthopaedic Surgery","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1111/os.70092","RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ORTHOPEDICS","Score":null,"Total":0}
引用次数: 0
Abstract
Background: S-ROM prosthesis, one well-used femoral prosthesis in the patients with developmental dysplasia of the hip (DDH), has a skipping size of the distal stem diameter. The purpose of this study was to investigate whether its 2-mm incremental diameter could meet clinical needs for high-riding DDH patients.
Methods: Between July 2018 and December 2022, the Hartofilakidis type C DDH patients with S-ROM stem (9 or 11 mm) were retrospectively enrolled according to the inclusion criteria and exclusion criteria in our institute. The intraoperative femur fractures, the diameter of the femoral medullary cavity, the canal filling ratio of the S-ROM stem, the closure conditions of the stem slot, and the healing rate of subtrochanteric osteotomy were analyzed to evaluate the effect of stem design on clinical outcomes. Statistical analyses were conducted using independent samples t-tests, chi-square test, and logistic regression analysis with a significance threshold of p < 0.05.
Results: A total of 95 patients (109 hips) were included in this study, including 60 hips with 9 mm S-ROM and 49 hips with 11 mm S-ROM. Compared with the 9 mm S-ROM group, the 11 mm S-ROM group presented nearly 5 times the intraoperative fracture rate (16.3%, 3.3%, p < 0.05). The mean diameter of the femoral medullary cavity in the 9 mm S-ROM group was 0.84 ± 0.20 mm and in the 11 mm S-ROM group was 1.03 ± 0.18 mm. The canal filling ratio in the 9 mm S-ROM group is significantly lower than that of the 11 mm S-ROM group. In the 11 mm S-ROM group, the filling ratio of the femoral medullary cavity of fracture hips was significantly higher than that in non-fracture hips.
Conclusion: The S-ROM design with a distal stem diameter increment of every 2 mm would increase the risk of intraoperative periprosthetic femoral fractures in high-riding DDH patients. It is necessary for a 1-mm increment of distal stem diameter in such patients.
Level of evidence: Level III, retrospective comparative study.
背景：S-ROM假体是髋关节发育不良（DDH）患者常用的一种股骨假体，其远端柄直径有跳跃大小。本研究的目的是探讨其2毫米的直径增量是否能满足高骑行DDH患者的临床需求。方法：2018年7月至2022年12月，根据纳入标准和排除标准，回顾性纳入我院S-ROM干（9或11 mm）的C型DDH患者。分析术中股骨骨折情况、股骨髓腔直径、S-ROM柄管填充率、柄槽闭合情况、粗隆下截骨术愈合情况，评价柄设计对临床疗效的影响。统计学分析采用独立样本t检验、卡方检验和logistic回归分析，显著性阈值为p。结果：本研究共纳入95例患者（109髋），其中S-ROM为9 mm的患者60例，S-ROM为11 mm的患者49例。与9 mm S-ROM组相比，11 mm S-ROM组术中骨折发生率近5倍（16.3%,3.3%,p）结论：每增加2 mm远端柄直径的S-ROM设计会增加高位DDH患者术中股骨假体周围骨折的风险。在此类患者中，有必要将远端茎直径增加1毫米。证据等级：III级，回顾性比较研究。
期刊介绍：
Orthopaedic Surgery (OS) is the official journal of the Chinese Orthopaedic Association, focusing on all aspects of orthopaedic technique and surgery.
The journal publishes peer-reviewed articles in the following categories: Original Articles, Clinical Articles, Review Articles, Guidelines, Editorials, Commentaries, Surgical Techniques, Case Reports and Meeting Reports.
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号
