Ramirez Samuel X, Ferrell Stuart D, Kushare Indranil V, Kan J Herman
Division of Orthopaedic Surgery, Texas Children's Hospital, 6621 Fannin Street, Houston, TX 77030, United States.
Baylor College of Medicine, Houston, United States.
Pediatr Radiol. 2025 Aug 6. doi: 10.1007/s00247-025-06344-w.
The bipartite patella is a controversial variant, with definitions spanning from normal to stigmata related to patellofemoral dysplasia.
The purpose of this study is to quantitatively determine if a bipartite patella is in the spectrum of normal versus forme fruste of underlying patellofemoral dysplasia in children using magnetic resonance imaging (MRI) data. A secondary purpose is to assess the MRI findings of the symptomatic bipartite and its implications for patient care.
A retrospective review of bipartite patellae imaged on knee MRI from 1/2010-3/2024 was conducted. Matched cohorts of control and patellofemoral dysplasia knees were created. Trochlear depth, sulcus angle, CDI, TT-TG, lateral patellar tilt and subluxation, lateral trochlear inclination, and clinical management were evaluated, comparing the bipartite knee MRIs with control and dysplastic knees. Chi-square and Mann-Whitney U tests were used, with P-values for significance set to 0.05.
From 46 patients, 47 bipartite patellae (mean age, 13.3 ± 3.1) were included in the study. In total, 77% (36/47) were male (mean age, 13.6 ± 3.0) while 23% (11/47) were female (mean age, 12.2 ± 3.2). No significant difference in quantitative measurements existed between bipartite patellae and control knees. Significant differences existed for all quantitative measurements defining trochlear dysplasia between bipartite and patellofemoral dysplasia cohorts (P<0.001 for all measurements). Bipartite ossicle edema (39/47, 83%) and Hoffa fat pad edema (17/47, 36%) were frequently present. Six of 47(13%) required surgery for pain management- all had ossicle edema present.
The presence of a bipartite patella does not appear to be associated with underlying patellofemoral dysplasia. The bipartite patella can frequently be a source of a child's pain and should not be treated as a normal ossification variant.
二分髌骨是一种存在争议的变异情况，其定义范围涵盖从正常到与髌股发育不良相关的体征。
本研究的目的是利用磁共振成像（MRI）数据，定量确定二分髌骨在儿童中是属于正常范围还是潜在髌股发育不良的顿挫型。第二个目的是评估有症状的二分髌骨的MRI表现及其对患者护理的影响。
对2010年1月至2024年3月期间膝关节MRI检查显示二分髌骨的患者进行回顾性研究。创建了对照膝关节和髌股发育不良膝关节的匹配队列。评估滑车深度、沟角、CDI、TT-TG、髌骨外侧倾斜和半脱位、外侧滑车倾斜度以及临床管理情况，将二分髌骨的膝关节MRI与对照膝关节和发育不良膝关节进行比较。采用卡方检验和曼-惠特尼U检验，显著性P值设定为0.05。
本研究纳入了46例患者的47个二分髌骨（平均年龄13.3±3.1岁）。其中，77%（36/47）为男性（平均年龄13.6±3.0岁），23%（11/47）为女性（平均年龄12.2±3.2岁）。二分髌骨与对照膝关节之间在定量测量上无显著差异。二分髌骨队列与髌股发育不良队列之间在所有定义滑车发育不良的定量测量上均存在显著差异（所有测量P<0.001）。二分髌骨小骨水肿（39/47，83%）和 Hoffa 脂肪垫水肿（17/ /47，36%）很常见。47例中有6例（13%）因疼痛管理需要手术——所有患者均存在小骨水肿。
二分髌骨的存在似乎与潜在的髌股发育不良无关。二分髌骨常可成为儿童疼痛的来源，不应被视为正常的骨化变异。
