Mayer Stephanie W, Stewart Jaime R, Fadell Michael F, Kestel Lauryn, Novais Eduardo N
Department of Orthopaedic Surgery, Children's Hospital Colorado and University of Colorado School of Medicine, 13123 East 16th Ave., B060, Aurora, CO, 80045, USA.
Pediatr Radiol. 2015 Aug;45(9):1355-62. doi: 10.1007/s00247-015-3317-9. Epub 2015 Mar 24.
Posterior hip dislocation in children and adolescents may involve the non-ossified posterior acetabular wall. Plain radiographs and computed tomography (CT) have been shown to underestimate injury to the unossified acetabulum as well as associated soft-tissue structures.
The purpose of this study was to describe findings on radiographs, CT and magnetic resonance imaging (MRI) after posterior hip dislocation in a series of adolescents and to report the intraoperative findings, which are considered the gold standard. Measurements of the posterior wall length using MRI and CT scans were also performed.
After institutional review board approval, 40 patients who sustained a traumatic posterior dislocation of the hip between September 2007 and April 2014 were identified. Inclusion criteria were (1) age younger than 16 years old and (2) availability of MRI obtained following closed reduction of the hip. Eight male patients and one female patient with an average age of 13.2 years (range: 10.1-16.2 years) underwent hip MRI following posterior dislocation. Seven of the nine patients also underwent evaluation by CT. Plain radiographs, CT scans and MRI were evaluated in all patients by a single pediatric radiologist blinded to surgical findings for joint space asymmetry, posterior wall fracture, femoral head fracture, labrum tear, complete or partial ligamentum teres rupture and presence of intra-articular fragments. Six patients underwent surgical treatment and the intraoperative findings were compared with the imaging findings.
CT identified all bone injuries but underestimated the involvement of posterior wall fractures. Assessment of the posterior wall size and fracture displacement was possible with MRI. All surgically confirmed soft-tissue injuries, including avulsion of the posterior labrum, were identified preoperatively on MRI. The measurement of posterior wall length was not statistically different using CT and MRI.
Intraoperative pathological findings at the time of open surgical treatment were universally recognized on MRI but not on CT scans. MRI should be considered for evaluation of the hip following closed reduction for the treatment of a posterior dislocation in children and adolescents as it reliably allows assessment of intra-articular pathology without the risk of radiation exposure.
儿童和青少年的髋关节后脱位可能累及未骨化的髋臼后壁。X线平片和计算机断层扫描（CT）已被证明会低估未骨化髋臼以及相关软组织结构的损伤。
本研究的目的是描述一系列青少年髋关节后脱位后X线平片、CT和磁共振成像（MRI）的表现，并报告术中所见，术中所见被视为金标准。还使用MRI和CT扫描对后壁长度进行了测量。
经机构审查委员会批准，确定了2007年9月至2014年4月期间发生创伤性髋关节后脱位的40例患者。纳入标准为：（1）年龄小于16岁；（2）髋关节闭合复位后有MRI检查资料。9例患者（8例男性，1例女性）平均年龄13.2岁（范围：10.1 - 16.2岁），髋关节后脱位后接受了髋关节MRI检查。9例患者中的7例还接受了CT评估。由一位对手术结果不知情的儿科放射科医生对所有患者的X线平片、CT扫描和MRI进行评估，以观察关节间隙不对称、后壁骨折、股骨头骨折、盂唇撕裂、圆韧带完全或部分断裂以及关节内碎片情况。6例患者接受了手术治疗，并将术中所见与影像学表现进行了比较。
CT能识别所有骨损伤，但低估了后壁骨折的累及情况。MRI可对后壁大小和骨折移位情况进行评估。所有经手术证实的软组织损伤，包括后盂唇撕脱，术前MRI均能识别。使用CT和MRI测量后壁长度，差异无统计学意义。
开放手术治疗时术中的病理表现，MRI能普遍识别，而CT扫描则不能。对于儿童和青少年髋关节后脱位闭合复位后的评估，应考虑使用MRI，因为它能可靠地评估关节内病变，且无辐射暴露风险。
